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Introduction: Subdural haematomas (SDHs), acute or chronic, are common neurosurgical diagnoses. These problems can occur among patients requiring direct oral anticoagulation (DOAC) for atrial fibrillation. There are currently no guidelines regarding the optimal timing to resume anticoagulation for these patients after SDH. The objective of this study is to evaluate the feasibility of conducting a future large randomised controlled trial (RCT) evaluating the safety and efficacy of resuming DOACs early (ie, at 30 days) vs late (ie, at 3 months) for patients with atrial fibrillation following diagnosis of SDH., Methods and Analysis: This is a pilot, open-label, multicentre RCT that will enrol adults with newly diagnosed acute or chronic SDH with or without other intracranial bleeding who were receiving therapeutic anticoagulation with a DOAC as stroke prophylaxis for atrial fibrillation. Patients will be randomly allocated to resume a DOAC at standard dosing starting either days 30+7 or days 90±14. The primary outcomes for the pilot RCT are recruitment rate, protocol adherence and patient compliance with the randomly allocated interventions. Secondary outcomes are patient functional outcomes and safety and effectiveness outcomes, which will comprise key endpoints for the future planned RCT. This pilot RCT will provide important data to inform the feasibility of conducting a future, large RCT of early versus late resumption of DOACs for atrial fibrillation stroke prophylaxis in patients newly diagnosed with SDH. The future RCT will help inform management of a commonly encountered clinical dilemma with high associated morbidity and mortality., Ethics and Dissemination: This study has been approved by the research ethics board of record. It will be conducted in accordance with the Declaration of Helsinki, Good Clinical Practice guidelines and regulatory requirements. Informed consent will be obtained from eligible patients or substitute decision-makers. Data from this study will inform the design of future, larger RCTs., Trial Registration Number: NCT05472766., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

This case illustrates the utility and impact of molecular testing and molecular tumor board discussion in the management of AYA patients with brain tumors.

Purpose: The optimal modern radiation therapy (RT) approach after surgery for atypical and malignant meningioma is unclear. We present results of dose escalation in a single-institution cohort spanning 2000 to 2021., Methods and Materials: Consecutive patients with histopathologic grade 2 or 3 meningioma treated with RT were reviewed. A dose-escalation cohort (≥66 Gy equivalent dose in 2-Gy fractions using an α/β = 10) was compared with a standard-dose cohort (<66 Gy). Outcomes were progression-free survival (PFS), cause-specific survival, overall survival (OS), local failure (LF), and radiation necrosis., Results: One hundred eighteen patients (111 grade 2, 94.1%) were identified; 54 (45.8%) received dose escalation and 64 (54.2%) standard dose. Median follow-up was 45.4 months (IQR, 24.0-80.0 months) and median OS was 9.7 years (Q1: 4.6 years, Q3: not reached). All dose-escalated patients had residual disease versus 65.6% in the standard-dose cohort (P < .001). PFS at 3, 4, and 5 years in the dose-escalated versus standard-dose cohort was 78.9%, 72.2%, and 64.6% versus 57.2%, 49.1%, and 40.8%, respectively, (P = .030). On multivariable analysis, dose escalation (hazard ratio [HR], 0.544; P = .042) was associated with improved PFS, whereas ≥2 surgeries (HR, 1.989; P = .035) and older age (HR, 1.035; P < .001) were associated with worse PFS. The cumulative risk of LF was reduced with dose escalation (P = .016). Multivariable analysis confirmed that dose escalation was protective for LF (HR, 0.483; P = .019), whereas ≥2 surgeries before RT predicted for LF (HR, 2.145; P = .008). A trend was observed for improved cause-specific survival and OS in the dose-escalation cohort (P < .1). Seven patients (5.9%) developed symptomatic radiation necrosis with no significant difference between the 2 cohorts., Conclusions: Dose-escalated RT with ≥66 Gy for high-grade meningioma is associated with improved local control and PFS with an acceptable risk of radiation necrosis., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background and Objectives: Virtual reality (VR) surgical rehearsal is an educational tool that exists in a safe environment. Validation is necessary to establish the educational value of this platform. The middle cranial fossa (MCF) is ideal for simulation because trainees have limited exposure to this approach and it has considerable complication risk. Our objectives were to assess the face, content, and construct validities of an MCF VR simulation, as well as the change in performance across serial simulations., Methods: Using high-resolution volumetric data sets of human cadavers, the authors generated a high-fidelity visual and haptic rendering of the MCF approach using CardinalSim software. Trainees from Neurosurgery and Otolaryngology-Head and Neck Surgery at two Canadian academic centers performed MCF dissections on this VR platform. Randomization was used to assess the effect of enhanced VR interaction. Likert scales were used to assess the face and content validities. Performance metrics and pre- and postsimulation test scores were evaluated. Construct validity was evaluated by examining the effect of the training level on simulation performance., Results: Twenty trainees were enrolled. Face and content validities were achieved in all domains. Construct validity, however, was not demonstrated. Postsimulation test scores were significantly higher than presimulation test scores ( P < .001 ). Trainees demonstrated statistically significant improvement in the time to complete dissections ( P < .001 ), internal auditory canal skeletonization ( P < .001 ), completeness of the anterior petrosectomy ( P < .001 ), and reduced number of injuries to critical structures ( P = .001 )., Conclusion: This MCF VR simulation created using CardinalSim demonstrated face and content validities. Construct validity was not established because no trainee included in the study had previous MCF approach experience, which further emphasizes the importance of simulation. When used as a formative educational adjunct in both Neurosurgery and Otolaryngology-Head and Neck Surgery, this simulation has the potential to enhance understanding of the complex anatomic relationships of critical neurovascular structures., (Copyright © Congress of Neurological Surgeons 2023. All rights reserved.)

