Interictal discharge traveling waves recorded from stereoelectroencephalography electrodes.

OBJECTIVE: Interictal epileptiform discharges (IEDs) are intermittent high-amplitude electrical signals that occur between seizures. They have been shown to propagate through the brain as traveling waves when recorded with epicortical grid-type electrodes and small penetrating microelectrode arrays. However, little work has been done to translate experimental IED analyses to more clinically relevant platforms such as stereoelectroencephalography (SEEG). In this pilot study, the authors aimed to define a computational method to identify and characterize IEDs recorded from clinical SEEG electrodes and leverage the directionality of IED traveling waves to localize the seizure onset zone (SOZ). METHODS: Continuous SEEG recordings from 15 patients with medically refractory epilepsy were collected, and IEDs were detected by identifying overlapping peaks of a minimum prominence. IED pathways of propagation were defined and compared to the SOZ location determined by a clinical neurologist based on the ictal recordings. For further analysis of the IED pathways of propagation, IED detections were divided into triplets, defined as a set of 3 consecutive contacts within the same IED detection. Univariate and multivariate linear regression models were employed to associate IED characteristics with colocalization to the SOZ. RESULTS: A median (range) of 22.6 (4.4-183.9) IEDs were detected per hour from 15 patients over a mean of 23.2 hours of recording. Depending on the definition of the SOZ, a median (range) of 20.8% (0.0%-54.5%) to 62.1% (19.2%-99.4%) of IEDs per patient traversed the SOZ. IEDs passing through the SOZ followed discrete pathways that had little overlap with those of the IEDs passing outside the SOZ. Contact triplets that occurred more than once were significantly more likely to be detected in an IED passing through the SOZ (p < 0.001). Per our multivariate model, patients with a greater proportion of IED traveling waves had a significantly greater proportion of IEDs that localized to the SOZ (ß = 0.64, 95% CI 0.01-1.27, p = 0.045). CONCLUSIONS: By using computational methods, IEDs can be meaningfully detected from clinical-grade SEEG recordings of patients with epilepsy. In some patients, a high proportion of IEDs are traveling waves according to multiple metrics that colocalize to the SOZ, offering hope that IED detection, with further refinement, could serve as an alternative method for SOZ localization.

Defining the Post-Operative Progression of Degenerative Scoliosis: An Analysis of Cases without Instrument Failure.

OBJECTIVE: The expected post-operative changes in radiographic alignment over time remain poorly defined in patients surgically treated for degenerative scoliosis without instrument failure. Here we aim to describe the optimal natural progression of radiographic degenerative scoliosis at multiple timepoints in patients treated with a transforaminal lumbar interbody fusion (TLIF). METHODS: We identified an initial retrospective cohort of 114 patients treated with a TLIF for degenerative scoliosis between 2018 and 2022, with 39 patients ultimately meeting the imaging inclusion criteria. Patients who completed a primary or revision procedure with no evidence of instrument failure, proximal junctional kyphosis, or proximal junctional failure at last follow-up were included. Radiographic measurements of spinopelvic alignment were manually extracted from X-Ray scoliosis films. RESULTS: Thirty-nine patients (mean age 62.6 ± 8.7, mean follow-up 2.9 years), of which 23 underwent a primary TLIF (Primary) and 16 a revision procedure (Revision), were analyzed. Patients in the Primary group experienced a durable improvement in Thoracolumbar Cobb angle (-25° ± 15°), Thoracic Kyphosis (10° ± 13°), and Pelvic Incidence/lumbar lordosis mismatch (PI/LL) (-19° ± 19°) through the first year of follow-up. In the Revision group, at one year follow-up, all measures of spinopelvic alignment except PI/LL mismatch had reverted to pre-operative levels. Thoracolumbar Cobb angle decreased to a significantly greater degree in the Primary group compared to the Revision group. CONCLUSION: Primary TLIF operations without instrument failure consistently improve radiographic outcomes in three key measures through the first year. For revision procedures, there appears to be modest radiographic benefit at follow-up.

Neurological Surgery Residency Programs in the United States: A National Cross-Sectional Survey.

