Articles : Surgical Neurology International as on February 16, 2012)

Pitfalls in precision stereotactic surgery

Ludvic Zrinzo — Sat,14 Jan 2012

Ludvic Zrinzo

Surgical Neurology International 2012 3(2):53-61

Precision is the ultimate aim of stereotactic technique. Demands on stereotactic precision reach a pinnacle in stereotactic functional neurosurgery. Pitfalls are best avoided by possessing in-depth knowledge of the techniques employed and the equipment used. The engineering principles of arc-centered stereotactic frames maximize surgical precision at the target, irrespective of the surgical trajectory, and provide the greatest degree of surgical precision in current clinical practice. Stereotactic magnetic resonance imaging (MRI) provides a method of visualizing intracranial structures and fiducial markers on the same image without introducing significant errors during an image fusion process. Although image distortion may potentially limit the utility of stereotactic MRI, near-complete distortion correction can be reliably achieved with modern machines. Precision is dependent on minimizing errors at every step of the stereotactic procedure. These steps are considered in turn and include frame application, image acquisition, image manipulation, surgical planning of target and trajectory, patient positioning and the surgical procedure itself. Audit is essential to monitor and improve performance in clinical practice. The level of stereotactic precision is best analyzed by routine postoperative stereotactic MRI. This allows the stereotactic and anatomical location of the intervention to be compared with the anatomy and coordinates of the intended target, avoiding significant image fusion errors.

Vagus nerve stimulation for epilepsy: A review of the peripheral mechanisms

Scott E Krahl — Sat,14 Jan 2012

Scott E Krahl

Surgical Neurology International 2012 3(2):47-52

Vagus nerve stimulation (VNS) is a unique epilepsy treatment in that a peripheral intervention is used to treat a disease that is entirely related to pathological events occurring within the brain. To understand how stimulation of the vagus nerve can be used to stop seizures, an understanding of the peripheral anatomy and physiology of the vagus nerve is essential. The peripheral aspects of the vagus nerve are discussed in this review, with an explanation of which fibers and branches are involved in producing these antiepileptic effects, along with speculation about the potential for improving the therapy.

The amygdala as a target for behavior surgery

Jean-Philippe Langevin — Sat,14 Jan 2012

Jean-Philippe Langevin

Surgical Neurology International 2012 3(2):40-46

The amygdala was a popular target during the era of psychosurgery, specifically for the treatment of intractable aggression. This mesiotemporal structure was thought to primarily mediate fear and anger. However, recent evidence suggests that the amygdala is part of a complex network that mediates the formation of a larger repertoire of positive and negative emotions. Dysfunctions within the network or the amygdala itself can lead to various mental illnesses. In those cases, deep brain stimulation (DBS) applied focally may treat the symptoms. This review presents data supporting the potential therapeutic role of DBS of the amygdala in the treatment of anxiety disorders, addiction, and mood disorders. The success of DBS for psychiatric conditions will likely depend on our ability to precisely determine the optimal target for a specific case.

Strategies for the return of behavioral surgery

Sam Eljamel — Sat,14 Jan 2012

Sam Eljamel

Surgical Neurology International 2012 3(2):34-39

Background: Behavioral surgery (BS) is resurging because of unmet clinical need, advances in basic sciences, neuroimaging, neurostimulation, and stereotaxy. However, there is a danger that BS will fall unless acceptable strategies are adopted by BS providers. Methods: A critical review of conditions leading to rise of psychosurgery (PS) and concerns resulting in its fall was conducted to learn lessons and safeguard BS of the future. Results: PS rose and spread in 1960 like wildfire without adequate preclinical and clinical studies. Hundreds of patients had PS without adequate preoperative diagnosis or assessment, proper consent, and non-objective reporting of outcome. Furthermore, there was public opposition against PS because of its potential abuse to control violent behavior and dissidents. Advances in neurostimulation, neuroimaging, and stereotaxy, and emergence of treatment-resistant mental disorders led to increased interest in BS. Several recent studies have shown BS to be safe and effective. However, concerns related to strength of evidence, safety, efficacy, consent, and objectivity of studies have been raised. Unless clinical and regulatory governance structures are adopted in each jurisdiction, BS will face the same fate as that of PS in the past. Conclusion: The future of BS as a safe and effective therapy is dependent upon adopting clear moral ethical and governance standards on the following lines: Patients must have failed adequate therapies; must be assessed by psychiatrist-led multidisciplinary teams; patients' abilities to give consent and diagnosis must be verified by independent authorities designated for this purpose by the state; and the independent authority must also decide whether the teams were adequately trained to perform BS.

Novel applications of deep brain stimulation

Tejas Sankar — Sat,14 Jan 2012

Tejas Sankar, Travis S Tierney, Clement Hamani

Surgical Neurology International 2012 3(2):26-33

The success of deep brain stimulation (DBS) surgery in treating medically refractory symptoms of some movement disorders has inspired further investigation into a wide variety of other treatment-resistant conditions. These range from disorders of gait, mood, and memory to problems as diverse as obesity, consciousness, and addiction. We review the emerging indications, rationale, and outcomes for some of the most promising new applications of DBS in the treatment of postural instability associated with Parkinson's disease, depression, obsessive-compulsive disorder, obesity, substance abuse, epilepsy, Alzheimer's-type dementia, and traumatic brain injury. These studies reveal some of the excitement in a field at the edge of a rapidly expanding frontier. Much work still remains to be done on basic mechanism of DBS, optimal target and patient selection, and long-term durability of this technology in treating new indications.

Radiation mechanisms of pain control in classical trigeminal neuralgia

Alessandra Gorgulho — Sat,14 Jan 2012

Alessandra Gorgulho

Surgical Neurology International 2012 3(2):17-25

Classical trigeminal neuralgia is a chronic pain condition that was clinically recognized centuries ago. Nevertheless, the pathological mechanism(s) involved in the development of classical trigeminal neuralgia is still largely based on the theory of peripheral versus central nervous system origin. Limitations of both hypotheses are discussed. Evidence of radiation effects in the electrical conduction of peripheral nerves is reviewed. Results of experimental studies using modern and current radiosurgery techniques and doses are also brought to discussion in an attempt to elucidate the radiation mechanisms involved in the conduction block of excessive sensory information triggering pain attacks. Clinical features and prognostic factors associated with pain control, recurrence, and facial numbness in patients submitted to surgical procedures for classical trigeminal neuralgia are discussed in the context of the features related to the pathogenesis of this condition. Studies focusing on the electrophysiology properties of partially demyelinated trigeminal nerves submitted to radiosurgery are vital to truly advance our current knowledge in the field.

Stereotactic radiosurgery for movement disorders

Leonardo Frighetto — Sat,14 Jan 2012

Leonardo Frighetto, Jorge Bizzi, Rafael D'Agostini Annes, Rodrigo dos Santos Silva, Paulo Oppitz

Surgical Neurology International 2012 3(2):10-16

Initially designed for the treatment of functional brain targets, stereotactic radiosurgery (SRS) has achieved an important role in the management of a wide range of neurosurgical pathologies. The interest in the application of the technique for the treatment of pain, and psychiatric and movement disorders has returned in the beginning of the 1990s, stimulated by the advances in neuroimaging, computerized dosimetry, treatment planning software systems, and the outstanding results of radiosurgery in other brain diseases. Since SRS is a neuroimaging-guided procedure, without the possibility of neurophysiological confirmation of the target, deep brain stimulation (DBS) and radiofrequency procedures are considered the best treatment options for movement-related disorders. Therefore, SRS is an option for patients who are not suitable for an open neurosurgical procedure. SRS thalamotomy provided results in tremor control, comparable to radiofrequency and DBS. The occurrence of unpredictable larger lesions than expected with permanent neurological deficits is a limitation of the procedure. Improvements in SRS technique with dose reduction, use of a single isocenter, and smaller collimators were made to reduce the incidence of this serious complication. Pallidotomies performed with radiosurgery did not achieve the same good results. Even though the development of DBS has supplanted lesioning as the first alternative in movement disorder surgery; SRS might still be the only treatment option for selected patients.

Trends and importance of radiosurgery for the development of functional neurosurgery

Douglas Kondziolka — Sat,14 Jan 2012

Douglas Kondziolka, John C Flickinger, Ajay Niranjan, L Dade Lunsford

Surgical Neurology International 2012 3(2):3-9

Functional neurosurgery includes surgery conducted to ablate, augment, or modulate targets that lead to improvement in neurological function or behavior. Surgical approaches for this purpose include destructive lesioning with different mechanical or biologic agents or energy sources, non-destructive electrical modulation, and cellular or chemical augmentation. Our purpose was to review the role of stereotactic radiosurgery used for functional indications and to discuss future applications and potential techniques. Imaging and neurophysiological research will enable surgeons to consider new targets and circuits that may be clinically important. Radiosurgery is one minimal access approach to those targets.

Surgical Neurology International Stereotactic: Inaugural Editorial

Antonio De Salles — Sat,14 Jan 2012

Antonio De Salles

Surgical Neurology International 2012 3(2):1-2

The Russian political turmoil (2012): An American perspective

Miguel A Faria — Wed,15 Feb 2012

Miguel A Faria

Surgical Neurology International 2012 3(1):28-28

Changes in stroke research productivity: A global perspective

Daniel S Chow — Wed,15 Feb 2012

Daniel S Chow, Jason S Hauptman, Tony T Wong, Nestor R Gonzalez, Neil A Martin, Angella A Lignelli, Michael W Itagaki

Surgical Neurology International 2012 3(1):27-27

Background: While stroke is the second leading cause of death worldwide, little work has been done to quantify the growth and progress of stroke publications. The purpose of this study is to quantitatively analyze trends in the stroke literature over the past 12 years, specifically examining changes in worldwide productivity and study methodology. Methods: The study was a retrospective bibliometric analysis of all stroke articles published between 1996 and 2008 indexed in MEDLINE. Country of origin, MEDLINE-defined methodology, specialty of the first author, and funding sources (for US articles) were recorded. Growth was analyzed by using linear and nonlinear regression. Results: Total articles numbered 32,309 during the study period, with leading global contributors including the United States with 8795 (27.2%) articles, Japan with 2757 (8.5%) articles, and the United Kingdom with 2629 (8.1%) articles. Growth globally and in the United States followed a linear pattern at 209.9 and 56.2 articles per year, respectively (both P < 0.001). Review articles and clinical trials numbered 5932 (18.4%) and 2934 (9.1%), respectively. Clinical trials followed an exponential growth pattern of 7.7% per year (P < 0.001). Regarding specialty influence, pain management and rehabilitation had the largest proportional growth in clinical trials from 4 to 51 articles. Conclusions: Within the stroke literature, we observed continued growth worldwide, sustained growth in the United States, and a steady increase in the number of clinical trials, especially by pain management and rehabilitation.

Anesthetic management during Cesarean section in a woman with residual Arnold-Chiari malformation Type I, cervical kyphosis, and syringomyelia

Ramsis F Ghaly — Wed,15 Feb 2012

Ramsis F Ghaly, Kenneth D Candido, Ruben Sauer, Nebojsa Nick Knezevic

Surgical Neurology International 2012 3(1):26-26

Background: Type I Arnold-Chiari malformation (ACM) has an adult onset and consists of a downward displacement of the cerebellar tonsils and the medulla through the foramen magnum. There is paucity of literature on the anesthetic management during pregnancy of residual ACM Type I, with cervical xyphosis and persistent syringomyelia. Case Description: A 34-year-old woman with surgically corrected ACM Type I presented for Cesarean delivery. A recent MRI demonstrated worsening of cervical xyphosis after several laminectomies and residual syringomyelia besides syringopleural shunt. Awake fiberoptic intubation was performed under generous topical anesthesia to minimize head and neck movement during endotracheal intubation. We used a multimodal general anesthesia without neuromuscular blockade. The neck was maintained in a neutral position. Following delivery, the patient completely recovered in post-anesthesia care unit (PACU), with no headache and no exacerbation or worsening of neurological function. Conclusions: The present case demonstrates that patients with partially corrected ACM, syringomyelia, cervical kyphosis, and difficult intubation undergoing Cesarean delivery require an interdisciplinary team approach, diligent preparation, and skilled physicians.

Complications in patients undergoing combined transforaminal lumbar interbody fusion and posterior instrumentation with deformity correction for degenerative scoliosis and spinal stenosis

Sigita Burneikiene — Wed,15 Feb 2012

Sigita Burneikiene, E Lee Nelson, Alexander Mason, Sharad Rajpal, Benjamin Serxner, Alan T Villavicencio

Surgical Neurology International 2012 3(1):25-25

Background: Utilization of the transforaminal lumbar interbody fusion (TLIF) approach for scoliosis offers the patients deformity correction and interbody fusion without the additional morbidity associated with more invasive reconstructive techniques. Published reports on complications associated with these surgical procedures are limited. The purpose of this study was to quantify the intra- and postoperative complications associated with the TLIF surgical approach in patients undergoing surgery for spinal stenosis and degenerative scoliosis correction. Methods: This study included patients undergoing TLIF for degenerative scoliosis with neurogenic claudication and painful lumbar degenerative disc disease. The TLIF technique was performed along with posterior pedicle screw instrumentation. The average follow-up time was 30 months (range, 15-47). Results: A total of 29 patients with an average age of 65.9 years (range, 49-83) were evaluated. TLIFs were performed at 2.2 levels on average (range, 1-4) in addition to 6.0 (range, 4-9) levels of posterolateral instrumented fusion. The preoperative mean lumbar lordosis was 37.6° (range, 16°-55°) compared to 40.5° (range, 26°-59.2°) postoperatively. The preoperative mean coronal Cobb angle was 32.3° (range, 15°-55°) compared to 15.4° (range, 1°-49°) postoperatively. The mean operative time was 528 min (range, 276-906), estimated blood loss was 1091.7 mL (range, 150-2500), and hospitalization time was 8.0 days (range, 3-28). A baseline mean Visual Analog Scale (VAS) score of 7.6 (range, 4-10) decreased to 3.6 (range, 0-8) postoperatively. There were a total of 14 (49%) hardware and/or surgical technique related complications, and 8 (28%) patients required additional surgeries. Five (17%) patients developed pseudoarthrosis. The systemic complications (31%) included death (1), cardiopulmonary arrest with resuscitation (1), myocardial infarction (1), pneumonia (5), and pulmonary embolism (1). Conclusion: This study suggests that although the TLIF approach is a feasible and effective method to treat degenerative adult scoliosis, it is associated with a high rate of intra- and postoperative complications and a long recovery process.

Acute hemorrhage in a colloid cyst of the third ventricle: A rare cause of sudden deterioration

Rodrigo Carrasco — Wed,15 Feb 2012

Rodrigo Carrasco, José M Pascual, Diego Medina-López, Ana Burdaspal-Moratilla

Surgical Neurology International 2012 3(1):24-24

Background: Acute neurological deterioration and death in a patient harboring a colloid cyst of the third ventricle remains a poorly understood phenomenon. Sudden neurological derangement caused by spontaneous bleeding within a colloid cyst is a rare and potentially fatal event, usually requiring immediate diagnosis and emergency surgical treatment. Case Description: A 47-year-old male presented with acute right-sided hemiparesis and speech impediment, followed by rapid deterioration of consciousness. Neuroimaging studies showed a rounded mass at the roof of the anterior third ventricle, causing biventricular hydrocephalus along with a left-sided basal ganglia hematoma. The lesion showed scattered foci of a recent hemorrhage which extended into the left lateral ventricle. Surgical treatment involved emergency external ventricular drainage followed by the prompt elective total resection of the lesion via a transcallosal route. Pathological findings confirmed the diagnosis of a colloid cyst with focal areas of vascular congestion and blood extravasation within its wall. Conclusions: Spontaneous bleeding into a colloid cyst of the third ventricle may cause acute obstructive hydrocephalus and intracranial hypertension due to rapid enlargement of the lesion. This event may account for the sudden neurological deterioration and/or death observed in a previously asymptomatic patient. The diagnosis of hemorrhagic phenomena within a colloid cyst represents a challenge due to the variable signal usually displayed by these lesions on computed tomography (CT) and magnetic resonance imaging (MRI). Emergency ventricular drainage followed by elective tumoral removal constitutes a valid and safe treatment strategy.

Duplication of the pituitary gland associated with multiple blastogenesis defects: Duplication of the pituitary gland (DPG)-plus syndrome. Case report and review of literature

Sunil Manjila — Wed,15 Feb 2012

Sunil Manjila, Erin A Miller, Sumeet Vadera, Rishi K Goel, Fahd R Khan, Carol Crowe, Robert T Geertman

Surgical Neurology International 2012 3(1):23-23

Background: Duplication of the pituitary gland (DPG) is a rare craniofacial developmental anomaly occurring during blastogenesis with postulated etiology such as incomplete twinning, teratogens, median cleft face syndrome or splitting of the notochord. The complex craniocaudal spectrum of blastogenesis defects associated with DPG is examined with an illustrative case. Case Description: We report for the first time in the medical literature some unique associations with DPG, such as a clival encephalocele, third cerebral peduncle, duplicate odontoid process and a double tongue with independent volitional control. This patient also has the previously reported common associations such as duplicated sella, cleft palate, hypertelorism, callosal agenesis, hypothalamic enlargement, nasopharyngeal teratoma, fenestrated basilar artery and supernumerary teeth. This study also reviews 37 cases of DPG identified through MEDLINE literature search from 1880 to 2011. It provides a detailed analysis of the current case through physical examination and imaging. Conclusion: The authors propose that the developmental deformities associated with duplication of pituitary gland (DPG) occur as part of a developmental continuum, not as chance associations. Considering the fact that DPG is uniquely and certainly present throughout the spectrum of these blastogenesis defects, we suggest the term DPG-plus syndrome.

Non-operative management is superior to surgical stabilization in spine injury patients with complete neurological deficits: Some additional perspectives

Farooq A Rathore — Wed,15 Feb 2012

Farooq A Rathore, Fareeha Farooq, Sahibzada N Mansoor

Surgical Neurology International 2012 3(1):22-22

Basioccipital bone osteochondroma growing into the foramen magnum

Iraj Lotfinia — Wed,15 Feb 2012

Iraj Lotfinia, Payman Vahedi, R Shane Tubbs, Mostafa Gavame, Amir Vahedi

Surgical Neurology International 2012 3(1):21-21

Background: Osteochondroma is a common bone tumor and rarely affects the central nervous system. Although intraspinal osteochondromas are known to cause neurological deficits, intracranial osteochondromas with neurological compromise are very rare. Case Description: The authors report an exceptional case of a quadriparetic 73-year-old patient with a basioccipital bone osteochondroma growing into the foramen magnum. The embryology, differential diagnoses, and optimal management strategies are discussed. Conclusion: Although extremely rare, osteochondromas should be included in the differential diagnoses of tumors within the foramen magnum. For the tumors originating from the basioccipital bone, a simple medial suboccipital approach might suffice, while for ventral tumors, a far lateral transcondylar approach is necessary to avoid any neurovascular complications. Despite potentially catastrophic presenting symptoms, these tumors are pathologically benign and complete excision often results in long-term cure. To the best of our knowledge, this is the first report of an osteochondroma arising from the basiocciput.

Dynamic changes in blood flow of a bypassed superficial temporal artery with unstable internal carotid artery stenosis

Atsushi Ishida — Wed,15 Feb 2012

Atsushi Ishida, Seigo Matsuo, Keizoh Asakuno, Haruko Yoshimoto, Hideki Shiramizu, Kaku Niimura, Tomokatsu Hori

Surgical Neurology International 2012 3(1):20-20

Background: There are limited indications for superficial temporal artery to middle cerebral artery (STA-MCA) bypass in the treatment of cerebral atherosclerotic disease. However, recent reports emphasize that STA-MCA bypass may be beneficial for select patients. In this report, we describe a case in which a flow-dependent STA-MCA bypass was achieved in a patient with unstable internal carotid artery (ICA) stenosis. Case Description: A 51-year-old woman presented with left ICA occlusion. A severely elongated mean transit time (MTT) indicated misery perfusion. STA-MCA bypass was performed immediately and blood flow through the graft appeared excellent on magnetic resonance angiography (MRA). Two weeks later, MRA revealed normal anterograde ICA blood flow and the bypass graft was not visible. Three years later, the left ICA stenosis again became severe and the patient developed contralateral hemiparesis. She underwent endovascular surgery and the ipsilateral MCA became occluded during the procedure. The STA-MCA bypass graft appeared immediately after the MCA occlusion and became a major provider of blood flow to the ipsilateral MCA area. She recovered with almost no deficit. Conclusion: This is a rare case which shows that dynamic flow changes through an STA-MCA bypass can occur with variable ICA blood flow. STA-MCA bypass can be beneficial for the treatment of unstable ICA stenosis.

Natural plant products and extracts that reduce immunoexcitotoxicity-associated neurodegeneration and promote repair within the central nervous system

Russell L Blaylock — Wed,15 Feb 2012

Russell L Blaylock, Joseph Maroon

Surgical Neurology International 2012 3(1):19-19

Our understanding of the pathophysiological and biochemical basis of a number of neurological disorders has increased enormously over the last three decades. Parallel with this growth of knowledge has been a clearer understanding of the mechanism by which a number of naturally occurring plant extracts, as well as whole plants, can affect these mechanisms so as to offer protection against injury and promote healing of neurological tissues. Curcumin, quercetin, green tea catechins, balcalein, and luteolin have been extensively studied, and they demonstrate important effects on cell signaling that go far beyond their antioxidant effects. Of particular interest is the effect of these compounds on immunoexcitotoxicity, which, the authors suggest, is a common mechanism in a number of neurological disorders. By suppressing or affecting microglial activation states as well as the excitotoxic cascade and inflammatory mediators, these compounds dramatically affect the pathophysiology of central nervous system disorders and promote the release and generation of neurotrophic factors essential for central nervous system healing. We discuss the various aspects of these processes and suggest future directions for study.

Progressive tentorial cavernous malformation

Takuya Furuta — Wed,15 Feb 2012

Takuya Furuta, Mitsutoshi Nakada, Takuya Watanabe, Yutaka Hayashi, Jun-Ichiro Hamada

Surgical Neurology International 2012 3(1):18-18

Background: Because extra-axial cavernous malformations (CMs) are rare, the common clinical course remains unclear. We report the case of a patient with progressive CM originating from the cerebellar tentorium. Case Description: A 64-year-old woman was admitted to our hospital with the complaint of diplopia. Magnetic resonance (MR) imaging revealed a lesion attached to the left cerebellar tentorium, close to the cerebral peduncle. This well-demarcated lesion rapidly enlarged for 3 months and eroded into the midbrain. Cerebral angiography showed a branch of the middle meningeal artery supplying the lesion and pooling of the contrast medium in the venous phase. A dark reddish and mulberry-like mass of the tentorium was observed intraoperatively, allowing the diagnosis of a tentorial CM. The feeding artery was identified in the tentorium and was coagulated. Postoperative MR imaging showed remarkable mass reduction and central necrosis of the lesion. However, the lesion recurred in 3 months; consequently, gamma knife radiosurgery was performed. After an additional 2 months, the lesion shrank in response to the radiosurgery. Conclusions: We report an extremely rare case of tentorial CM which showed rapid growth in a short period. Coagulation of the feeding artery was not sufficient to control the lesion. Gamma knife radiosurgery may prove highly effective for recurrent lesions.

Diagnostic and surgical challenges in resection of cerebellar angle tumors and acoustic neuromas

Neal Patel — Wed,15 Feb 2012

Neal Patel, Jared Wilkinson, Nicholas Gianaris, Aaron A Cohen-Gadol

Surgical Neurology International 2012 3(1):17-17

Background: Cerebellopontine angle (CPA) lesions can mimic more common tumors through nonspecific symptoms and radiologic findings. Methods: To increase the preoperative diagnostic accuracy for CPA pathologies, the authors review the full spectrum of reported CPA lesions. Results: A wide spectrum of lesions mimics vestibular schwannoma (VS) in the space of the CPA. Conclusion: The presence of any suspicious clinical and radiographic finding uncharacteristic of VS makes it necessary to maintain a broad differential diagnosis list. Differentiation of CPA lesions, although challenging, may be best achieved by incorporating the clinical history, physical exam findings, audiometry results, and multi-modality imaging studies to construct a comprehensive preoperative knowledge of the lesion. This knowledge will allow improved operative execution and outcomes.

Concussions: What a neurosurgeon should know about current scientific evidence and management strategies

Matthew T Neal — Wed,15 Feb 2012

Matthew T Neal, Jonathan L Wilson, Wesley Hsu, Alexander K Powers

Surgical Neurology International 2012 3(1):16-16

Background: There has been a tremendous amount of interest focused on the topic of concussions over the past few decades. Neurosurgeons are frequently consulted to manage patients with mild traumatic brain injuries (mTBI) that have radiographic evidence of cerebral injury. These injuries share significant overlap with concussions, injuries that typically do not reveal radiographic evidence of structural injury, in the realms of epidemiology, pathophysiology, outcomes, and management. Further, neurosurgeons often manage patients with extracranial injuries that have concomitant concussions. In these cases, neurosurgeons are often the only "concussion experts" that patients encounter. Results: The literature has been reviewed and data have been synthesized on the topic including sections on historical background, epidemiology, pathophysiology, diagnostic advances, clinical sequelae, and treatment suggestions, with neurosurgeons as the intended target audience. Conclusions: Neurosurgeons should have a fundamental knowledge of the scientific evidence that has developed regarding concussions and be prepared to guide patients with treatment plans.

Exposure of the sciatic nerve in the gluteal region without sectioning the gluteus maximus: Analysis of a series of 18 cases

Mariano Socolovsky — Wed,15 Feb 2012

Mariano Socolovsky, Gilda Di Masi

Surgical Neurology International 2012 3(1):15-15

Background: Dissecting through the gluteus maximus muscle by splitting its fibers, instead of complete sectioning of the muscle, is faster, involves less damage to tissues, and diminishes recovery time. The objective of the current paper is to present a clinical series of sciatic nerve lesions where the nerve was sufficiently exposed via the transgluteal approach. Methods: We retrospectively selected 18 traumatic sciatic nerve lesions within the buttock, operated upon from January 2005 to December 2009, with a minimum follow-up of 2 years. In all patients, a transgluteal approach was employed to explore and reconstruct the nerve. Results: Ten males and eight females, with a mean age of 39.7 years, were studied. The etiology of the nerve lesion was previous hip surgery (n = 7), stab wound (n = 4), gunshot wound (n = 3), injection (n = 3), and hip dislocation (n = 1). In 15 (83.3%) cases, a motor deficit was present; in 12 (66.6%) cases neuropathic pain and in 12 (66.6%) cases sensory alterations were present. In all cases, the transgluteal approach was adequate to expose the injury and treat it by neurolysis alone (10 cases), neurolysis and neurorrhaphy (4 cases), and reconstruction with grafts (4 cases; three of these paired with neurolysis). The mean pre- and postoperative grades for the tibial nerve (LSUHSC scale) were 1.6 and 3.6, respectively; meanwhile, for the peroneal division, preoperative grade was 1.2 and postoperative grade was 2.4. Conclusions: The transgluteal approach adequately exposes sciatic nerve injuries of traumatic origin in the buttock and allows for adequate nerve reconstruction without sectioning the gluteus maximus muscle.

Perspectives on key articles in neurosurgery

Gordon Li — Wed,15 Feb 2012

Gordon Li, Gabriel Zada, Jonathan H Sherman, Vincent Yat Wang, Chaim B Colen, Chae Yong Kim, Jin Mo Cho, Michael Lim, Isaac Yang

Surgical Neurology International 2012 3(1):14-14

Neurosurgery case review

Pieter L Kubben — Wed,15 Feb 2012

Pieter L Kubben

Surgical Neurology International 2012 3(1):13-13

The predominance of metabolic regulation of cerebral blood flow and the lack of "Classic" autoregulation curves in the viable brain

George I Chovanes — Sat,21 Jan 2012

George I Chovanes, Rafael M Richards

Surgical Neurology International 2012 3(1):12-12

Background: The influence of cerebral perfusion pressure (CPP) on real-time focal cerebral blood flow (fCBF) is not fully understood, in either intact or injured brain. We wanted to evaluate that relationship, and by implication investigate the relative importance of perfusion pressure versus metabolism in the regulation and control of cerebral blood flow. Our hypothesis was that metabolic needs dominated over a physiologic range of blood pressure. Methods: This was an observational study of 23 patients, most of them with closed head injury, three with subarachnoid hemorrhage, one with a gunshot wound to the brain, and one monitored after craniotomy for unruptured aneurysm. Arterial lines, ventriculostomies, and fCBF monitors were placed. CPP (mean arterial pressure − intracranial pressure) and fCBF were measured and recorded to a computer database every minute. The relationship between CPP and fCBF was graphed and correlation coefficients were compared between survivors and non-survivors. Results: Graphs of CPP versus fCBF did not show any linearity over a range of 50-150 mm Hg in patients who survived. In those who died, four of seven showed some indication of linearity. The difference in the correlation coefficients between survivors and non-survivors was statistically significant (P < 0.05), with survivors having essentially no correlation, as expected with autoregulation intact, and non-survivors having a mean correlation of 0.311. Conclusions: In the functioning and viable brain, metabolic regulation of cerebral blood flow (CBF) predominates, leading to the lack of an obvious relationship between perfusion pressure and flow. This predominance of metabolic regulation is robust and preserved over a wide range of brain injury, with pressure autoregulation necessary but not clinically apparent in the metabolically active brain. This robust and constantly varying relationship of pressure and flow shown by our real-time measurements of fCBF has important implications for interpreting clinical measurements of autoregulation. Perhaps most importantly, the development of a correlation between pressure and flow may indicate and be an early warning of deterioration.

Edema and elasticity of a fronto-temporal decompressive craniectomy

Daikei Takada — Sat,21 Jan 2012

Daikei Takada, Hidemasa Nagai, Kouzo Moritake, Yasuhiko Akiyama

Surgical Neurology International 2012 3(1):11-11

Background: Decompressive craniectomy is undertaken for relief of brain herniation caused by acute brain swelling. Brain stiffness can be estimated by palpating the decompressive cranial defect and can provide some relatively subjective information to the neurosurgeon to help guide care. The goal of the present study was to objectively evaluate transcutaneous stiffness of the cranial defect using a tactile resonance sensor and to describe the values in patients with a decompressive window in order to characterize the clinical association between brain edema and stiffness. Methods: Data were prospectively collected from 13 of 37 patients who underwent a decompressive craniectomy in our hospital during a 5-year period. Transcutaneous stiffness was measured as change in frequency and as elastic modulus. Results: Stiffness variables of the decompressive site were measured without any adverse effect and subsequent calculations revealed change in frequency = 101.71 ± 36.42 Hz, and shear elastic modulus = 1.99 ± 1.11 kPa. Conclusions: The elasticity of stiffness of a decompressive site correlated with brain edema, cisternal cerebrospinal fluid pressure, and brain shift, all of which are related to acute brain edema.