Background: Duret hemorrhage is a rare phenomenon wherein rapid transtentorial herniation results in brainstem injury and hemorrhage. It is usually regarded as a poor prognostic factor representing irreversible and often catastrophic brain injury. The authors report an unusual case of Duret hemorrhage with spontaneous delayed neurological recovery postoperatively after surgical treatment of an acute subdural hematoma (SDH)., Observations: The authors present the case of a 65-year-old male who initially presented to the hospital with a large acute left-sided SDH causing 1.3 cm of midline shift. He was taken urgently for a craniotomy, with no significant intraoperative swelling or visible contusions. Postoperative imaging revealed an unexpected pontine hyperdensity concerning for a Duret hemorrhage. He initially had no neurological improvement; however, at 3 weeks postoperatively, he gradually recovered and was able to follow commands and was extubated. At 10 weeks after surgery, his Glasgow Coma Scale score improved to 15, with mild residual left hemiparesis., Lessons: This case challenges a classic dogma that Duret hemorrhage carries a universally poor outcome. In select cases, patients can make meaningful recoveries in a delayed fashion. The lack of intraoperative contusions and swelling may have contributed to this patient's recovery.

Mesenchymal Stem Cells (MSCs) are non-hematopoietic and multipotent stem cells, which have been considered in regenerative medicine. These cells are easily separated from different sources, such as bone marrow (BM), umbilical cord (UC), adipose tissue (AT), and etc. MSCs have the differentiation capability into chondrocytes, osteocytes, and adipocytes; This differentiation potential along with the paracrine properties have made them a key choice for tissue repair. MSCs also have various advantages over other stem cells, which is why they have been extensively studied in recent years. The effectiveness of MSCs-based therapies depend on several factors, including differentiation status at the time of use, concentration per injection, delivery method, the used vehicle, and the nature and extent of the damage. Although, MSCs have emerged promising sources for regenerative medicine, there are potential risks regarding their safety in their clinical use, including tumorigenesis, lack of availability, aging, and sensitivity to toxic environments. In this study, we aimed to discuss how MSCs may be useful in treating defects and diseases. To this aim, we will review recent advances of MSCs action mechanisms in regenerative medicine, as well as the most recent clinical trials. We will also have a brief overview of MSCs resources, differences between their sources, culture conditions, extraction methods, and clinical application of MSCs in various fields of regenerative medicine., (© 2023 American Institute of Chemical Engineers.)

Malignant peripheral nerve sheath tumors of the cerebellopontine angle are rare, especially even outside of the context of neurofibromatosis or malignant transformation of previously radiated vestibular schwannomas. This case report describes a case of a presumed vestibular schwannoma without previous radiation or history of neurofibromatosis presenting with progressive hearing loss, facial weakness, growth, and ultimately catastrophic hemorrhage requiring urgent surgery. Histopathology revealed an exceptionally rare malignant peripheral nerve sheath tumor with divergent mesenchymal (chondrosarcomatous) differentiation with few rigorously interrogated cases in the literature. In retrospect, facial weakness, growth, and early intratumoral hemorrhage were harbingers of atypical malignant pathology. We advocate for a heightened index of suspicion, shorter interval follow-up, and consideration of early surgery in such cases in hopes of preventing potentially catastrophic outcomes.

Background: Virtual reality simulation has gained prominence as a valuable surgical rehearsal and education tool in neurosurgery. Approaches to the internal auditory canal, cerebellopontine angle, and ventral brainstem region using the middle cranial fossa are not well explored by simulation., Objective: We hope to contribute to this paucity in simulation tools devoted to the lateral skull base, specifically the middle cranial fossa approach., Methods: Eight high-resolution microcomputed tomography scans of human cadavers were used as volumetric data sets to construct a high-fidelity visual and haptic rendering of the middle cranial fossa using CardinalSim software. Critical neurovascular structures related to this region of the skull base were segmented and incorporated into the modules., Results: The virtual models illustrate the 3-dimensional anatomic relationships of neurovascular structures in the middle cranial fossa and allow a realistic interactive drilling environment. This is facilitated by the ability to render bone opaque or transparent to reveal the proximity to critical anatomy allowing for practice of the virtual dissection in a graduated fashion., Conclusion: We have developed a virtual library of middle cranial fossa approach models, which integrate relevant neurovascular structures with aims to improve surgical training and education. A ready extension is the potential for patient-specific application and pathology., (Copyright © Congress of Neurological Surgeons 2022. All rights reserved.)

