Sub-Saharan African experience of neurosurgical oncology care: challenges and barriers encountered at 7 cancer treatment centers.

OBJECTIVE: Wide disparities in neurosurgical oncology care and treatment outcomes exist globally despite recent improvements in diagnostics and cancer therapy. To better understand the challenges to neurosurgical oncology care in low-resource settings, the authors collected data on national neurosurgical capacity and hospital diagnostic and treatment capacity across 7 national referral hospitals in 7 countries in sub-Saharan Africa (SSA). METHODS: In April 2023, a 42-item self-administered questionnaire was distributed to partner neurosurgeons at the 7 centers via REDCap to provide country- and hospital-level capacity data on neurosurgical oncology care. RESULTS: Neurosurgical and neurosurgical oncology care were reported to be available in a limited number of provinces, states, regions, and counties in 6 of the 7 countries. The general neurosurgical workforce density across the 7 countries ranged from 0.03 to 0.67 per 100,000 persons, and that of the pediatric neurosurgical workforce ranged from 0 to 0.05 per 100,000 persons. Two centers had no pediatric ICUs, and the remaining 5 centers had pediatric ICUs with bed capacities between 1 and 8. One hospital had neither a CT nor an MRI scanner available and relied solely on private diagnostic facilities for neuroimaging. Histopathology services were largely limited to basic histopathology staining only; molecular subtyping was available at a single center. Three hospitals offered pediatric anesthesia expertise. None of the hospitals offered subspecialty neuro-oncology care or had a pediatric neuro-oncologist. None of the 7 hospitals had formal neurocritical care, neuroradiology, or neuropathology expertise. Neither adjuvant chemotherapy nor radiotherapy was available at 3 centers. Rehabilitation was largely limited to basic physical and occupational therapy at all 7 centers. Although all 7 countries had a multiple health payer system, the payment structure differed across the 7 hospitals for different neurosurgical oncology services, with patients making out-of-pocket payments for all services in some cases. CONCLUSIONS: There are significant challenges to timely and quality neurosurgical oncology care in SSA especially for children. System-level interventions are needed to strengthen neurosurgical oncology care capacity in SSA.

Pediatric neurosurgical-oncology scope and management paradigms in Sub-Saharan Africa: a collaboration among 7 referral hospitals on the subcontinent.

Background: Understanding of the epidemiology and biology of pediatric CNS tumors has advanced dramatically over the last decade; however there remains a discrepancy in the understanding of epidemiologic data and clinical capacity between high- and lower-income countries. Objective: We collected and analyzed hospital-level burden and capacity-oriented data from pediatric neurosurgical oncology units at 7 referral hospitals in Sub-Saharan Africa (SSA). Methods: A cross sectional epidemiological survey was conducted using REDCap at the 7 SSA sites, capturing 3-month aggregate data for patients managed over a total of 9 months. Descriptive statistical analyses for the aggregate data were performed. Results: Across the neurosurgical spectrum, 15% of neurosurgery outpatient and 16% of neurosurgery operative volume was represented by pediatric neuro-oncology across the 7 study sites. Eighty-six percent and 87% of patients who received surgery underwent preoperative CT scan and/or MRI respectively. Among 312 patients evaluated with a CNS tumor, 211 (68%) underwent surgery. Mean surgery wait time was 26.6 ± 36.3 days after initial presentation at the clinic. The most common tumor location was posterior fossa (n=94, 30%), followed by sellar/suprasellar region (n=56, 18%). Histopathologic analysis was performed for 189 patients (89%). The most common pathologic diagnosis was low grade glioma (n=43, 23%), followed by medulloblastoma (n=37, 20%), and craniopharyngioma (n=31, 17%). Among patients for whom adjuvant therapy was indicated, only 26% received chemotherapy and 15% received radiotherapy. Conclusion: The histopathologic variety of pediatric brain and spinal tumors managed across 7 SSA referral hospitals was similar to published accounts from other parts of the world. About two-thirds of patients received a tumor-directed surgery with significant inter-institutional variability. Less than a third of patients received adjuvant therapy when indicated. Multi-dimensional capacity building efforts in neuro-oncology are necessary to approach parity in the management of children with brain and spinal tumors in SSA.