Dermoid tumor of the lateral wall of the cavernous sinus

Rui Miguel Ferreira Rato — Sat,21 Jan 2012

Rui Miguel Ferreira Rato, Lia Branco Pappamikail, Bernardo Oliveira Ratilal, Carlos Alberto Vara Luiz

Surgical Neurology International 2012 3(1):10-10

Background: Congenital intracranial dermoid tumors are very rare. The location of these dermoid lesions in the cavernous sinus and the complexity of the operative procedure for these lesions have been noted by several authors. Dermoid tumors originating in the cavernous sinus are usually interdural, and thus blurred vision is an uncommon presentation. Case Description: Herein we report the first incidental case of a cavernous sinus dermoid cyst in a 21-year-old woman. Conclusions: A literature review was done and the possible treatments and approaches for this lesion are discussed. We consider that surgical treatment is indicated in most incidental cavernous sinus dermoid lesions due to the possible symptoms related to compression or rupture leading to chemical meningitis.

Navigation-guided endoscopic biopsy for pathological diagnosis for intraparenchymal pure germinoma near the ventricular trigone

Kuniyuki Onuma — Sat,21 Jan 2012

Kuniyuki Onuma, Eiichi Ishikawa, Masahide Matsuda, Yasushi Shibata, Kaishi Satomi, Tetsuya Yamamoto, Alexander Zaboronok, Shingo Takano, Akira Matsumura

Surgical Neurology International 2012 3(1):9-9

Background: The authors report a case of intraparenchymal germinoma pathologically diagnosed using navigation-guided endoscopic biopsy. Case Description: A 27-year-old man had mild left hemiparesis, transcortical motor aphasia, and amnesia. Magnetic resonance (MR) imaging revealed an intraparenchymal mass lesion near the left ventricular trigone. Navigation-guided endoscopic biopsy was performed, and histopathology revealed large neoplastic cells immunohistochemically positive for germinoma-specific antigens, which were diagnosed as pure germinoma. Chemotherapy with whole-brain radiotherapy was performed, and the neurological symptoms did not change during the treatment. Follow-up MR imaging 1 year after the surgery showed no evidence of recurrence or dissemination. Conclusions: Navigation-guided endoscopic biopsy can be a useful technique in such intraparenchymal germinoma cases.

Handbook of Spine Surgery

Nancy E Epstein — Sat,21 Jan 2012

Nancy E Epstein

Surgical Neurology International 2012 3(1):8-8

A review of interspinous fusion devices: High complication, reoperation rates, and costs with poor outcomes

Nancy E Epstein — Sat,21 Jan 2012

Nancy E Epstein

Surgical Neurology International 2012 3(1):7-7

Background: Interspinous fusion devices (IFDs) are increasingly offered to patients over the age of 50 with lumbar spinal stenosis and intermittent neurogenic claudication. Here, we review the literature on complication rates, reoperation rates, and outcomes for implanting IFD, and offer an assessment of IFD charges at a single institution in 2010. Methods: The literature concerning IFD implants was reviewed with particular attention focused on complications, reoperation rates, and outcomes. Additionally, the costs of implanting 31 IFD devices in 16 patients at one to three levels at a single institution in 2010 are presented. Results: Reviewing the spinal literature concerning the postoperative status of IFD followed over an average of 23-42.9 postoperative months revealed that IFD resulted in 11.6-38% complication rate, 4.6-85% reoperation rate, and 66.7-77% frequency of poor outcomes. Additionally, the 31 devices implanted in 16 patients at a single university hospital in 2010 cost a total of $576,407. Conclusions: With high maximal complication rates (38%), reoperation rates (85%), poor outcomes (77%), and high costs ($576,407 for 31 devices in 16 patients), the utilization and implantation of IFD remains extremely controversial and should be investigated further.

Early microsurgical treatment for spinal hemangioblastomas improves outcome in patients with von Hippel-Lindau disease

Ali Harati — Sat,21 Jan 2012

Ali Harati, Jarno Satopää, Lydia Mahler, Romain Billon-Grand, Ahmed Elsharkawy, Mika Niemelä, Juha Hernesniemi

Surgical Neurology International 2012 3(1):6-6

Background: Spinal hemangioblastomas (HB) are rare, histologically benign, highly vascularized tumors often associated with von Hippel-Lindau (VHL) disease. The aim of the current study is to demonstrate the benefit of early surgical resection of large spinal HBs in selected asymptomatic patients with VHL. Methods: Seventeen patients underwent microsurgical resection of 20 spinal HBs at the Department of Neurosurgery at Helsinki University Central Hospital (HUCH). Thirteen tumors were in the cervical spine, five in thoracic and one patient had two lumbar lesions. MRI tumor showed an associated syrinx in 16 patients (94%). Tumor volume ranged from 27 to 2730 mm3 . Out of 17 patients, 11 (65%) tested positive for VHL in mutation analysis. Five of these patients with tumors ranging from 55 to 720 mm3 were treated prophylactically. Results: Complete tumor resection was performed in 16 patients (94%) who were followed up for a median of 57 months (range 2-165 months). No patient had neurological decline on long-term follow-up. Among the patients with VHL, five patients with preoperative sensorimotor deficits showed improvement of their symptoms but never regained full function. One patient who presented with tetraplegia remained the same. Otherwise, all five patients with prophylactic surgery remained neurologically intact. Conclusion: Although documented growth on serial MRIs and the need for pathological diagnosis have been suggested as indications for surgery in otherwise asymptomatic patients, our series showed that a potentially larger group of asymptomatic patients with spinal HB associated with VHL would benefit from microsurgical resection. Long-term results of the surgical management of spinal HB are generally favorable. Our results suggest staging and early treatment for spinal HB larger than 55 mm3 , especially in patients with VHL. Small spinal HBs may be followed up.

Endovascular embolization of carotid-cavernous fistulas: A pioneering experience in Peru

Andres R Plasencia — Sat,21 Jan 2012

Andres R Plasencia, Alejandro Santillan

Surgical Neurology International 2012 3(1):5-5

Background: Endovascular embolization represents the method of choice for the treatment of carotid-cavernous fistulas (CCFs). Methods: We report our experience using the endovascular technique in 24 patients harboring 25 CCFs treated between October 1994 and April 2010, with an emphasis on the role of detachable balloons for the treatment of direct CCFs. Results: Of the 16 patients who presented with direct CCFs (Barrow Type A CCFs) (age range, 7-62 years; mean age, 34.3 years), 14 were caused by traumatic injury and 2 by a ruptured internal carotid artery (ICA) aneurysm. Eight patients (age range, 32-71 years; mean age, 46.5 years) presented with nine indirect CCFs (Barrow Types B, C, and D). The clinical follow-up after endovascular treatment ranged from 2 to 108 months (mean, 35.2 months). In two cases (8%), the endovascular approach failed. Symptomatic complications related to the procedure occurred in three patients (12.5%): transient cranial nerve palsy in two patients and a permanent neurological deficit in one patient. Detachable balloons were used in 13 out of 16 (81.3%) direct CCFs and were associated with a cure rate of 92.3%. Overall, the angiographic cure rate was obtained in 22 out of 25 (88%) fistulas. Patients presenting with III nerve palsy improved gradually between 1 day and 6 months after treatment. Good clinical outcomes [modified Rankin scale (mRS) ≤ 2] were observed in 22 out of 24 (91.6%) patients at last follow-up. Conclusions: Endovascular treatment using detachable balloons still constitutes a safe and effective method to treat direct carotid-cavernous fistulas.

Leber congenital amaurosis associated with Chiari I malformation: Two cases and a review of the literature

Anthony L Petraglia — Sat,21 Jan 2012

Anthony L Petraglia, Harris U Chengazi, Mina M Chung, Howard J Silberstein

Surgical Neurology International 2012 3(1):4-4

Objective: Leber congenital amaurosis (LCA) is a rare, clinically and genetically heterogeneous disorder characterized by severe loss of vision in the first year of life, affecting approximately 3000 people in the United States. Some LCA patients manifest developmental abnormalities of the central nervous system (CNS) and neuroradiological studies have revealed a variety of cerebral anomalies in association with LCA; however, Chiari I malformations (CMI) have never been described. Case Description: We report two sisters who were referred to the pediatric neurosurgery clinic for evaluation of CMI. The elder sister presented with convergence nystagmus from 3 months of age and magnetic resonance imaging (MRI) demonstrated evidence of significant CMI. Her younger sister began developing nystagmus at 4 months of age. Both had symptomatic progression and underwent suboccipital decompression. Both were subsequently diagnosed with LCA. Case specifics and imaging findings are presented. Conclusions: CMI have been found in association with several genetic syndromes, but not with LCA. These patients represent the first reported cases of CMI with LCA and suggest an additional potential CNS anomaly. The unique occurrence in siblings and the association with another inherited disorder are suggestive of a genetic basis for CMI.

Safety and efficacy of sildenafil citrate in reversal of cerebral vasospasm: A feasibility study

Kanchan K Mukherjee — Sat,21 Jan 2012

Kanchan K Mukherjee, Shrawan K Singh, Virender K Khosla, Sandeep Mohindra, Pravin Salunke

Surgical Neurology International 2012 3(1):3-3

Objective: Cerebral vasospasm is the commonest cause for mortality and morbidity in patients following clipping of a ruptured aneurysm. Selective phosphodiesterase (PDE) inhibitor like sildenafil acts as a vasodilator. The objective of this study was to evaluate the safety and feasibility of oral sildenafil citrate in patients with symptomatic refractory vasospasm. Methods: A total of 832 patients with aneurysmal subarachnoid bleed were operated in 4 years. Two hundred and seventy-three patients had vasospasm. Of these, 72 patients had refractory cerebral vasospasm. Vasospasm was defined as "refractory" when institution of "HHH" failed to reverse the transcranial Doppler (TCD) values even after 24 hours. Computed tomography (CT) scan showed no infarct, hematoma, or hydrocephalus, and the serum electrolytes were within normal limits. They received 100-150 mg of sildenafil every 4 hours. Response was evaluated by 2-hourly TCD. Results: Eight patients had sustained (TCD values normal for >48 hours) and four had temporary relief in vasospasm, as suggested. Four patients developed complications significant enough to terminate the therapy. Conclusions: Sildenafil citrate may be effective in patients with refractory symptomatic vasospasm. It calls upon the pharmacologists and scientists to discover newer supraselective PDE inhibitors, specific to PDE receptors in brain vessels.

Surgical checklists: A detailed review of their emergence, development, and relevance to neurosurgical practice

Douglas J McConnell — Sat,21 Jan 2012

Douglas J McConnell, Kyle M Fargen, J Mocco

Surgical Neurology International 2012 3(1):2-2

In the fall of 1999, the Institute of Medicine released "To Err is Human: Building a Safer Health System," a sobering report on the safety of the American healthcare industry. This work and others like it have ushered in an era where the science of quality assurance has quickly become an integral facet of the practice of medicine. One critical component of this new era is the development, application, and refinement of checklists. In a few short years, the checklist has evolved from being perceived as an assault on the practitioners' integrity to being welcomed as an important tool in reducing complications and preventing medical errors. In an effort to further expand the neurosurgical community's acceptance of surgical checklists, we review the rationale behind checklists, discuss the history of medical and surgical checklists, and remark upon the future of checklists within our field.

Complications of surgical treatment of Rosai-Dorfman Disease: A case report and review

Ryosuke Tomio — Sat,21 Jan 2012

Ryosuke Tomio, Makoto Katayama, Nobuo Takenaka, Tomoyuki Imanishi

Surgical Neurology International 2012 3(1):1-1

Background: Rosai-Dorfman disease (RDD) was first described in 1969 as an idiopathic histiocytic proliferative disorder. It commonly presents as a massive and painless adenopathy. Until 1990, extranodal involvement of the central nervous system (CNS) was rare and reported in less than 5% of the total number of patients with extranodal RDD. Complete removal of CNS RDD has been achieved in many cases. Case Description: We report a case of an isolated intracranial RDD in a 53-year-old man. The patient had an episode of generalized seizures. Imaging studies of the brain were compatible with a meningioma en plaque. The mass was exposed by a right frontotemporal craniotomy. The tumor was adhered tightly to the adjacent cerebral cortex and was permeated by pial arteries of the brain surface. The sacrificing of these arteries was inevitable in order to achieve the total removal of the tumor. The patient had incomplete left hemiparesis after the surgery. Brain computed tomography (CT) imaging revealed a postoperative hemorrhage and a low-density lesion in the right frontal lobe. The patient was postoperatively diagnosed with isolated central nervous system RDD. Conclusion: Although the complete removal of dural-based lesions without any neurological deficits has been performed in many cases, the treatment of cases with high risks, such as the present case, indicates conservative excisions and adjuvant radiotherapy with or without chemotherapy.

Erratum

Sat,31 Dec 2011

Surgical Neurology International 2011 2(1):189-189

Spine surgery in geriatric patients: Sometimes unnecessary, too much, or too little

Nancy E Epstein — Sat,31 Dec 2011

Nancy E Epstein

Surgical Neurology International 2011 2(1):188-188

Background: Although the frequency of spinal surgical procedures has been increasing, particularly in patients of age 65 and over (geriatric), multiple overlapping comorbidities increase their risk/complication rates. Nevertheless, sometimes these high-risk geriatric patients are considered for "unnecessary", too much (instrumented fusions), or too little [minimally invasive surgery (MIS)] spine surgery. Methods: In a review of the literature and reanalysis of data from prior studies, attention was focused on the increasing number of operations offered to geriatric patients, their increased comorbidities, and the offers for "unnecessary" spine fusions, including both major open and MIS procedures. Results: In the literature, the frequency of spine operations, particularly instrumented fusions, has markedly increased in patients of age 65 and older. Specifically, in a 2010 report, a 28-fold increase in anterior discectomy and fusion was observed for geriatric patients. Geriatric patients with more comorbid factors, including diabetes, hypertension, coronary artery disease (prior procedures), depression, and obesity, experience higher postoperative complication rates and costs. Sometimes "unnecessary," too much (instrumented fusions), and too little (MIS spine) surgeries were offered to geriatric patients, which increased the morbidity. One study observed a 10% complication rate for decompression alone (average age 76.4), a 40% complication rate for decompression/limited fusion (average age 70.4), and a 56% complication rate for full curve fusions (average age 62.5). Conclusions: Increasingly, spine operations in geriatric patients with multiple comorbidities are sometimes "unnecessary," offer too much surgery (instrumentation), or too little surgery (MIS).

Vestibular schwannoma of oscillating size: A case report and review of literature

Gazanfar Rahmathulla — Mon,26 Dec 2011

Gazanfar Rahmathulla, Gene H Barnett

Surgical Neurology International 2011 2(1):187-187

Background: Vestibular schwannomas are benign brain tumors arising from the 8th cranial nerve with a varying natural history. Various reports have described discernable growth patterns for these tumors. However, growth predictability remains low because of slow and indeterminate changes over time with follow-up reports not usually exceeding 3 years. Our report describes the long-term follow-up of an unusual cystic schwannoma with growth patterns prior to and following treatment, adding valuable information to the variable natural history and outcome of these infrequent tumors. Case Description: A 68-year-old gentleman presented with a left-sided cystic vestibular schwannoma, initially managed conservatively. Imaging revealed wide variations in the size of his tumor over a period of 3 years. He was finally treated with Gamma Knife radiosurgery, and at 1 year following treatment shows tumor shrinkage with a change in tumor morphology. Conclusion: To our knowledge, the present case represents the first instance of a schwannoma showing wide fluctuations in tumor size and morphology over a period of time, with a good response to radiosurgery. We emphasize in this report that there is no "one size fits all" treatment paradigm for these tumors and each patient requires individualized care and intervention, taking into account their differing natural histories.

Minimally invasive removal of a giant extradural lumbar foraminal schwannoma

Alexander G Weil — Mon,26 Dec 2011

Alexander G Weil, Sami Obaid, Mohammed Shehadeh, Daniel Shedid

Surgical Neurology International 2011 2(1):186-186

Background: Purely extradural lumbar schwannomas are rare lesions. Resection traditionally requires an open laminectomy and ipsilateral complete facectomy. Recent reports have demonstrated safety and efficacy of removal of these tumors using mini-open access devices with expandable retractors. We report a case of a giant L3 schwannoma successfully resected through a minimally invasive approach using the non-expandable Spotlight tubular retrator (Depuy Spine). Case Description: A 77-year-old woman presented with a history of chronic right leg pain, paresthesias and proximal right leg weakness. Magnetic Resonance imaging (MRI) scan revealed a large dumbbell-shaped extradural foraminal lesion at the L3-L4 level with significant extraforaminal extension. The patient underwent a minimally invasive gross total resection (GTR) of the tumor using an 18-mm Spotlight tubular retractor system. Pathology confirmed the lesion to be a benign schwannoma. Postoperatively, the patient's symptoms resolved and she was discharged from the hospital on the second postoperative day. Postoperative MRI showed no residual tumor. The patient returned to normal activities after 2 weeks and remained asymptomatic with no neurological deficits at final 6 months follow-up. Conclusion: Giant lumbar extradural schwannomas can be safely and completely resected using minimally invasive surgery without the need for facectomy or subsequent spinal fusion.

We need a revolution in medicine

James I Ausman — Mon,26 Dec 2011

James I Ausman

Surgical Neurology International 2011 2(1):185-185

The arcade of Struthers: An anatomical study with potential neurosurgical significance

R Shane Tubbs — Mon,26 Dec 2011

R Shane Tubbs, Aman Deep, Mohammadali M Shoja, Martin M Mortazavi, Marios Loukas, Aaron A Cohen-Gadol

Surgical Neurology International 2011 2(1):184-184

Background: Significant controversy exists regarding the existence of the so-called arcade of Struthers and whether this structure is involved in some cases of proximal ulnar nerve entrapment. Therefore, the aim of the present study was to further elucidate this anatomy. Methods: Fifteen cadavers (30 sides) underwent dissection of the medial arm with special attention to the course of the ulnar nerve and its relationships to the soft tissues of this region. Results: We identified a thickening in the inferior medial arm that crosses the ulnar nerve and is consistent with the so-called arcade of Struthers in 86.7% of sides. On 57.7% of the sides, the arcade was found to be due to a thickening of the brachial fascia and was classified as a type I arcade. On 19.2% of the sides, the arcade was due to the internal brachial ligament and these were classified as type II arcades. On 23.1% of the sides, the arcade was due to a thickened medial intermuscular septum and these were classified as type III arcades. The mean length of the arcade was 4.3 cm and the distal end of the arcade was, on average, 6.8 cm above the medial epicondyle. Although the presence of an arcade of Struthers was slightly more common in female specimens, this did not reach statistical significance. However, arcades were found more often on right side (P < 0.001). Conclusions: Based on our findings, the arcade of Struthers is an anatomical band of connective tissue in the medial distal arm that crosses the ulnar nerve. This structure was found in the majority of our specimens and may need to be evaluated in proximal ulnar neuropathies. We believe that past studies that have not observed the arcade and past studies with varied findings are due to the various definitions used for this anatomical structure. Using the classification system as demonstrated in the present study may make future communications regarding the arcade of Struthers more exact.

A critical analysis of the current state of neurosurgery training in Pakistan

M Shahzad Shamim — Mon,26 Dec 2011

M Shahzad Shamim, M Zubair Tahir, Saniya Siraj Godil, Rajesh Kumar, Arshad Ali Siddiqui

Surgical Neurology International 2011 2(1):183-183

Objective: To observe interdepartmental variation in the availability of resources and academic activities within the various neurosurgery programs of Pakistan. Methods: This was a proforma-based survey of neurosurgery trainees and young neurosurgeons of Pakistan, looking at the academic infrastructure and output of their programs. The proforma was filled by 36 respondents from 11 neurosurgery centers of the country. All these centers were accredited for neurosurgery training in Pakistan. Results: Out of the 36 respondents, 30 were completing a Fellowship training (FCPS) and six were enrolled for a Master in Surgery (MS) program. About 80% of the participants used the Youman's Textbook of Neurosurgery as a reference book. Only 40% of the candidates had access to more than one indexed neurosurgery journal. Structured academic sessions (e.g., journal clubs and neuropathology meetings) were lacking in a majority of the training institutes, 95% of the trainees had no microsurgical laboratory experience, and modern neurosurgical tools (frameless neuronavigation system, neuroendoscopy) were in use at a few centers only. Conclusion: Neurosurgery training in Pakistan is not uniform and wide variations exist between the programs at the centers evaluated. We recommend exchange programs between centers at national and international levels, to allow trainees to gain first-hand exposure to training components not available in their own center.

Cranial computed tomography scan findings in head trauma patients in Enugu, Nigeria

Samuel C Ohaegbulam — Mon,26 Dec 2011

Samuel C Ohaegbulam, Wilfred C Mezue, Chika A Ndubuisi, Uwadiegwu A Erechukwu, Chinenye O Ani

Surgical Neurology International 2011 2(1):182-182

Background: The choice of radiological investigations in head trauma in Africa is influenced by factors such as cost. Some patients who require computed tomography (CT) scan elsewhere are either managed blindly or do not present for it at the appropriate time. This paper evaluates the CT scan findings as they are obtained in cases of head trauma in a region of Nigeria. Methods: Prospectively recorded data of all head injury patients who presented for CT scan between January 2009 and April 2010 at Memfys Hospital for Neurosurgery (MHN), Enugu, Nigeria, were analyzed. Mobile CereTom 8-Slice CT was used in all cases. New and follow-up cases were included. Results: There were 204 CT scans for head trauma (171 new, 33 follow-up), accounting for about 34% of all head CT scans performed with this unit. The male to female ratio was 3.5:1. About 33.9% of the patients were in the third and fourth decades of life. In 19.9% cases, CT was unremarkable, while 80.1% cases had abnormal CT findings. The CT diagnosis was not in keeping with the indication of head trauma in 7%, and 13% had more than one finding. The most common CT findings were: subdural hematoma 30%, cerebral contusions and edema 30.7%, skull fractures 23.4% and extradural hematoma 8.0%. About 64% of the CT findings required surgical interventions. The overall mortality was 11.1%, but amongst the 137 patients who had abnormal CT findings, it was 13.9%. Conclusion: The high yield and diversity of CT scan findings in head trauma patients support the indication for the appropriate use of CT in diagnosis and management of head trauma even in developing countries.

Meningioma interdigitated with primary central nervous system B-cell lymphoma: A case report and literature review

Amber S Gordon — Tue,13 Dec 2011

Amber S Gordon, Kenneth E Fallon, Kristen O Riley

Surgical Neurology International 2011 2(1):181-181

Background: Simultaneous presentation of multiple primary central nervous system (CNS) malignancies is extremely rare. There have been only eight cases of meningiomas co-existing with primary cerebral lymphoma, reported in the literature. Case Description: We present a case of a patient who underwent surgical resection of an olfactory grove meningioma that was interdigitated with a primary CNS B-cell lymphoma. Following surgery, the patient was treated with high-dose methotrexate, and has no evidence of recurrence after 18 months. Conclusion: Because of the early recognition of these two distinct pathologies, the patient received directed adjuvant therapies, and has exceeded the survival of all other cases reported in the literature.

The sub-pial resection technique for intrinsic tumor surgery

Adam O Hebb — Tue,13 Dec 2011

Adam O Hebb, Tong Yang, Daniel L Silbergeld

Surgical Neurology International 2011 2(1):180-180

Background: The technique of sub-pial resection, first described in the early 1900s, was later refined by Penfield and Jasper for removal of supratentorial epileptic cortex. This technique has not been widely adopted for intrinsic tumor resection, for which the most widely used technique involves piecemeal aspiration of the tumor. This technique of "staying within the tumor" results in persistent bleeding, with obscuration of the tumor/brain interface, potentially yielding less than satisfactory results. In our experience, the sub-pial technique is useful for resections of supratentorial intrinsic tumor. We report the use of sub-pial resection technique and present illustrative cases. Methods: The sub-pial resection technique is described along with important clinical decision-making guidelines. Representative cases are presented to discuss application of the sub-pial technique and to demonstrate surgical results. Results: The sub-pial technique preserves the pia during cortical resections and makes it easier to protect and identify normal anatomy, including sulci, gyri, cranial nerves, and major vascular structures. This reduces bleeding, making surgery safer and more efficient. In most cases, an en bloc resection can be accomplished, permitting more accurate histopathology and more extensive tissue acquisition for research purposes. Conclusion: The sub-pial technique can be incorporated into strategies for supratentorial intrinsic tumor resections, including temporal, frontal, occipital, and insular tumors, at para-Sylvian or para-insular-sulcus locations.

Managed truth: The great danger to our republic

Russell L Blaylock — Tue,13 Dec 2011

Russell L Blaylock

Surgical Neurology International 2011 2(1):179-179

The innervation of the scalp: A comprehensive review including anatomy, pathology, and neurosurgical correlates

William J Kemp III — Tue,13 Dec 2011

William J Kemp III, R Shane Tubbs, Aaron A Cohen-Gadol

Surgical Neurology International 2011 2(1):178-178

Background: Neurosurgical intervention involving the scalp may cause neuralgia or other pain syndromes. Therefore, a comprehensive understanding of scalp innervation may be helpful in prevention of pain potentially induced by surgery. Methods: Using standard search engines, a review of the literature regarding the anatomy of the nerves that innervate the scalp was performed with attention given to anatomic landmarks. Results: This paper provides a comprehensive review of the anatomy, embryology, pathology, and neurosurgical application of the knowledge of the innervation of the scalp. Conclusions: Knowledge of the nerves that supply the scalp is important to the neurosurgeon who hopes to maximize patient recovery and minimize post-procedural complications.

Surgical remotion of a cysticercotic granuloma responsible for refractory seizures: A case report

Md. Shariful Hasan — Tue,13 Dec 2011

Md. Shariful Hasan, Hamidon Bin Basri, Lim Poh Hin, Johnson Stanslas

Surgical Neurology International 2011 2(1):177-177

Background: Neurocysticercosis is the most common parasitic infestation of the central nervous system and an important cause of acquired epilepsy. Although endemic in developing countries, with an increased immigration from the endemic regions, it is also seen progressively in other parts of the world. Hence, there is an increased need for awareness of neurocysticercosis in the non-endemic areas. Case Description: The case described here is of a 13-year-old girl who presented with refractory seizures. She had been on antiepileptic medication and had also received anti-parasitic treatment for neurocysticercosis. Surgical intervention was recommended because the seizures were resistant to treatment and also because the diagnosis could not be clearly established. Following surgery, the seizures have been under control and the patient has been doing well. Conclusion: Neurocysticercosis can be a potential cause of refractory seizure even in non-endemic countries. Some cases may be difficult to diagnose. Clinical presentation of seizure and brain imaging should be given priority over blood investigations for diagnosing neurocysticercosis and advanced neurosurgical intervention can be considered in suitable cases for better outcome.

Increasing incidence of glioblastoma multiforme and meningioma, and decreasing incidence of Schwannoma (2000-2008): Findings of a multicenter Australian study

Martin Dobes — Tue,13 Dec 2011

Martin Dobes, Vini G Khurana, Bruce Shadbolt, Sanjiv Jain, Sarah F Smith, Robert Smee, Mark Dexter, Raymond Cook

Surgical Neurology International 2011 2(1):176-176

Background: The incidence of primary brain tumors by subtype is currently unknown in Australia. We report an analysis of incidence by tumor subtype in a retrospective multicenter study in the state of New South Wales (NSW) and the Australian Capital Territory (ACT), with a combined population of >7 million with >97% retention rate for medical care. Methods: Data from histologically confirmed primary brain tumors diagnosed from January 2000 through December 2008 were weighted for patient outflow and data completeness, and age standardized and analyzed using joinpoint analysis. Results: A significant increasing incidence in glioblastoma multiforme (GBM) was observed in the study period (annual percentage change [APC], 2.5; 95% confidence interval [CI], 0.4-4.6, n = 2275), particularly after 2006. In GBM patients in the ≥65-year group, a significantly increasing incidence for men and women combined (APC, 3.0; 95% CI, 0.5-5.6) and men only (APC, 2.9; 95% CI, 0.1-5.8) was seen. Rising trends in incidence were also seen for meningioma in the total male population (APC, 5.3; 95% CI, 2.6-8.1, n = 515) and males aged 20-64 years (APC, 6.3; 95% CI, 3.8-8.8). Significantly decreasing incidence trends were observed for Schwannoma for the total study population (APC, −3.5; 95% CI, −7.2 to −0.2, n = 492), significant in women (APC, −5.3; 95% CI, −9.9 to −0.5) but not men. Conclusion: This collection is the most contemporary data on primary brain tumor incidence in Australia. Our registries may observe an increase in malignant tumors in the next few years that they are not detecting now due to late ascertainment. We recommend a direct, uniform, and centralized approach to monitoring primary brain tumor incidence by subtype, including the introduction of nonmalignant data collection.

Recurrence of a cerebral arteriovenous malformation following complete surgical resection: A case report and review of the literature

Alexander G Weil — Tue,13 Dec 2011

Alexander G Weil, Shu Li, Ji-Zong Zhao

Surgical Neurology International 2011 2(1):175-175

Background: Angiography-confirmed complete resection of an arteriovenous malformation (AVM) has traditionally been considered curative. However, recurrence of AVM following angiographically proven complete resection does exist, especially in children. This rare occurrence has been reported 29 times in the English language literature. Although recurrence may be asymptomatic, many reported cases result in epilepsy or intracranial hemorrhage anywhere from 0.5 to 9 years following complete resection. We report a rare case of AVM recurrence that became symptomatic 16 years after complete resection. We review the literature and discuss the relevance of performing follow-up imaging to detect AVM recurrence. Case Description: An 8-year-old girl presented with a right occipital hemorrhage with intraventricular extension from a ruptured AVM of the right occipital lobe. She underwent AVM resection through a right occipital craniotomy. Postoperative angiography confirmed complete resection and she made an uneventful recovery. Sixteen years later, she presented with a 2-month history of headaches, nausea and dizziness. Angiography revealed recurrence of the AVM which was completely resected, as documented on postoperative angiography. Conclusion: In children, an AVM may recur after angiography-proven complete resection. Recurrence may be due to persistence and growth of an initially angiographically occult arteriovenous shunt left in place during surgery or the development of a new AVM. In addition to obtaining follow-up angiography 6-12 months after surgery, a late angiography 5 years after resection may be warranted in patients at risk for recurrence. Asymptomatic recurrence detection allows treatment and may prevent the morbidity associated with intracranial hemorrhage.