There is an increasing number of trauma patients presenting on pre-injury antiplatelet (AP) agents attributable to an aging population and expanding cardio- or cerebrovascular indications for antithrombotic therapy. The effects of different AP regimens on outcomes after traumatic brain injury (TBI) have yet to be elucidated, despite the implications on patient/family counseling and the potential need for better reversal strategies. The goal of this systematic review and meta-analysis was to assess the impact of different pre-injury AP regimens on outcomes after TBI. In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the OVID Medline, Embase, BIOSIS, Scopus, and Cochrane databases were searched from inception to February 2022 using a combination of terms pertaining to TBI and use of AP agents. Baseline demographics and study characteristics as well as outcome data pertaining to intracerebral hematoma (ICH) progression, need for neurosurgical intervention, hospital length of stay, mortality, and functional outcome were extracted. Pooled odds ratios (ORs) and mean differences comparing groups were calculated using random-effects models. Thirteen observational studies, totaling 1244 patients receiving single AP therapy with acetylsalicylic acid or clopidogrel, 413 patients on dual AP therapy, and 3027 non-AP users were included. No randomized controlled trials were identified. There were significant associations between dual AP use and ICH progression (OR, 2.81; 95% confidence interval [CI], 1.19-6.61; I 2 , 85%; p  = 0.02) and need for neurosurgical intervention post-TBI (OR, 1.61; 95% CI, 1.15-2.28; I 2 , 15%; p  = 0.006) compared to non-users, but not between single AP therapy and non-users. There were no associations between AP use and hospital length of stay or mortality after trauma. Pre-injury dual AP use, but not single AP use, is associated with higher rates of ICH progression and neurosurgical intervention post-TBI. However, the overall quality of studies was low, and this association should be further investigated in larger studies., Competing Interests: F.A.Z. receives research support from the Manitoba Public Insurance (MPI) Neuroscience/TBI Research Endowment; the Health Sciences Centre Foundation Winnipeg; the Canada Foundation for Innovation (CFI; Project No.: 38583); Research Manitoba (Grant No.: 3906); the University of Manitoba VPRI Research Investment Fund (RIF); and the University of Manitoba Rudy Falk Clinician-Scientist Professorship. D.C.S. holds operating grants from the Canadian Institute for Health Research., (© François Mathieu et al., 2022; Published by Mary Ann Liebert, Inc.)

Background: High-grade gliomas are the most common primary malignant brain tumor in adults having a median survival of only 13-16 months. This is despite the current standard of maximal safe surgical resection followed by fractionated radiotherapy and chemotherapy. Extending the tumor resection limit beyond the gadolinium (GAD)-enhancing margin (i.e., supra-marginal resection) could in principle provide an added survival benefit as it has been shown that > 80% of post-operative tumor recurrence is within a 2-cm region surrounding the original GAD-enhancing margin. However, this must be weighed against the risk of potential damage to functional brain tissue., Methods: In this phase II pilot randomized control trial (RCT), we aim to assess the feasibility of "supra-marginal" resection extending 1 cm beyond the enhancing tumor in adults with radiographic evidence of GAD-enhancing intra-axial tumor consistent with high-grade glioma in a safe anatomical location and a Karnofsky Performance Score > 60. With six academic institutions with established neurosurgical oncology practices in participation, we aim to enroll 72 patients over 2 years. Primary outcomes include evaluating the feasibility of performing a large-scale trial with regard to recruitment, allocation, and outcome documentation as well as safety data. Secondary outcomes include determining if there is an increased survival benefit with supra-marginal resection and impact on quality of life (Modified Rankin Scale (mRS), EuroQol-5D (ED-5D), 30-day all-cause mortality)., Discussion: Recent studies have revealed survival advantages comparing supra-marginal resection to standard attempt at gross total resection (GTR) with no additional perioperative surgical risk; however, the current quality of evidence is low and under-powered. Therefore, there are no current practice guidelines, and the philosophy of surgical resection is guided by individual surgeon preferences on an individual patient basis. This creates additional uncertainty and is potentially detrimental to our patients. This clinical equipoise supports the need for an adequately powered RCT to determine whether a supra-marginal resection can have a positive impact on survival for patients with HGGs. Our pilot RCT will test the feasibility of comparing the standard gross total resection of GAD-enhancing tumors and supra-marginal resection to prepare for a larger definitive multicenter RCT., Trial Registration: ClinicalTrials.gov , NCT04737577. Registered on February 4, 2021., (© 2022. The Author(s).)

Objective: Meningiomas can have significant impact on health-related quality of life (HRQOL). Patient-centered, disease-specific instruments for assessing HRQOL in these patients are lacking. To this end, the authors sought to develop and validate a meningioma-specific HRQOL questionnaire through a standardized, patient-centered questionnaire development methodology., Methods: The development of the questionnaire involved three main phases: item generation, item reduction, and validation. Item generation consisted of semistructured interviews with patients (n = 30), informal caregivers (n = 12), and healthcare providers (n = 8) to create a preliminary list of items. Item reduction with 60 patients was guided by the clinical impact method, multiple correspondence analysis, and hierarchical cluster analysis. The validation phase involved 162 patients and collected evidence on extreme-groups validity; concurrent validity with the SF-36, FACT-Br, and EQ-5D; and test-retest reliability. The questionnaire takes on average 11 minutes to complete., Results: The meningioma-specific quality-of-life questionnaire (MQOL) consists of 70 items representing 9 domains. Cronbach's alpha for each domain ranged from 0.61 to 0.91. Concurrent validity testing demonstrated construct validity, while extreme-groups testing (p = 1.45E-11) confirmed the MQOL's ability to distinguish between different groups of patients., Conclusions: The MQOL is a validated, reliable, and feasible questionnaire designed specifically for evaluating QOL in meningioma patients. This disease-specific questionnaire will be fundamentally helpful in better understanding and capturing HRQOL in the meningioma patient population and can be used in both clinical and research settings.