Awake Craniotomy in Africa: A Scoping Review of Literature and Proposed Solutions to Tackle Challenges.

BACKGROUND: Awake craniotomy (AC) is a common neurosurgical procedure for the resection of lesions in eloquent brain areas, which has the advantage of avoiding general anesthesia to reduce associated complications and costs. A significant resource limitation in low- and middle-income countries constrains the usage of AC. OBJECTIVE: To review the published literature on AC in African countries, identify challenges, and propose pragmatic solutions by practicing neurosurgeons in Africa. METHODS: We conducted a scoping review under Preferred Reporting Items for Systematic Reviews and Meta-Analysis-Scoping Review guidelines across 3 databases (PubMed, Scopus, and Web of Science). English articles investigating AC in Africa were included. RESULTS: Nineteen studies consisting of 396 patients were included. Egypt was the most represented country with 8 studies (42.1%), followed by Nigeria with 6 records (31.6%). Glioma was the most common lesion type, corresponding to 120 of 396 patients (30.3%), followed by epilepsy in 71 patients (17.9%). Awake-awake-awake was the most common protocol used in 7 studies (36.8%). Sixteen studies (84.2%) contained adult patients. The youngest reported AC patient was 11 years old, whereas the oldest one was 92. Nine studies (47.4%) reported infrastructure limitations for performing AC, including the lack of funding, intraoperative monitoring equipment, imaging, medications, and limited human resources. CONCLUSION: Despite many constraints, AC is being safely performed in low-resource settings. International collaborations among centers are a move forward, but adequate resources and management are essential to make AC an accessible procedure in many more African neurosurgical centers.

Comparing the accuracy of ultrasound-based measurements of the cervical vagus nerve.

Vagus nerve stimulation (VNS) has become a promising therapy especially for drug resistant epilepsy and other pathologies. Side effects or missing therapeutic success are observed due to cuff electrodes that are too narrow or too wide. Preoperative high-resolution ultrasound is used to evaluate the size of the cervical vagus nerve (CVN) to estimate the size of cuff electrodes for VNS. It remains unclear how precise ultrasound reflects the CVN dimensions, which has been the objective of this study. CVN cross-sections and diameters were investigated in 23 sides from 12 bodies, using ultrasound, histology, and CVN casting in situ as a reference. Morphometric data were obtained including fascicle count and nerve composition in histology. CVN yielded significant side-, age-, and BMI-related differences. CVN cross-sections were smaller in ultrasound when compared to casting and histology (1.5 ± 0.4 vs. 3.1 ± 0.9 vs. 2.3 ± 0.7 mm2). With the given setting in ultrasound, CVN cross-sections were consistently underestimated when compared to casting. Ultrasound-based cross-section measurements are related to a biased estimation of CVN size. A factor to correct for method related differences may help to adjust for accurate cuff electrode sizes for patient needs and to reduce undesired effects and potentially material consumption.

Flexible endoscope-assisted suture release and barrel stave osteotomy for the correction of sagittal synostosis.

OBJECTIVE: Early suturectomy with a rigid endoscope followed by orthotic cranial helmet therapy is an accepted treatment option for single-suture craniosynostosis. To the authors' knowledge, flexible endoscope-assisted suture release (FEASR) has not been previously described. Presented herein is their experience with FEASR for the treatment of isolated sagittal craniosynostosis. METHODS: A retrospective analysis of the health records of patients who had undergone FEASR between March 2018 and December 2020 was performed. Patients under the age of 6 months who had been diagnosed with isolated sagittal synostosis were considered eligible for FEASR. Exclusion criteria included syndromic synostosis or multiple-suture synostosis. The cephalic index, the primary measure of the cosmetic endpoint, was calculated at prespecified intervals: immediately preoperatively and 6 weeks and 12 months postoperatively. Parental satisfaction with the cosmetic outcome was determined throughout the clinical follow-up and documented according to a structured questionnaire for the first 12 months. RESULTS: A total of 18 consecutive patients met the criteria for study inclusion. The mean patient age at the time of surgery was 3.4 months (range 2-6 months). All patients underwent a wide craniectomy with no need to convert to an open procedure. The mean craniectomy width was 3.61 cm. Estimated blood loss ranged from 5 to 30 ml. The mean operative time was 75 minutes. No intraoperative complications were observed. The average length of stay was 2.6 days. The mean cephalic index was 67.7 preoperatively, 77.1 at 6 weeks postoperatively, and 76.3 at 1 year postoperatively. The mean percentage change in the cephalic index from preoperatively to the 12-month follow-up was 10.44 (p < 0.001). The mean follow-up was 17 months (range 12-28 months). All parents were satisfied with the cosmetic outcome of the procedure. No patients developed symptoms of raised intracranial pressure (ICP) or needed invasive ICP monitoring during the follow-up period. No patients required reoperation. CONCLUSIONS: In this modest single-hospital series, the authors demonstrated the feasibility of FEASR in treating sagittal synostosis with favorable cosmetic outcomes. The morbidity profile and resource utilization of the procedure appear similar to those of procedures conducted via traditional rigid endoscopy.