BACKGROUND AND OBJECTIVES: The Accreditation Council for Graduate Medical Education has approved 117 neurological surgery residency programs which develop and educate neurosurgical trainees. We present the current landscape of neurosurgical training in the United States by examining multiple aspects of neurological surgery residencies in the 2022-2023 academic year and investigate the impact of program structure on resident academic productivity. METHODS: Demographic data were collected from publicly available websites and reports from the National Resident Match Program. A 34-question survey was circulated by e-mail to program directors to assess multiple features of neurological surgery residency programs, including curricular structure, fellowship availability, recent program changes, graduation requirements, and resources supporting career development. Mean resident productivity by program was collected from the literature. RESULTS: Across all 117 programs, there was a median of 2.0 (range 1.0-4.0) resident positions per year and 1.0 (range 0.0-2.0) research/elective years. Programs offered a median of 1.0 (range 0.0-7.0) Committee on Advanced Subspecialty Training-accredited fellowships, with endovascular fellowships being most frequently offered (53.8%). The survey response rate was 75/117 (64.1%). Of survey respondents, the median number of clinical sites was 3.0 (range 1.0-6.0). Almost half of programs surveyed (46.7%) reported funding mechanisms for residents, including R25, T32, and other in-house grants. Residents received a median academic stipend of $1000 (range $0-$10 000) per year. Nearly all programs (93.3%) supported wellness activities for residents, which most frequently occurred quarterly (46.7%). Annual academic stipend size was the only significant predictor of resident academic productivity (R 2 = 0.17, P = .002). CONCLUSION: Neurological surgery residency programs successfully train the next generation of neurosurgeons focusing on education, clinical training, case numbers, and milestones. These programs offer trainees the chance to tailor their career trajectories within residency, creating a rewarding and personalized experience that aligns with their career aspirations.

Advances and Evolving Challenges in Spinal Deformity Surgery.

BACKGROUND: Surgical intervention is a critical tool to address adult spinal deformity (ASD). Given the evolution of spinal surgical techniques, we sought to characterize developments in ASD correction and barriers impacting clinical outcomes. METHODS: We conducted a literature review utilizing PubMed, Embase, Web of Science, and Google Scholar to examine advances in ASD surgical correction and ongoing challenges from patient and clinician perspectives. ASD procedures were examined across pre-, intra-, and post-operative phases. RESULTS: Several factors influence the effectiveness of ASD correction. Standardized radiographic parameters and three-dimensional modeling have been used to guide operative planning. Complex minimally invasive procedures, targeted corrections, and staged procedures can tailor surgical approaches while minimizing operative time. Further, improvements in osteotomy technique, intraoperative navigation, and enhanced hardware have increased patient safety. However, challenges remain. Variability in patient selection and deformity undercorrection have resulted in heterogenous clinical responses. Surgical complications, including blood loss, infection, hardware failure, proximal junction kyphosis/failure, and pseudarthroses, pose barriers. Although minimally invasive approaches are being utilized more often, clinical validation is needed. CONCLUSIONS: The growing prevalence of ASD requires surgical solutions that can lead to sustained symptom resolution. Leveraging computational and imaging advances will be necessary as we seek to provide comprehensive treatment plans for patients.

FDA-approved machine learning algorithms in neuroradiology: A systematic review of the current evidence for approval.

Over the past decade, machine learning (ML) and artificial intelligence (AI) have become increasingly prevalent in the medical field. In the United States, the Food and Drug Administration (FDA) is responsible for regulating AI algorithms as "medical devices" to ensure patient safety. However, recent work has shown that the FDA approval process may be deficient. In this study, we evaluate the evidence supporting FDA-approved neuroalgorithms, the subset of machine learning algorithms with applications in the central nervous system (CNS), through a systematic review of the primary literature. Articles covering the 53 FDA-approved algorithms with applications in the CNS published in PubMed, EMBASE, Google Scholar and Scopus between database inception and January 25, 2022 were queried. Initial searches identified 1505 studies, of which 92 articles met the criteria for extraction and inclusion. Studies were identified for 26 of the 53 neuroalgorithms, of which 10 algorithms had only a single peer-reviewed publication. Performance metrics were available for 15 algorithms, external validation studies were available for 24 algorithms, and studies exploring the use of algorithms in clinical practice were available for 7 algorithms. Papers studying the clinical utility of these algorithms focused on three domains: workflow efficiency, cost savings, and clinical outcomes. Our analysis suggests that there is a meaningful gap between the FDA approval of machine learning algorithms and their clinical utilization. There appears to be room for process improvement by implementation of the following recommendations: the provision of compelling evidence that algorithms perform as intended, mandating minimum sample sizes, reporting of a predefined set of performance metrics for all algorithms and clinical application of algorithms prior to widespread use. This work will serve as a baseline for future research into the ideal regulatory framework for AI applications worldwide.