The surgical management of diffuse low-grade gliomas (DLGGs) has undergone a paradigm shift toward striving for maximal safe resection when feasible. While extensive observational data supports this transition, unbiased evidence in the form of high quality randomized-controlled trials (RCTs) is lacking. Furthermore, despite a high volume of molecular, genetic, and imaging data, the field of neuro-oncology lacks personalized care algorithms for individuals with DLGGs based on a robust foundation of evidence. In this manuscript, we (1) discuss the logistical and philosophical challenges hindering the development of surgical RCTs for DLGGs, (2) highlight the potential impact of well-designed international prospective observational registries, (3) discuss ways in which cutting-edge computational techniques can be harnessed to generate maximal insight from high volumes of multi-faceted data, and (4) outline a comprehensive plan of action that will enable a multi-disciplinary approach to future DLGG management, integrating advances in clinical medicine, basic molecular research and large-scale data mining., (Copyright © 2020 Brar, Hachem, Badhiwala, Mau, Zacharia, Moraes, Pirouzmand and Mansouri.)

Background: Chronic subdural hematoma (cSDH) is an increasingly common condition due to the growing use of anticoagulation. Currently, there remains a lack of evidence to guide the optimal timing of anticoagulant reinitiation for stroke prevention in atrial fibrillation after cSDH evacuation. We aimed to better understand the perceived risks of hemorrhagic and embolic complications along with current practice patterns on restarting anticoagulation after surgical evacuation of cSDH., Methods: We conducted a survey of Canadian neurosurgeons and stroke neurologists using a novel self-administered questionnaire using clinical cases that included questions on clinical experience, practice setting, practice patterns, and perceptions on stroke/bleeding risk with anticoagulation reinitiation after cSDH evacuation. The instrument was evaluated for clinical sensibility by 5 neurosurgeons, neurologists, and intensivists., Results: The response rate after 4 mailings was 40% for neurosurgeons (55/136) and 21% for stroke neurologists (26/122). Almost all participants would restart anticoagulation for stroke prevention in atrial fibrillation after cSDH evacuation (91.8% in low-risk patients, 98.6% in high-risk patients). Time to reinitiation of anticoagulation varied considerably, particularly for high-risk patients where 36% of participants would restart anticoagulation within 1 week of surgery, 44% between 1 and 4 weeks after surgery, and 19% after 4 weeks postoperatively. The perceived risk of stroke and SDH reaccumulation varied considerably among participants and was dependent on timing of anticoagulation reinitiation., Conclusions: There is considerable variation in current practice patterns and perceived risks of embolic and hemorrhagic complications with anticoagulation reinitiation after cSDH evacuation. These results demonstrate clinical equipoise that warrant further targeted investigation in large-scale randomized controlled trials., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Patients with neurofibromatosis type 2 develop bilateral vestibular schwannomas with progressive hearing loss. Auditory brainstem implants (ABIs) stimulate hearing in the cochlear nuclei and show promise in improving hearing. Here, we assess the impact of ABI on hearing over time by systematically reviewing the literature and re-analyzing available individual patient data., Methods: A multidatabase search identified 3 studies with individual patient data of longitudinal hearing outcomes after ABI insertion in adults. Data were collected on hearing outcomes of different sound complexities from sound to speech using an ABI ± lip reading ability plus demographic data. Because of heterogeneity each study was analyzed separately using random effects multilevel mixed linear modeling., Results: Across all 3 studies (n = 111 total) there were significant improvements in hearing over time from ABI placement (P < 0.000 in all). Improvements in comprehension of sounds, words, sentences, and speech occurred over time with ABI use + lip reading but lip reading ability did not improve over time. All categories of hearing complexity had over 50% comprehension after over 1 year of ABI use and some subsets had over 75% or near 100% comprehension. Vowel comprehension was greater than consonant, and word comprehension was greater than sentence comprehension (P < 0.0001 in both). Age and sex did not predict outcomes., Conclusions: ABIs improve hearing beyond lip reading alone, which represents baseline patient function prior to treatment, and the benefits continue to improve with time. These findings may be used to guide patient counseling regarding ABI insertion, rehabilitation course after insertion, and future studies., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Objectives: Venous thromboembolism (VTE) is a serious complication following severe traumatic brain injury (TBI), however, anticoagulant prophylaxis remains controversial due to concerns of intracranial hemorrhage (ICH) progression. We examined anticoagulant prophylaxis practice patterns at a major trauma centre and determined risk estimates for VTE and ICH progression classified by timing of anticoagulant initiation., Patients and Methods: A 1-year prospective analysis of consecutive patients with severe TBI admitted to a Level-I trauma centre was conducted. In addition, we systematically reviewed the literature to identify studies on VTE and anticoagulant prophylaxis after severe TBI., Results: 64 severe TBI patients were included. 83% of patients received anticoagulant prophylaxis, initiated ≥3d post-TBI in 67%. The in-hospital VTE incidence was 16% and there was no significant difference between patients who received early (<3d) versus late (≥3d) prophylaxis (10% vs. 16%). Rates of ICH progression (0% vs. 7%) were similar between groups. Our systematic review identified 5 studies with VTE rates ranging from 5 to 10% with prophylaxis, to 11-30% without prophylaxis. The effect of timing of anticoagulant prophylaxis initiation on ICH progression was not reported in any study., Conclusion: VTE is a common complication after severe TBI. Anticoagulant prophylaxis is often started late (≥3d) post-injury. Randomized trials are justifiable and necessary to provide practice guidance with regards to optimal timing of anticoagulant prophylaxis., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Somatosensory evoked potentials (SSEPs) are used for neuroprognosis after severe traumatic brain injury (TBI). However decompressive craniectomy (DC), involving removal of a portion of the skull to alleviate elevated intracranial pressure, is associated with an increase in SSEP amplitude. Accordingly, SSEPs are not available for neuroprognosis over the hemisphere with DC. We aim to determine the degree to which SSEP amplitudes are increased in the absence of cranial bone. This will serve as a precursor for translation to clinically prognostic ranges. Intra-operative SSEPs were performed before and after bone flap replacement in 22 patients with severe TBI. SSEP measurements were also performed in a comparison non-traumatic group undergoing craniotomy for tumor resection. N20/P25 amplitudes and central conduction time were measured with the bone flap in (BI) and out (BO). Linear regressions, adjusting for skull thickness and study arm, were performed to evaluate the contribution of bone presence to SSEP amplitudes. Latencies were not different between BO or BI trials in either group. Mean N20/P25 amplitudes recorded with BO were statistically different (p = 0.0001) from BI in both cohorts, showing an approximate doubling in BO amplitudes. For contralateral-ipsilateral montages r 2 was 0.28 and for frontal pole montages r 2 was 0.62. Cortical SSEP amplitudes are influenced by the presence of cortical bone as is particularly evident in frontal pole montages. Larger, longitudinal trials to assess feasibility of neuroprognosis over the hemisphere with DC in severe TBI patients are warranted.