Disseminated Human Subarachnoid Coenurosis.

Background: Traditionally, human coenurosis has been ascribed to Taenia multiceps while neurocysticercosis has been attributed solely to Taenia solium infection. Historically, however, the identification and differentiation of cestodal infection was primarily based on inaccurate morphological criteria. With the increasing availability of molecular methods, the accuracy of identification of the larval cestode species has improved, and cestodal species not typically associated with central nervous system (CNS) infection are now being identified as aetiological agents. Case report: We present a case of a 5-year-old male patient who presented with acute hydrocephalus. Initial MRI revealed multiple cysts in the cerebrospinal fluid (CSF) spaces with a predominance of clumped grape-like cysts in the basal cisterns with resultant acute obstructive hydrocephalus. The child underwent an emergency ventriculo-peritoneal (VP) shunt. A presumptive diagnosis of neurocysticercosis racemosus was made and the child was started on empiric albendazole (15 mg/kg/day) and praziquantel (30 mg/kg/day) treatment, along with concomitant prednisone (1 mg/kg) treatment. Despite prolonged anti-helminthic therapy, the child continued to deteriorate, and endoscopic removal of the 4th ventricular cysts was required. Post-operative MRI revealed radiological improvements, with a reduction in the number and size of cysts, especially in the basal cisterns, with no cysts visualized in the fourth ventricle. DNA was extracted from CSF and cyst tissue using the QiAMP DNA mini kit (Qiagen). The PCR performed on the extracted DNA displayed a band of 275 bp on an agarose gel. The consensus sequence had 97.68% similarity to Taenia serialis 12S ribosomal RNA gene. The child, unfortunately, continued to do poorly, requiring multiple VP shunt revisions for repeated blockage of the VP shunt system, and ultimately demised, despite the 'successful' surgical intervention and continued maximal medical management. Discussion and conclusions: There have been approximately 40 reported cases of human CNS coenurosis, with the assumed etiological agent being confined to T. multiceps. In 2020, the first case of human CNS coenurosis caused by T. serialis was reported. This case involved a single parenchymal lesion in the occipital lobe, which, following complete surgical excision, was confirmed to be T. serialis by mitochondrial gene sequencing. The case we present is the first case of disseminated subarachnoid coenurosis caused by T. serialis. It appears that T. serialis infection can mimic either of the two basic pathological forms of neurocysticercosis, namely, cysticercosis cellulosae or cysticercosis racemosus. We postulate that the term coenurosis racemosus is applicable if CNS T. serialis infection presents with extensive, multiple grape-like bladders proliferating within the subarachnoid space.

Suprasellar arachnoid cyst due to ectopic choroid plexus: case report.