Deep Brain Stimulation Lead Localization Variability Comparing Intraoperative MRI Versus Postoperative Computed Tomography.

BACKGROUND AND OBJECTIVES: Commercially available lead localization software for deep brain stimulation (DBS) often relies on postoperative computed tomography (CT) scans to define electrode positions. When cases are performed with intraoperative MRI, another imaging set exists with which to perform these localizations. To compare DBS localization error between postoperative CT scans and intraoperative MRI. METHODS: A retrospective cohort of patients who underwent MRI-guided placement of DBS electrodes using the ClearPoint platform was identified. Using Brainlab Elements, postoperative CT scans were coregistered to intraoperative magnetic resonance images visualizing the ClearPoint guidance sheaths and ceramic stylets. DBS electrodes were identified in CT scans using Brainlab's lead localization tool. Trajectory and vector errors were quantified between scans for each lead in each patient. RESULTS: Eighty patients with a total of 157 implanted DBS electrodes were included. We observed mean trajectory and vector errors of 0.78 ± 0.44 mm (range 0.1-2.0 mm) and 1.57 ± 0.79 mm (range 0.2-4.2 mm), respectively, between postoperative CT and intraoperative MRI. There were 7 patients with CT scans collected at multiple time points. Trajectory error increased by 0.15 ± 0.42 mm ( P = .31), and vector error increased by 0.22 ± 0.53 mm ( P = .13) in the later scans. Across all scans, there was no significant association between trajectory ( P = .053) or vector ( P = .98) error and the date of CT acquisition. DBS electrodes targeting the subthalamic nucleus had significantly greater trajectory errors ( P = .02) than those targeting the globus pallidus pars internus nucleus. CONCLUSION: Commercially available software produced largely concordant lead localizations when comparing intraoperative MRIs with postoperative CT scans, with trajectory errors on average <1 mm. CT scans tend to be more comparable with intraoperative MRI in the immediate postoperative period, with increased time intervals associated with a greater magnitude of error between modalities.

Metastatic pituitary tumors: an institutional case series.

PURPOSE: Pituitary carcinomas are a rare entity that respond poorly to multimodal therapy. Patients follow a variable disease course that remains ill-defined. METHODS: We present an institutional case series of patients treated for pituitary carcinomas over a 30-year period from 1992 to 2022. A systematic review was conducted to identify prior case series of patients with pituitary carcinomas. RESULTS: Fourteen patients with a mean age at pituitary carcinoma diagnosis of 52.5 years (standard deviation [SD] 19.4) met inclusion criteria. All 14 patients had tumor subtypes confirmed by immunohistochemistry and hormone testing, with the most common being ACTH-producing pituitary adenomas (n = 12). Patients had a median progression-free survival (PFS) of 1.4 years (range 0.7-10.0) and a median overall survival (OS) of 8.4 years (range 2.3-24.0) from pituitary adenoma diagnosis. Median PFS and OS were 0.6 years (range 0.0-2.2) and 1.5 years (range 0.1-9.6) respectively upon development of metastases. Most patients (n = 12) had locally invasive disease to the cavernous sinus, dorsum sellae dura, or sphenoid sinus prior to metastasis. Common sites of metastasis included the central nervous system, liver, lung, and bone. In a pooled analysis including additional cases from the literature, treatment of metastases with chemotherapy or a combination of radiation therapy and chemotherapy significantly prolonged PFS (p = 0.02), while failing to significantly improve OS (p = 0.14). CONCLUSION: Pituitary carcinomas are highly recurrent, heterogenous tumors with variable responses to treatment. Multidisciplinary management with an experienced neuro-endocrine and neuro-oncology team is needed given the unrelenting nature of this disease.

Global, Regional, and National Economic Consequences of Stroke.