Dural sinus thrombosis is a well-recognized and potentially serious complication following lateral skull base surgery. Methods of diagnosis are limited to post-operative computerized tomography scans or magnetic resonance venography. There are currently no reports of an intraoperative technique used to detect dural sinus thrombosis. Here, we describe the case of a 62-year-old woman who underwent translabyrinthine resection of a right vestibular schwannoma with no evidence of sinus thrombosis on pre-operative scans. Following tumor resection, patency of the sigmoid sinus was assessed intraoperatively using indocyanine green (ICG) videography which revealed a lack of flow in the right sigmoid sinus. Postoperative CT scan confirmed thrombosis of the right sigmoid sinus. We present the first report of real-time intraoperative diagnosis of sigmoid sinus thrombosis during removal of a vestibular schwannoma. ICG videography may be used for intraoperative visualization of dural sinus integrity and patency during prolonged or technically challenging microsurgical procedures. This technique may enable periodic monitoring and early identification of filling defects which can guide further intraoperative strategies and postoperative monitoring., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: The rates of clinical and radiographic progression and the need for neurosurgical intervention in patients with isolated traumatic subarachnoid hemorrhage (itSAH) after mild traumatic brain injury (Glasgow Coma Scale score, 13-15) has not been well established.The aim of this work was to review the evidence regarding patient outcomes after mild traumatic brain injury with itSAH., Methods: Two authors independently extracted the data according to a predefined protocol. The proportions of patients who had the outcomes of interest were pooled using random-effects model. The quality of included studies was assessed using the methodological index for nonrandomized studies scale., Results: Thirteen studies reporting on 15,327 patients met inclusion criteria, and outcomes were pooled where available. No patient required neurosurgical intervention on presentation to hospital, and the incidence of need for eventual neurosurgical intervention was 0.0017% (95% confidence interval [CI], 0-0.39%). Moreover, the pooled analyses for all patients with available data showed an incidence of 5.76% (95% CI, 1.18-12.94%) for radiographic progression, 0.75% (95% CI, 0-2.39%) for neurologic deterioration, and 0.60% (95% CI, 0.09-1.41%) for mortality. Only one patient had died due to neurological injury., Conclusions: These patients experience very low rates of radiographic progression and neurologic deterioration and rarely require neurosurgical intervention or die due to neurological injury., Level of Evidence: Meta-analysis, level III.

Background: Citation classics represent the highest cited works in a field and are often regarded as the most influential literature. Analyzing thematic trends in citation classics across eras enables recognition of important historical advances within a field. We present the first analysis of the citation classics in neuro-oncology., Methods: The Web of Science database was searched using terms relevant to "neuro-oncology." Articles with >400 citations were identified and the top 100 cited articles were evaluated., Results: The top 100 neuro-oncology citation classics consisted of 43 clinical studies (17 retrospective, 10 prospective, 16 randomized trials), 43 laboratory investigations, 8 reviews/meta-analyses, and 6 guidelines/consensus statements. Articles were classified into 4 themes: 13 pertained to tumor classification, 37 to tumor pathogenesis/clinical presentation, 6 to imaging, 44 to therapy (15 chemotherapy, 10 radiotherapy, 5 surgery, 14 new agents). Gliomas were the most common tumor type examined, with 70 articles. There was a significant increase in the number of citation classics in the late 1990s, which was paralleled by an increase in studies examining tumor pathogenesis, chemotherapy, and new agents along with laboratory and randomized studies., Conclusions: The majority of citation classics in neuro-oncology are related to gliomas and pertain to tumor pathogenesis and treatment. The rise in citation classics in recent years investigating tumor biology, new treatment agents, and chemotherapeutics may reflect increasing scientific interest in nonsurgical treatments for CNS tumors and the need for fundamental investigations into disease processes., (© The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com)

Lumbar discal cysts are rare entities causing radicular pain with unknown etiologies. We report a case of a 42-year-old man who developed radiculopathy secondary to a lumbar discal cyst. Our case sheds some light on anatomy, possible etiological association and clinical course which can help management.