Arachnoid cysts (ACs) are malformations that account for about 1% of all intracranial lesions. The aetiology and progression of these lesions have been debated, with one possible explanation being the production of cerebro-spinal fluid (CSF) by ectopic choroid plexus (CP). To our knowledge, only seven cases of ACs incorporating CP have been reported, and we believe this to be the first reported case of a suprasellar AC containing ectopic CP. A 1-year-old boy presented with developmental delay and macrocephaly. MRI scan revealed hydrocephalus due to a suprasellar AC. An endoscopic ventriculocisternostomy was undertaken. Intra-operatively, intra-cystic, pink frond-like tissue resembling choroid plexus was identified. Histologically, the cyst wall was composed of fibrous tissue, with layered arachnoid cells, while the frond-like tissue was composed of papillary structures in keeping with normal choroid plexus tissue. We postulate that the rest of the ectopic CP may have been trapped within the double layered arachnoid fold of the diencephalic leaf of Liliequist's membrane which may drive the formation and development of certain suprasellar ACs.

Intra-operative monitoring as an adjuvant to standard vagus nerve stimulation implantation.

PURPOSE: The treatment of refractory epilepsy by vagus nerve stimulation (VNS) is a well-established therapy. Complications following VNS insertion may be procedure-related or stimulation-related. Herein, we describe our technique of intra-operative neuro-monitoring (IONM) in an attempt to diminish these adverse events. METHODS: This retrospective study describes 66 consecutive patients between the ages of 3 and 12 years who had undergone primary VNS implantation. The study population consisted of two cohorts, one in which the VNS device was implanted according to the standard described technique and a second group in which IONM was used as an adjuvant during the VNS device placement. Prior to VNS insertion, a Pediatric Voice Handicap Index (PVHI) was performed to assess voice-related quality of life, and this was repeated at 3 months following VNS insertion. RESULTS: Sixty-six patients underwent the VNS implantation. Forty-three patients had a "standard" VNS insertion technique performed, whereas 23 had IONM performed during the VNS implantation. There were significant changes in the PVHI scores across both cohorts at 3-month follow-up. There were no statistically significant differences in PVHI scores between the monitored group and non-monitored group at 3-month follow up. CONCLUSIONS: IONM can be used during VNS insertions to ensure correct placement of the leads on CNX. IONM may minimise vocal cord stimulation by placing the lead coils on the area of nerve eliciting the least amount of vocal cord EMG response. IONM however does not appear to improve voice outcomes at early follow up.

Use of intra-operative stimulation of brainstem lesion target sites for frameless stereotactic biopsies.

INTRODUCTION: Frameless stereotactic navigation is used to direct the trajectory and biopsy site of target lesions. We report on a novel intra-operative stimulating (IOS) probe that is integrated into a commercially available stereotactic biopsy needle with the rationale that stimulation of the intended biopsy site should predict functional tissue thus preventing inadvertent biopsy of eloquent tissue. METHODS: Patients undergoing brainstem biopsies for atypical lesions were offered the additional stimulation procedure. The IOS probe was used to deliver stimulation in an attempt to determine the proximity of eloquent tissue. Once the desired location of the biopsy needle was achieved, the IOS probe was inserted down the centre of the biopsy needle and the stimulus applied. If no action potential was recorded, biopsies from four quadrants of the lesion were taken. If however a compound action potential was recorded, a new target was selected. RESULTS: Nine patients had the biopsy and stimulation procedure performed. The median age was 36 months. A minimum of 8 samples were obtained from each patient. Biopsy material was adequate to obtain a diagnosis in all 9 patients. In 2 cases use of the device influenced the insertion trajectory or biopsy site. No patients experienced any complications directly attributable to either the biopsy procedure or application of the stimulation. CONCLUSIONS: Use of the IOS probe for intra-operative stimulation of the intended brainstem biopsy site was found to be safe and feasible. The addition of stimulation using the IOS probe can be done with minimal change in workflow.

5-aminolevulinic acid-guided surgery for focal pediatric brainstem gliomas: A preliminary study.