Cerebrospinal fluid rhinorrhea: An institutional perspective from Pakistan

Muhammad Zubair Tahir — Tue,13 Dec 2011

Muhammad Zubair Tahir, Muhammad Babar Khan, Muhammad Umair Bashir, Shabbir Akhtar, Ehsan Bari

Surgical Neurology International 2011 2(1):174-174

Background: The management of cerebrospinal fluid (CSF) rhinorrhea has evolved over the last two decades. We present here a review of our 11-year data on CSF rhinorrhea and its management at a tertiary care hospital in a developing country, with particular reference to the diagnosis, surgical management and outcome of the disease. Methods: The medical charts of all patients with a diagnosis of CSF rhinorrhea over an 11-year period were reviewed. The etiology of CSF rhinorrhea was classified into three categories: spontaneous, iatrogenic and traumatic. All the patients were divided into three categories based on the type of management as conservative, intracranial and transnasal endoscopic groups. Results: A total of 43 patients fulfilled our inclusion criteria and were included in the final analysis. Eleven of the 43 patients were managed conservatively, while 22 underwent intracranial repairs; 10 patients had transnasal endoscopic repairs. The primary success rate for the transnasal approach was 70% compared to 86% for the intracranial repair. Blood loss, special care unit (SCU) stay and total cost were found to be significantly less in the transnasal endoscopic group. Computed tomography (CT) cisternography was found to have the highest sensitivity and specificity. Further, no postoperative complications were found in the transnasal endoscopic group, while five patients from the intracranial group developed various complications. Conclusions: We conclude that the transnasal endoscopic approach has comparable success rates with the intracranial approach and significantly lower morbidity.

Neurosurgery concepts

Isaac Yang — Wed,30 Nov 2011

Isaac Yang, Jin Mo Cho, Chaim B Colen, Gordon Li, Michael Lim, Jonathan H Sherman, Vincent Yat Wang

Surgical Neurology International 2011 2(1):173-173

From the bench to the bedside: Genetics of intellectual disability, Gustatopic mapping, Molecular origins of oligodendrogliomas, Back pain and the brain, and more…

Jason S Hauptman — Wed,30 Nov 2011

Jason S Hauptman

Surgical Neurology International 2011 2(1):172-172

Sternberg's canal as a cause of encephalocele within the lateral recess of the sphenoid sinus: A report of two cases

Damián C Bendersky — Sat,19 Nov 2011

Damián C Bendersky, Federico A Landriel, Pablo M Ajler, Santiago M Hem, Antonio C Carrizo

Surgical Neurology International 2011 2(1):171-171

Background : Intrasphenoidal encephaloceles are extremely rare findings. Sternberg's canal is a lateral craniopharyngeal canal resulting from incomplete fusion of the greater wings of the sphenoid bone with the basisphenoid. It acts as a weak spot of the skull base, which may lead to develop a temporal lobe encephalocele protruding into the lateral recess of the sphenoid sinus (SS). Case Description : We present two cases of intrasphenoidal encephalocele due to persistence of the lateral craniopharyngeal canal. The first case presented with cerebrospinal fluid (CSF) rhinorrhea and the second one was referred to the neurosurgical department with CSF rhinorrhea and meningitis. Radiological investigations consisted of computed tomography (CT) scan, CT cisternography and magnetic resonance images in both cases. These imaging studies identified a herniated temporal lobe through a bony defect which communicates the middle cranial fossa with the lateral recess of the SS. Both patients underwent a transcranial repair of the encephalocele because of the previous failure of the endoscopic surgery. There was no complication related to the surgical procedure and no recurrence of CSF leakage occurred 2 and 3 years after surgery, respectively. Conclusion : Encephalocele within the lateral recess of the SS is a rare entity which must be suspected in patients who present with spontaneous CSF rhinorrhea. Congenital intrasphenoidal encephaloceles, which are located medial to the foramen rotundum, seem to be due to persistence of the Sternberg's canal. Transcranial approach is a good option when a transnasal approach had failed previously.

Bolt from the blue: Basal ganglion bleed following lightning strike

Ashish Aggarwal — Sat,19 Nov 2011

Ashish Aggarwal, Pravin Salunke

Surgical Neurology International 2011 2(1):170-170

Posterior communicating artery aneurysm rupture mimicking apoplexy

Christopher M Bonfield — Sat,19 Nov 2011

Christopher M Bonfield, Paul A Gardner

Surgical Neurology International 2011 2(1):169-169

Background : Cerebral aneurysm rupture can lead to devastating neurological complications and present a complex problem to treat. We report a unique case of a ruptured posterior communicating artery (PCoA) aneurysm presenting with sudden and complete vision loss. Case Description : A 39-year-old man presented with the acute onset of severe headache and complete bilateral vision loss. The patient described headaches for several months prior to presentation. However, prior to the day of presentation, he had no visual disturbance. A CT angiogram (CTA) and magnetic resonance imaging (MRI) of the brain revealed a 1.6-cm, non-contrast enhancing suprasellar mass, eccentric to the left side, consistent with hemorrhagic mass. There was no obvious aneurysm or vascular malformation. The sella tursica was normal in appearance. The patient was taken for an immediate endoscopic endonasal transtuberculum approach for optic nerve decompression. Hematoma without an associated tumor was encountered and partially evacuated before aborting with resultant partial improvement in vision. A subsequent cerebral angiogram revealed an irregularly shaped, postero-laterally pointing, 2.5-mm left PCoA aneurysm. The patient was then taken for open clipping of the ruptured aneurysm. A large, fibrinous capsule was found over the superolateral aspect of the aneurysm. The ruptured aneurysm was secured with clips and the surrounding hematoma was evacuated. Conclusion : In the immediate postoperative period, the patient regained vision in the nasal field of his right eye. This case illustrates a unique presentation of a ruptured PCoA aneurysm, and thus must be considered in the differential diagnosis of a suprasellar hemorrhage resulting in visual loss in absence of a recognizable associated tumor.

Closing the gap between research techniques and clinical practice in the treatment of dementia

Alissa H Wicklund — Sat,19 Nov 2011

Alissa H Wicklund, Moises Gaviria

Surgical Neurology International 2011 2(1):168-168

Slack brain in meningioma surgery through lateral supraorbital approach

Rossana Romani — Sat,19 Nov 2011

Rossana Romani, Marja Silvasti-Lundell, Aki Laakso, Hanna Tuominen, Juha Hernesniemi, Tomi Niemi

Surgical Neurology International 2011 2(1):167-167

Background : Surgery of skull base meningiomas by the lateral supraorbital (LSO) approach requires relaxed brain. Therefore, we assessed combined effects of the elements of neuroanesthesia on neurosurgical conditions during craniotomy. Methods : The anesthesiological and surgical charts of 66 olfactory groove, 73 anterior clinoidal, and 52 tuberculum sellae meningioma patients operated on by the senior author (J.H.) at the Department of Neurosurgery of Helsinki University Central Hospital, Helsinki, Finland, between September 1997 and August 2010, were retrospectively analyzed. Results : One-hundred fifty-four (82%) patients had good surgical conditions, and this was achieved by (1) elevating the head 20 cm above the cardiac level in all patients with only slightly lateral turn or neck flexion, (2) administering mannitol preoperatively in medium or large meningiomas (n = 60), (3) maintaining anesthesia with propofol infusion (n = 46) or volatile anesthetics (n = 107) also in patients with large tumors (n = 37), and (4) controlling intraoperative hemodynamics. Brain relaxation was satisfactory in 18 (10%) and poor in 15 (8%) patients. The median intraoperative blood loss was 200 (range, 0-2000) ml. Only 9% of patients received red blood cell transfusion. The median time to extubation was 18 (range, 8-105) min after surgery. Extubation time correlated with the patients' preoperative clinical status and the size of tumor but not with the modality of anesthesia. Conclusions : Slack brain during the LSO approach is achieved by correct patient positioning, preoperative mannitol, either by propofol or in small tumors inhaled anesthetics, and optimizing cerebral perfusion pressure. Under these circumstances, intraoperative brain swelling is prevented, bleeding is minimal, and no blood transfusions are needed.

Non-operative management is superior to surgical stabilization in spine injury patients with complete neurological deficits: A perspective study from a developing world country, Pakistan

Muhammad Shahzad Shamim — Sat,19 Nov 2011

Muhammad Shahzad Shamim, Syed Faizan Ali, Syed Ather Enam

Surgical Neurology International 2011 2(1):166-166

Background : Surgical stabilization of injured spine in patients with complete spinal cord injury is a common practice despite the lack of strong evidence supporting it. The aim of this study is to compare clinical outcomes and cost-effectiveness of surgical stabilization versus conservative management of spinal injury in patients with complete deficits, essentially from a developing country's point of view. Methods : A detailed analysis of patients with traumatic spine injury and complete deficits admitted at the Aga Khan University Hospital, Pakistan, from January 2004 till January 2010 was carried out. All patients presenting within 14 days of injury were divided in two groups, those who underwent stabilization procedures and those who were managed non-operatively. The two groups were compared with the endpoints being time to rehabilitation, length of hospital stay, 30 day morbidity/mortality, cost of treatment, and status at follow up. Results : Fifty-four patients fulfilled the inclusion criteria and half of these were operated. On comparing endpoints, patients in the operative group took longer time to rehabilitation (P-value = 0.002); had longer hospital stay (P-value = 0.006) which included longer length of stay in special care unit (P-value = 0.002) as well as intensive care unit (P-value = 0.004); and were associated with more complications, especially those related to infections (P-value = 0.002). The mean cost of treatment was also significantly higher in the operative group (USD 6,500) as compared to non-operative group (USD 1490) (P-value < 0.001). Conclusion : We recommend that patients with complete SCI should be managed non-operatively with a provision of surgery only if their rehabilitation is impeded due to pain or deformity.

A minimally invasive technique for percutaneous lumbar facet augmentation: Technical description of a novel device

Zachary A Smith — Sat,19 Nov 2011

Zachary A Smith, Sean Armin, Dan Raphael, Larry T Khoo

Surgical Neurology International 2011 2(1):165-165

Background : We describe a new posterior dynamic stabilizing system that can be used to augment the mechanics of the degenerating lumbar segment. The mechanism of this system differs from other previously described surgical techniques that have been designed to augment lumbar biomechanics. The implant and technique we describe is an extension-limiting one, and it is designed to support and cushion the facet complex. Furthermore, it is inserted through an entirely percutaneous technique. The purpose of this technical note is to demonstrate a novel posterior surgical approach for the treatment of lumbar degenerative. Methods : This report describes a novel, percutaneously placed, posterior dynamic stabilization system as an alternative option to treat lumbar degenerative disk disease with and without lumbar spinal stenosis. The system does not require a midline soft-tissue dissection, nor subperiosteal dissection, and is a truly minimally invasive means for posterior augmentation of the functional facet complex. This system can be implanted as a stand-alone procedure or in conjunction with decompression procedures. Results : One-year clinical results in nine individual patients, all treated for degenerative disease of the lower lumbar spine, are presented. Conclusions : This novel technique allows for percutaneous posterior dynamic stabilization of the lumbar facet complex. The use of this procedure may allow a less invasive alternative to traditional approaches to the lumbar spine as well as an alternative to other newly developed posterior dynamic stabilization systems.

Usefulness of the contralateral Omega sign for the topographic location of lesions in and around the central sulcus

Alvaro Campero — Mon,14 Nov 2011

Alvaro Campero, Pablo Ajler, Carolina Martins, Juan Emmerich, Luiz Felipe de Alencastro, Albert Rhoton

Surgical Neurology International 2011 2(1):164-164

Background: The central sulcus may be located through magnetic resonance imaging (MRI) by identifying the ipsilateral inverted Omega shape. In a brain with a lesion in this area, its identification becomes a hard task irrespective of the technique applied. The aim of this study is to show the usefulness of the contralateral Omega sign for the location of tumors in and around the central sulcus. We do not intend to replace modern techniques, but to show an easy, cheap and relatively effective way to recognize the relationship between the central sulcus and the lesion. Methods: From July 2005 through December 2010, 43 patients with lesions in and around the central sulcus were operated using the contralateral Omega sign concept. Additionally, 5 formalin-fixed brains (10 hemispheres) were studied to clarify the anatomy of the central sulcus where the Omega shape is found. Results: The central sulcus has three genua. The middle genu is characterized by an inverted Omega-shaped area in axial sections known as the Omega sign. On anatomical specimens, Omega was 11.2 ± 3.35 mm in height, on average, and 18.7 ± 2.49 mm in width, at the base. The average distance from the medial limit of the Omega to the medial edge of the hemisphere was 24.5 ± 5.35 mm. Identification of the Omega sign allowed for the topographic localization of the contralateral central sulcus in all our surgical cases but one. Conclusion: The contralateral Omega sign can be easily and reliably used to clarify the topographic location of the pathology. Hence, it gives a quick preoperative idea of the relationships between the lesion and the pre- and post-central gyri.

The therapeutic potential of inhibitors of the signal transducer and activator of transcription 3 for central nervous system malignancies

Amy B Heimberger — Mon,14 Nov 2011

Amy B Heimberger

Surgical Neurology International 2011 2(1):163-163

Background: High-grade primary and metastatic central nervous system (CNS) tumors are common, deadly, and refractory to conventional therapy and continue to be therapeutically challenging. A key nodal transcriptional factor, the signal transducer and activator of transcription 3 (STAT3), drives the fundamental components of tumor malignancy and metastases in the CNS by enhancing proliferation, angiogenesis, invasion, metastasis, and immunosuppression. The introduction of STAT3 inhibitors in clinical trials for this patient population is imminent. Methods: STAT3 inhibitors have been extensively tested in a variety of preclinical murine models. Results: The STAT3 inhibitor, WP1066, has displayed marked efficacy with minimal toxicity against malignancy in murine models, including established intracerebral tumors. The mechanism of this in vivo efficacy of the STAT3 blockade agents is a combination of direct tumor cytotoxicity and immune cytotoxic clearance. Conclusions: Given their direct antitumor cytotoxic effects, STAT3 inhibitors may exert therapeutic activity in the monotherapy setting but may also have compelling use as immunotherapeutic modulators or as a salvage therapy.

Mycobacterium bovis spondylodiscitis after intravesical Bacillus Calmette-Guérin therapy

Sami Obaid — Mon,14 Nov 2011

Sami Obaid, Alexander G Weil, Ralph Rahme, Cathy Gendron, Daniel Shedid

Surgical Neurology International 2011 2(1):162-162

Background: Intravesical instillations of live-attenuated Bacillus Calmette-Guérin (BCG) are a well-known and effective method for prevention and treatment of bladder carcinoma and carcinoma in situ. Although considered a safe procedure with rare side effects, local and systemic complications may occur. While long bone ostemolyelitis has been well described, very few reports of BCG spondylodiscitis exist in the literature. Case Description: A 67-year-old man developed low back pain, anorexia, and weight loss 11 months after a 6-week course of intravesical BCG instillations for the treatment of bladder carcinoma in situ. Imaging studies revealed L1-L2 spondylodiscitis with epidural and bilateral psoas abscesses. Tissue cultures obtained by percutaneous computed tomography-guided aspiration were positive for Mycobacterium bovis. Despite triple antituberculous therapy (isoniazid, rifampin, and ethambutol), clinical and radiological progression occurred. Therefore, L1 and L2 corpectomies with extensive debridement were performed, followed by 360° anterior-posterior instrumented fusion. After 20 months of follow-up, the patient remains asymptomatic and recurrence-free. Conclusion: Mycobacterium bovis spondylodiscitis is a rare complication of intravesical BCG therapy. Although medical therapy with antituberculous agents is the first-line treatment, surgical decompression, debridement, and stabilization may be necessary in refractory cases.

Stalin's mysterious death

Miguel A Faria — Mon,14 Nov 2011

Miguel A Faria

Surgical Neurology International 2011 2(1):161-161

Neurosurgical management of leukoencephalopathy, cerebral calcifications, and cysts: A case report and review of literature

John Berry-Candelario — Mon,14 Nov 2011

John Berry-Candelario, Ekkehard Kasper, Emad Eskandar, Clark C Chen

Surgical Neurology International 2011 2(1):160-160

Background: Leukoencephalopathy, Calcification, and Cyst (LCC) is a syndrome describing the rare concurrence of these three unusual radiographic findings. Here, we describe the neurosurgical management in a patient afflicted with LCC and review the existing literature on surgical indications and outcomes. Case Description: A 24-year-old man presented with symptoms of progressive headache, gait imbalance and horizontal diplopia. Magnetic resonance imaging (MRI) showed radiographic findings typically associated with LCC, including a large pontine cyst with significant mass effect. The patient's symptoms resolved after open surgical cyst drainage. However, he suffered cyst re-accumulation 3 months after the initial procedure and ultimately underwent placement of a ventriculo-cysto-peritoneal shunt. At the 3-year follow-up, the patient remained symptom free with continued cyst decompression. Conclusion: Our case report suggests that ventriculo-cysto-peritoneal shunting appeared an effective strategy in LCC patients in whom the cyst fenestration failed. We present this case report in the context of the first systematic review of literature on neurosurgical management strategies for patients afflicted with LCC.

Surgical treatment of cerebellar metastases

Ali J Ghods — Mon,14 Nov 2011

Ali J Ghods, Lorenzo Munoz, Richard Byrne

Surgical Neurology International 2011 2(1):159-159

Background: Cerebral metastases are a common neurosurgical finding. Surgery confers several advantages to other therapies, including immediate symptomatic improvement, diagnosis, and relief from corticosteroid dependence. Here we evaluate patients with cerebellar metastases who underwent surgery and compare their findings to those in the literature, and address the benefit of avoiding ventriculo-peritoneal shunting in patients undergoing surgery. Methods: We performed a retrospective analysis involving 50 patients with cerebellar metastases who underwent surgical resection. Ventriculo-peritoneal shunts were placed in patients necessitating permanent CSF drainage. We evaluated presentation, diagnosis, complications, and outcome. Results: Our review included 21 males and 29 females, 29 to 82 years of age. Primary tumors included lung (48%), breast (14%), GI (14%), endometrial/ovarian (6%), melanoma (6%), sarcoma (4%), lymphoma (4%), laryngeal (2%), and other (2%). Clinical symptoms at presentation commonly were those secondary to elevated intracranial pressure and were the initial complaint in 34% of patients. Preoperatively, 29 patients were noted to have hydrocephalus. Importantly, 76% of these patients were able to avoid placement of a ventriculo-peritoneal shunt following surgery. Only two complications were noted in our series of 50 patients, including a symptomatic pseudomeningocele and a wound infection. No symptomatic postoperative hematoma developed in any surgical case. Conclusion: A review of the literature has shown a high complication rate in patients undergoing surgical resection of cerebellar metastases. We have shown that surgical resection of cerebellar metastases is a safe procedure and is effective in the treatment of hydrocephalus in the majority of patients harboring cerebellar lesions.

Benefits and limitations of diameter measurement in the conservative management of meningiomas

Soichi Oya — Mon,14 Nov 2011

Soichi Oya, Burak Sade, Joung H Lee

Surgical Neurology International 2011 2(1):158-158

Background: Meningiomas are the most common benign brain tumors that are frequently followed-up by neurologists, general practitioners, and neurosurgeons. Some recent studies advocate the accurate volumetric method (VM) over measuring the linear maximum diameter although its clinical significance still remains unknown. The aim of this study is to directly compare the linear method (LM) and VM to delineate the characteristics of both measurements. Methods: Between 2003 and 2010, growth analysis using magnetic resonance imaging DICOM files was performed for 189 meningiomas in 161 patients at the Cleveland Clinic. In LM, a minimum increase of 2 mm in maximum diameter was defined as tumor growth. The absolute volume growth (VG, in cm 3 ) was calculated for each tumor. Results: Linear growth (LG) was seen in 71 tumors (37.6%) within the median follow-up of 2.0 years. These tumors with LG showed a mean VG of 2.80 cm 3 . Some large LG-positive tumors can be larger than estimated from LG. In addition, the skull base location was correlated to greater VG. On the other hand, 118 tumors without LG demonstrated the minimal actual volume increase, i.e., mean VG of 0.16 cm 3 . Although a small subset of these LG-negative tumors might have slightly high VG when they were large, the location of tumor had no correlation to VG. Conclusions: Our data demonstrated some important precautions in measuring the tumor growth. We believe that it is mandatory in the conservative management of meningiomas to correctly understand benefits and potential limitations of different measurement methods utilized.

In situ free-floating craniectomy for traumatic cerebral decompression in an infant: A field hospital solution

Victoria T Trinh — Mon,14 Nov 2011

Victoria T Trinh, Edward A. M. Duckworth

Surgical Neurology International 2011 2(1):157-157

Background: Despite refinements in neurotrauma care, the morbidity and mortality of severe traumatic brain injury (TBI) in pediatric patients remains high. We report a novel approach to the surgical management of increased intracranial pressure in severe TBI utilizing an in situ free-floating craniectomy technique, which was originally devised as a creative solution to the unique challenges in a Haitian field hospital following the 2010 earthquake. Case Description: A 13-month-old Haitian boy presented to Project Medishare field hospital in Port-au-Prince with left hemiplegia, a bulging fontanelle, and increasing lethargy following a traumatic head injury 4 days prior. An urgent craniectomy was performed based on clinical grounds (no brain imaging was available). A standard trauma flap incision was made, followed by a hemicraniectomy and expansion duraplasty. A small hematoma was evacuated. Frontal, temporal, and parietal bone flaps were placed on the dura in approximation to their normal anatomical configuration, but not affixed, leaving space for further brain edema, and the scalp was closed. The child experienced favorable peri-operative and early postoperative results. Conclusion: In situ free-floating craniectomy, while devised as a creative solution to limited resources in a natural disaster zone, may offer advantages over more traditional techniques.

Anterior decompression, fusion and plating in cervical spine injury: Early experience in Abuja, Nigeria

Biodun Ogungbo — Mon,14 Nov 2011

Biodun Ogungbo

Surgical Neurology International 2011 2(1):156-156

Background: We present a review of the results of the current surgical management of acute cervical spine injuries in the Federal Capital Territory, Abuja, Nigeria. This is the first detailed retrospective study on the surgical management of patients with cervical spine injuries from Nigeria. Methods: The medical reports of patients with traumatic cervical spine and spinal cord injuries undergoing surgery from 1 August 2009 till 30 August 2010 were reviewed. Management and early results of outcome were ascertained and detailed consecutively in a prospective Microsoft Office Access® database (Microsoft Group of Companies). Frankel grading was used for pre- and immediate post-operative evaluation (within 48 hours). The Barthel index (BI) was used to classify patients as dependent or independent at follow-up. Results: Twenty consecutive patients presented with acute cervical spine and spinal cord injuries since August 2009. Twenty anterior cervical spine decompression and fixation with an iliac graft and an anterior cervical plate (ACDF) were performed in 18 patients. All operations were performed with general anaesthesia using standard techniques but without a microscope or a high speed drill. Of the 18 patients who were operated, 4 patients died within a short period following surgical intervention. Seven patients have made a full recovery and seven remain fully dependent. Only two of the dependent quadriplegic patients have become reintegrated back into the society. Conclusion: The management of spinal cord injuries in Abuja is evolving. The operations were performed adequately with much limited complement of equipment. Poor intensive care therapy is a major challenge and improvements in this area of care will likely lead to better patient outcomes.

Intraspinal primitive neuroectodermal tumor in a man with neurofibromatosis type 1: Case report and review of the literature

Celene B Mulholland — Sat,29 Oct 2011

Celene B Mulholland, Garni Barkhoudarian, Marcia E Cornford, Duncan Q McBride

Surgical Neurology International 2011 2(1):155-155

Background: The occurrence of primitive neuroectodermal tumors (PNET) in patients with neurofibromatosis type 1 (NF1) has only been reported in two other cases in English-Language literature. Owing to the rarity of intraspinal PNET and the extremely high gene mutation variability in NF1, there is currently no conclusive evidence to suggest that PNET is associated with NF1. Here, we report a case of intradural PNET in a patient with NF1. Case Description: A 27-year-old male underwent a C1-C3 laminectomy for resection of an intramedullary mass. Histopathology and immunohistopathology analysis was performed. Microscopic examination and immunohistochemical staining indicated the mass was a primitive neuroectodermal tumor. Within 1 month after tumor resection, the patient developed leptomeningeal carcinomatosis. The patient was not a candidate for radiation therapy but underwent palliative systemic chemotherapy. He subsequently developed neutropenia and died 3 months after tumor resection. Conclusion: To our knowledge, this is the first reported intraspinal PNET associated with NF1. Genetic analysis of CNS PNETs suggests a possible correlation, but larger case series are needed to support this theory.

Surgical approaches to tinnitus treatment: A review and novel approaches

Teo Soleymani — Sat,29 Oct 2011

Teo Soleymani, David Pieton, Patrick Pezeshkian, Patrick Miller, Alessandra A Gorgulho, Nader Pouratian, Antonio A.F. De Salles

Surgical Neurology International 2011 2(1):154-154

Background: Tinnitus, a profoundly widespread auditory disorder, is characterized by the perception of sound in the absence of external stimulation. The aim of this work is to review the various surgical treatment options for tinnitus, targeting the various disruption sites along the auditory pathway, as well as to indicate novel neuromodulatory techniques as a mode of tinnitus control. Methods: A comprehensive analysis was conducted on published clinical and basic neuroscience research examining the pathophysiology and treatment options of tinnitus. Results: Stereotactic radiosurgery methods and microvascular decompressions are indicated for tinnitus caused by underlying pathologies such as vestibular schwannomas or neurovascular conflicts of the vestibulocochlear nerve at the level of the brainstem. However, subsequent hearing loss and secondary tinnitus may occur. In patients with subjective tinnitus and concomitant sensorineural hearing loss, cochlear implantation is indicated. Surgical ablation of the cochlea, vestibulocochlear nerve, or dorsal cochlear nucleus, though previously suggested in earlier literature as viable treatment options for tinnitus, has been shown to be ineffective and contraindicated. Recently, emerging research has shown the neuromodulatory capacity of the somatosensory system at the level of the trigeminal nerve on the auditory pathway through its inputs at various nuclei in the central auditory pathway. Conclusion: Tinnitus remains to be a difficult disorder to treat despite the many surgical interventions aimed at eliminating the aberrant neuronal activity in the auditory system. A promising novel neuromodulatory approach using the trigeminal system to control such a bothersome and difficult-to-treat disorder deserves further investigation and controlled clinical trials.

Familial glioblastoma: A case report of glioblastoma in two brothers and review of literature

Ifeoma Ugonabo — Sat,29 Oct 2011

Ifeoma Ugonabo, Nader Bassily, Alexandra Beier, Jacky T Yeung, Lynette Hitchcock, Frances De Mattia, Aftab Karim

Surgical Neurology International 2011 2(1):153-153

Background: Gliomas that aggregate in families with history of malignancy may have an inheritable genetic basis. Gliomas can occur in several well known tumor syndromes. However, their occurrence in the absence of these syndromes is quite rare. High-grade gliomas, such as glioblastoma multiforme (GBM), are the most common and most lethal primary cancers of the central nervous system (CNS). Case Description: We present a case of two brothers both diagnosed with GBM. Both siblings underwent biopsy with debulking of the tumors by different surgeons. Only one sibling elected to undergo chemotherapy and radiation. Cytogenetic studies were possible only on one sibling and the tumor specimen revealed multiple chromosomal abnormalities, including triploidies 4, 8, 12, 22 and loss of heterozygosity of 1p, 9p, and 10. Histological samples for both tumors were similar, both revealing increased cellularity consisting of gemistocytic astrocytes, central necrosis, and microvascularization. Conclusion: We present two brothers who display a rare familial relationship in the development of their GBMs. Supplementary and improved genetic studies may allow for specific treatment modalities as certain genetic abnormalities have better response to tailored treatments and carry better prognoses.

Comparison of tertiary-center aneurysm location frequencies in 400 consecutive cases: Decreasing incidence of posterior communicating artery region aneurysms

Alexander L Coon — Sat,29 Oct 2011

Alexander L Coon, Alexandra R Paul, Geoffrey P Colby, Li-Mei Lin, Gustavo Pradilla, Judy Huang, Rafael J Tamargo

Surgical Neurology International 2011 2(1):152-152

Background: The growing number of community hospitals with neurointerventional services over the past decade has changed the type and complexity of cerebral aneurysms referred to tertiary centers. The authors hypothesized that this would be reflected in changes in the location frequencies of aneurysms treated now compared to before the widespread institution of endovascular coiling. Methods: Using a prospectively collected aneurysm database, aneurysm location frequencies were retrospectively reviewed for the last 200 consecutively treated aneurysms (2009-2010) and 200 consecutive aneurysms treated starting from May 1999 to December 2000. International Subarachnoid Aneurysm Trial (ISAT) aneurysm location nomenclature was utilized. Two-tailed Student's t-tests were used to compare means and Fisher exact tests were used to compare proportions. Results: The location frequencies of all aneurysms (ruptured and unruptured) treated in the 2000 epoch as compared to the modern epoch showed significant changes for middle cerebral aneurysms (12.0% vs. 21.0%, P = 0.014), posterior communicating (21.0% vs. 13.0%, P = 0.0001), and para-ophthalmic aneurysms (10.0% vs. 25.5%, P = 0.0002). For unruptured/elective aneurysms, the change in posterior communicating aneurysms was even more pronounced (27.8% vs 3.6%, P = 0.0001). The rate of aneurysm coiling at the center rose from 26% to 37% (P = 0.02). Conclusions: The significant reduction in the referrals to our tertiary center of less technically complex aneurysms (posterior communicating segment) and increased referrals of aneurysms not as amenable to coil embolization (middle cerebral artery) is likely attributable to the growth of neurointerventional services at community hospitals over the past 10 years.