Background: Patients with severe traumatic brain injury (sTBI) are at high risk for developing venous thromboembolism (VTE). Nonetheless, pharmacologic VTE prophylaxis is often delayed out of concern for precipitating extension of intracranial hemorrhage (ICH). The purpose of this study was to compare the effectiveness of early vs late VTE prophylaxis in patients with sTBI, and to characterize the risk of subsequent ICH-related complication., Study Design: Adults with isolated sTBI (head Abbreviated Injury Scale score ≥3 and total Glasgow Coma Scale score ≤8) who received VTE prophylaxis with low-molecular-weight or unfractionated heparin were derived from the American College of Surgeons Trauma Quality Improvement Program (2012 to 2014). Patients were divided into EP (<72 hours) or LP (≥72 hours) groups. Propensity score matching was used to minimize selection bias. The primary end point was VTE (pulmonary embolism or deep vein thrombosis). Secondary outcomes were defined as late neurosurgical intervention (≥72 hours) or death., Results: We identified 3,634 patients with sTBI. Early prophylaxis was given in 43% of patients. Higher head injury severity, presence of ICH, and early neurosurgery were associated with late prophylaxis. Propensity score matching yielded a well-balanced cohort of 2,468 patients. Early prophylaxis was associated with lower rates of both pulmonary embolism (odds ratio = 0.48; 95% CI, 0.25-0.91) and deep vein thrombosis (odds ratio = 0.51; 95% CI, 0.36-0.72), but no increase in risk of late neurosurgical intervention or death., Conclusions: In this observational study of patients with sTBI, early initiation of VTE prophylaxis was associated with decreased risk of pulmonary embolism and deep vein thrombosis, but no increase in risk of late neurosurgical intervention or death. Early prophylaxis may be safe and should be the goal for each patient in the context of appropriate risk stratification., (Copyright © 2016 American College of Surgeons. Published by Elsevier Inc. All rights reserved.)

The purpose of this note is to describe an obtuse-angled laminotomy of C7 during cervical decompression that aims to preserve cervicothoracic junction stability and potentially reduce pain. Cervical spondylotic myelopathy can result from degenerative cervical spinal disease including, herniated disk material, osteophytes, redundant ligamentum flavum, or ossification of the posterior longitudinal ligament. Surgical intervention for multilevel myelopathy aims to decompress the spinal cord and maintain stability of the cervical spine. Multilevel laminectomy is traditionally used when degenerative changes affect 3 or more levels and when there is primarily dorsal compressive disease. Traditional laminectomy can result in instability and kyphosis. The C7 lamina can be particularly vulnerable given the location at cervicothoracic junction. We describe an obtuse-angled laminotomy for the most caudal lamina in a planned decompression. This lamina is left attached to ligamentum nuchea, adjacent fascia, and paravertebral muscles. Only the base of spinous process and ventral portion of lamina's cortical and cancellous bone are removed in an obtuse angle through the opening. This variation is aimed to preserve as much of the cervical stability while still achieving the goal of decompression.

Background: Bone flap re-approximation during cranioplasty can be complicated by underlying pseudomeningocele or meningoencephalocele. A technique for controlled reduction duraplasty to aid bone flap positioning is suggested., Methods: A simple method using bipolar electrocautery in a predetermined radial pattern from the center of defect is described. Localized tissue contraction allows controlled reduction in the surface area and degree of protrusion. This in turn facilitates bone flap positioning., Results: The main advantage of this technique is slow and evenly distributed pressure conferred by controlled tissue contraction using multiple radial coagulation lines. No technical difficulties or complications have occurred with this method during cranioplasty for 11 patients., Conclusion: This simple technique for controlled reduction duraplasty can provide an easy and efficient method for bone flap re-approximation, and add to the existing techniques for a commonly performed procedure.

Objectives/hypothesis: To evaluate percent maximum as an intraoperative facial nerve measurement for the long-term prognostication of vestibular schwannoma surgery., Study Design: Prospective cohort study., Methods: Evoked amplitude responses to varying levels of stimulus intensity at the nerve root were compared to their supramaximal responses (Mmax) as a percentage, that is, percent maximum. Response charts were constructed for each of the levels of stimulus intensity between 0.05 to 0.3 mA, vis-à-vis facial nerve outcome at 1 year, to establish sensitivities, specificities, and positive predictive values. Logistic regression analyses were used to determine the impact of sex, age, tumor size, and historically defined response parameter on outcomes., Results: Seventy-eight patients who underwent vestibular schwannoma surgeries between 2005 and 2010 were studied. The positive predictive value (PPV) of a good facial nerve outcome, defined as House-Brackmann (HB) I-II, increases with percent maximum responses. A 90% PPV could be established when the response amplitude was 50% or greater compared to Mmax. Long-term prognostication appeared best at a higher stimulus level of 0.3 mA. Age and sex did not have an impact on outcome, but tumor size did; with each centimeter increase in tumor size, patients were 105% more likely to have a poor outcome (HB III-VI). If the response parameter "≥240 μV at 0.05 mA" was not present, there was a trend toward poor outcome., Conclusions: Percent maximum is a valid intraoperative monitoring measure to prognosticate long-term facial nerve outcome. It should be considered a complementary method of monitoring when evoked responses do not conform to conventional predictors., Level of Evidence: 4., (Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.)