BACKGROUND: There is a growing body of literature supporting the use of 5-aminolevulinic acid (5-ALA) in the pediatric population, however, its use is still considered "off label" in this setting. In this retrospective study, we report our experience using 5-ALA in pediatric patients with focal brainstem gliomas (BSGs). METHODS: Patients younger than 16 years presenting with a newly diagnosed BSG that was focal in nature were considered suitable for treatment with 5-ALA-assisted surgery. Exclusion criteria included MRI features suggestive of a diffuse intrinsic pontine glioma. A single dose of 5-ALA was administered preoperatively. Intraoperative fluorescence was recorded as "solid," "vague," or "none." The effectiveness of the fluorescence was graded as "helpful" or "unhelpful." RESULTS: Eight patients underwent 5-ALA-assisted surgery. There were four tumors located in the pons, two midbrain tumors, and two cervicomedullary tumors. Histological analysis demonstrated three diffuse astrocytomas, three pilocytic astrocytomas, and two anaplastic astrocytomas. Solid fluorescence was found in three of the eight cases, vague fluorescence was found in two cases, and no fluorescence was found in three cases. Fluorescence was useful in 3 (37%) cases. No patients experienced any complications attributable to the administration of the 5-ALA. CONCLUSION: With a total fluorescence rate of 62.5% but a subjectively assessed "usefulness" rate of only 37.5%, the role of 5-ALA in BSG surgery is limited. Given the toxicological safety, however, of the agent, caution is perhaps needed before dismissing the use of 5-ALA entirely.

The Use of 5-Aminolevulinic Acid to Assist Gross Total Resection of Paediatric Posterior Fossa Tumours.

BACKGROUND: 5-aminolevulinic acid (5-ALA) use is well established in the resection of adult high-grade gliomas. There is growing interest in its usefulness in the paediatric population. The potential benefit of 5-ALA-guided resection motivated our unit to offer the established adult protocol as off-label use. OBJECTIVE: to determine if 5-ALA guided resection was routinely useful and offered increased gross total resection (GTR) results. METHODS: Nineteen patients harbouring a posterior fossa tumour suggestive of either an ependymoma or medulloblastoma (MB) underwent surgery between January 2018 and October 2019. The mean age was 5 years (range 2-12 years). A dose of 20 mg/kg of 5-ALA (Gliolan®) was given 4 h preoperatively. Intraoperatively, the tumours were viewed under violet-blue light and the presence of fluorescence was recorded. Fluorescence status was compared with histopathological classification and grade, Ki-67 index, GTR rate, and a subjective determination of "usefulness" was determined. RESULTS: The case series included ependymoma grade II (n = 6), ependymoma grade III (n = 4), and MB grade IV (n = 9). For the combined cohort, the strong fluorescence rate was 68% (n = 13), the heterogenous fluorescence rate was 26% (n = 5), and the completely negative fluorescence rate was 5% (n = 1). The strong fluorescence rate of 90% found in the combined ependymoma group compared to the 45% strong fluorescence rate in the MB group was statistically significant (p = 0.05). Within the MB group the Ki-67 index was found to be significantly higher in the strongly fluorescent group as opposed to the patchy or non-fluorescent group (77.5 vs. 40%, p = 0.016). Fluorescence was determined to be useful in 63% of all cases. There was no significant relationship between fluorescence and GTR. The relationship between perceived usefulness and resection was not statistically significant. No adverse drug reactions were recorded. CONCLUSION: This case series adds to the growing body of evidence demonstrating the safety of 5-ALA in the paediatric population. 5-ALA guided resection was found to be useful in the majority of cases but this did not correlate with GTR status. Ependymomas reliably fluoresce in 90% of cases, and 5-ALA-guided resection should be considered when a preoperative diagnosis of ependymoma is suspected.

Geospatial Mapping of International Neurosurgical Partnerships and Evaluation of Extent of Training and Engagement.

OBJECTIVE: To evaluate the presence, extent, and temporality of transnational neurosurgical partnerships, to understand and inform measures to address neurosurgical deficiencies in low- and middle-income countries (LMICs). METHODS: A Web search was conducted to identify actors from high-income countries (HICs) participating in neurosurgical delivery and/or capacity-building with LMICs from 2010 to 2018. Descriptive data on current neurosurgical partnerships were collected from published case reports, literature reviews, reports from academic institutions, and information on stakeholder Web pages. The level of training and engagement of each partnership was separately graded based on prespecified criteria, in which grade 3 represented partnerships that have most extensive training and engagement, and grade 1, the least extent. Data were analyzed using descriptive statistics and geospatially depicted on ArcMap GIS software. RESULTS: A total of 123 unique HIC-LMIC partnerships were described. Of these partnerships, 85 (69%) are derived from HICs in North America, followed by Europe, with 23 (19%). The most common LMIC partners were from Africa (n = 56, 45%) and Latin America (n = 32, 26%). In addition, most partnerships provided services in pediatric neurosurgery (88%). The most frequent engagement classifications were grade 2 (35%) or 1 (36%). Similarly, for training, the most common classifications were grade 1 (40%) or 2 (30%). CONCLUSIONS: A robust network of HIC-LMIC partnerships exists with varying degrees of engagement and training activities. Several regions are particularly suitable for growth and development. Systematic consolidation and indexing of transnational neurosurgical partnerships aim to enhance resource allocation and present opportunities for future partnership.