Choroid plexus papilloma originating from the cerebrum parenchyma

Masaaki Imai — Tue,18 Oct 2011

Masaaki Imai, Jiro Tominaga, Mitsunori Matsumae

Surgical Neurology International 2011 2(1):151-151

Background: Choroid plexus papilloma (CPP) can develop at a primary intraparenchymal location completely unrelated to the ventricular system. Here, we present a case of CPP that was difficult to diagnose preoperatively. Case Description: Preoperative imaging and operative findings showed that the tumor originated entirely within the cerebrum parenchyma, with no connections between the tumor and the ventricular system. Histopathological examination of the tumor revealed a papillary structure with a single layer of well-differentiated columnar epithelium in the lesion. Furthermore, part of this lesion had infiltrated the cerebral parenchyma. Therefore, the tumor was diagnosed as CPP, and the diagnosis was confirmed by immunohistological examination. Conclusions: CPP originating as intraparenchymal growths are extremely rare. Origins of extraventricular CCP are discussed in the context of the literature.

Decompressive craniectomy bone flap hinged on the temporalis muscle: A new inexpensive use for an old neurosurgical technique

A Olufemi Adeleye — Tue,18 Oct 2011

A Olufemi Adeleye, A Luqman Azeez

Surgical Neurology International 2011 2(1):150-150

Background: The neurosurgical procedure of hinge decompressive craniectomy (hDC), or hinge craniotomy (HC), as described from units in the advanced countries makes use of metallic implants, usually titanium plates and screws, which may not be economically viable in resource-limited practice settings. Methods: We describe our surgical techniques for performing this same procedure of hDC in a developing country using the patient's own temporalis muscle instead of any other potentially costly implants. Results: The technique as described appears to be successful in achieving intracranial decompression in cases of traumatic brain swelling in which it has been used. Clinical and radiological illustrations of the feasibility, and practical utility, of the procedures in four clinical scenarios of traumatic brain injury are presented. Like all other techniques of HC, this "new" surgical technique of hDC temporalis saves the survivors the added imperative of future cranioplasty of the usual postcraniectomy skull defect. Unlike the others, the procedure eliminates the added cost of the metallic implants needed to perform the former techniques. Conclusions: The procedure of hDC temporalis appears to be a viable option for performing the surgical procedure of HC and has added cost-cutting economic benefits for resource-limited practice settings.

Rare case of intracranial Salmonella enteritidis abscess following glioblastoma resection: Case report and review of the literature

Mohammed Sait — Tue,18 Oct 2011

Mohammed Sait, Gazanfar Rahmathulla, Tsu Lee Chen, Gene H Barnett

Surgical Neurology International 2011 2(1):149-149

Background: Worldwide, Salmonella enteritidis (SE) is becoming a common cause of gastrointestinal infections by contaminated food products, mainly eggs. Extra-intestinal manifestations such as brain abscess are more commonly associated with Salmonella typhimurium and are rare in adults. We report the clinical features, treatment outcomes and risk factors predisposing our patient to Salmonella enteritidis brain abscess and discuss relevant literature. Case Description: A 57-year-old-man developed SE subdural empyema, abscess and possible ventriculitis following reoperation for progression of a right temporal glioblastoma. He initially presented with rapidly worsening headaches over a few days, with a wound discharge and associated meningeal signs. An emergent wound washout revealed pus in the epidural, subdural space and resection cavity. An external ventricular drain (EVD) was placed and cultures revealed gram negative rods. Timely intervention, EVD, and antibiotics resulted in complete resolution. Nine cases of Salmonella abscess associated with primary brain tumor have been reported in literature, most frequently caused by SE in association with glioblastoma multiforme (GBM). We describe our management and outcome in addition to discussing neurosurgical literature on the reported cases. Conclusions: Re-operative tumor surgery has a higher incidence of post-operative infections, with Gram positive cocci being the most common pathogens. Predisposing factors reported for intracranial salmonellosis include compromised immunity, diabetes, HIV, and recent travel. Chronic corticosteroid use, multiple regimens of chemotherapy, and regions of tumor necrosis likely potentiate this rare infection in GBM patients.

Neurosurgery Rounds: Questions and Answers

Colin C Buchanan — Wed,12 Oct 2011

Colin C Buchanan

Surgical Neurology International 2011 2(1):148-148

"Neurosurgery Oral Board Review" by Jonathan Stuart Citow and David Cory Adamson

Jason S Hauptman — Wed,12 Oct 2011

Jason S Hauptman

Surgical Neurology International 2011 2(1):147-147

Stuck at the bench: Potential natural neuroprotective compounds for concussion

Anthony L Petraglia — Wed,12 Oct 2011

Anthony L Petraglia, Ethan A Winkler, Julian E Bailes

Surgical Neurology International 2011 2(1):146-146

Background: While numerous laboratory studies have searched for neuroprotective treatment approaches to traumatic brain injury, no therapies have successfully translated from the bench to the bedside. Concussion is a unique form of brain injury, in that the current mainstay of treatment focuses on both physical and cognitive rest. Treatments for concussion are lacking. The concept of neuro-prophylactic compounds or supplements is also an intriguing one, especially as we are learning more about the relationship of numerous sub-concussive blows and/or repetitive concussive impacts and the development of chronic neurodegenerative disease. The use of dietary supplements and herbal remedies has become more common place. Methods: A literature search was conducted with the objective of identifying and reviewing the pre-clinical and clinical studies investigating the neuroprotective properties of a few of the more widely known compounds and supplements. Results: There are an abundance of pre-clinical studies demonstrating the neuroprotective properties of a variety of these compounds and we review some of those here. While there are an increasing number of well-designed studies investigating the therapeutic potential of these nutraceutical preparations, the clinical evidence is still fairly thin. Conclusion: There are encouraging results from laboratory studies demonstrating the multi-mechanistic neuroprotective properties of many naturally occurring compounds. Similarly, there are some intriguing clinical observational studies that potentially suggest both acute and chronic neuroprotective effects. Thus, there is a need for future trials exploring the potential therapeutic benefits of these compounds in the treatment of traumatic brain injury, particularly concussion.

Ectopic pineal chordoma

Eberval G Figueiredo — Wed,12 Oct 2011

Eberval G Figueiredo, Wagner M Tavares, Leonardo Welling, Sergio Rosemberg, Manoel Jacobsen Teixeira

Surgical Neurology International 2011 2(1):145-145

Background: Chordomas are rare tumors that arise from the remnants of embryonic notochord anywhere along the neuroaxis. Even though they may occur in an extraosseous intradural location, the most common sites include the sacrococcygeal and clivus regions. The authors report a unique presentation encompassing the pineal region with metastasis to the peritoneum after a ventriculoperitoneal (VP) shunt procedure and review the current knowledge about their pathophysiology and management. The presentation and clinical history endorse the idea that intradural extraosseous chordomas may be distinct from ecchordosis physaliphora and probably do not derive from it. Case Description: An 18-year-old male with previous history of VP shunt presented to the emergency room with pain and abdominal distension. Computed tomography (CT) scans revealed a mass in the pineal region and in the abdominal cavity. Histopathologic exams showed chordoma in both abdominal and cranial samples. The patient died due to systemic complications. Conclusion: The authors hypothesized that notochord remnants may subsist within the brain and occasionally may generate a neoplastic lesion.

Ocular melanoma: Keep your eyes open for late brain metastases

Danilo O de A. Silva — Wed,12 Oct 2011

Danilo O de A. Silva, Georgios K Matis, Leonardo F Costa, Matheus A. P Kitamura, Eduardo V de C. Júnior, Breno J A. P Barbosa, Isaac B Santiago, Tatiane I Silva, Fabiana Q de P. A. Silva, Carlos U Pereira, Hildo R C Azevedo Filho

Surgical Neurology International 2011 2(1):144-144

Background: The most frequent intraocular malignant tumor is choroidal melanoma (CM). Although brain metastasis is a common feature of other types of cancers, metastasis of CM to the brain is a rare entity. Case Description: The authors report a case of a 28-year-old woman presenting with a single brain metastasis, 10 years after the treatment of a CM. She underwent a total en-bloc resection of the lesion, and the diagnosis was conﬁrmed histopathologically. The patient concomitantly received whole-brain irradiation therapy combined with chemotherapy, with a survival period of 24 months. Conclusion: The present case report draws attention to the necessity of a close and lifelong follow-up of patients treated for this malignancy. The international literature is also reviewed.

A review of skin incisions and scalp flaps for the retromastoid approach and description of an alternative technique

William J Kemp — Wed,12 Oct 2011

William J Kemp, Aaron A Cohen-Gadol

Surgical Neurology International 2011 2(1):143-143

Background: The retromastoid approach has been effective in exposing the cerebellopontine angle for resection of a variety of lesions, including vestibular schwannomas and decompression of cranial nerves. The following incisions and their variations have been most commonly used for the retromastoid approach: linear (and its variations, such as "lazy S-shaped") and "C-shaped" incision. Methods: Herein, we describe a curvilinear incision and compare its advantages and disadvantages with the other previously described incisions based on the senior author's experience with 120 retromastoid operations. Results: The senior author has used the curvilinear incision for the last 70 of 120 patients who underwent retromastoid operations. Of these, one patient encountered postoperative cerebrospinal fluid (CSF) leakage through the incision, requiring a repeat operative wound revision, and one patient suffered from a soft asymptomatic pseudomeningocele. Among the initial 50 patients who underwent a linear incision, one patient suffered from a CSF leakage managed with local wound care and another patient required a repeat operation for a tense pseudomeningocele. No wound breakdown or infection was encountered in either group. Conclusions: The curvilinear incision is simple and efficient and may provide a shorter working distance and protect the suboccipital muscles and associated neurovascular bundle.

Use of preoperative magnetic resonance imaging T1 and T2 sequences to determine intraoperative meningioma consistency

Jason M Hoover — Wed,12 Oct 2011

Jason M Hoover, Jonathan M Morris, Fredric B Meyer

Surgical Neurology International 2011 2(1):142-142

Background: Meningioma firmness is a critical factor that influences ease of resection and risk, notably when operating on tumors intimate with neurovascular structures such as the mesial sphenoid wing. This study develops a predictive tool using preoperative magnetic resonance imaging (MRI) characteristics to determine meningioma consistency. Methods: 101 patients with intracranial meningioma (50 soft/51 firm) were included. MRI characteristics of 38 tumors (19 soft/19 firm) were retrospectively reviewed to identify preoperative imaging features that were then correlated with intraoperative description of the tumor as either "soft and/or suckable" or "firm and/or fibrous." Criteria were developed to predict consistency and then blindly applied to the remaining 63 meningiomas (31 soft/32 firm). Results: The overall sensitivities for detecting soft and firm consistency were 90% and 56%, respectively (95% CI = 73-97% and 38-73%; P < 0.001). Compared to gray matter, meningiomas that were T2 hypointense were almost always firm. Soft meningiomas were hyperintense on T2 and hypointense on T1. Soft meningiomas were slightly larger and less likely to be associated with edema. There was a slight preponderance of firm meningiomas in the infratentorial compartment. Grade of meningioma was not predictive. Contrast enhancement, diffusion restriction, changes in overlying bone, intratumoral cysts, and angiographic features were not predictable. Conclusions: This tool using T1 and T2 series predicts meningioma consistency. Such knowledge should assist the surgeon in preoperative planning and counseling.

Relocation of ventricular catheter trough ventriculostomy due to congenital unilateral hydrocephalus: Nine year follow-up

Zoran Milenkovic — Wed,12 Oct 2011

Zoran Milenkovic, Biljana Stevanovic, Ivana Markovic

Surgical Neurology International 2011 2(1):141-141

Background: Congenital unilateral hydrocephalus is an uncommon entity occurring almost exclusively in children. Atresia, stenosis, membranous occlusion and even functional obstruction of the foramen of Monro have been described to be the main cause of this type of hydrocephalus. There are two options available in the surgical management of unilateral hydrocephalus: one is the placement of shunt CSF diversion from the dilated ventricle and the other is fenestration of the occluded foramen of Monro or septum pellucidum by endoscopy or by stereotactic method. Migration of the ventriculoperitoneal (VP) shunt in or out of ventricles is not so uncommon, but the relocation of the ventricular tip of a catheter from the ventricle into the quadrigeminal cisterns and superior vermis in association with ventriculostomy is extremely rare. Spontaneous ventriculostomy is a rare event and results from spontaneous rupture of a ventricle into the subarachnoid space. Case Description: A 5½-month-old baby with a right-sided congenital unilateral hydrocephalus underwent a VP shunt andhad experienced an uneventful outcome. Four years later on an MR imaging examination, the tip of the ventricular catheter passing through the medial wall of the ventricle and the quadrigeminal cistern was found to be situated in the superior vermis. During the follow-up period, there were no neurological difficulties. The cognitive and motor skill development corresponded well with the child's age. It transpired that the hydrocephalic ventricle reduced its size dramatically to normal. Conclusion: We have described the extremely rare site of the relocation of the ventricular catheter after the treatment of the congenital unilateral hydrocephalus by VP shunting. Spontaneous ventriculostomy as a rare phenomenon may be the explanation of the relocation of the ventricular catheter.

Anterior clinoidectomy: Description of an alternative hybrid method and a review of the current techniques with an emphasis on complication avoidance

Charles Kulwin — Wed,12 Oct 2011

Charles Kulwin, R Shane Tubbs, Aaron A Cohen-Gadol

Surgical Neurology International 2011 2(1):140-140

Background: Anterior clinoidectomy is a difficult but important part of surgery for a variety of parasellar, proximal carotid and central skull base pathologies. First developed intradurally nearly 60 years ago, the promotion of an extradural technique decades later offered an approach with a different set of difficulties, risks and benefits. Many recent studies have demonstrated that there is no consensus about the "correct" side of the dura from which to remove the anterior clinoid process in a number of pathologies. Here, we review and compare the current techniques for intra- and extradural clinoidectomy and describe a hybrid alternative technique. Methods: We used a hybrid method to potentially engage the advantages of the intradural and extradural techniques. The hybrid method starts with an extradural sphenoid wing osteotomy to the level of the superior orbital fissure (SOF). The dura is then incised parallel to the sphenoid wing lateral to the SOF, and the need for further bony removal, including clinoidectomy, is assessed after gentle elevation of the frontal lobe and release of cerebrospinal fluid through opening the optico-carotid cisterns and inspection of the pathology in relation to the clinoid. Sylvian fissure may be dissected to relieve retraction on the frontal lobe. Results: The hybrid method allows an early identification of the optic nerve and its protection during clinoidectomy. The operator leaves the dura medial to the SOF intact and the clionoidectomy proceeds in an extradural fashion while intradural inspection periodically is performed to assess the extent of necessary extradural bony removal. Conclusion: The hybrid method theoretically can be used as a versatile method under some circumstances. Cutting the dura along the sphenoid wing will prevent the dural layers from obscuring the clinoid and offers intradural visualization to monitor the lesion and potentially tailor bony removal.

Impact of total disc arthroplasty on the surgical management of lumbar degenerative disc disease: Analysis of the Nationwide Inpatient Sample from 2000 to 2008

Olatilewa O Awe — Wed,12 Oct 2011

Olatilewa O Awe, Mitchel G Maltenfort, Srinivas Prasad, James S Harrop, John K Ratliff

Surgical Neurology International 2011 2(1):139-139

Background : Spinal fusion is the most rapidly increasing type of lumbar spine surgery for various lumbar degenerative pathologies. The surgical treatment of lumbar spine degenerative disc disease may involve decompression, stabilization, or arthroplasty procedures. Lumbar disc athroplasty is a recent technological advance in the field of lumbar surgery. This study seeks to determine the clinical impact of anterior lumbar disc replacement on the surgical treatment of lumbar spine degenerative pathology. This is a retrospective assessment of the Nationwide Inpatient Sample (NIS). Methods : The NIS was searched for ICD-9 codes for lumbar and lumbosacral fusion (81.06), anterior lumbar interbody fusion (81.07), and posterolateral lumbar fusion (81.08), as well as for procedure codes for revision fusion surgery in the lumbar and lumbosacral spine (81.36, 81.37, and 81.38). To assess lumbar arthroplasty, procedure codes for the insertion or replacement of lumbar artificial discs (84.60, 84.65, and 84.68) were queried. Results were assayed from 2000 through 2008, the last year with available data. Analysis was done using the lme4 package in the R programming language for statistical computing. Results : A total of nearly 300,000 lumbar spine fusion procedures were reported in the NIS database from 2000 to 2008; assuming a representative cross-section of the US health care market, this models approximately 1.5 million procedures performed over this time period. In 2005, the first year of its widespread use, there were 911 lumbar arthroplasty procedures performed, representing 3% of posterolateral fusions performed in this year. Since introduction, the number of lumbar spine arthroplasty procedures has consistently declined, to 653 total procedures recorded in the NIS in 2008. From 2005 to 2008, lumbar arthroplasties comprised approximately 2% of lumbar posterolateral fusions. Arthroplasty patients were younger than posterior lumbar fusion patients (42.8 ± 11.5 vs. 55.9 ± 15.1 years, P < 0.0000001). The distribution of arthroplasty procedures was even between academic and private urban facilities (48.5% and 48.9%, respectively). While rates of posterolateral lumbar spine fusion steadily grew during the period (OR 1.06, 95% CI: 1.05-1.06, P < 0.0000001), rates of revision surgery and anterior spinal fusion remained static. Conclusions : The impact of lumbar arthroplasty procedures has been minimal. Measured as a percentage of more common lumbar posterior arthrodesis procedures, lumbar arthroplasty comprises only approximately 2% of lumbar spine surgeries performed in the United States. Over the first 4 years following the Food and Drug Administration (FDA) approval, the frequency of lumbar disc arthroplasty has decreased while the number of all lumbar spinal fusions has increased.

Spontaneous C1 anterior arch fracture as a postoperative complication of foramen magnum decompression for Chiari malformation type 1

Yoshitaka Hirano — Wed,12 Oct 2011

Yoshitaka Hirano, Atsushi Sugawara, Junichi Mizuno, Masaaki Takeda, Kazuo Watanabe, Kuniaki Ogasawara

Surgical Neurology International 2011 2(1):138-138

Background : C1 fracture accounts for 2% of all spinal column injuries and 10% of cervical spine fractures, and is most frequently caused by motor vehicle accidents and falls. We present a rare case of C1 anterior arch fracture following standard foramen magnum decompression for Chiari malformation type 1. Case Description : A 63-year-old man underwent standard foramen magnum decompression (suboccipital craniectomy and C1 laminectomy) under a diagnosis of Chiari malformation type 1 with syringomyelia in June 2009. The postoperative course was uneventful until the patient noticed progressive posterior cervical pain 5 months after the operation. Computed tomography of the upper cervical spine obtained 7 months after the operation revealed left C1 anterior arch fracture. The patient was referred to our hospital at the end of January 2010 and C1-C2 posterior fusion with C1 lateral mass screws and C2 laminar screws was carried out in March 2010. Complete pain relief was achieved immediately after the second operation, and the patient resumed his daily activities. Conclusion : Anterior atlas fracture following foramen magnum decompression for Chiari malformation type 1 is very rare, but C1 laminectomy carries the risk of anterior arch fracture. Neurosurgeons should recognize that fracture of the atlas, which commonly results from an axial loading force, can occur in the postoperative period in patients with Chiari malformation.

Thoraco-lumbar artery aneurysms associated with a metameric paraspinal lesion presenting with retroperitoneal hemorrhage: Endovascular management

Alejandro Santillan — Wed,12 Oct 2011

Alejandro Santillan, Walter Zink, Athos Patsalides, Y Pierre Gobin

Surgical Neurology International 2011 2(1):137-137

Background : Retroperitoneal hemorrhage is a life-threatening condition. This is the first reported case of rupture of one of multiple thoraco-lumbar artery aneurysms associated with a metameric paraspinal vascular lesion. Case Description : A 77-year-old female patient presented to the emergency room with a new onset of left-sided low back pain shooting down the leg associated with weakness, numbness, and inability to walk. On physical examination, there was a notable left paraspinal swelling with a harsh bruit audible in the same area, left flank ecchymosis and a positive straight leg raising test. A computed tomography (CT) scan showed a large retroperitoneal hematoma. Digital subtraction angiography showed a large left paraspinal high-flow arteriovenous lesion, with large arterial aneurysms of the left T11, T12, and L1 segmental arteries. The patient was successfully treated with endovascular aneurysm embolization using coils and Onyx-34. Six months following the procedure, the patient had fully recovered, and a follow-up angiogram showed no residual or recurrent aneurysms. Conclusion : Thoraco-lumbar artery aneurysms have never previously been described in association with a metameric paraspinal vascular malformation. We report a case of retroperitoneal hemorrhage due to rupture of one of several high-flow artery aneurysms of a paraspinal arteriovenous malformation (AVM). The diagnosis was made on CTA, MRI, and angiography, and the lesion was successfully treated by transarterial embolization.

Malignant psammomatous melanotic schwannoma of the spine: A component of Carney complex

Lisa B.E Shields — Fri,30 Sep 2011

Lisa B.E Shields, Steven D Glassman, George H Raque, Christopher B Shields

Surgical Neurology International 2011 2(1):136-136

Background : Psammomatous melanotic schwannomas (PMS) of the spine may be a component of the Carney complex in 50% of cases and is inherited in an autosomal dominant manner. Most PMS are benign and frequently associated with lentiginous pigmentation; cardiac, cutaneous, or breast myxomas; endocrine overactivity; and cutaneous blue nevi. These tumors are characterized by melanin containing cells having ultrastructural characteristics of Schwann cells. Case Description : Two patients had spinal PMS that were surgically resected with adjacent local radiotherapy, followed by local recurrence and metastasis. The aggressive nature of this tumor is reported. Conclusion : Spinal PMS are rarely malignant with local recurrence and distal metastases. Inquiry into the patient's and family members' hereditary background for the Carney complex is important to avoid overlooking potential lethal associated abnormalities.

Thrombosed giant aneurysm of the distal anterior cerebral artery treated with aneurysm resection and proximal pericallosal artery-callosomarginal artery end-to-end anastomosis: Case report and review of the literature

Ken Matsushima — Fri,30 Sep 2011

Ken Matsushima, Masatou Kawashima, Kenji Suzuyama, Yukinori Takase, Tetsuro Takao, Toshio Matsushima

Surgical Neurology International 2011 2(1):135-135

Background : Giant distal anterior cerebral artery (DACA) aneurysms are extremely rare, with only 32 cases reported in the literature. Most giant DACA aneurysms have features that make standard neck clipping difficult, and bypass surgery is sometimes required, although this surgery was performed in only three reported cases. This report presents the fourth case treated with bypass surgery. Case Description : A 69-year-old female presented with an unruptured thrombosed giant DACA aneurysm. She underwent wrapping operation 7 years before, but radiological imaging revealed enlargement of the aneurysm at the left pericallosal artery (PerA)-callosomarginal artery (CMA) junction. Before operation, three different strategies were considered for bypass surgery in case the neck could not be clipped. Aneurysm resection and left proximal PerA-CMA end-to-end anastomosis were successfully performed under intraoperative digital subtraction angiography (DSA) and motor-evoked potential (MEP) monitoring. Conclusion : Most DACA aneurysms are located at the PerA-CMA junction. In some cases, adequate retrograde flow to the distal PerA from the posterior or middle cerebral artery can be expected, making distal PerA reconstruction unnecessary. Moreover, when the distal PerA is cut, proximal PerA-CMA end-to-end anastomosis can be easily performed because of reduced tension in both vessels. We therefore conclude that this strategy should be utilized for treating such patients. We also presented here the effectiveness of intraoperative modalities, such as intraoperative DSA and MEP monitoring, for performing a safe operation.

"Real-world" comparison of non-invasive imaging to conventional catheter angiography in the diagnosis of cerebral aneurysms

Luke Tomycz — Fri,30 Sep 2011

Luke Tomycz, Neil K Bansal, Catherine R Hawley, Tracy L Goddard, Michael J Ayad, Robert A Mericle

Surgical Neurology International 2011 2(1):134-134

Background : Based on numerous reports citing high sensitivity and specificity of non-invasive imaging [e.g. computed tomography angiography (CTA) or magnetic resonance angiography (MRA)] in the detection of intracranial aneurysms, it has become increasingly difficult to justify the role of conventional angiography [digital subtraction angiography (DSA)] for diagnostic purposes. The current literature, however, largely fails to demonstrate the practical application of these technologies within the context of a "real-world" neurosurgical practice. We sought to determine the proportion of patients for whom the additional information gleaned from 3D rotational DSA (3DRA) led to a change in treatment. Methods : We analyzed the medical records of the last 361 consecutive patients referred to a neurosurgeon at our institution for evaluation of "possible intracranial aneurysm" or subarachnoid hemorrhage (SAH). Only those who underwent non-invasive vascular imaging within 3 months prior to DSA were included in the study. For asymptomatic patients without a history of SAH, aneurysms less than 5 mm were followed conservatively. Treatment was advocated for patients with unruptured, non-cavernous aneurysms measuring 5 mm or larger and for any non-cavernous aneurysm in the setting of acute SAH. Results : For those who underwent CTA or MRA, the treatment plan was changed in 17/90 (18.9%) and 22/73 (30.1%), respectively, based on subsequent information gleaned from DSA. Several reasons exist for the change in the treatment plan, including size and location discrepancies (e.g. cavernous versus supraclinoid), or detection of a benign vascular variant rather than a true aneurysm. Conclusions : In a "real-world" analysis of intracranial aneurysms, DSA continues to play an important role in determining the optimal management strategy.

A role for motor and somatosensory evoked potentials during anterior cervical discectomy and fusion for patients without myelopathy: Analysis of 57 consecutive cases

Risheng Xu — Fri,30 Sep 2011

Risheng Xu, Eva K Ritzl, Mohammed Sait, Daniel M Sciubba, Jean-Paul Wolinsky, Timothy F Witham, Ziya L Gokaslan, Ali Bydon

Surgical Neurology International 2011 2(1):133-133

Background : Although the usage of combined motor and sensory intraoperative monitoring has been shown to improve the surgical outcome of patients with cervical myelopathy, the role of transcranial electric motor evoked potentials (tceMEP) used in conjunction with somatosensory evoked potentials (SSEP) in patients presenting with radiculopathy but without myelopathy has been less clear. Methods : We retrospectively reviewed all patients (n = 57) with radiculopathy but without myelopathy, undergoing anterior cervical decompression and fusion at a single institution over the past 3 years, who had intraoperative monitoring with both tceMEPs and SSEPs. Results : Fifty-seven (100%) patients presented with radiculopathy, 53 (93.0%) with mechanical neck pain, 35 (61.4%) with motor dysfunction, and 29 (50.9%) with sensory deficits. Intraoperatively, 3 (5.3%) patients experienced decreases in SSEP signal amplitudes and 4 (6.9%) had tceMEP signal changes. There were three instances where a change in neuromonitoring signal required intraoperative alteration of the surgical procedure: these were deemed clinically significant events/true positives. SSEP monitoring showed two false positives and two false negatives, whereas tceMEP monitoring only had one false positive and no false negatives. Thus, tceMEP monitoring exhibited higher sensitivity (33.3% vs. 100%), specificity (95.6% vs. 98.1%), positive predictive value (33.3% vs. 75.0%), negative predictive value (97.7% vs. 100%), and efficiency (91.7% vs. 98.2%) compared to SSEP monitoring alone. Conclusions : Here, we present a retrospective series of 57 patients where tceMEP/SSEP monitoring likely prevented irreversible neurologic damage. Though further prospective studies are needed, there may be a role for combined tceMEP/SSEP monitoring for patients undergoing anterior cervical decompression without myelopathy.

Post-surgical spine syndrome

Joe Ordia — Tue,27 Sep 2011

Joe Ordia, Julien Vaisman

Surgical Neurology International 2011 2(1):132-132

The importance of testing deep brain stimulation lead impedances before final lead implantation

Jules M Nazzaro — Tue,27 Sep 2011

Jules M Nazzaro, Kelly E Lyons, Rajesh Pahwa, Larry W Ridings

Surgical Neurology International 2011 2(1):131-131

Background : In the setting of a deep brain stimulation (DBS) lead with defective electrical circuitry, potential patient morbidity and additional surgery may be avoided if impedance testing of the brain lead is performed prior to final lead implantation. In the present report, detection of a short circuit upon lead placement and prior to lead anchoring was detected utilizing recently released DBS hardware and software (Medtronic, Minneapolis, MN). This report suggests that neurosurgeons need to be aware and consider the use of the newly available DBS testing equipment. Methods : During the first DBS lead placement in a 69-year-old man with advanced idiopathic Parkinson's disease undergoing bilateral subthalamic nucleus DBS over staged procedures, test stimulation and lead impedance testing were accomplished prior to lead anchoring. An external neurostimulator (ENS) was affixed to an updated clinician programmer and connected to the DBS lead with a screening cable specific for the ENS and DBS. Results : Impedance testing demonstrated a short circuit involving the 1 and 3 lead-electrode bipolar combination in a visually intact lead. The lead was replaced, repeat impedance testing and test stimulation were completed and the intact lead was secured. Subsequent DBS surgeries were completed uneventfully. The lead abnormality was verified by the manufacturer. Conclusions : This case highlights a new method to test DBS lead circuitry at the time of placement. The method may also be employed to directly test lead integrity when localizing a DBS system short or open circuit of unclear etiology. Our case suggests that the method is valuable and should be utilized.

Post-transplantation primary central nervous system lymphoma: A case report and review of the literature

Arthur P Chou — Tue,27 Sep 2011

Arthur P Chou, Shadi Lalezari, Brendan M Fong, Justin Dye, Tracie Pham, Harry V Vinters, Nader Pouratian

Surgical Neurology International 2011 2(1):130-130

Background : Post-transplantation primary central nervous system lymphoma (PT-PCNSL) is a rare neoplasm that can develop within months to years after transplantation, and imaging often reveals multiple lesions with homogeneous or ring enhancement. The clinical and imaging presentation of PT-PCNSL can often be nonspecific and present a diagnostic challenge. Case Description : A 56-year-old woman presented to a tertiary university emergency room with altered mental status 15 months after undergoing renal transplantation. On brain MRI, she was found to have three rim-enhancing mass lesions, and biopsy revealed PT-PCNSL. Conclusion : There has been a steady increase in the number of patients living following organ transplantation in the United States and an increasing likelihood that PT-PCNSL will increasingly be encountered in neurosurgical practice. We present here a case of PT-PCNSL and a brief review of the relevant clinical characteristics, treatment options, and prognosis of PT-PCNSL.