Purpose: Muscle twitch threshold has been used to determine optimal stimulus intensity for somatosensory evoked potentials but neuromuscular blockade precludes the use of muscle twitch during surgery. Accordingly, nerve action potential (NAP) amplitude was investigated as a surrogate to muscle twitch., Methods: The ulnar and tibial nerves were stimulated at the wrist and ankle, respectively, in 27 patients undergoing spine and brain surgery. After neuromuscular blockade was gone, the stimulus intensity for just maximal NAP amplitude recorded from Erb's point and the popliteal fossa was compared with the stimulus intensity for hypothenar and plantar foot muscle twitch threshold (times two), respectively (Wilcoxon matched pairs test)., Results: There was no significant difference between stimulus intensity for just maximal Erb's point and popliteal fossa NAP amplitude when compared with stimulus intensity for hypothenar and plantar foot twitch threshold (times two), respectively. Eight patients required more than twitch intensity (times two) to obtain maximum NAP., Conclusions: The NAP amplitude may be used to determine optimal somatosensory evoked potential stimulus intensity when muscle twitch is not visible. This method should improve the success of intraoperative somatosensory evoked potential monitoring and decrease erroneous interpretation.

Background: Computed tomogram (CT) imaging is often used for immediate postoperative assessment of transsphenoidal pituitary adenoma resection while magnetic resonance imaging (MRI) is used for follow-up. The residual mass is known to decrease in size over time but the difference between the two imaging modalities has not been quantified. Our objective was to quantify the size difference of the residual mass on immediate postoperative CT compared with delayed MRI., Methods: Retrospective analysis of 69 patients who had undergone pituitary adenoma resection at our institution between 2004-2010. Sellar and suprasellar diameter, along with the overall volume of the residual mass were measured on both the immediate postoperative CT and delayed MRI., Results: Average preoperative sellar and suprasellar diameter was 22.2 ± 4.6mm and 20.9 ± 5.9mm, respectively. Average sellar residual diameter on immediate postoperative CT (16.5 ± 5.4 mm, 25% reduction) was significantly larger than delayed MRI (10.6 ± 6.2mm, 52% reduction). The average suprasellar component on CT (15.5±6.5mm, 26% reduction) was also significantly larger than that on MRI (3.3 ± 5.4 mm, 84% reduction). The postoperative CT showed a 46% reduction in volume while a 71% reduction was noted on the delayed MRI., Conclusion: A significant reduction in residual mass is noted on delayed MR imaging compared with immediate postoperative CT. Therefore, from a resource management and prognostication point of view, CT should be used for immediate postoperative assessment while delayed MRI should be used to assess operative success and for communication with patients.

Background and Importance: Synovial sarcoma (SS) is a malignant soft-tissue tumor that rarely involves brachial plexus. The authors report a case of brachial plexus SS and review the relevant literature., Clinical Presentation: A 53-year-old woman presented with gradually enlarging right subclavicular mass over 5 years associated with sharp aching pain radiating down toward the radial 3 fingers. On examination, she had a corresponding firm mass in the supraclavicular region with a positive Tinel sign. There was no objective neurological deficit. She underwent partial excision of this mass without any further adjuvant radiation or chemotherapy. Pathology was consistent with SS., Conclusion: Lack of any recurrence in this case 6 years after incomplete excision with no adjuvant therapy suggests slow clinical course in some of these sarcomas.

Background: There has been a paucity of information on the epidemiology of traumatic optic neuropathy (TON). This study documents epidemiology of TON over 2 decades in the largest level I adult trauma center in Canada., Methods: Data on all the trauma patients admitted to Sunnybrook Health Sciences Centre from 1986 to 2007 were collected in a prospective database. The aggregate data on optic nerve injuries including demographic data, etiology, Injury Severity Score (ISS), and associated head and facial injuries were recorded. These were analyzed using univariate and multivariate techniques to summarize the association of different variables with TON., Results: During the study period, 0.4% of all trauma patients had TON. The respective demographics for TON group were as follows: male, 76%; median for age, 33.5 years; length of hospital stay, 14 days; ISS, 32; and case fatality, 14%. About two thirds of patients with TON had associated significant head injuries. Conversely, 2.3% of patients with head injury had TON. The relative incidence of TON per year has remained variable from 0% to 1.2%. Motorized vehicle accidents remained the main etiology of TON (63%), but fall had the highest relative frequency leading to TON. In univariate analysis, both ISS and significant head injury were associated with TON. In multivariate analysis, TON was associated with only nasoethmoid complex fractures and significant head injury., Conclusions: These data provide useful information on the frequency and etiologies of TON. It also highlights the importance of studies on better diagnostic tools for TON.

Object: This study documents the epidemiology of head injury over the course of 22 years in the largest Level I adult trauma center in Canada. This information defines the current state, changing pattern, and relative distribution of demographic factors in a defined group of trauma patients. It will aid in hypothesis generation to direct etiological research, administrative resource allocation, and preventative strategies., Methods: Data on all the trauma patients treated at Sunnybrook Health Sciences Centre (SHSC) from 1986 to 2007 were collected in a consecutive, prospective fashion. The authors reviewed these data from the Sunnybrook Trauma Registry Database in a retrospective fashion. The aggregate data on head injury included demographic data, cause of injury, and Injury Severity Score (ISS). The collected data were analyzed using univariate techniques to depict the trend of variables over years. The authors used the length of stay (LOS) and number of deaths per year (case fatality rate) as crude measures of outcome., Results: A total of 16,678 patients were treated through the Level I trauma center at SHSC from January 1986 to December 2007. Of these, 9315 patients met the inclusion criteria (ISS > 12, head Abbreviated Injury Scale score > 0). The median age of all trauma patients was 36 years, and 69.6% were male. The median ISS of the head-injury patients was 27. The median age of this group of patients increased by 12 years over the study period. Motorized vehicle accidents accounted for the greatest number of head injuries (60.3%) although the relative percentage decreased over the study period. The median transfer time of patients sustaining a head injury was 2.58 hours, and there was an approximately 45 minute improvement over the 22-year study period. The median LOS in our center decreased from 19 to 10 days over the study period. The average case fatality rate was 17.4% over the study period. In multivariate analysis, more severe injuries were associated with increased LOS as was increasing time from injury to hospital presentation. Age and injury severity were independently predictive of mortality., Conclusions: These data will provide useful information to guide future studies on the changing patterns of head injury, possible mechanisms of injury, and efficient resource allocation for management of this condition.