BACKGROUND: An understanding of global, regional, and national macroeconomic losses caused by stroke is important for allocation of clinical and research resources. The authors investigated the macroeconomic consequences of stroke disease burden in the year 2019 in 173 countries. METHODS: Disability-adjusted life year data for overall stroke and its subtypes (ischemic stroke, intracerebral hemorrhage, and subarachnoid hemorrhage) were collected from the GBD study (Global Burden of Disease) 2019 database. Gross domestic product (GDP, adjusted for purchasing power parity [PPP]) data were collected from the World Bank; GDP and disability-adjusted life year data were combined to estimate macroeconomic losses using a value of lost welfare (VLW) approach. All results are presented in 2017 international US dollars adjusted for PPP. RESULTS: Globally, in 2019, VLW due to stroke was $2059.67 billion or 1.66% of the global GDP. Global VLW/GDP for stroke subtypes was 0.78% (VLW=$964.51 billion) for ischemic stroke, 0.71% (VLW=$882.81 billion) for intracerebral hemorrhage, and 0.17% (VLW=$212.36 billion) for subarachnoid hemorrhage. The Central European, Eastern European, and Central Asian GBD super-region reported the highest VLW/GDP for stroke overall (3.01%), ischemic stroke (1.86%), and for subarachnoid hemorrhage (0.26%). The Southeast Asian, East Asian, and Oceanian GBD super-region reported the highest VLW/GDP for intracerebral hemorrhage (1.48%). CONCLUSIONS: The global macroeconomic consequences related to stroke are vast even when considering stroke subtypes. The present quantification may be leveraged to help justify increased spending of finite resources on stroke in an effort to improve outcomes for patients with stroke globally.

Utility of Expandable Interbody Cages in Open Transforaminal Interbody Fusions: A Comparison With Static Cages.

Background Expandable interbody cages, while popular in minimally invasive fusions due to their slim profile and increased ease of insertion, have not been widely explored in open surgery. The benefits of expandable cages may also extend to open fusions through their potential to achieve a greater restoration of lumbar lordosis while minimizing intraoperative complications. To highlight these benefits, we present a case series of adult spinal deformity (ASD) patients treated with an open transforaminal lumbar interbody fusion (TLIF) using expandable cages and compare outcomes to those of patients treated with static cages from the literature. Methods A retrospective cohort study of patients who underwent a deformity correction procedure and TLIF with expandable interbody cages at Brigham and Women's Hospital between 2018 and 2022 was conducted. Patient demographics, complications, and pre- and postoperative radiographic parameters of spinopelvic alignment were collected. A literature search was completed to identify studies employing static cages. T-tests were performed to compare postoperative changes in radiographic parameters by cage type. Results Forty-five patients (mean age of 62.6 years) with an average of 2.1 cages placed met the inclusion criteria. Patients experienced five intraoperative complications and 23 neurologic deficits (from minor to major), while nine patients required a revision operation. Lumbar lordosis increased by 9.8° ± 14.5° (p < 0.0001), the sagittal vertical axis (SVA) decreased by 25.5 mm ± 56.7 mm (p = 0.0048), and pelvic incidence-lumbar lordosis mismatch decreased by 13.3° ± 17.5° (p < 0.0001) with the use of expandable cages. Expandable cages yielded similar changes in lumbar lordosis to 15° and 8° cages but improved the lumbar lordosis generated from rectangular and 4° cages. When compared to static cages, expandable cages mildly reduced intraoperative complications. Conclusions Expandable interbody cages are an effective means of restoring spinopelvic alignment in ASD that have the potential to improve patient outcomes in open fusions compared to standard static cages. Especially when compared to rectangular and 4° static cages, expandable cages provide a clear benefit in the correction of lumbar lordosis. The impact of open spinal fusions with expandable cages on outcomes should continue to be explored in other cohorts.

Spinal Metastases from Colorectal Cancer at Mass General Brigham: A Twenty-Year Case Series With Literature Review.