Sacral laminoplasty and cystic fenestration in the treatment of symptomatic sacral perineural (Tarlov) cysts: Technical case report

Zachary A Smith — Tue,27 Sep 2011

Zachary A Smith, Zhenzhou Li, Dan Raphael, Larry T Khoo

Surgical Neurology International 2011 2(1):129-129

Background : Perineural cysts of the sacrum, or Tarlov cysts, are cerebrospinal fluid (CSF)-filled sacs that commonly occur at the intersection of the dorsal root ganglion and posterior nerve root in the lumbosacral spine. Although often asymptomatic, these cysts have the potential to produce significant symptoms, including pain, weakness, and/or bowel or bladder incontinence. We present a case in which the sacral roof is removed and reconstructed via plated laminoplasty and describe how this technique could be of potential use in maximizing outcomes. Methods : We describe technical aspects of a sacral laminoplasty in conjunction with cyst fenestration for a symptomatic sacral perineural cyst in a 50-year-old female with severe sacral pain, lumbosacral radiculopathy, and progressive incontinence. This patient had magnetic resonance imaging (MRI) and computed tomography (CT)-myelographic evidence of a non-filling, 1.7 Χ 1.4 cm perineural cyst that was causing significant compression of the cauda equina and sacral nerve roots. This surgical technique was also employed in a total of 18 patients for symptomatic tarlov cysts with their radiographic and clinical results followed in a prospective fashion. Results : Intraoperative images, drawings, and video are presented to demonstrate both the technical aspects of this technique and the regional anatomy. Postoperative MRI scan demonstrated complete removal of the Tarlov cyst. The patient's symptoms improved dramatically and she regained normal bladder function. There was no evidence of radiographic recurrence at 12 months. At an average 16 month followup interval 10/18 patients had significant relief with mild or no residual complaints, 3/18 reported relief but had persistent coccydynia around the surgical area, 2/18 had primary relief but developed new low back pain and/or lumbar radiculopathy, 2/18 remained at their preoperative level of symptoms, and 1/18 had relief of their preoperative leg pain but developed new pain and neurological deficits. Conclusions : Sacral laminoplasty and microscopic cystic fenestration is a feasible approach in the operative treatment of this difficult, and often controversial, spinal pathology. This technique may be used further and studied in an attempt to minimize potential surgical morbidity, including CSF leaks, cyst recurrence, and sacral insufficiency fractures.

Nucleus caudalis lesioning: Case report of chronic traumatic headache relief

Stephen E Sandwell — Tue,27 Sep 2011

Stephen E Sandwell, Amr O El-Naggar

Surgical Neurology International 2011 2(1):128-128

Background : The nucleus caudalis dorsal root entry zone (DREZ) surgery is used to treat intractable central craniofacial pain. This is the first journal publication of DREZ lesioning used for the long-term relief of an intractable chronic traumatic headache. Case Description : A 40-year-old female experienced new-onset bi-temporal headaches following a traumatic head injury. Despite medical treatment, her pain was severe on over 20 days per month, 3 years after the injury. The patient underwent trigeminal nucleus caudalis DREZ lesioning. Bilateral single-row lesions were made at 1-mm interval between the level of the obex and the C2 dorsal nerve roots, using angled radiofrequency electrodes, brought to 80°C for 15 seconds each, along a path 1 to 1.2 mm posterior to the accessory nerve rootlets. The headache improved, but gradually returned. Five years later, her headaches were severe on over 24 days per month. The DREZ surgery was then repeated. Her headaches improved and the relief has continued for 5 additional years. She has remained functional, with no limitation in instrumental activities of daily living. Conclusions : The nucleus caudalis DREZ surgery brought long-term relief to a patient suffering from chronic traumatic headache.

Multiple non-branching dissecting aneurysms of the mid-basilar trunk presenting with sequential subarachnoid hemorrhages

Archie Defillo — Sat,17 Sep 2011

Archie Defillo, Eric S Nussbaum, Andrea Zelensky, Leslie Nussbaum

Surgical Neurology International 2011 2(1):127-127

Objective : We describe a rare case of a patient with subarachnoid hemorrhage (SAH) due to a ventral dissecting mid-basilar aneurysm that was treated surgically. One week after surgery, the patient experienced sudden deterioration due to a new SAH caused by the development of a new aneurysm of the basilar trunk distinct from the previously clipped aneurysm. Case Description : A 54-year-old woman with acute subarachnoid hemorrhage was found to have a small, broad-based aneurysm arising from the ventral aspect of the mid-basilar artery. This complicated lesion was treated with a microsurgical clipping via a translabyrinthine pre-sigmoidal sub-temporal approach. One week postoperatively, the patient suffered a new SAH and was found to have developed a distinct basilar artery aneurysm. The patient was returned to the Operating Room for microsurgical clipping via the previous craniotomy. After surgery, the patient made a slow, but steady, recovery. She underwent repeated angiographic imaging, demonstrating a stable appearance. Two years post surgery, the patient had returned to work and had no obvious neurological deficit, with the exception of unilateral iatrogenic hearing loss. Conclusion : We describe a rare case of multiple aneurysms originating in relation to a mid-basilar dissection, resulting in multiple episodes of SAH. These are difficult and dangerous lesions that can be treated with open microsurgical reconstruction or possibly via an endovascular approach. The intricate location of the lesions poses a particular challenge to neurosurgeons attempting to directly treat mid-basilar lesions.

Ruptured cerebral aneurysm associated with a persistent primitive trigeminal artery variant

Takahiro Yamamoto — Sat,17 Sep 2011

Takahiro Yamamoto, Yu Hasegawa, Yuki Ohmori, Takayuki Kawano, Yutaka Kai, Motohiro Morioka, Jun-ichi Kuratsu

Surgical Neurology International 2011 2(1):126-126

Background : Primitive trigeminal artery variants (PTAVs) are one of the rare persistent fetal anastomoses between the carotid and vertebrobasilar circulations. They originate from the internal carotid artery and join one of the cerebellar arteries instead of the basilar artery. Case Description : We present an 82-year-old woman with subarachnoid hemorrhage due to a ruptured aneurysm originating at a PTAV. Three-dimensional computed tomography angiogram and cerebral angiography revealed bilateral PTAV and two aneurysms originating at the left PTAV. The proximal and distal aneurysms were saccular and fusiform, respectively. She underwent surgical treatment and her postoperative course was uneventful. Conclusion : Our case demonstrates that extremely rare cerebral aneurysms associated with PTAV can be addressed successfully by surgical intervention.

Treatment of aneurysmal subarachnoid hemorrhage and unruptured intracranial aneurysms by neurosurgeons in Colombia: A survey

Gabriel Alcalá-Cerra — Sat,17 Sep 2011

Gabriel Alcalá-Cerra, Juan J Gutiérrez Paternina, María E Buendía de �vila, Edgar I Preciado Mesa, Rubén Sabogal Barrios, Lucía M Niño-Hernández, Keith Suárez Jaramillo

Surgical Neurology International 2011 2(1):125-125

Background : Trends in management of aneurysmal subarachnoid hemorrhage and unruptured intracranial aneurysms among neurosurgeons is very variable and had not been previously described in any Latin American country. This study was conducted to determine the preferences of Colombian neurosurgeons in pharmacologic, surgical, and endovascular management of patients with aneurysmal subarachnoid hemorrhage and unruptured intracranial aneurysms. Methods : A survey-based descriptive study was performed in a sample of members from the Colombian Association of Neurosurgery. Questions about pharmacologic, surgical, and endovascular management of aneurysmal subarachnoid hemorrhage and unruptured intracranial aneurysm were carried out. We calculated the mean and the standard deviation of the results obtained from the continuous variables. The results of the categorical variables are presented as percentages. Results : The preference of medication with poor clinical evidence, such as magnesium sulfate, aspirin, statins, and anti-fibrinolytics was lower than 10%. The use of intravenous nimodipine and systemic glucocorticoids was as high as 31%. The availability of endovascular therapy was 69%. The indication for treatment of patients with unruptured intracranial aneurysms that required intervention was less than 13.8%. In patients with ruptured or unruptured intracranial aneurysms, coiling was the preferred method for exclusion. Conclusions : Reported compliance of evidence-based clinical guidelines was similar to that described in developed countries, and even better. However, there is little agreement in treating patients with unruptured intracranial aneurysms. For other issues, the conducts reported by Colombian neurosurgeons are in accordance with the current guidelines.

Unilateral subfrontal approach to anterior communicating artery aneurysms: A review of 28 patients

Anthony L Petraglia — Sat,17 Sep 2011

Anthony L Petraglia, Vasisht Srinivasan, Michael J Moravan, Michelle Coriddi, Babak S Jahromi, G Edward Vates, Paul K Maurer

Surgical Neurology International 2011 2(1):124-124

Background : The pterional approach is the most common for AComm aneurysms, but we present a unilateral approach to a midline region for addressing the AComm complex. The pure subfrontal approach eliminates the lateral anatomic dissection requirements without sacrificing exposure. The subfrontal approach is not favored in the US compared to Asia and Europe. We describe our experience with the subfrontal approach for AComm aneurysms treated at a single institution. Methods : We identified 28 patients treated for AComm aneurysms through the subfrontal approach. Patient records and imaging studies were reviewed. Demographics and case data, as well as clinical outcome at 6 weeks and 1 year were collected. Results : Mean patient age was 48 (range 21-75) years and 64% suffered subarachnoid hemorrhage (SAH). All aneurysms were successfully clipped. Gyrus rectus was resected in 57% of cases, more commonly in ruptured cases. Intraoperative rupture occurred in 11% of cases. The average operative time was 171 minutes. There were two patient deaths. Ninety-two percent of patients had a Glasgow Outcome Scale (GOS) of 5 at 6 weeks. All unruptured patients had a GOS of 5. At 12 months, 96% of all patients had a GOS of 5. Conclusions : The subfrontal approach provides an efficient avenue to the AComm region, which reduces opening and closing friction but still yields a comprehensive operative window for access to the anterior communicating region.

Cranioplasty after decompressive craniectomy: An institutional audit and analysis of factors related to complications

Zain A Sobani — Sat,17 Sep 2011

Zain A Sobani, Muhammad Shahzad Shamim, Syed Nabeel Zafar, Mohsin Qadeer, Najiha Bilal, Syed Ghulam Murtaza, Syed Ather Enam, Muhammad Ehsan Bari

Surgical Neurology International 2011 2(1):123-123

Background : Although a relatively simple procedure, cranioplasties have been associated with high complication rates. Keeping this in perspective, we aimed to determine the factors associated with immediate and long-term complications of cranioplasties at our institution. Methods : A retrospective review of patient records was carried out for patients having undergone reconstructive cranioplasties at our institution during the last 10 years (2001-2010). All case notes, records, and investigations were reviewed and the data were recorded in a predesigned questionnaire. Complications were recorded along with existing comorbids and measures taken for their prevention and management. Univariate and multivariate logistic regression analysis was performed to determine possible predictors of complications. Results : A total of 96 patients with a mean age of 33 + 15 years were included in the study. Of the sample, 76% (n = 73) had no comorbids. The leading primary pathology was blunt traumatic brain injuries in 46% (n = 44), followed by cerebrovascular incidents in 24% (n = 23), penetrating traumatic brain injuries in 12% (n = 11), and tumors in 10% (n = 10) of cases, with 41% (n = 39) of patients requiring multiple craniotomies. In a mean follow-up of 386 ± 615 days, complications were noted in 36.5% (n = 35) of the patients. Twenty six percent of patients (n = 25) had minor complications which included breakthrough seizures (15.6%, n = 15), subgaleal collections (3.1%, n = 3), and superficial wound infections (3.1%, n = 3), whereas major complications (10.4% n = 10) included hydrocephalus (3.1%, n = 3), transient neurological deficits (3.1%, n = 3), and osteomyelitis (2.1%, n = 2). Univariate and multivariate analysis revealed External Ventricular Drain (EVD) placement and parietal flaps to be associated with complications. This could be explained by the fact that the patients requiring EVD usually have relatively severe head injuries, increasing the possibility of hydrocephalus. Conclusion : We have found a higher risk of complications of cranioplasty in patients who had EVD placement and removal prior to their constructive surgery. We however did not find any association between risks of complications in any other studied variable. We also did not find any association between intraoperative placement of subgaleal drains and postoperative risk of subgaleal fluid collections. Overall, our results are comparable with other reported series on cranioplasties.

Stray bullet: An accidental killer during riot control

Abrar A Wani — Sat,10 Sep 2011

Abrar A Wani, Altaf U Ramzan, Yawar Shoib, Nayil K Malik, Furqan A Nizami, Anil Dhar, Shafiq Alam

Surgical Neurology International 2011 2(1):122-122

Background: The use of force to control public uprisings, riots, unruly mobs is an important tool in any administrative setup. Law enforcement agencies often resort to aerial firing, which can be responsible for unintended injuries due to stray bullets.This study was designed to study the pattern of stray bullet injuries and to generate awareness about the hazards related to the use of live ammunition during riot control. Methods: This study was conducted in our unit of the neurosurgery department over a period of 18 months, from June 2008 to December 2010. We enrolled all patients who had head or spine injuries caused by stray bullets from firing during riot control far away from the site of injury. Results: We had two patients with head injury and two with spinal injury sustained because of stray bullets. One of the patients with head injury was operated and the other one was managed conservatively; the latter died on the third day of injury, while the former is surviving with some residual neurological deficit. Amongst the patients with spinal injury, neurological deficits persist till date. None of the patients were aware that they had sustained a bullet injury, and it was only after inquiry that we came to know that the police had resorted to aerial firing for controlling public agitation in nearby areas. Conclusion: Aerial firing of live cartridges is generally considered an 'innocuous' method; however, in view of the potential for injury to innocent bystanders, we recommend that the use of live cartridges during aerial firing be banned.

Nerve transfers in tetraplegia I: Background and technique

Justin M Brown — Tue,30 Aug 2011

Justin M Brown

Surgical Neurology International 2011 2(1):121-121

Background: The recovery of hand function is consistently rated as the highest priority for persons with tetraplegia. Recovering even partial arm and hand function can have an enormous impact on independence and quality of life of an individual. Currently, tendon transfers are the accepted modality for improving hand function. In this procedure, the distal end of a functional muscle is cut and reattached at the insertion site of a nonfunctional muscle. The tendon transfer sacrifices the function at a lesser location to provide function at a more important location. Nerve transfers are conceptually similar to tendon transfers and involve cutting and connecting a healthy but less critical nerve to a more important but paralyzed nerve to restore its function. Methods: We present a case of a 28-year-old patient with a C5-level ASIA B (international classification level 1) injury who underwent nerve transfers to restore arm and hand function. Intact peripheral innervation was confirmed in the paralyzed muscle groups corresponding to finger flexors and extensors, wrist flexors and extensors, and triceps bilaterally. Volitional control and good strength were present in the biceps and brachialis muscles, the deltoid, and the trapezius. The patient underwent nerve transfers to restore finger flexion and extension, wrist flexion and extension, and elbow extension. Intraoperative motor-evoked potentials and direct nerve stimulation were used to identify donor and recipient nerve branches. Results: The patient tolerated the procedure well, with a preserved function in both elbow flexion and shoulder abduction. Conclusions: Nerve transfers are a technically feasible means of restoring the upper extremity function in tetraplegia in cases that may not be amenable to tendon transfers.

Armored brain: A case report and review of the literature

Anthony L Petraglia — Tue,30 Aug 2011

Anthony L Petraglia, Michael J Moravan, Babak S Jahromi

Surgical Neurology International 2011 2(1):120-120

Background: Calcified chronic subdural hematomas occur infrequently. When the calcifications are extensive and bilateral, the condition is termed "armored brain". We describe a case of "armored brain" incidentally discovered in an adult presenting with abdominal pain and mild headaches, long after initial placement of a ventriculo-peritoneal (VP) shunt. Case Description: A 38-year-old woman, treated at infancy with a VP shunt, presented with a 2-month history of abdominal pain associated with nausea and chills. She was neurologically intact on exam. An abdominal computed tomography (CT) scan demonstrated a rim-enhancing loculated fluid collection surrounding the patient's distal VP shunt catheter tip. As a part of her initial work-up, she received a head CT to evaluate the proximal VP shunt, which demonstrated large bilateral chronic subdural hematomas with heavily calcified walls. She was eventually taken to the operating room (OR) for replacement of the distal catheter. It was felt that her acute clinical presentation was unrelated to the bilateral, calcified subdural hematomas and thus the decision was made to manage them conservatively. Conclusions: This rare complication of chronic shunting for hydrocephalus is sometimes referred to as armored brain. Surgery for armored brain is infrequently indicated and beneficial in only small subgroup of patients, with management guided by clinical presentation. Our patient fully recovered after shunt revision alone.

Spinal intradural, extramedullary anaplastic ependymoma with an extradural component: Case report and review of the literature

Kern H Guppy — Tue,30 Aug 2011

Kern H Guppy, Lewis Hou, Greg S Moes, Kamran Sahrakar

Surgical Neurology International 2011 2(1):119-119

Background: There have been 18 reported cases of primary spinal intradural, extramedullary ependymomas reported in the literature. One of the 18 cases had an extradural component and was benign. Our case is the second spinal intradural, extramedullary ependymoma with an extradural component and the first with its initial presentation as an anaplastic ependymoma. Case Description: A 50-year-old male presented with bilateral upper thigh weakness and thoracic numbness. His exam showed the pin-prick level at T5. Magnetic resonance imaging (MRI) of the thoracic spine showed an enhancing lesion at T5-6 with severe compression of the spinal cord with a dumbbell shape extension of the tumor through the right T5-6 neural foramen. The patient had a laminectomy at T4-T6 with the resection of the tumor. Postoperatively, the patient regained full strength in his lower extremities. Intraoperatively, the tumor was found to be intradural, extramedullary with an extradural component. The tumor was found to be an anaplastic ependymoma. Conclusions: Even though spinal intradural extramedullary ependymomas are very rare, surgeons must be aware that on MRI, they can be mistaken for meningiomas or nerve sheath tumors especially if there is an extradural component. Our case report is the first intradural, extramedullary ependymoma that is anaplastic and has an extradural component. A review of the literature provides little information on the treatment and prognosis for these tumors especially if they are anaplastic. We propose that the treatment, as done in our case, should be complete resection of the tumor with spinal radiotherapy to the tumor level.

Giant intracranial osteochondroma: A case report and review of the literature

Renuka Inuganti Venkata — Tue,30 Aug 2011

Renuka Inuganti Venkata, Satya Varaprasad Kakarala, Sailabala Garikaparthi, Seshadri Sekhar Duttaluru, Annapoorna Parvatala, Aparna Chinnam

Surgical Neurology International 2011 2(1):118-118

Background: Intracranial osteochondromas are uncommon. The majority of lesions arise from the base of the skull or from bones developed by endochondral ossification. A minority of cases are attached to the falxcerebri in the fronto parietal location. Case Description: We report a case of a giant intracranial osteochondroma in a 24-year-old man. This patient presented with complaints of convulsions and headache. Imaging studies of the brain, gross, and histological features concluded it to be an osteochondroma. Conclusion: This case is reported in view of extreme rarity of the lesion, and to emphasize the fact that complete surgical resection is curative.

Permanent cerebrospinal fluid diversion in subarachnoid hemorrhage: Influence of physician practice style

Domenic P Esposito — Tue,30 Aug 2011

Domenic P Esposito, Fernando D Goldenberg, Jeffrey I Frank, Agnieszka A Ardelt, Ben Z Roitberg

Surgical Neurology International 2011 2(1):117-117

Background: Acute hydrocephalus (HCP) after aneurysmal subarachnoid hemorrhage (SAH) often persists. Our previous study described factors that singly and combined in a formula correlate with permanent CSF diversion. We now aimed to determine whether the same parameters are applicable at an institution with different HCP management practice. Methods: We reviewed records of 181 consecutive patients who presented with SAH and received an external ventricular drain (EVD) for acute HCP. After exclusion and inclusion criteria were met, 71 patients were analyzed. Data included admission Fisher and Hunt and Hess grades, aneurysm location, treatment modality, ventricle size, CSF cell counts and protein levels, length of stay (LOS) in the hospital, and the presence of craniectomy. Outcome measures were: (1) initial EVD challenge outcome; (2) shunting within 3 months; and (3) LOS. Results: Shunting correlated with Hunt and Hess grade, CSF protein, and the presence of craniectomy. The formula derived in our previous study demonstrated a weaker correlation with initial EVD challenge failure. Several parameters that correlated with shunting in the previous study were instead associated with LOS in this study. Conclusions: The decision to shunt depends on management choices in the context of a disease process that may improve over time. Based on the treatment strategy, the shunting rate may be lowered but LOS increased. Markers of disease severity in patients with HCP after SAH correlate with both shunt placement and LOS. This is the first study to directly evaluate the effect of different practice styles on the shunting rate. Differences in HCP management practices should inform the design of prospective studies.

Spindle cell oncocytoma of the pituitary and pituicytoma: Two tumors mimicking pituitary adenoma

Hideki Ogiwara — Wed,17 Aug 2011

Hideki Ogiwara, Steve Dubner, Stephen Shafizadeh, Jeffrey Raizer, James P Chandler

Surgical Neurology International 2011 2(1):116-116

Background : Spindle cell oncocytoma (SCO) and pituicytoma are rare nonfunctioning tumors of the pituitary. Both tumors are low grade and macroscopically indistinguishable from a nonfunctioning pituitary adenoma.We report one case of SCO and one case of pituicytoma and review the previous literature. Case Description : One patient was a 39-year-old man who presented with progressive headache, visual blurring, and polyuria of 3-year duration. He underwent partial resection (30% of the tumor) and postoperative adjuvant radiation therapy. Histopathology revealed SCO. However, after 9 months, the residual tumor grew and partial resection (70% of the tumor) was performed again. Four months after the second surgery, the tumor recurred again and he underwent transsphenoidal resection of the tumor with stable residual tumor to date. The other patient was a 59-year-old man who presented with a 3-month history of visual decline, fatigue, difficulty in writing, and polyuria. He underwent transsphenoidal resection (total) of the tumor. Histopathology revealed pituicytoma. He has been stable without evidence of recurrence for 1 year and 4 months. Conclusion : To date, there are 15 reported cases of SCO and 45 reported cases of pituicytoma including our cases. An incomplete resection of the tumor was a significant risk factor for recurrence in both SCO and pituicytoma (P = 0.0014 and P = 0.019, respectively). These tumors have a tendency to be hypervascular, which may hamper total resection. Epithelial membrane antigen (EMA) and mitochondria positivity is characteristic to SCO and they are considered to be important immunomarkers to distinguish these tumors.

Costs and frequency of "off-label" use of INFUSE for spinal fusions at one institution in 2010

Nancy E Epstein — Wed,17 Aug 2011

Nancy E Epstein, Garry S Schwall

Surgical Neurology International 2011 2(1):115-115

Background : INFUSE, bone morphogenetic protein-2 combined with bovine Type I collagen in the lumbar tapered fusion device (LT Cage), is used to promote anterior lumbar interbody fusion (ALIF). In spinal surgery, INFUSE is only Federal Drug Administration (FDA) approved for this "on-label" use. While the efficacy and possible complications due to INFUSE have been debated, we know less about the costs and frequency of "on-label" versus "off-label" use of INFUSE to perform spinal fusions. Methods : At one institution, we determined the costs (with overhead) and frequency of utilizing INFUSE "on-label" and "off-label" in performing spinal fusions during 2010. Results : During 2010, 177 spinal fusions utilized INFUSE. Ninety-six percent, or 170 of 177 spinal fusions, utilized INFUSE in an "off-label" capacity at a cost of $4,547,822. Only 4%, or seven of 177 cases, utilized INFUSE in an "on-label" capacity (ALIF); the total cost was $296,419. Conclusions : In 2010, at one institution, 96% of the spinal fusions utilized INFUSE in an "off-label" capacity (cost $4,547,822), while only 4% were performed "on-label" (cost $296,4194).

Trigeminal neuralgia as the initial manifestation of temporal glioma: Report of three cases and a review of the literature

Mahmood Khalatbari — Sat,13 Aug 2011

Mahmood Khalatbari, Abbas Amirjamshidi

Surgical Neurology International 2011 2(1):114-114

Background: It is almost an accepted scenario that trigeminal neuralgia (TN) occurs when there is a kind of vascular compression on the root entry zone of trigeminal nerve at pons. There are occasional reports about trigeminal neuralgia as the presenting sign of intracranial tumors but temporal glioma has rarely been included in the list. Case Description: We report three cases of temporal lobe glioma which presented with trigeminal neuralgia as the initial manifestation and review the relevant literature briefly. The patients were 19-, 20-, and 31-year-old males who presented with partially controlled TN. The tumor mass could be detected in paraclinical evaluations when the usual modalities of therapy for facial pain in our community were not effective. Excisional surgery led in full pain control in all the cases. Two of the patients died because of tumor recurrence after a year and the other one is being treated by adjuvants. Conclusion: We add these types of intracranial tumors to the list of the etiologies for TN and the possible mechanisms for the initiation of pain in these types of intracranial tumors are discussed.

Intraventricular trigonal meningioma: Neuronavigation? No, thanks!

Danilo O. A. Silva — Sat,13 Aug 2011

Danilo O. A. Silva, Georgios K Matis, Leonardo F Costa, Matheus A. P. Kitamura, Theodossios A Birbilis, Hildo R. C. Azevedo Filho

Surgical Neurology International 2011 2(1):113-113

Background: Most of the time meningiomas are benign brain tumors and surgical removal ensures cure in the vast majority of the cases. Thus, whenever possible, complete surgical resection should be the goal of the treatment. Methods: This is a report of our surgical technique for the operative resection of a trigonal meningioma in a resource-limited setting. The necessity of accurate and deep knowledge of the regional anatomy is outlined. Results: A 44-year-old male presented to our outpatient clinic complaining of cephalalgia increasing in frequency and intensity over the last month. His neurological exam was normal, yet a brain computed tomography scan revealed a lesion in the right trigone of the ventricular system. The diagnosis of possible meningioma was set. After thoroughly informing the patient, tumor resection was decided. An intraparietal sulcus approach was favored without the use of any modern technological aids such as intraoperative magnetic resonance imaging or neuronavigation. The postoperative course was uneventful and a postoperative computed tomography scan demonstrated the complete resection of the tumor. The patient was discharged two days later with no neurological deficits. In a two-year-follow-up he remains recurrence-free. Conclusion: In the current cost-effective era it is still possible to safely remove an intraventricular trigonal meningioma without the convenience of neuronavigation. Since the best neuronavigator is the profound neuroanatomical knowledge, no technological advancement could replace a well-educated and trained neurosurgeon.

Spinal cord injury: From inflammation to glial scar

Manoel Baldoino Leal-Filho — Sat,13 Aug 2011

Manoel Baldoino Leal-Filho

Surgical Neurology International 2011 2(1):112-112

Background: Glial scar (GS) is the most important inhibitor factor to neuroregeneration after spinal cord injury (SCI) and behaves as a tertiary lesion. The present review of the literature searched for representative studies concerning GS and therapeutic strategies to neuroregeneration. Methods: The author used the PubMed database and Google scholar to search articles published in the last 20 years. Key words used were SCI, spinal cord (SC) inflammation, GS, and SCI treatment. Results: Both inflammation and GS are considered important events after SCI. Despite the fact that firstly they seem to cause benefit, in the end they cause more harm than good to neuroregeneration. Each stage has its own aspects under the influence of the immune system causing inflammation, from the primary to secondary lesion and from those to GS (tertiary lesion). Conclusion: Future studies should stress the key points where and when GS presents itself as an inhibitory factor to neuroregeneration. Considering GS as an important event after SCI, the author defends GS as being a tertiary lesion. Current strategies are presented with emphasis on stem cells and drug therapy. A better understanding will permit the development of a therapeutic basis in the treatment of the SCI patients considering each stage of the lesion, with emphasis on GS and neuroregeneration.

Sensitivity and specificity in transcranial motor-evoked potential monitoring during neurosurgical operations

Satoshi Tanaka — Sat,13 Aug 2011

Satoshi Tanaka, Takashi Tashiro, Akira Gomi, Junko Takanashi, Hiroshi Ujiie

Surgical Neurology International 2011 2(1):111-111

Background: Intraoperative transcranial motor-evoked potential (TCMEP) monitoring is widely performed during neurosurgical operations. Sensitivity and specificity in TCMEP during neurosurgical operations were examined according to the type of operation. Methods: TCMEP monitoring was performed during 283 neurosurgical operations for patients without preoperative motor palsy, including 121 spinal operations, 84 cerebral aneurysmal operations, and 31 brain tumor operations. Transcranial stimulation at 100-600 V was applied by screw electrodes placed in the scalp and electromyographic responses were recorded with surface electrodes placed on the affected muscles. To exclude the effects of muscle relaxants on TCMEP, compound muscle action potential (CMAP) by supramaximal stimulation of the peripheral nerve immediately after transcranial stimulation was used for compensation of TCMEP. Results: In spinal operations, with an 80% reduction in amplitude as the threshold for motor palsy, the sensitivity and specificity with CMAP compensation were 100% and 96.4%, respectively. In aneurysmal operations, with a 70% reduction in amplitude as the threshold for motor palsy, the sensitivity and specificity with CMAP compensation were 100% and 94.8%, respectively. Compensation by CMAP was especially useful in aneurysmal operations. In all neurosurgical operations, with a 70% reduction in amplitude as the threshold for motor palsy, the sensitivity and specificity with CMAP compensation were 95.0% and 90.9%, respectively. Conclusions: Intraoperative TCMEP monitoring is a significantly reliable method for preventing postoperative motor palsy in both cranial and spinal surgery. A 70% reduction in the compensated amplitude is considered to be a suitable alarm point in all neurological operations.

Trends over time in the management of 2253 patients with cerebral aneurysms: A single practice experience

Troy D Payner — Sat,13 Aug 2011

Troy D Payner, Itay Melamed, Shaheryar Ansari, Thomas J Leipzig, John A Scott, Andrew J DeNardo, Terry G Horner, Kathleen Redelman, Aaron A Cohen-Gadol

Surgical Neurology International 2011 2(1):110-110

Background: To better understand the longitudinal trend in the proportion of techniques employed for cerebral aneurysm treatment, we reviewed our experience with 2253 patients over the last 11 years. Methods: We reviewed data in our prospective aneurysm database for all consecutive patients treated from January 1998 through December 2009. Data regarding age, sex, aneurysm location, presence or absence of hemorrhage, Fisher grade, clinical grade, treatment methods, length of hospitalization, and mortality rates by the time of discharge were retrieved and retrospectively analyzed. The most common aneurysm types were subsequently classified and analyzed separately. Results: The patient population included 663 males (29%) and 1590 females (71%). A total of 2253 patients presented with 3413 aneurysms; 1523 (63%) of the aneurysms were diagnosed as aneurysmal subarachnoid hemorrhage. A total of 2411 (71%) aneurysms were treated. Overall, 645 (27%) of the 2411 aneurysms underwent endosaccular coiling and 1766 (73%) underwent clip ligation; 69 (3%) of these aneurysms required both treatment modalities. The percentage of all aneurysms treated by endosaccular coiling increased from 8% (21) in 1998 to 28% (87) in 2009. There was no statistical difference between the average length of hospitalization for patients who underwent endosaccular coiling and clip ligation for their ruptured (P = 0.19) and unruptured (P = 0.80) aneurysms during this time period. Conclusions: In our practice, endovascular treatment has continued to be more frequently employed to treat cerebral aneurysms. This technique has had the greatest proportional increase in the treatment of posterior circulation aneurysms.