Intra-Operative Detection of a Left-Sided Non-Recurrent Laryngeal Nerve during Vagus Nerve Stimulator Implantation.

Left sided non-recurrent laryngeal nerves (NRLN) are very rarely observed during surgery in the head and neck region. Arising directly from the cervical aspect of the vagus nerve, the NRLN lies in a vulnerable position distant from its normal location. NRLNs are normally associated with embryological branchial arch aberrations and subsequent vascular anomalies. The anomalous course of the NRLN makes it more susceptible to injury during surgery in the neck region. Knowledge of this anatomical variant will reduce the potential for injury and resultant vocal cord paralysis. During microsurgical dissection of the carotid sheath for the implantation of a vagus nerve stimulator in a 19-year-old female patient with refractory epilepsy, a moderate-sized branch of the main vagus nerve trunk was identified postero-medially within the carotid sheath. Intra-operative stimulation of this nerve resulted in a compound muscle evoked potential from the left vocal cord. Thus, this branch was confirmed to be a left-sided NRLN. The patient had no associated vascular anomalies. This is first reported case of a left-sided NRLN found during VNS insertion. Awareness of the possibility of an NRLN is imperative to prevent iatrogenic injury. A medial location of the vagus nerve within the carotid sheath should alert the surgeon to the possible presence of an NRLN. The absence of fourth branchial arch remnant anomalies is not a guarantee as to the absence of a left-sided NRLN. The addition of intra-operative nerve monitoring for vagus nerve stimulator (VNS) implantation procedures should be strongly considered to help avoid iatrogenic injury.

Awake Craniotomy in a Child: Assessment of Eligibility with a Simulated Theatre Experience.

BACKGROUND: Awake craniotomy is a useful surgical approach to identify and preserve eloquent areas during tumour resection, during surgery for arteriovenous malformation resections and for resective epilepsy surgery. With decreasing age, a child's ability to cooperate and mange an awake craniotomy becomes increasingly relevant. Preoperative screening is essential to identify the child who can undergo the procedure safely. Case Description. A 11-year-old female patient presented with a tumour in her right motor cortex, presumed to be a dysembryoplastic neuroepithelial tumour (DNET). We had concerns regarding the feasibility of performing awake surgery in this patient as psychological testing revealed easy distractibility and an inability to follow commands repetitively. We devised a simulated surgical experience to assess her ability to manage such a procedure. During the simulated theatre experience, attempts were made to replicate the actual theatre experience as closely as possible. The patient was dressed in theatre attire and brought into the theatre on a theatre trolley. She was then transferred onto the theatre bed and positioned in the same manner as she would be for the actual surgery. Her head was placed on a horseshoe headrest, and she was made to lie in a semilateral position, as required for the surgery. A blood pressure cuff, pulse oximeter, nasal cannula with oxygen flow, and calf pumps were applied. She was then draped precisely as she would have been for the procedure. Theatre lighting was set as it would be for the surgical case. The application of the monitoring devices, nasal cannula, and draping was meant not only to prepare her for the procedure but to induce a mild degree of stress such that we could assess the child's coping skills and ability to undergo the procedure. The child performed well throughout the simulated run, and surgery was thus offered. An asleep-awake-asleep technique was planned and employed for surgical removal of the tumour. Cortical and subcortical mapping was used to identify the eloquent tissue. Throughout the procedure, the child was cooperative and anxiety free. Follow-up MRI revealed gross total removal of the lesion. CONCLUSION: A simulated theatre experience allowed us to accurately determine that this young patient, despite relative contraindications, was indeed eligible for awake surgery. We will continue to use this technique for all our young patients in assessing their eligibility for these procedures.