OBJECTIVE: We present an institutional case series of patients treated for colorectal carcinoma (CRC) spinal metastases to investigate the outcomes between no treatment, radiation, surgery, and surgery/radiation. METHODS: A retrospective cohort of patients with CRC spinal metastases presenting to affiliated institutions between 2001 and 2021 wereidentified. Information related to patient demographics, treatment modality, treatment outcomes, symptom improvement, and survival was collected by chart review. Overall survival (OS) was compared between treatments by log-rank significance testing. A literature review was conducted to identify other cases series of CRC patients with spinal metastases. RESULTS: Eighty-nine patients (mean age 58.5) with CRC spinal metastases across a mean of 3.3 levels met inclusion criteria: 14 (15.7%) received no treatment, 11 (12.4%) received surgery alone, 37 (41.6%) received radiation alone, and 27 (30.3%) received both radiation and surgery. Patients treated with combination therapy had the longest median OS of 24.7 months (range 0.6-85.9), which did not significantly differ from the median OS of 8.9 months (range 0.2-42.6) observed in patients who received no treatment (P = 0.075). Combination therapy provided objectively longer survival time in comparison to other treatment modalities but failed to reach statistical significance. The majority of patients that received treatment (n = 51/75, 68.0%) experienced some degree of symptomatic or functional improvement. CONCLUSIONS: Therapeutic intervention has the potential to improve the quality of life in patients with CRC spinal metastases. We demonstrate that surgery and radiation are useful options for these patients, despite their lack of objective improvement in OS.

Integration of Veterans Affairs Medical Centers Into Neurosurgical Residency Programs.

Veterans Affairs (VA) medical centers serve as a unique training environment for US residency programs. In this study, we aim to explore the scope and details of VA integration into neurosurgery resident training. We used data from the Accreditation Council for Graduate Medical Education database to provide an overview of neurosurgery training programs with an active VA affiliation and developed a multi-institutional survey to gather information related to rotation design, operative volume, expectations, and core training values. Of the 116 neurosurgery residency programs, 40 have an active affiliation with a VA medical center (34%). Residents most frequently rotated at the VA during their third postgraduate year, with an average rotation length of 7.5 months (range 2-21). Nearly all programs reported a weekly mix of clinic and operative days (96%), with residents longitudinally following patients throughout their rotations. Attending neurosurgeons from VA-affiliated programs reported operative experience (100%), independent decision-making (89%), and continuity of care (81%) as core values of VA neurosurgery rotations. Surgical volume varied between programs with an average of 13.4 ± 6.4 (SD) cases per month per rotating resident. A significant portion of neurosurgery residency programs in the United States incorporate VA rotations into resident training. Although rotation details vary from program-to-program, shared values include a strong operative experience, independent decision-making, and continuity of care. This analysis provides a comprehensive assessment of VA rotation structure across the country, which is valuable for programs considering implementing a VA rotation into their training program or modifying an existing rotation.

Machine Learning in the Classification of Pediatric Posterior Fossa Tumors: A Systematic Review.

Background: Posterior fossa tumors (PFTs) are a morbid group of central nervous system tumors that most often present in childhood. While early diagnosis is critical to drive appropriate treatment, definitive diagnosis is currently only achievable through invasive tissue collection and histopathological analyses. Machine learning has been investigated as an alternative means of diagnosis. In this systematic review and meta-analysis, we evaluated the primary literature to identify all machine learning algorithms developed to classify and diagnose pediatric PFTs using imaging or molecular data. Methods: Of the 433 primary papers identified in PubMed, EMBASE, and Web of Science, 25 ultimately met the inclusion criteria. The included papers were extracted for algorithm architecture, study parameters, performance, strengths, and limitations. Results: The algorithms exhibited variable performance based on sample size, classifier(s) used, and individual tumor types being investigated. Ependymoma, medulloblastoma, and pilocytic astrocytoma were the most studied tumors with algorithm accuracies ranging from 37.5% to 94.5%. A minority of studies compared the developed algorithm to a trained neuroradiologist, with three imaging-based algorithms yielding superior performance. Common algorithm and study limitations included small sample sizes, uneven representation of individual tumor types, inconsistent performance reporting, and a lack of application in the clinical environment. Conclusions: Artificial intelligence has the potential to improve the speed and accuracy of diagnosis in this field if the right algorithm is applied to the right scenario. Work is needed to standardize outcome reporting and facilitate additional trials to allow for clinical uptake.

The current state of glioma data registries.