Safety and efficacy of rhBMP2 in posterior cervical spinal fusion for subaxial degenerative spine disease: Analysis of outcomes in 204 patients

Risheng Xu — Sat,13 Aug 2011

Risheng Xu, Mohamad Bydon, Daniel M Sciubba, Timothy F Witham, Jean-Paul Wolinsky, Ziya L Gokaslan, Ali Bydon

Surgical Neurology International 2011 2(1):109-109

Background: Many studies offer excellent demonstration of the ability of bone morphogenic protein (BMP) to enhance fusion rates in anterior as well as posterior lumbar surgery. Recently, BMP has also been shown to increase arthrodesis rates in anterior cervical surgery, albeit with concomitant increases in complication rates. To date, however, few studies have investigated the safety and efficacy of BMP in cervical surgeries approached posteriorly. Methods: We retrospectively reviewed 204 consecutive patients with degenerative cervical spinal conditions necessitating posterior cervical fusion at a single institution over the past 4 years. The incidence of postoperative mechanical neck pain, fusion rates, as well as neurologic outcomes were compared between patients who received BMP vs those who did not receive BMP intraoperatively. Results: There were no significant differences in preoperative variables between the non-BMP vs the BMP cohorts. Over an average follow-up of 24.2 months, there were no significant differences between the two cohorts in duration of hospitalization, cerebrospinal fluid leakage, deep vein thrombosis, pulmonary embolism, hyperostosis, infection, pneumonia, hematoma, C5 palsy, wound dehiscence, reoperation rates, or Nurick/ASIA scores. Eleven (7.1%) patients in the non-BMP group experienced instrumentation failure vs none in the BMP group (P=0.06). Patients receiving BMP had a significantly increased rate of fusion by the chi-square test (P=0.01) and the log-rank test (P=0.02). However, patients receiving BMP also had the highest rates of recurrent/persistent neck pain by the chi-square test (P=0.003) and the log-rank test (P=0.01). Conclusions: To date, few studies have evaluated the safety and efficacy of BMP in the posterior cervical spine. Here, we show that BMP usage does not increase complication rates, but it significantly increases arthrodesis rates and also may increase the rate of recurrent/persistent neck pain.

Response to "Unnecessary spinal surgery"

Clark Watts — Sat,30 Jul 2011

Clark Watts

Surgical Neurology International 2011 2(1):108-108

Immunoexcitotoxicity as a central mechanism in chronic traumatic encephalopathy-A unifying hypothesis

Russell L Blaylock — Sat,30 Jul 2011

Russell L Blaylock, Joseph Maroon

Surgical Neurology International 2011 2(1):107-107

Some individuals suffering from mild traumatic brain injuries, especially repetitive mild concussions, are thought to develop a slowly progressive encephalopathy characterized by a number of the neuropathological elements shared with various neurodegenerative diseases. A central pathological mechanism explaining the development of progressive neurodegeneration in this subset of individuals has not been elucidated. Yet, a large number of studies indicate that a process called immunoexcitotoxicity may be playing a central role in many neurodegenerative diseases including chronic traumatic encephalopathy (CTE). The term immunoexcitotoxicity was first coined by the lead author to explain the evolving pathological and neurodevelopmental changes in autism and the Gulf War Syndrome, but it can be applied to a number of neurodegenerative disorders. The interaction between immune receptors within the central nervous system (CNS) and excitatory glutamate receptors trigger a series of events, such as extensive reactive oxygen species/reactive nitrogen species generation, accumulation of lipid peroxidation products, and prostaglandin activation, which then leads to dendritic retraction, synaptic injury, damage to microtubules, and mitochondrial suppression. In this paper, we discuss the mechanism of immunoexcitotoxicity and its link to each of the pathophysiological and neurochemical events previously described with CTE, with special emphasis on the observed accumulation of hyperphosphorylated tau.

MRS findings in electrical status epilepticus in sleep: Report of two cases

Burak Tatli — Sat,30 Jul 2011

Burak Tatli, Baris Ekici, Kubilay Aydin

Surgical Neurology International 2011 2(1):106-106

Background : To evaluate the changes in brain metabolites by H1 magnetic resonance spectroscopy in two patients with electrical status epilepticus. Case Description : Two boys (aged 6 and 7 years) with electrical status epilepticus in sleep have been evaluated. N-acetyl aspartate levels were slightly elevated, and showed no decline in the postictal period. Creatine and choline levels were similar to that in controls. No evidence of neuronal cell damage was seen. Conclusion : Electrical status epilepticus is a balanced condition of hypermetabolism, when not accompanied with seizure.

Predictors of inpatient complications and outcomes following surgical resection of hypothalamic hamartomas

Debraj Mukherjee — Sat,30 Jul 2011

Debraj Mukherjee, Christine Carico, Miriam Nuño, Chirag G Patil

Surgical Neurology International 2011 2(1):105-105

Background : Our aim was to identify the preoperative factors associated with a greater risk of poor inpatient outcomes in those undergoing resection of hypothalamic hamartomas. Methods : We performed a multi-institutional retrospective cohort analysis via the Nationwide Inpatient Sample (1998 - 2007). Patients of any age who underwent resection of hypothalamic hamartomas were identified by ICD-9 coding. The primary outcomes included inpatient complications, length of stay (LOS), and total charges. Multivariate regression models were constructed to analyze the outcomes. Results : Two hundred and eighty-two patients were identified with a mean age of 27.7 years, with most being male (53.2%), Caucasian (78.9%), privately insured (69.3%), and treated electively (74.7%) at academic centers (91.7%). A majority (82.2%) had Elixhauser comorbidity scores of < 1, indicating few comorbidities. No inpatient deaths were reported. Mean LOS was 7.39 days and the mean total hospital charges were $53,935. Overall, 19.5% developed an inpatient complication, primarily stroke (16.7%). Female gender, ethnic / racial minorities, higher comorbidity scores, private insurance, and non-academic hospitals were associated with greater LOS and total charges. Private insurance (Odds Ratio, OR: 1.59, P = 0.045) and academic hospitals (OR: 1.43, P = 0.008) were associated with significantly higher odds of any complication. Minority race / ethnicity was associated with a minimal increase in the odds of postoperative stroke (OR: 1.02, P < 0.001) relative to Caucasians. Conclusions : Through an analysis of a 10-year multi-institutional database, we have described the surgical outcomes of patients undergoing resection of hypothalamic hamartomas. Results demonstrate significant inpatient morbidity, particularly postoperative stroke. Patient- and institution-level factors should be considered in determining the perioperative risk for such patients.

QR codes in neurosurgery

Pieter L Kubben — Sat,30 Jul 2011

Pieter L Kubben

Surgical Neurology International 2011 2(1):104-104

Anomalous vertebral artery compression of the spinal cord at the cervicomedullary junction

Bret Gene Ball — Thu,28 Jul 2011

Bret Gene Ball, Bruce R Krueger, David G Piepgras

Surgical Neurology International 2011 2(1):103-103

Background: Myelopathy from ectatic vertebral artery compression of the spinal cord at the cervicomedullary junction is a rare condition. Case Description: A 63-year-old female was originally diagnosed with occult hydrocephalus syndrome after presenting with symptoms of ataxia and urinary incontinence. Ventriculoperitoneal shunting induced an acute worsening of the patient's symptoms as she immediately developed a sensory myelopathy. An MR scan demonstrated multiple congenital abnormalities including cervicomedullary stenosis with anomalous vertebral artery compression of the dorsal spinal cord at the cervicomedullary junction. The patient was taken to surgery for a suboccipital craniectomy, C1-2 laminectomy, vertebral artery decompression, duraplasty, and shunt ligation. Intraoperative findings confirmed preoperative radiography with ectactic vertebral arteries deforming the dorsal aspect of the spinal cord. There were no procedural complications and at a 6-month follow-up appointment, the patient had experienced a marked improvement in her preoperative signs and symptoms. Conclusion: Myelopathy from ectatic vertebral artery compression at the cervicomedullary junction is a rare disorder amenable to operative neurovascular decompression.

Transfer of flexor carpi ulnaris branches to selectively restore AIN function in median nerve sections: Anatomical feasibility study and case report

Mariano Socolovsky — Thu,28 Jul 2011

Mariano Socolovsky, Gonzalo Bonilla, Gilda Di Masi, Homero Bianchi

Surgical Neurology International 2011 2(1):102-102

Background: In recent years, distal nerve transfers have become a valid tool for nerve reconstruction. Though grafts remain the gold standard for proximal median nerve injuries, a new distal transfer of flexor carpi ulnaris branches of the ulnar nerve to selectively restore anterior interosseous nerve function, concomitant with median nerve graft repair, could enhance outcomes. The objective of this paper is to anatomically analyze a technique to selectively reinnervate the thumb and index flexors. Methods: Both the median and ulnar nerves were dissected in 10 cadavers. First and second branches to the flexor carpi ulnaris (FCU) were measured for length at its emergence from the ulnar nerve, and for width. The emergence of the AIN, just proximal to the arch of the flexor digitorum superficialis, was dissected, and the distance measured from this point to its motor entry at the long flexor pollicis and its branch to the long index flexor. A tensionless repair was performed between one FCU branch and the AIN. Results: The mean AIN length was 32.3±8.20 mm and width 2.4±0.49 mm. The first branch from the ulnar nerve to the FCU measured 20.8±2.04 mm and 1.52±0.44 mm, while the second, more distal branch measured 24.3±6.71 and 1.9±0.17 mm, respectively. In all dissections, it was possible to contact both the proximal and distal branches of the ulnar nerve to the FCU with the distal stump of the divided AIN, with no tension or need for interposed nerve grafts. Conclusions: Though proximal reconstruction remains the gold standard, new distal nerve transfer techniques may improve outcomes.

Tectal plate glioblastoma multiforme

Michael D Nemer — Mon,18 Jul 2011

Michael D Nemer, Cathy Blight, Jacky T Yeung, Karim M Fram, Aftab S Karim

Surgical Neurology International 2011 2(1):101-101

Background: Tectal plate tumors have traditionally been considered low-grade, indolent lesions. We report a patient who presented with a tectal region glioblastoma multiforme (GBM), a rare pathology in this anatomic location. Case Description: This is a case report of a 45-year-old female that presented with worsening confusion, memory loss, and loss of bladder control for 3 days. There was no family history of brain malignancy. The patient presented with Parinaud's phenomenon. Pronator drift was not present. The patient had dysarthric speech. An elevated white blood cell count was also noted. Non-contrast CT scan of the head showed the presence of a tectal region mass and hydrocephalus. A follow-up MRI with and without contrast confirmed the presence of a 4.2 × 3.3 × 4.6 cm 3 mass. Magnetic Resonance Spectroscopy (MRS) demonstrated an elevated choline/N-acetylaspartate ratio and an increase in lactate suggesting an aggressive neoplasm. A ventriculoperitoneal shunt was initially placed to relieve the hydrocephalus. The patient subsequently underwent a suboccipital craniotomy for debulking of tumor and for tissue diagnosis. Pathology of the lesion was consistent with GBM. The patient declined postoperative treatment with chemotherapy and radiation. Conclusion: Although tectal region masses are predominantly low-grade lesions, high-grade lesions can present in this anatomical location. Furthermore, MRS can help to differentiate benign lesions from more aggressive lesions in the tectal plate. Biopsy of tectal plate lesions should be considered in select cases to establish diagnosis and prognosis in order to optimize treatment.

From the bench to the bedside: Sleeping when you're awake, lasers and the blood-brain barrier, neurons with a taste for lactate, and more…

Jason S Hauptman — Mon,18 Jul 2011

Jason S Hauptman

Surgical Neurology International 2011 2(1):100-100

A minimally-invasive rat model of subarachnoid hemorrhage and delayed ischemic injury

Joshua R Dusick — Mon,18 Jul 2011

Joshua R Dusick, Brandon C Evans, Azim Laiwalla, Scott Krahl, Nestor R Gonzalez

Surgical Neurology International 2011 2(1):99-99

Background: Double-injection models of subarachnoid hemorrhage (SAH) in rats are the most effective in producing vasospasm, delayed neurological deficits and infarctions. However, they require two large surgeries to expose the femoral artery and the atlanto-occipital membrane. We have developed a minimally-invasive modification that prevents confounding effects of surgical procedures, leakage of blood from the subarachnoid space and minimizes risk of infection. Methods: Rats are anesthetized and the ventral tail artery is exposed through a small (5 mm), midline incision, 0.2 mL of blood is taken from the artery and gentle pressure is applied for hemostasis. The rat is flipped prone, and with the head flexed to 90 degrees in a stereotactic frame, a 27G angiocath is advanced in a vertical trajectory, level with the external auditory canals. Upon puncturing the atlanto-occipital membrane, the needle is slowly advanced and observed for cerebrospinal fluid (CSF). A syringe withdraws 0.1 mL of CSF and the blood is injected into the subarachnoid space. The procedure is repeated 24 hours later by re-opening the tail incision. At 8 days, the rats are euthanized and their brains harvested, sectioned, and incubated with triphenyltetrazolium chloride (TTC). Results: Rats develop neurological deficits consistent with vasospasm and infarction as previously described in double-injection models. Cortical and deep infarctions were demonstrated by TTC staining and on histopathology. Conclusions: A minimally invasive, double-injection rat model of SAH and vasospasm is feasible and produces neurological deficits and infarction. This model can be used to study neuroprotective treatments for vasospasm and delayed neurological deficits following SAH, reducing the confounding effects of surgical interventions.

A short segment intracranial-intracranial jump graft bypass followed by proximal arterial occlusion for a distal MCA aneurysm

Leslie Nussbaum — Mon,18 Jul 2011

Leslie Nussbaum, Archie Defillo, Andrea Zelensky, Eric S Nussbaum

Surgical Neurology International 2011 2(1):98-98

Background: To describe the use of a short segment cortical intracranial-intracranial (IC-IC) bypass for the treatment of a distal middle cerebral artery (MCA) aneurysm. Case Description: A 54-year-old woman presented with a loss of consciousness followed by multiple seizures and was found to have a partially thrombosed distal MCA aneurysm. This possibly mycotic aneurysm was treated by creating a short segment jump graft between a normal cortical artery and a nearby cortical branch arising from the aneurysmal M3 arterial segment. The bypass allowed for subsequent occlusion of the aneurysmal vessel without ischemic consequence. At surgery, the anterior division of the superficial temporal artery (STA) was exposed and dissected. Intraoperative angiography was utilized to localize a cortical artery arising from the involved segment as well as a nearby cortical artery arising from a distinct, uninvolved MCA branch. A segment of the STA was harvested, and then 10-0 suture was utilized to anastomose this short segment, to both the involved and normal cortical arteries. This created a short jump graft allowing for subsequent sacrifice of the diseased artery. Following surgery, the patient immediately underwent coil embolization of the aneurysm back into the parent artery resulting in local vascular sacrifice. The remainder of the patient's hospital course was uneventful. She was discharged home in good condition. Conclusions: We suggest that cortical IC-IC bypass followed by endovascular arterial sacrifice as performed in our case represents a simple and safe option for treating unclippable distal MCA aneurysms including mycotic lesions.

Spinal dural attachments to the vertebral column: An anatomic report and review of the literature

Kristopher T Kimmell — Mon,18 Jul 2011

Kristopher T Kimmell, Hayan Dayoub, Hakeem Shakir, Eric H Sincoff

Surgical Neurology International 2011 2(1):97-97

Background: The spinal dura is anchored within the vertebral canal by connective tissue in the epidural space as well as the spinal roots. Inadvertent disruption of these dural attachments may lead to durotomy and cerebrospinal fluid (CSF) leaks. We observed well-developed connective tissue ligaments connecting the lumbar dura to the spinal column and examined these tissues microscopically. Methods: Intraoperative images were obtained during lumbar laminectomy procedures. They demonstrated connective tissue attachments, linking the lumbar dura to the spinal column in the dorsal midline and dorsolaterally. Tissue samples were obtained and examined microscopically. We then conducted a search of the literature to find references to dural attachments to the spinal column. Results: Histological examination of the samples showed minimal cellular fibrous tissue. To date no references to these attachments have been made in neurosurgical literature. Previous studies, including live, cadaveric, and radiographic examinations, have demonstrated a dorsomedian fold of dura attached to the junction of the ligamentum flavum, and dorsolateral ligaments that divide the dorsal epidural space into an anterior and posterior compartment. Conclusions: Epidural fibrous connections or ligaments between the dura and the lumbar spinal column may be of clinical importance to the neurosurgeon. Care should be taken during lumbar procedures not to disrupt or tear these ligaments as this may cause dural tears and CSF leaks. Identifying these ligaments and cutting them sharply may prevent inadvertent durotomies.

Paraganglioma of the cauda equina region: A report of three cases

Hilko Ardon — Mon,18 Jul 2011

Hilko Ardon, Christiaan Plets, Raf Sciot, Frank Van Calenbergh

Surgical Neurology International 2011 2(1):96-96

Background: Cauda equina paragangliomas (CEP) are rare tumors. Low back pain and sciatica are the main presenting symptoms. Magnetic resonance imaging (MRI) is the study of choice and treatment consists of total excision when feasible. Definitive diagnosis can only be made after immunohistochemical investigation. CEP is classified as grade I WHO and after total removal the prognosis is excellent. Nonetheless, after subtotal removal, tumor recurrence can occur. Case Description: We present 3 cases of CEP, preoperatively diagnosed as an intradural mass on MRI and suspected to be ependymoma. All 3 patients presented with low back pain and variable sciatic pain. Total resection of the tumor was performed after which all patients fully recovered. There is no recurrence after 13, 11, and 5 years, respectively. Conclusion: CEP is a rare tumor. We diagnosed 3 paragangliomas out of a series of 105 intradural extramedullary tumors in adults (1994-2005). No recurrence was seen after total resection. In retrospect, both the intraoperative appearance and the MR image were not completely typical for schwannoma or ependymoma, but final diagnosis can only be made histologically.

Endovascular management of distal anterior inferior cerebellar artery aneurysms: Report of two cases and review of the literature

Alejandro Santillan — Thu,30 Jun 2011

Alejandro Santillan, Y Pierre Gobin, Athos Patsalides, Howard A Riina, Axel Rosengart, Philip E Stieg

Surgical Neurology International 2011 2(1):95-95

Background: Aneurysms of the anterior inferior cerebellar artery (AICA), especially those located in the distal portion of the AICA, are rare. There are few reported cases treated with surgery or endovascular embolization. Case Description: We report two cases of fusiform distal AICA aneurysms presenting with subarachnoid hemorrhage. Parent artery occlusion with coils and n-butyl cyanoacrilate (n-BCA) resulted in complete aneurysm occlusion and prevented rebleeding. Both patients presented postprocedure neurological deficits, but have made a good recovery at 4 and 10 months, respectively. Conclusion: Occlusion of the parent artery for the treatment of ruptured fusiform distal AICA aneurysms is effective but has significant neurological risks.

Comparison of postoperative values for C-reactive protein in minimally invasive and open lumbar spinal fusion surgery

John K Houten — Thu,30 Jun 2011

John K Houten, Adesh Tandon

Surgical Neurology International 2011 2(1):94-94

Background: A major purported benefit of minimally-invasive spinal surgery (MIS) technique is less disruption of paraspinal soft tissues, but there is little quantifiable evidence of this in medical literature. Postoperative C-reactive protein (CRP) levels been shown to become more significantly elevated with larger surgical procedures, and this may allow for more measurable appreciation of any benefits of MIS verses open spinal surgery. Methods: CRP values were measured prior to and at multiple time points following surgery in patients undergoing posterior spinal fusion using both open and minimally invasive techniques. Results: Peak postoperative CRP was significantly lower in the 35 single-level minimally invasive procedures compared with the 11 single-level open procedures (13.5 vs. 21.3, p <0.01) and lower in the 12 two-level minimally invasive surgeries compared with 16 two-level open procedures (20.5 vs. 31.8, p <0.01). Conclusions: MIS lumbar fusion is associated with a lower peak in postoperative CRP compared with open surgery. This appears to support the notion that minimally invasive spine surgery technique leads to a measurable reduction in paraspinal soft tissue destruction mediated inflammation in the immediate postoperative period.

Endoscopic discectomy of L5-S1 disc herniation via an interlaminar approach: Prospective controlled study under local and general anesthesia

Hsien-Te Chen — Thu,30 Jun 2011

Hsien-Te Chen, Chun-Hao Tsai, Shao-Ching Chao, Ting-Hsien Kao, Yen-Jen Chen, Horng-Chaung Hsu, Chiung-Chyi Shen, Hsi-Kai Tsou

Surgical Neurology International 2011 2(1):93-93

Background: Open discectomy remains the standard method for treatment of lumbar disc herniation, but can traumatize spinal structure and leaves symptomatic epidural scarring in more than 10% of cases. The usual transforaminal approach may be associated with difficulty reaching the epidural space due to anatomical peculiarities at the L5-S1 level. The endoscopic interlaminar approach can provide a direct pathway for decompression of disc herniation at the L5-S1 level. This study aimed to evaluate the clinical results of endoscopic interlaminar lumbar discectomy at the L5-S1 level and compare the technique feasibility, safety, and efficacy under local and general anesthesia (LA and GA, respectively). Methods: One hundred twenty-three patients with L5-S1 disc herniation underwent endoscopic interlaminar lumbar discectomy from October 2006 to June 2009 by two spine surgeons using different anesthesia preferences in two medical centers. Visual analog scale (VAS) scores for back pain and leg pain and Oswestry Disability Index (ODI) sores were recorded preoperatively, and at 3, 6, and 12 months postoperatively. Results were compared to evaluate the technique feasibility, safety, and efficacy under LA and GA. Results: VAS scores for back pain and leg pain and ODI revealed statistically significant improvement when they were compared with preoperative values. Mean hospital stay was statistically shorter in the LA group. Complications included one case of dural tear with rootlet injury and three cases of recurrence within 1 month who subsequently required open surgery or endoscopic interlaminar lumbar discectomy. There were no medical or infectious complications in either group. Conclusion: Disc herniation at the L5-S1 level can be adequately treated endoscopically with an interlaminar approach. GA and LA are both effective for this procedure. However, LA is better than GA in our opinion.

Medial lenticulostriate artery aneurysm presenting with isolated intraventricular hemorrhage

Jason A Ellis — Thu,30 Jun 2011

Jason A Ellis, Randy D'Amico, Dorothea Altschul, Richard Leung, E Sander Connolly, Philip M Meyers

Surgical Neurology International 2011 2(1):92-92

Background: Isolated intraventricular hemorrhage (IVH) secondary to lenticulostriate artery aneurysm rupture is extremely rare. Thus, the diagnostic imaging modalities and therapeutic interventions utilized in the management of such cases are not clearly defined. Case Description: Here we describe a case of isolated or primary IVH (PIVH) in a 71-year-old woman presenting with severe headache. Emergent catheter cerebral angiography, performed after nondiagnostic computed tomography angiography (CTA), revealed the bleeding source to be a 4 × 2.6 mm distal medial lenticulostriate artery aneurysm that ruptured directly into the lateral ventricle. The poorly accessible location of the aneurysm for both endovascular and direct surgical treatment argued for conservative management. A good clinical outcome was obtained with rapid angiographic resolution of the ruptured aneurysm. Conclusion: Thus, lenticulostriate artery aneurysm rupture must be given diagnostic consideration in cases of isolated IVH. Emergent catheter cerebral angiography should be performed in cases such as this when noninvasive imaging is unrevealing. Conservative management may be a reasonable therapeutic option in patients with this kind of aneurysm, and spontaneous resolution can be observed.

The distance between the posterior communicating arteries and their relation to the endoscopic third ventriculostomy in adults: An anatomic study

Alicia Del Carmen Becerra Romero — Thu,30 Jun 2011

Alicia Del Carmen Becerra Romero, Carlos Eduardo da Silva, Paulo Henrique Pires de Aguiar

Surgical Neurology International 2011 2(1):91-91

Background: The diencephalic leaf of the Liliequist's membrane is a continuous structure that should be perforated in the endoscopic third ventriculostomy. Its lateral borders are penetrated by the third cranial nerve and the posterior communicating arteries. The most important complication of endoscopic third ventriculostomy is the vascular injury, such as the posterior communicating artery. The purpose of this study is to measure the distance between posterior communicating arteries located below the third ventricle floor and anterior of the mammillary bodies. Methods: In this observational prospective study 20 fresh brains from cadavers were utilized to measure the distance between the posterior communicating arteries in April 2008 at the Death Check Unit of our Institution. A digital photograph of the posterior communicating arteries was taken and the distance between the arteries was measured. The measurement was analyzed using descriptive statistics. Results: In the descriptive analysis of the 20 specimens, the posterior communicating arteries distance was 9 to 18.9 mm, a mean of 12.5 mm, median of 12.2 mm, standard deviation of 2.3 mm. Conclusion: The detailed knowledge of vascular structures involved in the endoscopic third ventriculostomy as to the posterior communicating arteries distance provides a safe lateral vascular border when performing such procedure.

The spectrum of management practices in nontraumatic subarachnoid hemorrhage: A survey of high-volume centers in the United States

Luke Tomycz — Thu,30 Jun 2011

Luke Tomycz, Nakul Shekhawat, Jonathan Forbes, Mayshan Ghiassi, Mahan Ghiassi, Dennis Lockney, Dennis Velez, Robert Mericle

Surgical Neurology International 2011 2(1):90-90

Background: There is a considerable variety of management practices for nontraumatic subarachnoid hemorrhage (ntSAH) across high-volume centers in the United States. We sought to design a survey which would highlight areas of controversy in the modern management of ntSAH and identify specific areas of interest fo further study. Methods: A questionnaire on management practices in ntSAH was formulated using a popular web-based survey tool (SurveyMonkey TM , Palo Alto, CA) and sent to endovascular neurointerventionists and cerebrovascular surgeons who manage a high volume of these patients annually. Two-hundred questionnaires were delivered electronically, and after a period of 2 months, the questionnaire was resent to nonresponders. Results: Seventy-three physicians responded, representing a cross-section of academic and other high-volume centers of excellence from around the country. On average, the responding interventionists in this survey each manage approximately 100 patients with ntSAH annually. Over 57% reported using steroids to treat this patient population. Approximately 18% of the respondents use intrathecal thrombolytics in ntSAH. Over 90% of responding physicians administer nimodipine to all patients with ntSAH. Over 40% selectively administer antiepileptic drugs to patients with ntSAH. Several additional questions were posed regarding the methods of detecting and treating vasospasm, as well as the indications for CSF diversion in patients with ntSAH further demonstrating the great diversity in management. Conclusion: This survey illustrates the astonishing variety of treatment practices for patients with ntSAH and underscores the need for further study.

Bilateral infraoptic A1 arteries in association with a craniopharyngioma: Case report and review of the literature

Charles B Stevenson — Thu,30 Jun 2011

Charles B Stevenson, Lola B Chambless, David A Rini, Reid C Thompson

Surgical Neurology International 2011 2(1):89-89

Background: While variation within the anterior cerebrovascular circulation is common, an infraoptic course of the proximal anterior cerebral artery (ACA), or infraoptic A1, is a relatively rare cerebrovascular anomaly. Associations with suprasellar neoplasms may occur, and accurate identification of this aberrant vessel during dissection is crucial to preventing vascular injury or stroke. Case Description: We present the first reported case of surgically confirmed bilateral infraoptic A1 arteries associated with a craniopharyngioma. We review the relevant magnetic resonance imaging (MRI), angiographic, and intraoperative anatomic features of the infraoptic A1 to emphasize the importance of these variables when planning and performing surgery in the region of the anterior communicating artery (AComm) complex. Conclusions: Awareness of the existence and clinical significance of this unusual anomaly can facilitate its recognition on preoperative studies and during dissection in the suprasellar space, allowing neurosurgeons to adjust operative plans accordingly.

Normal pressure subdural hygroma with mass effect as a complication of decompressive craniectomy

Igor Paredes — Thu,30 Jun 2011

Igor Paredes, Marta Cicuendez, Manuel A Delgado, Rafael Martinez-Pérez, Pablo M Munarriz, Alfonso Lagares

Surgical Neurology International 2011 2(1):88-88

Background: Subdural posttraumatic collections are called usually Traumatic Subdural Hygroma (TSH). TSH is an accumulation of cerebrospinal fluid (CSF) in the subdural space after head injury. These collections have also been called Traumatic Subdural Effusion (TSE) or External Hydrocephalous (EHP) according to liquid composition, or image features. There is no agreement about the pathogenesis of these entities, how to define them or if they are even different phenomena at all. Case Description: We present a case of a complex posttraumatic subdural collection, the role of cranioplasty as definite solution and review the literature related to this complication. Conclusion: Patients who undergo decompressive craniectomy (DC) have a risk of suffering a subdural collection of 21-50%. Few of these collections will become symptomatic and will need evacuation. When this happens, cranioplasty might be the definitive solution.

Emergency surgical salvage for severe intracranial aneurysm rupture during endovascular coiling procedures not amenable to additional coiling

Eric S Nussbaum — Thu,30 Jun 2011

Eric S Nussbaum, Archie Defillo, Tariq M Janjua, Andrea Zelensky, Penny Tatman, Richard Stoller, Jodi Lowary, Leslie A Nussbaum

Surgical Neurology International 2011 2(1):87-87

Background: We report the management and outcomes of six patients who underwent emergency surgical intervention in the setting of severe intraprocedural rupture during endovascular treatment of an intracranial aneurysm not amenable to additional coiling. Methods: From July 1997 through December 2010, our neurovascular service treated 1613 patients with coil embolization. During this time, we encountered six patients who suffered severe intraprocedural aneurysm rupture, defined by contrast extravasation during the coiling procedure, in whom additional attempted coiling failed to stop the ongoing extravasation. Hospital records, neuroimaging studies, operative reports, and follow-up clinic notes were complete and reviewed in all cases. The follow-up review in surviving patients ranged from 1.5 to 9 years (average 3.8 years), and no patient was lost to the follow-up review. Results: In all cases, persistent extravasation necessitated urgent surgical decompression and securing of the ruptured aneurysm. Of these six cases, three patients achieved a good functional status after prolonged rehabilitation, and one of these had only subtle cognitive changes on formal neuropsychological testing. Two patients died. Conclusion: Intraprocedural rupture during aneurysm coiling is a dangerous and potentially fatal event. Despite the seemingly hopeless nature of this situation, in our experience, aggressive management to control intracranial pressure combined with a rapid reversal of anticoagulation and early surgical intervention can result in reasonable outcomes in some patients.