Introduction: This is the first case study to report on using stereotactic body radiotherapy as an alternative and novel treatment modality for embolization to reduce the risk of operative bleeding for a metastatic renal cell tumor., Case Presentation: A 58-year-old woman presented with an asymptomatic large 7-cm tumor on the parieto-occipital vertex of the skull. Given the location of this lesion along with its vascular histology, it was a challenge to provide safe and effective treatment using conventional management strategies., Conclusion: We report on a rare presentation of a metastatic renal cell cancer and the use of stereotactic body radiotherapy as an innovative radiation approach to deliver high-dose radiation safely to control this large aggressive and vascular metastasis. The success of this management strategy allowed for minimal intraoperative blood loss, and the patient continues with local control 1-year posttreatment.

Object: In this study the author documents the epidemiology of spine and spinal cord injuries (SCIs) over 2 decades at the largest Level I adult trauma center in Canada. He describes the current state of spine injuries (SIs), their changing patterns over the years, and the relative distribution of different demographic factors in a defined group of trauma patients., Methods: Data on all trauma patients admitted to Sunnybrook Health Sciences Centre between 1986 and 2006 were collected from the Sunnybrook Trauma Registry Database. Aggregate data on SIs and SCIs, including demographic information, etiology, severity of injuries (injury severity score [ISS]), and associated injuries, were recorded. The data were analyzed in a main category of spinal fracture and/or dislocation with or without SI and in two subgroups of patients with SIs, one encompassing all forms of SCIs and the other including only complete SCIs (CSCIs). Collected data were evaluated using univariate techniques to depict the trend of variables over the years. The number of deaths per year and the length of stay (LOS) were used as crude measures of outcome. Several multivariate analysis techniques, including Poisson regression, were used to model the frequency of death and LOS as functions of various trauma variables., Results: There were 12,192 trauma patients in the study period with 23.2% having SIs, 5.4% having SCIs, and 3% having CSCIs. The SCIs constituted 23.3% of all SIs. The respective characteristics of the SI, SCI, and CSCI groups were as follows: median age 36, 33, and 30 years; median LOS 18, 27, and 29 days; median ISS 29, 30, and 34; female sex ratio 34, 24, and 23%; and case fatality rate 16.7, 16.6, and 21%. Seventy-nine percent of patients had associated head injuries; conversely, 24% of patients with head injuries had SIs. The mean admission age of patients increased by approximately 10 years over the study period, from the early 30s to the early 40s. The relative incidence of SIs remained stable at approximately 23%, but the incidence of SCIs decreased approximately 40% over time to 4.5%. Motor vehicle accidents remained the principal etiology of trauma, although falling and violence became more frequent contributors of SIs. The average annual ISS remained stable over time, but the LOS was reduced by 50% in both the SI and SCI groups. Age, ISS, and SCIs were associated with a longer LOS. The case fatality rate remained relatively unchanged over time. Poisson analysis suggested that the presence of an SCI does not change the case fatality rate., Conclusions: Data in this analysis will provide useful information to guide future studies on changing SI patterns, possible etiologies, and efficient resource allocation for the management of these diseases.

Brain metastases usually occur secondary to lung, breast, unknown primary, melanoma, and colon cancers. A growing tumor in the brain is commonly associated with edema and increased intracranial pressure (ICP). Common signs and symptoms due to increased ICP or brain edema include headache, nausea, and vomiting. One of the main treatment modalities in the management of brain metastases is whole-brain radiation. However, increased ICP may lead to acute deterioration of the neurologic status due to development of radiation-induced edema. Therefore, alternative management options should be considered for these patients to avoid complications from whole-brain radiation treatment. We discuss the case of a brain metastases patient who presented with bradycardia induced by brain edema.

Objective: We describe a novel technique of cranioplasty using a vascularized mastoid bone flap in patients after translabyrinthine excision of vestibular schwannomas (VS). Postoperative outcomes in terms of pinna and postauricular deformity are evaluated., Study Design: Retrospective study., Setting: Tertiary referral center., Results: Seventeen patients underwent cranioplasty with bone flap after translabyrinthine VS excision. At minimum follow-up of 12 months, none had a cerebrospinal fluid (CSF) leak. The measured pinna projections between the operated and non-operated sides had a mean difference of 0.80 mm (+/-1.70), which is not statistically significant (p > 0.05). The mean depth of the postauricular depressions was 1.38 mm (+/-0.93). Over the same period, 10 patients underwent translabyrinthine VS surgery without cranioplasty. In this group, there was a significant difference of 4.71 mm (+/-1.53) in mean pinna underprojections on the operated sides compared with the non-operated sides. Compared with patients who have undergone cranioplasty, the retroauricular depressions were significantly deeper (p < 0.05) with a mean depth of 2.92 mm (+/-1.21)., Conclusions: Vascularized mastoid cortical bone flap cranioplasty is a simple and effective technique to ameliorate the pinna and retroauricular deformities after translabyrinthine VS excision without increased surgical cost or the use of alloplastic materials.