5-Aminolevulinic Acid-Guided Surgery for Recurrent Supratentorial Pediatric Neoplasms.

BACKGROUND: The use of 5-aminolevulinic acid (5-ALA) in pediatric neuro-oncology is considered off-label, and little data are available on its use in tumor recurrence surgery. Here we present our experience with 5-ALA fluorescence-guided surgery for recurrent supratentorial tumors in the pediatric population. METHODS: Eleven pediatric patients presenting with recurrence of a supratentorial high-grade malignancy (5 glioblastoma [GBM], 6 non-GBM) underwent 5-ALA-assisted surgery. Biopsy specimens were obtained from pathological and normal-appearing areas of the tumor margin. RESULTS: From the margin of the tumor displaying solid fluorescence, a total of 36 samples were obtained. All of these histological samples were found to harbor tumor cells. From areas of vague enhancement, a total of 49 histological samples were taken, of which 38 samples (77%) harbored tumor cells. There was no significant difference in the percentage of biopsy-positive vague fluorescent areas between the GBM cases (80%) and non-GBM cases (75%). A total of 59 biopsy specimens were taken from the tumor margin that appeared completely negative for fluorescence. On analysis, 24 (40.7%) of these specimens demonstrated tumor cells. There was no significant difference in the number of false-negative biopsies between the GBM group (40%) and the non-GBM group (41%). CONCLUSIONS: The positive predictive value of solid fluorescence is high in recurrent disease but is substantially lower in areas of vague fluorescence. The rate of false-negative fluorescence is high. 5-ALA should be considered as an adjuvant in revision surgery with the aforementioned caveats in mind.

Duplicated Vagus Nerve in Adolescence: Case Report and Review of Literature.

BACKGROUND: Vagus nerve stimulation (VNS) has become an increasingly popular procedure for the treatment of epilepsy and depression. Significant complications or side effects associated with VNS surgery may result from either the inadvertent direct injury to the vagus nerve as part of the surgical approach, placement of the electrode, or the concomitant stimulation of vagal efferent fibers. To mitigate these effects, the recognition of anatomic variants that may place the nerve at increased risk is necessary. CASE DESCRIPTION: During microsurgical dissection of the carotid sheath for the implantation of a vagus nerve stimulator in a 17-year-old male patient with refractory epilepsy, additional nonidentified nerve tissue was found running parallel to the vagus nerve. These fibers were two thirds of the thickness of the vagus nerve and ran medial to it, from the most superior to the most inferior aspect of the carotid sheath dissection, found at a distance of at least 4 cm in a craniocaudal direction. This duplicated nerve did not appear to branch from the vagal trunk nor exit the sheath but rather paralleled the course of the vagus nerve. The parallel course and the proximity of the unidentified nerve make this structure likely to be a duplicated vagus nerve. CONCLUSIONS: This is the first reported case of cervical vagus nerve duplication presented in the literature. Surgeons performing VNS implantations should be cognizant of this potential anomaly in order to avoid inadvertent injury to the nerve.

Glioblastoma multiforme as a secondary malignancy following stereotactic radiosurgery of a meningioma: case report.

The documentation and exact incidence of stereotactic radiosurgery (SRS)-induced neoplasia is not well understood, with most literature restricted to single case reports and single-center retrospective reviews. The authors present a rare case of radiosurgery-induced glioblastoma multiforme (GBM) following radiosurgical treatment of a meningioma. A 74-year-old patient with a sporadic meningioma underwent radiosurgery following surgical removal of a WHO grade II meningioma. Eighteen months later she presented with seizures, and MRI revealed an intraaxial tumor, which was resected and proven to be a glioblastoma. As far as the authors are aware, this case represents the third case of GBM following SRS for a meningioma. This report serves to increase the awareness of this possible complication following SRS. The possibility of this rare complication should be explained to patients when obtaining their consent for radiosurgery.