Cervical carotid pseudoaneurysm: A carotid artery stenting complication

Jair Raso — Thu,30 Jun 2011

Jair Raso, Rogerio Darwich, Carlos Ornellas, Gustavo Cariri

Surgical Neurology International 2011 2(1):86-86

Background: As carotid artery stenting becomes increasingly used, more complications are likely to occur. We present a case of Staphylococcus septicemia and pseudoaneurysm arising in the neck portion of the carotid artery after stenting. Case Description: A 51-year-old man was admitted with mild left hemiparesis. CT and MRI showed right hemisphere ischemia. Duplex Scan and MRA showed bilateral severe stenosis of the carotid arteries in the neck. A percutaneous angioplasty with stenting of the left carotid artery was performed. Two weeks after the procedure, he developed fever and swelling in the right leg and shoulder. An abscess, near where the groin had been punctured for the angioplasty was surgically drained. Blood samples were positive for S. aureus. After treatment the patient complained of a painful bulky pulsatile left cervical mass. Duplex scan and MRA showed a pseudoaneurysm of the left carotid artery. We excised the pseudoaneurysm and rebuilt the carotid artery with a saphenous vein graft. The postoperative period was uneventful, and the MRA revealed a patent saphenous graft. Conclusion: Mycotic pseudoaneurysm of the carotid artery is a rare complication of percutaneous angioplasty and stenting. Surgical treatment with saphenous vein graft is the treatment of choice.

Endovascular coil embolization for ruptured kissing aneurysms associated with A1 fenestration

Takafumi Mitsuhara — Tue,21 Jun 2011

Takafumi Mitsuhara, Shigeyuki Sakamoto, Yoshihiro Kiura, Kaoru Kurisu

Surgical Neurology International 2011 2(1):85-85

Background : Fenestration of intracranial arteries is a rare anomaly, and is frequently associated with cerebral aneurysms. In this paper, we report rare kissing aneurysms associated with A1 fenestration. Case Description : A 71-year-old woman presented with subarachnoid hemorrhage. Diagnostic digital subtraction angiography revealed two saccular aneurysms at the proximal junction of a fenestration and posterior aspect of the fenestration that appeared to be 'kissing' each other. Emergent endovascular coil embolization was performed. Conclusion : Kissing aneurysms associated with fenestration of the horizontal segment in the anterior cerebral artery are rare, and have not been reported. During treatment of such specific types of aneurysms by endovascular treatment, three-dimensional rotational digital subtraction angiography was very useful for deciding the appropriate working angles.

Brain metastasis from large cell neuroendocrine carcinoma of the urinary bladder

Atsushi Tsugu — Tue,21 Jun 2011

Atsushi Tsugu, Michitsura Yoshiyama, Mitsunori Matsumae

Surgical Neurology International 2011 2(1):84-84

Background : In patients with urinary bladder cancer, brain metastases are quite rare and occur in only 1-7% of these patients. Of the urinary bladder cancers, large cell neuroendocrine carcinoma (LCNEC) is extremely rare; only 16 cases have been reported to date. In this report, a case of brain metastasis from LCNEC of the urinary bladder is described. Case Description : A 74-year-old man was admitted with confusion and left-sided hemiparesis. Head magnetic resonance imaging demonstrated a ring-enhancing lesion in the right frontal lobe. Whole body computed tomography revealed a suspicious lesion in the urinary bladder. These findings were considered consistent with metastatic brain tumor. Craniotomy and tumor removal were performed. After craniotomy, the patient underwent cystoscopy and the bladder mass was biopsied. Histological and immunohistochemical examination of both the brain tumor and bladder mass revealed LCNEC. According to these findings, the patient was diagnosed with a brain metastasis from LCNEC of the urinary bladder. Conclusion : To our knowledge, this is the first report of a patient with a brain metastasis from LCNEC of the urinary bladder.

"Unnecessary" spinal surgery: A prospective 1-year study of one surgeon's experience

Nancy E Epstein — Tue,21 Jun 2011

Nancy E Epstein, Donald C Hood

Surgical Neurology International 2011 2(1):83-83

Background : There are marked disparities in the frequency of spinal surgery performed within the United States over time, as well as across different geographic areas. One possible source of these disparities is the criteria for surgery. Methods : During a one-year period [November 2009-October 2010], the senior author, a neurosurgeon, saw 274 patients for cervical and lumbar spinal, office consultations. A patient was assigned to the "unnecessary surgery" group if they were told they needed spinal surgery by another surgeon, but exhibited pain alone without neurological deficits and without significant abnormal radiographic findings [dynamic X-rays, MR scans, and/or CT scans]. Results : Of the 274 consults, 45 patients were told they needed surgery by outside surgeons, although their neurological and radiographic findings were not abnormal. An additional 2 patients were told they needed lumbar operations, when in fact the findings indicated a cervical operation was necessary. These 47 patients included 21 [23.1%] of 91 patients with cervical complaints, and 26 [14.2%] of 183 patients with lumbar complaints. The 21 planned cervical operations included 1-4 level anterior diskectomy/fusion [18 patients], laminectomies/fusions [2 patients], and a posterior cervical diskectomy [1 patient]. The 26 planned lumbar operations involved single/multilevel posterior lumbar interbody fusions: 1-level [13 patients], 2-levels [7 patients], 3-levels [3 patients], 4-levels [2 patients], and 5-levels [1 patient]. In 29 patients there were one or more overlapping comorbidities. Conclusions : During a one-year period, 47 [17.2%] of 274 spinal consultations seen by a single neurosurgeon were scheduled for "unnecessary surgery".

Pupillary reactivity as an early indicator of increased intracranial pressure: The introduction of the neurological pupil index

Jeff W Chen — Tue,21 Jun 2011

Jeff W Chen, Zoe J Gombart, Shana Rogers, Stuart K Gardiner, Sandy Cecil, Ross M Bullock

Surgical Neurology International 2011 2(1):82-82

Background : This paper introduces the Neurological Pupil index (NPi), a sensitive measure of pupil reactivity and an early indicator of increasing intracranial pressure (ICP). This may occur in patients with severe traumatic brain injury (TBI), aneurysmal subarachnoid hemorrhage, or intracerebral hemorrhage (ICH). Methods : 134 patients (mean age 46 years, range 18-87 years, 54 women and 80 men) in the intensive care units at eight different clinical sites were enrolled in the study. Pupillary examination was performed using a portable hand-held pupillometer. Results : Patients with abnormal pupillary light reactivity had an average peak ICP of 30.5 mmHg versus 19.6 mmHg for the normal pupil reactivity population (P = 0.0014). Patients with "nonreactive" pupils had the highest peaks of ICP (mean = 33.8 mmHg, P = 0.0046). In the group of patients with abnormal pupillary reactivity, we found that the first evidence of pupil abnormality occurred, on average, 15.9 hours prior to the time of the peak of ICP. Conclusions : Automated pupillary assessment was used in patients with possible increased ICP. Using NPi, we were able to identify a trend of inverse relationship between decreasing pupil reactivity and increasing ICP. Quantitative measurement and classification of pupillary reactivity using NPi may be a useful tool in the early management of patients with causes of increased ICP.

Ruptured peripheral aneurysms in a collateral pathway associated with stenosis of a major cerebral artery: Report of two cases

Ichiyo Shibahara — Tue,21 Jun 2011

Ichiyo Shibahara, Shingo Yonezawa, Hiroki Takazawa, Tomohiro Kawaguchi, Masayuki Kanamori, Kensuke Murakami, Hiroshi Midorikawa, Tatsuya Sasaki, Michiharu Nishijima

Surgical Neurology International 2011 2(1):81-81

Background : While hemodynamic stress can result in aneurysm formation, it rarely contributes to the development of peripheral aneurysms in collateral pathways. We report two patients with ruptured distal aneurysms in a collateral pathway associated with stenosis of a major cerebral artery. Case Description : A 67-year-old man presented with intracerebral hemorrhage in the right frontal lobe. Digital subtraction angiography (DSA) revealed severe stenosis of the right middle cerebral artery and two aneurysms in the collateral pathway of the right anterior cerebral artery. The ruptured aneurysm was trapped and resected; histologically, it was a true saccular aneurysm. The unruptured aneurysm was clipped and the patient was discharged without additional neurological deficits. The second patient was a 73-year-old woman with subarachnoid hemorrhage. DSA revealed three arterial dilations. On the 7 th day of hospitalization, one of the aneurysms in a posterior inferior cerebellar artery-anterior inferior cerebellar artery anastomosis that functioned as a collateral pathway in the presence of severe basilar artery stenosis was found to be enlarged. It was treated by selective aneurysmal coil embolization with parent artery preservation. Her postoperative course was uneventful and she was discharged without any neurological deficits. Conclusion : We document the successful treatment of two patients with ruptured aneurysms in the peripheral portion of a collateral pathway. We discuss the histology of peripheral aneurysms and present a review of the literature.

Non-aneurysmal subarachnoid hemorrhage as presentation of moyamoya disease in an adult

Gabriel A Alcalá-Cerra — Tue,21 Jun 2011

Gabriel A Alcalá-Cerra, Luis R Moscote-Salazar, Rubén Sabogal Barrios, Lucía M Niño-Hernández, Juan J Gutiérrez Paternina

Surgical Neurology International 2011 2(1):80-80

Background : The presentation of moyamoya disease (MMD) as an aneurysmal subarachnoid hemorrhage (SAH) is relatively frequent and in the absence of aneurysms is extremely rare. Case Description : A 53-year-old male patient suddenly developed severe headache associated with dysarthria and an altered state of consciousness. At the time of admission, he was found drowsy with global aphasia, stiff neck, right hemiparesis and right Babinski's sign. A non-contrast brain computed tomography was performed and a small bleeding in the subarachnoid space over the left frontal and parietal cortex was observed. Four-vessel cerebral angiography showed bilateral stenosis of the internal carotid arteries, with multiple tortuous vessels branching from the anterior and middle cerebral arteries. These abnormal vessels were anastomosing with branches from the posterior cerebral and middle meningeal arteries. With this information, a diagnosis of MMD was made. A three-dimensional reconstruction from digital angiography ruled out aneurysms or vascular malformations. After 4 weeks, another angiography was performed and remained the same as previous one. Conclusion : Clinical and radiological characteristics of this case are consistent with previous reports, supporting the theory that non-aneurysmal SAH in MMD is caused by rupture of fragile moyamoya vessels.

The brain and computer: The neurosurgical interface

Nader Pouratian — Wed,15 Jun 2011

Nader Pouratian

Surgical Neurology International 2011 2(1):79-79

Neurosurgery has always had a strong interest in innovating new technologies to improve neurological function and quality of life. Now, novel interventions that modulate central nervous system activity at the nanoparticle, molecular, genetic, cellular, and network level all seem to be on the horizon. Advances in biomedical engineering, including imaging techniques, sensor technologies, bio-signal analyses and classification, and prosthetics, have particularly accelerated the development brain-computer interfaces (BCI). Clinical translation of BCI technology will require multidisciplinary collaboration and effort to develop all necessary components, including advanced sensor technologies, sophisticated and real-time signal analyses and classifications, and complex effector technologies. Although the field has primarily been driven by basic scientists, neurosurgeons need to play a critical role in the further development of each component of these technologies because of our unique access to the awake and behaving human brain, our perspective with respect to the practicalities of technology implementation in the clinical setting, and because of our historical commitment to improving neurological function and quality-of-life. The current state of BCI research, the challenges, and the critical role that neurosurgeons must play in BCI development are briefly reviewed to advocate for increased neurosurgical involvement and commitment to this emerging translational field.

Traumatic retroclival epidural hematoma in pediatric patient--Case report and review of literature

Muhammad Zubair Tahir — Wed,15 Jun 2011

Muhammad Zubair Tahir, SA Quadri, Sonia Hanif, Gohar Javed

Surgical Neurology International 2011 2(1):78-78

Background: Retroclival epidural hematoma (REDH) is a very rare entity in the practical field of neurosurgery. Only a few cases have been reported in literature. The authors present to you case of a 12-year-old female, a victim of road traffic accident (RTA), who had presented to us with loss of consciousness and seizures. Case Description: Magnetic resonance imaging revealed retroclival hematoma. She was managed on conservative grounds and discharged with assurance of multiple follow-up visits. Conclusion: Very few cases of REDH have been reported in pediatric population to date. It should be suspected in children with head and neck injuries who have been a victim of RTAs. Most likely underdiagnosed due to its rarity; therefore, MRI should be considered when the suspicion is high. Atlanto-occipital dislocation should always be kept under consideration in all cases, and therefore should be managed and monitored very cautiously. In this report, the authors also present concise review of the literature pertaining to the pathogenesis and management of this rare clinical entity which has a high likelihood to be encountered and underdiagnosed by neurosurgeons in Emergency Room.

Trigeminal ganglion neuron density and regulation of anterior choroid artery vasospasm: In a rabbit model of subarachnoid hemorrhage

Adem Yilmaz — Wed,15 Jun 2011

Adem Yilmaz, Cemal Gündogdu, Mehmet Dumlu Aydin, Murat Musluman, Ayhan Kanat, Yunus Aydin

Surgical Neurology International 2011 2(1):77-77

Background: Subarachnoid hemorrhage (SAH) is associated with severe vasospasm caused by a variety of neurochemical mechanisms. The anterior choroid arteries (AChAs) are innervated by vasodilated fibers of the trigeminal ganglion (TGG). The goal of this study was to determine whether there is a relationship between the neuron density of the TGG and the severity of AChAs vasospasm with SAH. Methods: Thirty-two rabbits were used for the study; eight served as the baseline control group, seven as a SHAM group, with injections of 1 cc of isotonic saline solution, and 17 rabbits were included in the experimental SAH group, with injection of homologous blood into the cisterna magna. After 10 days, the histopathology of the AChAs and TGGs were examined. The AChAs vasospasm index (VSI) of the external/internal diameter and the neuron density of the ophthalmic root of the TGGs were evaluated stereologically. The AChAs VSI was preferred -- a measure of the degree of vasospasm. As the VSI increased, the degree of arterial vasospasm increased. The results were statistically analyzed. Results: The mean AChAs VSI was significantly higher and the mean neuronal density of the ophthalmic root of the TGG was significantly lower in the group with severe vasospasm associated with SAH compared to the controls, SHAM, and the group with mild vasospasm associated with SAH (P< 0.05). The ophthalmic root of the TGG neuron density in the 7 rabbits that developed severe vasospasm was statistically less than that observed in the 10 rabbits with mild vasospasm. There was a linear relationship between the low neuronal density in the ophthalmic root of the TGG and the severity of the AChA vasospasm. Conclusions: The trigeminal ganglion neuron density may be an important factor in the regulation of AChAs diameter and cerebral blood flow. Low neuron density of the ophthalmic root of the TGG may play a role in the pathogenesis of AChAs vasospasm associated with SAH.

Palliative stereotactic-endoscopic third ventriculostomy for the treatment of obstructive hydrocephalus from cerebral metastasis

Clark C Chen — Wed,15 Jun 2011

Clark C Chen, Ekkehard Kasper, Peter Warnke

Surgical Neurology International 2011 2(1):76-76

Background: Endoscopic third ventriculostomy (ETV) is increasingly used in the treatment of obstructive hydrocephalus. The literature supporting its use in the setting of metastatic disease, however, remains limited. Methods: Between 2005 and 2010, 16 patients underwent ETV for treatment of obstructive hydrocephalus secondary to cerebral metastasis. Efficacy of symptomatic palliation and associated complications were reviewed. The results were compared to reported data for ventriculoperitoneal shunt placement in adult brain tumor patients. Patient selection criteria for ETV are reviewed. Results: Eleven of the 16 patients experienced symptomatic improvement after ETV (69%). Patients who presented with headache associated with nausea, vomiting, or lethargy were more likely to respond to treatment relative to patients presenting with headache alone. Of the 16 ETV patients, one suffered a wound infection and another underwent external ventricular drainage for assessment of intracranial pressure, yielding an overall complication rate of 12.5%. Conclusions: In select patients with obstructive hydrocephalus related to cerebral metastasis, ETV constitutes a minimally invasive palliative option. The efficacy of ETV in this population is comparable to those reported for obstructive hydrocephalus secondary to primary cerebral neoplasm or other non-neoplastic causes. Patients receiving chemotherapy close to the time of ETV may be at increased risk for infection.

Post-transplant aspergillosis and the role of combined neurosurgical and antifungal therapies under belatacept immunosuppression

Ekkehard M Kasper — Thu,9 Jun 2011

Ekkehard M Kasper, Jiri Bartek, Scott Johnson, Burkhard S Kasper, Martha Pavlakis, Michael Wong

Surgical Neurology International 2011 2(1):75-75

Opportunistic CNS-infection represent a major threat to patients after organ transplantation due to the need for ongoing immunosuppression and belatacept is a novel CTL4A inhibitor, which is increasingly used for patients following cadaveric kidney transplantation. Among the CNS infections, intracranial Aspergillus is a particular challenge and poses difficulties for its insidious onset, a timely and accurate diagnosis, and its management due to high mortality rates. To this end we want to illustrate the management of this scenario as encountered in a 71-year-old female patient, who was admitted into our institution in June 2007 with speech difficulties and gait instability 1.5 years after cadaveric kidney transplantation. On imaging, both a mediastinal and left frontal mass were found. Radiographically guided sampling of the mediastinal mass and a stereotactic biopsy of the left frontal brain lesion revealed Aspergillus fumigatus. With modification of immunosuppression and directed antifungal therapy there was complete resolution of the chest lesion; the brain lesion initially responded well but later progressed in size. Surgical intervention via a left fronto-temporal craniotomy with intraoperative image guidance was performed for a gross total resection of the lesion. Twenty-four months from resection, she remains on voriconazole with no evidence of recurrence and complete neurologic recovery and preserved renal function.

A proposed definition of symptomatic vasospasm based on treatment of cerebral vasospasm after subarachnoid hemorrhage in Japan: Consensus 2009, a project of the 25 th Spasm Symposium

Satoshi Shirao — Thu,9 Jun 2011

Satoshi Shirao, Hiroshi Yoneda, Hideyuki Ishihara, Koji Kajiwara, Michiyasu Suzuki, Survey Study Members of Japan Neurosurgical Society

Surgical Neurology International 2011 2(1):74-74

Background : There is a lack of unified information on diagnosis and treatment of cerebral vasospasm (CV) after subarachnoid hemorrhage (SAH) among the hospitals in Japan. Thus, the aim of the study was to define the current practice in this area based on a survey by Japanese neurosurgeons. Methods : A survey on diagnosis and treatment of CV was sent to 414 hospitals each of which performs >100 neurosurgeries annually. Results : Responses were received from 240 hospitals (58.0%). Because accurate criteria for diagnosis of symptomatic vasospasm (SVS) were used in only 33.8% of the hospitals, we proposed a clinical definition of SVS that was approved at the 25 th Spasm Symposium (Consensus 2009). This definition is simplified as follows: (1) the presence of neurological worsening; (2) no other identifiable cause of neurological worsening; and (3) confirmation of vasospasm by medical examinations. The results also showed that the Fisher CT scale is used differently for patients with ICH or IVH, with 41.3% of cases with ICH/IVH based on SAH that met Fisher criteria classified into Fisher group 1, 2 or 3, and 46.3% classified into Fisher group 4. There were no major differences in prophylactic therapies of CV and therapy for cerebral ischemia among the hospitals. Endovascular treatment for vasospasm was performed in most hospitals (78.7%); however, the criteria differed among the hospitals: (1) angiographic vasospasm and SVS appeared (37.9%), (2) only when aggressive therapy was ineffective (41.4%). Conclusion : We established a clinical definition of SVS based on the results of this survey (Consensus 2009).

From the bench to the bedside: Gene therapy for Parkinson's disease, The roles of the habenula and nucleus accumbens in depression, Microglia and neurodegeneration

Ausaf A Bari — Thu,9 Jun 2011

Ausaf A Bari, Jason S Hauptman

Surgical Neurology International 2011 2(1):73-73

Cranioplasty with subcutaneously preserved autologous bone grafts in abdominal wall-Experience with 75 cases in a post-war country Kosova

Arsim Morina — Sat,28 May 2011

Arsim Morina, Fatos Kelmendi, Qamile Morina, Shefki Dragusha, Feti Ahmeti, Dukagjin Morina, Kushtrim Gashi

Surgical Neurology International 2011 2(1):72-72

Background : The study is to show the advantages of preservation of a calvarial bone flap in the abdominal pocket after decompressive craniotomy. Decompressive craniectomy is an option in the surgical management of refractory hypertension when maximal medical treatment (sedation, drainage of cerebrospinal fluid, moderate cooling, etc) has failed to control refractory high intracranial pressure. Methods : We have prospectively analyzed 82 consecutively operated cases decompressive craniotomies done at the University Neurosurgical Clinic in Prishtina/KOSOVA over a period of eight years (June 1999 to Aug 2008). Of the 75 who had their grafts replaced (7 patient died before replacement of bone graft), 62 patients had hemicraniectomy (fronto-parieto-temporal) 7 of them were bilateral. Results : In 66 out of 75 patients was achieved a satisfactory and cosmetically reconstruction, in 9 cases was required augmentation with methyl methacrylate to achieve cosmetic needs. Two patients had infection and the bone was removed; 6 months later these patients had cranioplasty with methyl methacrylate. The duration of storage of calvarial bone in abdominal pouch before reimplantation was 14 - 232 days (range 56 days). Conclusion : We think that storage of the patients own bone flap in the abdominal pocket is a safe, easy, cheap, sterile, histocompatible, and better cosmetic results.

Tentorial branch of the superior cerebellar artery

Alexander G Weil — Sat,28 May 2011

Alexander G Weil, Nancy McLaughlin, Daniel Denis, Michel W Bojanowski

Surgical Neurology International 2011 2(1):71-71

Background : The tentorial branch of the superior cerebellar artery (SCA) is not well known and is underreported in the literature. In the present study, the authors report and describe a dural branch arising from the SCA that was encountered during the surgical treatment of a tentorial dural arteriovenous fistula (DAVF). The clinical relevance of this branch is discussed. Case Description : A 53-year-old patient suffered a third recurrent right thalamic hemorrhage within 2 weeks rendering him comatose. Computed tomography scan revealed a right thalamic hematoma extending into the ventricles, producing acute hydrocephalus and midline shift. Cerebral angiography revealed a right-sided tentorial Borden type III DAVF fed primarily by the tentorial artery of Bernasconi and Cassinari and, to a lesser extent, the petrous branch of the middle meningeal artery. A small dural feeder originating from the SCA was suspected. Venous drainage was via the lateral mesencephalic vein, through an aneurysmal dilated basal vein of Rosenthal, to the straight sinus. The DAVF was approached surgically via a right subtemporal approach. Intraoperatively, after division of the tentorium, a tentorial branch originating from the SCA was identified. This artery was sectioned while preserving the SCA. The draining vein was ligated adjacent to the sinus. Postoperatively, the patient's neurological status improved and postoperative angiography demonstrated complete obliteration of the tentorial DAVF. Conclusion : Knowledge of the tentorial branch of the SCA is important as it may potentially be sectioned during division of the tentorium or avulsed from its origin in the SCA during surgical manipulation in the ambient cistern.

Monitoring of brain oxygenation in surgery of ruptured middle cerebral artery aneurysms

António Cerejo — Sat,28 May 2011

António Cerejo, Pedro Alberto Silva, Celeste Dias, Rui Vaz

Surgical Neurology International 2011 2(1):70-70

Background : The occurrence of brain ischemic lesions, due to temporary arterial occlusion or incorrect placement of the definitive clip, is a major complication of aneurysm surgery. Temporary clipping is a current technique during surgery and there is no reliable method of predicting the possibility of ischemia due to extended regional circulatory interruption. Even with careful inspection, misplacement of the definitive clip can be difficult to detect. Brain tissue oxygen concentration (PtiO 2 ) was monitored during surgery of middle cerebral artery (MCA) aneurysm presenting with subarachnoid hemorrhage (SAH), for detection of changes in brain oxygenation due to reduced blood flow, as a predictor of ischemic events, during temporary clipping and after definitive clipping. Methods : PtiO 2 was monitored during surgery of 13 patients harboring MCA aneurysms presenting with SAH, using a polarographic microcatheter (Licox, GMS, Kiel, Germany) placed in the territory of MCA. Results : A decrease in PtiO 2 values was verified in every period of temporary clipping. Brain infarction occurred in 2 patients; in both cases, there was a decrease in PtiO 2 greater than 80% from basal value, a minimum value of less than 2 mmHg persisting for 2 or more minutes during temporary clipping, and an incomplete recovery of PtiO 2 after definitive clipping. In 2 patients, incomplete recovery of values after definitive clipping led to verification of inappropriate placement and repositioning of the clip. Conclusion : The results suggest that intraoperative monitoring of PtiO 2 may be a useful method of detection of changes in brain tissue oxygenation during MCA aneurysm surgery. Postoperative infarction in the territory of MCA developed in cases with an abrupt decrease of PtiO 2 and a very low and persistent minimum value, during temporary clipping, and an incomplete recovery after definitive clipping. Verification of clip position should be considered when there is an incomplete recovery or a persistent fall in PtiO 2 after definitive clipping.

Dissecting peripheral superior cerebellar artery aneurysms: Report of two cases and review of the literature

Eric S Nussbaum — Sat,28 May 2011

Eric S Nussbaum, Archie Defillo, Andrea Zelensky, Richard Stoller, Leslie Nussbaum

Surgical Neurology International 2011 2(1):69-69

Background : Only a limited number of dissecting aneurysms of the peripheral cerebellar arteries have been previously described, and very few of these cases involve the superior cerebellar artery (SCA). Due to the rarity of these lesions, there is little consensus regarding prognosis and management. We describe our experience with two cases of complex peripheral SCA dissecting aneurysms and review the existing literature on this fascinating entity. Case Description : Two patients, both with SCA dissecting aneurysms not amenable to endovascular treatment underwent microsurgical clipping, one with the associated removal of a tentorial meningioma. In each procedure a combined subtemporal, presigmoidal approach was performed. Surgical clips were utilized to reconstruct the aneurysms, and both patients were discharged without complication. Surgical management of complex distal SCA fusiform aneurysm is challenging and options include wrap/clip reconstruction, proximal occlusion, trapping, and distal outflow occlusion. When possible, preservation of the parent artery is preferred to mitigate the risk of brainstem infarction. If proximal occlusion or trapping are employed, we have advocated for the use of combined distal revascularization techniques to prevent permanent ischemic damage of the brainstem and cerebellar hemisphere. Conclusions : Peripherally dissecting aneurysm of the SCA is an uncommon entity. Management of these lesions is best handled by an experienced neuro-endovascular team combined with a neurovascular surgeon skilled in skull base approaches.

Multichannel near-infrared spectroscopy as a tool for assisting intra-arterial fasudil therapy for diffuse vasospasm after subarachnoid hemorrhage

Tatsushi Mutoh — Sat,28 May 2011

Tatsushi Mutoh, Shinya Kobayashi, Noriyuki Tamakawa, Tatsuya Ishikawa

Surgical Neurology International 2011 2(1):68-68

Background : Diffuse cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) refractory to medical management can be treated with intra-arterial administration of vasodilators, but valid bedside monitoring for the diagnosis and therapeutic assessment is poorly available. We demonstrate the successful application of regional cerebral oxygen saturation (rSO 2 ) monitoring with multichannel near-infrared spectroscopy (NIRS) in assisting intra-arterial infusions of fasudil hydrochloride to a patient suffering from post-SAH vasospasm in the distal vascular territories. Case Description : 0A 63-year-old man presented with SAH and intracerebral hematoma due to ruptured right middle cerebral artery aneurysm developed aphasia and right-sided weakness on day 9 after SAH onset. Delayed cerebral ischemia attributable to diffuse vasospasm in the distal territories of the left anterior and middle cerebral arteries was suspected. Since the symptoms persisted despite maximal hyperdynamic therapy with dobutamine, intra-arterial fasudil treatment in the setting of rSO 2 monitoring including the spasm-affected vascular territory with four-channel flexible NIRS sensors was subsequently performed. Decreased and fluctuating rSO 2 in angiographically documented vasospastic territories increased immediately after intra-arterial fasudil infusion in accordance with relief of vasospasm that correlated with neurological improvement. The procedure was repeated on day 11 since the effect was transient and neurological deterioration and reduction of rSO 2 recurred. The deficits resolved accompanied by uptake and maintenance of rSO 2 following the intra-arterial fasudil, resulting in favorable functional outcome. Conclusion : Continuous rSO 2 monitoring with multichannel NIRS is a feasible strategy to assist intraarterial fasudil therapy for detecting and treating the focal ischemic area exposed to diffuse vasospasm.

Endovascular implantation of covered stents in the extracranial carotid and vertebral arteries: Case series and review of the literature

Ali Alaraj — Sat,28 May 2011

Ali Alaraj, Adam Wallace, Sepideh Amin-Hanjani, Fady T Charbel, Victor Aletich

Surgical Neurology International 2011 2(1):67-67

Background : Covered stents are used endovascularly to seal arterial wall defects while preserving vessel patency. This report describes our experience with the use of covered stents to treat cervical pathology, and a review of the literature in regards to this topic is presented. Case Description : Two patients presenting with the carotid blowout syndrome and one patient with a vertebrojugular fistula were treated with covered stents. This allowed for preservation of the vessel and was a treatment alternative to cerebral bypass. Conclusion : Covered stents provide a viable means of preserving the cervical vessels in selected patients; however, long-term follow-up is necessary to determine stent patency and permanency of hemostasis.

Safety and cost effectiveness of early discharge following microscopic trans-sphenoidal resection of pituitary lesions

Jonathan A Forbes — Sat,28 May 2011

Jonathan A Forbes, Jani Wilkerson, Lola Chambless, Sheila D Shay, Clay M Elswick, Parker W Abblitt, Owoicho Adogwa, Paul Russell, Kyle D Weaver, George S Allen, Andrea L Utz

Surgical Neurology International 2011 2(1):66-66

Background : Inpatient hospitalization following trans-sphenoidal resection of a pituitary neoplasm has traditionally involved a hospital stay of 2 days or more. It has been the policy of the senior pituitary neurosurgeon (GSA) since February 2008 to allow discharge home on postoperative day (POD) 1 if thirst mechanism is intact and the patient is tolerating oral hydration. The goal of this study was to evaluate the safety and cost-effectiveness of this practice. Methods : We reviewed the charts of 30 patients, designated the early discharge group, who consecutively underwent microscopic trans-sphenoidal resection from February 2008 to December 2009. We then reviewed the charts of 30 patients, designated the standard discharge group, who consecutively underwent trans-sphenoidal resection from May 2007 to February 2008 before discharge home on POD1 was considered an appropriate option. Safety and cost-effectiveness of the two patient groups were retrospectively evaluated. Results : Patients in the early discharge group went home, on average, on POD 1.3. Following exclusion of two outliers, the average date of discharge of patients in the standard discharge group was POD 2.2. The policy of early discharge saved an average of $1,949 per patient-approximately 4% the total cost of the procedure. Trends toward decreased costs did not reach statistical significance. While no patient suffered any measurable morbidity as a result of early discharge home, 1 in 3 patients in the early discharge group required unscheduled postoperative re-evaluation-a figure significantly higher than the standard discharge group. Conclusions : At a dedicated pituitary center with the resources to closely monitor outpatient endocrinological and postsurgical issues, early discharge home following trans-sphenoidal surgery is a safe option that is associated with an increase in the number of unscheduled postoperative visits and a trend toward lower costs.

Near-infrared spectroscopy monitoring of cerebral oxygen during assisted ventilation

Erin A Booth — Sat,28 May 2011

Erin A Booth, Christopher Dukatz, Beena G Sood, Michael Wider

Surgical Neurology International 2011 2(1):65-65

Background : Changes in the arterial partial pressure of CO 2 (PaCO 2 ) has a direct though transient effect on the cerebral vasculature and cerebral circulation. Decreased PaCO 2 levels lead to vasoconstriction and can result in dangerously low levels of cerebral perfusion that resolve in 4-6 h. It is currently believed that perfusion abnormalities contribute to intraventricular hemorrhage (IVH) and periventricular leukomalacia (PVL) in the neonate. PaCO 2 -induced vasoconstriction may contribute to the pathology of IVH and PVL. Methods : Near-infrared spectroscopy [NIRS; (INVOS cerebral/somatic oximeter; Somanetics Corporation, Troy, MI, USA)] was utilized to determine changes in regional oxygenation (rSO 2 ) of the brain in response to changes in ventilation in isoflurane anesthetized newborn piglets. Results: Changes in cerebral rSO 2 correlated significantly with end-tidal CO 2 levels and to blood flow in the common carotid artery. This correlation was significant during baseline conditions, after periods of CO 2 loading and during periods of hypothermia. Conclusions : The results of the study demonstrate the utility of NIRS to accurately reflect changes in cerebral oxygenation and flow to the brain in response to changes in CO 2 levels in anesthetized, ventilated neonatal piglets. The use of NIRS may provide an early alert of low levels of cerebral blood flow and brain oxygenation, potentially helping in preventing the progression of IVH or PVL in the neonate.

Neuroscience research fails to support claims that excessive pornography consumption causes brain damage

Rory C Reid — Sat,21 May 2011

Rory C Reid, Bruce N Carpenter, Timothy W Fong

Surgical Neurology International 2011 2(1):64-64

Surgical excision of filum terminale arteriovenous fistulae after lumbar fusion: Value of indocyanine green and theory on origins (a technical note and report of two cases)

Victoria T Trinh — Sat,14 May 2011

Victoria T Trinh, Edward A. M. Duckworth

Surgical Neurology International 2011 2(1):63-63

Background: Intradural filum terminale arteriovenous fistulas (AVFs) are uncommon. We report two cases of this rare entity in which we used indocyanine green (ICG) videoangiography to identify the fistulous connection of each lesion. Case Description: Two male patients presented with unresolved lower extremity weakness and paresthesias following lumbar fusion surgery. In each case, angiography showed an AVF between the filum terminale artery (FTA), the distal segment of the anterior spinal artery (ASA), and an accompanying vein of the filum terminale. A magnetic resonance image (MRI) obtained before lumbar fusion was available in one of these cases and demonstrated evidence of the preexisting vascular malformation. Surgical obliteration of each fistulous connection was facilitated by the use of ICG videoangiography. This emerging technology was instrumental in pinpointing fistula anatomy and in choosing the exact segment of the filum for disconnection. Conclusion: Our findings indicate that intradural filum terminale AVFs may have a congenital origin and that ICG is a useful tool in their successful surgical management. As these cases demonstrate, spine surgeons should remain vigilant in evaluating patients based on their clinical symptomatology, even in the presence of obvious lumbar pathology.

Delayed intracranial and bony metastasis of paraganglioma

Andrew Yew — Sat,14 May 2011

Andrew Yew, Won Kim, Sue Chang, Isaac Yang

Surgical Neurology International 2011 2(1):62-62

Background: Paragangliomas are tumors of neural crest origin that arise from the extra-adrenal paraganglia. In contrast with the often quoted 10% rule of malignancy for pheochromocytomas, the rate of malignancy as defined by local invasion or distant metastasis has been reported to be from 20% to as high as 50% in some case series with the most common sites of distant metastases being the liver, lungs, and bones. Here we present the case of a patient who presented with a rare case of intracranial metastasis from abdominal paraganglioma. Case Description: Our patient was a 48-year-old male with a distant history of multiple resections of abdominal paraganglioma in 1975 who presented with left shoulder, and left occipital metastasis 35 years after his original paraganglioma operations. Conclusions: Intracranial metastasis of paraganglioma is rare. There are unfortunately no known criteria to assess the risk of metastatic potential and given the long possible latency period between the resection of the primary tumor and the discovery of metastatic disease, patients with paragangliomas require lifelong monitoring. The optimal interval of monitoring has not been elucidated but follow-up every 5-10 years seems warranted.

Expression of thioredoxin-1 and hypoxia inducible factor-1α in cerebral arteriovenous malformations: Possible role of redox regulatory factor in neoangiogenic property

Yasushi Takagi — Sat,30 Apr 2011

Yasushi Takagi, Ken-ichiro Kikuta, Takuya Moriwaki, Tomohiro Aoki, Kazuhiko Nozaki, Nobuo Hashimoto, Susumu Miyamoto

Surgical Neurology International 2011 2(1):61-61

Background: Recently it is reported that proliferative activity remains in vascular walls of cerebral arteriovenous malformations (AVMs). These reports indicate that endothelial cells in AVMs have the neoangiogenic property. In this study, we assess the role of thioredoxin-1 (Trx-1) and hypoxia-inducible factor 1a (HIF-1α) in AVMs. These factors are reported to play a role in neoangiogenesis. Methods: We analyzed the expressions of Trx1 in the specimens of human cerebral AVMs. In addition, we also analyzed the expression of HIF-1α in these specimens by immunohistochemical method and RT-PCR. Furthermore, we assessed the effect of redox state and expression of Trx-1 during neoangiogenesis using in vitro angiogenesis assay. Findings: Trx-1 and HIF-1α immunoreactivity was detected in almost all 17 specimens of AVMs. Trx-1 and HIF-1α immunoreactive cells were distributed mainly endothelium of intranidal arteries and enlarged veins with thickened vascular walls. Double staining shows that Trx-1 and VEGF (vascular endothelial growth factor) immunoreactivity were colocalized in the same cells. These cells were considered to be endothelial cells. HIF-1α immunoreactivity was also colocalized with VEGF immunoreactivity in endothelium. As for influencing factors, the presence of deep drainers and convulsion significantly associated with HIF-1α expression. Trx-1 assessed by western blotting decreased at 6 hours and 12 hours after plating on Matrigel, which is a model of angiogenesis. Conclusions: We have shown that the endothelial induction of Trx-1 and HIF-1α in cerebral AVMs. Based on all findings obtained in this study, Trx-1 may affect the neoangiogenic property of cerebral AVMs. Key Words: Angiogenesis, cerebral arteriovenous malformations, HIF-1α, Trx-1

A rare case of greater petrosal nerve schwannoma

Danilo De Paulis — Sat,30 Apr 2011

Danilo De Paulis, Francesco Di Cola, Sara Marzi, Alessandro Ricci, Gino Coletti, Renato J Galzio

Surgical Neurology International 2011 2(1):60-60

Background: Facial nerve schwannomas include only 0.8% of all intrapetrous mass lesions, and schwannomas originating exclusively from the greater petrosal nerve (GPN) are extremely rare. To date, only 13 reports have been described. In this case, the tumor was thought to originate from the GPN on the basis of clinical, radiological, and operative findings. Case Description: A 23-year-old girl presented an acute left facial palsy, a disturbance in tear secretion of the ipsilateral eye, and a left-sided conductive hypoacusia. Computed tomography (CT) scan and magnetic resonance imaging (MRI) showed an extradural mass in the left middle fossa. A subtemporal approach was performed and the lesion, originating from the proximal portion of the GPN, was excised. The post-operative course was satisfactory, except for a xerophtalmia, which was treated with artificial teardrops. Conclusion: GPN schwannomas can originate anywhere alongside the course of the nerve, from its proximal segment near the facial hiatus to its distal segment near the foramen lacerum. For these reasons, it requires differential diagnosis with trigeminal nerve schwannomas or with injuries arising from the geniculate ganglion, because it can be easily confused with those lesions. However, in less severe cases, an early diagnosis can be able to preserve the function of the facial nerve by reducing iatrogenic injuries caused by surgical maneuvers.

Balloon-assisted coiling of the proximal lobule of a paraophthalmic aneurysm causing panhypopituitarism: Technical case report

Ludwig D Orozco — Sat,30 Apr 2011

Ludwig D Orozco, Razvan F Buciuc

Surgical Neurology International 2011 2(1):59-59

Background: We describe an intra-aneurysmal balloon-assisted technique to limit the coil volume in a large bilobulated paraophthalmic aneurysm. Our intent was to reduce the mass effect and presenting symptoms of diabetes insipidus (DI) with hypopituitarism. Case Description: A 32-year-old woman presented with symptoms of DI and her work-up demonstrated hypopituitarism and partial bitemporal visual field defects. Cerebral angiography revealed a large paraophthalmic aneurysm with two distinctive lobules, projecting toward the pituitary fossa. The patient declined craniotomy but consented for endovascular treatment. The plan was to limit the embolization to the proximal lobule only. Initially, we used a dual microcatheter technique with a microcatheter in each lobule. A framing coil in the distal lobule did not prevent coil migration from the proximal lobule. Instead, we elected to use a Hyperform balloon in the distal lobule and were able to successfully coil the proximal lobule only. Her 3-year follow-up angiogram revealed a completely occluded aneurysm. The patient experienced resolution of the DI and improvement of her visual fields. However, she remained in hypopituitarism. Conclusion: Intra-aneurysmal balloon-assisted coiling of proximal aneurysmal lobules might be an alternative for the reduction of mass effect related to the coil mass. Careful follow-up is needed because subtotal occlusion carries a future risk of growth, recanalization and rupture. Unruptured intracranial carotid aneurysms can present with reversible DI and usually permanent pituitary disturbances.

Endoscopic endonasal removal of a cavernous hemangioma of the orbital apex

Marco Locatelli — Thu,28 Apr 2011

Marco Locatelli, Giorgio Carrabba, Claudio Guastella, Sergio M Gaini, Diego Spagnoli

Surgical Neurology International 2011 2(1):58-58

Background: Cavernous hemangioma are the most common benign lesions of the orbit. Their surgical resection is still challenging and several surgical approaches have been proposed. Case Description: We present the case of a 59-year-old woman with a cavernous hemangioma of the orbital apex, which was diagnosed incidentally. The hemangioma was extraconal and involved mainly the medial orbital apex; it also extended to the pterygoid fossa, to the middle fossa, to the maxillary and sphenoid sinuses. The surgical resection was performed by a pure endoscopic transphenoidal, transmaxillary, transethmoidal approach, achieving a total removal. The patient had a transient and incomplete paresis of the VI cranial nerve on the left side and did not experience other postoperative complications. Conclusion: The endoscopic endonasal approach proved successful in the management of this case and it should be considered in the surgical management of extraconal orbital apex lesions with medial or inferior extension.

Histiocytosis X: Characteristics, behavior, and treatments as illustrated in a case series

Ekkehard M Kasper — Thu,28 Apr 2011

Ekkehard M Kasper, David H Aguirre-Padilla, Raanan Y Alter, Matthew Anderson

Surgical Neurology International 2011 2(1):57-57

Background: Langerhans cell histiocytosis (LCH) is a proliferative disorder predominantly found in children. It often presents with pain in calvarium or spine and may cause neuroendocrine symptoms. The gold standard for diagnosing LCH is the detection of Birbeck Granules by EM. Here, we describe two unique presentations of LCH and we review current treatment guidelines. Case Description: The first patient was a 23-year-old man who presented with progressive swelling and redness of the left eye. MRI revealed a left retrobulbar lesion extending into the middle cranial fossa with no signal abnormality in the brain parenchyma. The lesion was resected and pathological analysis revealed LCH. Bone scans were negative and the patient was discharged soon after. He later underwent fractionated radiotherapy (cumulative dose 26 Gy). Follow-up MRIs show no disease at 24 months post-op. The second patient was a 56-year-old man with left frontal skull pain for 5 months. Imaging showed a solitary osteolytic lesion extending into both dura and scalp with no signal abnormality of the parenchyma. Excisional biopsy revealed LCH. Surgery was well tolerated and follow-up imaging shows no recurrence at 24 months post-op. Conclusion: We demonstrate that LCH, though uncommon, must remain on the differential when osteolytic lesions present in the adult. Although LCH often has the clinical and radiographical presentation of an abscess, pathology analysis can successfully diagnose LCH based on markers and morphological characteristics. LCH has an excellent prognosis when treated aggressively with surgical resection and radiotherapy as both of our patients were and are now disease free at 2 year follow-up.

Acute formation of a pseudoaneurysm adjacent to a previously clipped anterior communicating artery aneurysm

Mohammadali M Shoja — Thu,28 Apr 2011

Mohammadali M Shoja, R Shane Tubbs, Aaron A Cohen-Gadol

Surgical Neurology International 2011 2(1):56-56

Background : Cerebral pseudoaneurysms, especially of the anterior communicating artery (ACoA), are rare. Case Description : Herein, the authors report a 66-year-old patient who underwent successful clip ligation of a small ruptured ACoA aneurysm. Eighteen days after surgery, he suffered from another episode of subarachnoid hemorrhage due to the rupture of a newly formed pseudoaneurysm adjacent to the previously clipped aneurysm. This pseudoaneurysm was treated through clip ligation as well. Conclusion : A pseudoaneurysm may rarely form adjacent to a previously clipped cerebral aneurysm and should be included in the differential diagnosis of recurrent subarachnoid hemorrhage. Potential mechanisms of formation and management strategies for this challenging problem will be discussed.

Recombinant human bone morphogenetic protein 2 labeled use in spinal surgery and sexual dysfunction

Marija Rakovac — Thu,28 Apr 2011

Marija Rakovac, Ivan Bojanic, Tomislav Smoljanovic

Surgical Neurology International 2011 2(1):55-55

Human cadaver brain infusion skull model for neurosurgical training

Jon Olabe — Thu,28 Apr 2011

Jon Olabe, Javier Olabe, Jose Maria Roda, Vidal Sancho

Surgical Neurology International 2011 2(1):54-54

Background : Microsurgical technique and anatomical knowledge require extensive laboratory training. Human cadaver models are especially valuable as they supply a good microsurgical training environment simultaneously providing authentic brain anatomy. We developed the "skull infusion model" as an extension of our previous "brain infusion model" taking it a step further maintaining simplicity but enhancing realism. Methods : Four human cadaveric brains donated for educational purposes were explanted at autopsy. The specimens were prepared cannulating carotid and vertebral arteries with plastic tubings, flushed with abundant water and fixed for 1 month in formaldehyde. They were then enclosed with white silk clothing (emulating the dura mater) and inserted into human skulls cut previously into two pieces. Tap water at a flow rate of 10 L/h was infused through the arterial tubings. Results : Diverse microsurgical procedures were performed by two trainees, including craniotomies with microsurgical approaches and techniques such as sylvian fissure exposure, extra-intracranial and intra-intracranial bypass, approaches to the ventricles and choroidal fissure opening. The water infusion fills the arterial system, leaking into the interstitial and cisternal space and finally moistening the whole specimen. This makes vascular microsurgical techniques become extremely realistic, increasing its compliance making manipulations easier and more authentic. Conclusions : Standard microsurgical laboratories frequently have difficulties to work with decapitated human cadaver heads but could have human brains readily available. Using the infusion model and inserting it in a human skull makes the environment much more realistic. Its simplicity and inexpensiveness make it a good alternative for developing microsurgical techniques.

Rarest of the rare: Chordoid glioma infiltrating the optic chiasm

Qasim S Al Hinai — Thu,28 Apr 2011

Qasim S Al Hinai, Kevin Petrecca

Surgical Neurology International 2011 2(1):53-53

Background : Chordoid glioma is a rare brain tumor typically located within the anterior third ventricle. It is a well-circumscribed, non-infiltrative tumor that grows as a mass within the ventricle. Case Description : We present the case of a 50-year-old woman with a chordoid glioma located in the anterior third ventricle. Unusually, MRI revealed an enlarged optic chiasm. Histological sampling of the chiasm revealed tumor invasion. Conclusion : Involvement of the optic apparatus is generally thought to be an imaging feature that can be used to distinguish chordoid gliomas from optic/hypothalamic gliomas. This case provides the first reported exception to this dogma.

Virtual reality training in neurosurgery: Review of current status and future applications

Ali Alaraj — Thu,28 Apr 2011

Ali Alaraj, Michael G Lemole, Joshua H Finkle, Rachel Yudkowsky, Adam Wallace, Cristian Luciano, P Pat Banerjee, Silvio H Rizzi, Fady T Charbel

Surgical Neurology International 2011 2(1):52-52

Background : Over years, surgical training is changing and years of tradition are being challenged by legal and ethical concerns for patient safety, work hour restrictions, and the cost of operating room time. Surgical simulation and skill training offer an opportunity to teach and practice advanced techniques before attempting them on patients. Simulation training can be as straightforward as using real instruments and video equipment to manipulate simulated "tissue" in a box trainer. More advanced virtual reality (VR) simulators are now available and ready for widespread use. Early systems have demonstrated their effectiveness and discriminative ability. Newer systems enable the development of comprehensive curricula and full procedural simulations. Methods : A PubMed review of the literature was performed for the MESH words "Virtual reality", "Augmented Reality", "Simulation", "Training," and "Neurosurgery". Relevant articles were retrieved and reviewed. A review of the literature was performed for the history, current status of VR simulation in neurosurgery. Results : Surgical organizations are calling for methods to ensure the maintenance of skills, advance surgical training, and credential surgeons as technically competent. The number of published literature discussing the application of VR simulation in neurosurgery training has evolved over the last decade from data visualization, including stereoscopic evaluation to more complex augmented reality models. With the revolution of computational analysis abilities, fully immersive VR models are currently available in neurosurgery training. Ventriculostomy catheters insertion, endoscopic and endovascular simulations are used in neurosurgical residency training centers across the world. Recent studies have shown the coloration of proficiency with those simulators and levels of experience in the real world. Conclusion : Fully immersive technology is starting to be applied to the practice of neurosurgery. In the near future, detailed VR neurosurgical modules will evolve to be an essential part of the curriculum of the training of neurosurgeons.

Pediatric traumatic putamenal strokes: Mechanisms and prognosis

Zain A Sobani — Thu,28 Apr 2011

Zain A Sobani, Arshad Ali

Surgical Neurology International 2011 2(1):51-51

Background : Studies have shown that nearly 3% of closed head injuries result in basal ganglia hemorrhages and that this may be a more frequent occurrence in pediatric patients. Various mechanisms based on shearing forces have been implicated in the injury; however, the underlying mechanism leading to the increased incidence in pediatric patients has not been well described. Angiographic data suggest that putamenal perforators in children are more severely stretched at acute angles compared to those in adults, which may be a contributing factor to the increased incidence. Case Description : We discuss a series of five relatively benign cases of traumatic putamenal strokes in children and review their presentations, mechanism of injury, neurological deficits, and management with reference to available literature. Conclusion : Although generally an alarming situation, benign presentations of putamenal strokes may be seen in pediatric populations after closed head injuries. In such cases, conservative management with subsequent rehabilitation and physical therapy is recommended.

Amebic encephalitis

Peter L Mayer — Thu,28 Apr 2011

Peter L Mayer, Julie A Larkin, Jill M Hennessy

Surgical Neurology International 2011 2(1):50-50

Background : Amebic encephalitis (granulomatous amebic encephalitis, GAE) an extremely rare disease occurring in immunocompromised patients. Presentation and early imaging findings are nonspecific. In GAE, enhancement may or may not be seen on imaging studies despite the presence of an aggressive, necrotizing, parasitic infection. Case Description : The patient was a 79-year-old man with ill-defined autoimmune hepatitis. He was on mild immunosuppression with 6-MP and low-dose prednisone. He presented with an acute febrile illness and obtundation. Imaging revealed a nonenhancing mass lesion of the frontal lobe. The patient briefly improved on high-dose steroids, then deteriorated again, with repeat imaging showing enlargement of the edematous brain lesion and herniation. The patient underwent craniotomy for evacuation of a necrotic brain lesion. His condition did not improve. Frozen section revealed only necrosis. Permanent pathology revealed GAE caused by Acanthamoeba. Conclusion : Neurosurgeons should remain aware of this rare disease. Imaging is variable and may not show enhancement or necrosis despite large areas of parasitic infection.

Comparison of standard and nonstandard helmets and variants influencing the choice of helmets: A preliminary report of cross-sectional prospective analysis of 100 cases

Abbas Amirjamshidi — Tue,19 Apr 2011

Abbas Amirjamshidi, Ali Ardalan, Kourosh Holakouie Nainei, Sadegh Sadeghi, Mehrdad Pahlevani, Mohammad Reza Zarei

Surgical Neurology International 2011 2(1):49-49

Background : The literature does not offer the rate of protection provided by different types of helmets used, especially as it applies to developing countries. We hypothesize that standard versus nonstandard types of helmets might differ in the rate of complications of head and neck trauma occurring in victims of motorcycle accidents. Here we report the rate of occurrence, the type of injuries and differences thereof in standard and nonstandard helmet bearers, and its relevance to protection from serious injury. Methods : The data were gathered from a data set of motorcycle accident victims admitted to the emergency department of Sina Hospital (Teheran/Iran). A cross-sectional study was designed for a 6-month period of time, June to December 2007. Variants analyzed included: demographics, types of helmets used, level of education of the victims (as in: being trained for using helmets and status of holding a valid driving license). The latter variants were evaluated for possibly influencing the outcome of the injured motorcyclists using either kind of helmets. Results : Among a total of 576 injured motorcyclists who had head, face, or neck injuries, 432 (75%) were using some kind of helmet. A total of 144 (25%) of the injured patients were admitted to the neurosurgical emergency service. There were 100 patients whose data sheets contained all variables which could be included in the pilot analysis of this cohort. Discussion : All 100 subjects were male patients with the age range of 32 ΁ 11 years. Twenty-five percent were using standard helmets at the time of accident, 43% had no cranio-facio-cervical injury except very mild skin abrasions, and 23% had facial injury, including skin lacerations needing sutures, two nasal bone fractures, and no maxillofacial damage. Among the patients using standard helmets, 44% had head injuries which needed to be taken care of (mostly nonoperatively), while 61% using nonstandard helmets had head trauma (P > 0.05). The other variables did not reach a significant value affecting the use of either standard or nonstandard helmets in prevention of craniofacial damages. Conclusion : This pilot analysis (comprising the data from 100 cases of motorcycle accidents) could not demonstrate statistically significant differences in injury patterns of different types of helmets and variants influencing their respective use. However, it can lead the way for further analysis of larger and more comprehensive head trauma databases regarding factors contributing to the issue of head injury.

Medical ethics for dummies

Ron Pawl — Tue,19 Apr 2011

Ron Pawl

Surgical Neurology International 2011 2(1):48-48

Wrong-level surgery: A unique problem in spine surgery

John Hsiang — Tue,19 Apr 2011

John Hsiang

Surgical Neurology International 2011 2(1):47-47

Background : Even though a lot of effort has gone into preventing operating at the wrong site and wrong patient, wrong-level surgery is a unique problem in spine surgery. Methods : The current method to prevent wrong level spine surgery performed is mainly relied on intra-operative X-ray. Unfortunately, because of the unique features and anatomy of the spinal column, wrong level spine surgery still happens. There are situations that even with intraoperative X-ray, correct level still cannot be reliably identified. Results : Examples of patient whose surgery can easily be performed on the wrong level are illustrated. A protocol to prevent wrong-level spine surgery preformed is developed. Conclusion : The consequence of wrong-level spine surgery not only generates another surgery of the intended level; it is usually also associated with lawsuit. Strictly following this protocol can prevent wrong-level spine surgery.

Endovascular stenting of an extracranial-intracranial saphenous vein high-flow bypass graft: Technical case report

Giuliano Maselli — Tue,19 Apr 2011

Giuliano Maselli, Claudio De Tommasi, Alessandro Ricci, Massimo Gallucci, Renato J Galzio

Surgical Neurology International 2011 2(1):46-46

Background : The authors describe a case of endovascular stenting of an extracranial-intracranial saphenous vein high-flow bypass graft in the management of a complex bilateral carotid aneurysm case. Case Description : A 43-year-old woman was admitted with progressive visual field restriction and headache. Imaging studies revealed bilateral supraclinoid carotid aneurysms. The right carotid aneurysm was clipped and the left one was treated by an endovascular procedure, after performing an internal carotid artery-middle cerebral artery (ICA-MCA) saphenous vein bypass graft. A few months following the bypass procedure, a 70-80% stenosis of the graft was discovered and treated endovascularly with a stenting procedure. Follow-up at 36 months after the first operation showed the patency of the venous graft and no neurological deficits. Conclusions : Endovascular stenting of the extracranial-intracranial saphenous vein high-flow bypass graft is technically feasible when postoperative graft occlusion is discovered.

Recurrent paraganglioma of Meckel's cave: Case report and a review of anatomic origin of paragangliomas

Anna Prajsnar — Tue,19 Apr 2011

Anna Prajsnar, Naci Balak, Gerhard F Walter, Alexandru C Stan, Wolfgang Deinsberger, Leyla Tapul, Cicek Bayindir

Surgical Neurology International 2011 2(1):45-45

Background : Paragangliomas are rare, usually benign tumors of neural crest origin. They account for only 0.6% of all head and neck tumors. In the craniocervical area, they are more common in the carotid body and tympanico-jugular regions. To the authors' knowledge, a case of paraganglioma in Meckel's cave has not yet been reported in the medical literature. The pathogenesis and natural history of paragangliomas are still not well understood. We present a case of recurrent paraganglioma in Meckel's cave. Case Description : A 53-year-old woman was diagnosed with trigeminal neuralgia, dysesthesia and hypoesthesia on the left side of the face, hearing disturbance and a history of chronic, persistent temporal headaches. Magnetic resonance imaging (MRI) showed a lesion located in Meckel's cave on the left side, extending to the posterior cranial fossa and compressing the left cerebral peduncle. The lesion was first thought to be a recurrence of an atypical meningioma, as the pathologist described it in the tissue specimen resected 3 years earlier, and a decision for re-operation was made. A lateral suboccipital approach to the lesion was used under neuronavigational guidance. The tumor was removed, and histological examination proved the lesion to be a paraganglioma. Five months later, the follow-up MRI showed local regrowth, which required subsequent surgical intervention. Conclusions : A paraganglioma in Meckel's cave is an uncommon tumor in this location. Although ectopic paragangliomas have been described in the literature, a paraganglioma atypically located in Meckel's cave makes a topographic correlation difficult, mainly because paraganglionic cells are usually not found in Meckel's cave. Another peculiarity of the case is the local recurrence of the tumor in a relatively short time despite an attempted, almost gross total resection.

Spontaneous acute subdural hematoma due to fondaparinux: Report of two cases

Karsten Fryburg — Tue,19 Apr 2011

Karsten Fryburg, Ha Son Nguyen, Aaron A Cohen-Gadol

Surgical Neurology International 2011 2(1):44-44

Background : Spontaneous acute subdural hematomas (SDHs) are rare. Risk factors for development of these hematomas include conditions such as hypertension, vascular abnormalities such as aneurysm or arteriovenous malformation, or consumption of anticoagulants. Case Description : Here, the authors report two patients who suffered from spontaneous acute SDH while taking fondaparinux for venous thromboembolism prophylaxis. One patient suffered from a remote episode of traumatic brain injury and underwent a decompressive craniectomy 3 weeks prior to presentation, whereas the other patient had been self-medicating with aspirin. Conclusion : To our knowledge, these two patients illustrate the first cases of spontaneous acute SDH formation most likely attributed to consumption of fondaparinux.

Cerebral artery restenosis following transluminal balloon angioplasty for vasospasm after subarachnoid hemorrhage

Katsuya Umeoka — Tue,19 Apr 2011

Katsuya Umeoka, Shushi Kominami, Takayuki Mizunari, Yasuo Murai, Shiro Kobayashi, Akira Teramoto

Surgical Neurology International 2011 2(1):43-43

Background : Although percutaneous transluminal angioplasty (PTA) is a widely used less invasive method to treat coronary artery stenosis, 10% of treated patients experience restenosis. Restenosis also occurs in approximately 5% of patients subjected to carotid artery stenting. Animal and human data suggested that restenosis is a response to injury incurred during PTA. As PTA has come into wide use to manage symptomatic cerebral vasospasm after subarachnoid hemorrhage (SAH) we studied the incidence of restenosis after PTA for cerebral vasospasm. Methods : Our study population consisted of 32 patients who had undergone PTA. They were followed by cerebral or 3DCT angiography or MRA for 6 126 months post-PTA (mean 48.65 months) to diagnose restenosis of the cerebral artery. We compared the size of the cerebral artery on the PTA and the contralateral side. Results : All 32 patients underwent successful PTA of 38 vascular territories and all manifested angiographic improvement of vasospasm. None suffered restenosis during the follow up period. Conclusion : PTA resulted in a significant improvement in the vessel diameter in patients with vasospasm after SAH and they did not suffer restenosis in the course of prolonged follow-up.