Background: The landscape of glioma research has evolved in the past 20 years to include numerous large, multi-institutional, database efforts compiling either clinical data on glioma patients, molecular data on glioma specimens, or a combination of both. While these strategies can provide a wealth of information for glioma research, obtaining information regarding data availability and access specifications can be challenging. Methods: We reviewed the literature for ongoing clinical, molecular, and combined database efforts related to glioma research to provide researchers with a curated overview of the current state of glioma database resources. Results: We identified and reviewed a total of 20 databases with data collection spanning from 1975 to 2022. Surveyed databases included both low- and high-grade gliomas, and data elements included over 100 clinical variables and 12 molecular data types. Select database strengths included large sample sizes and a wide variety of variables available, while limitations of some databases included complex data access requirements and a lack of glioma-specific variables. Conclusions: This review highlights current databases and registries and their potential utility in clinical and genomic glioma research. While many high-quality resources exist, the fluid nature of glioma taxonomy makes it difficult to isolate a large cohort of patients with a pathologically confirmed diagnosis. Large, well-defined, and publicly available glioma datasets have the potential to expand the reach of glioma research and drive the field forward.

The Relationship Among Surgeon Experience, Complications, and Radiographic Outcomes in Spine Deformity Surgery: The Experience of a Junior Surgeon.

OBJECTIVE: To examine complication rates and radiographic outcomes in patients undergoing surgery for adult spinal deformity (ASD) by a junior surgeon. METHODS: A study was conducted of a retrospective cohort of patients who underwent an open posterior interbody fusion of the thoracic and/or lumbar regions by a single surgeon for ASD between 2018 and 2022. Patient characteristics, complications, and common radiographic parameters of spinopelvic alignment were collated. RESULTS: A total of 112 patients with an average of 4.2 comorbidities underwent surgical correction of ASD. Thirty-seven patients (33.0%) experienced 52 major complications and 50 patients (44.6%) experienced 66 minor complications. Twenty-three patients (20.5%) required a revision operation. Both sagittal vertical axis (P < 10-14) and pelvic incidence-lumbar lordosis mismatch (P < 10-7) significantly improved postoperatively. Number of levels (P < 0.05), operative time >650 minutes (P < 0.01), estimated blood loss >1500 mL (P < 0.01), length of intensive care unit stay >1 day (P < 0.05), and hospitalization length >5 days (P < 0.05) all significantly increased the risk of a major complication. No patient factors significantly increased the risk of minor complications or revision surgery. CONCLUSIONS: Observed complication and revision rates in this cohort were consistent with rates reported in the literature. No preoperative patient risk factors significantly increased risk of complications or need for revision, suggesting that no patient population is at increased risk undergoing surgery by a junior surgeon. The relatively high rate of complications observed in this cohort may be a result of high baseline morbidity.

A national stratification of the global macroeconomic burden of central nervous system cancer.

OBJECTIVE: Country-by-country estimates of the macroeconomic disease burden of central nervous system (CNS) cancers are important when determining the allocation of resources related to neuro-oncology. Accordingly, in this study the authors investigated macroeconomic losses related to CNS cancer in 173 countries and identified pertinent epidemiological trends. METHODS: Data for CNS cancer incidence, mortality, and disability-adjusted life years (DALYs) were collected from the Global Burden of Disease 2019 database. Gross domestic product data were combined with DALY data to estimate economic losses using a value of lost welfare approach. RESULTS: The mortality-to-incidence ratio of CNS cancer in 2019 was 0.60 in high-income regions compared to 0.82 in Sub-Saharan Africa and 0.87 in Central Europe, Eastern Europe, and Central Asia. Welfare losses varied across both high- and low-income countries. Welfare losses attributable to CNS cancer in Japan represented 0.07% of the gross domestic product compared to 0.23% in Germany. In low- and middle-income countries, Iraq reported welfare losses of 0.20% compared to 0.04% in Angola. Globally, the DALY rate in 2019 was the same for CNS cancer as for prostate cancer at 112 per 100,000 person-years, despite a 75% lower incidence rate, equating to CNS cancer welfare losses of 182 billion US dollars. CONCLUSIONS: Macroeconomic losses vary across high- and low-income settings and appear to be region specific. These differences may be explained by differences in regional access to screening and diagnosis, population-level genetic predispositions, and environmental risk factors. Mortality-to-incidence ratios are higher in low- and middle-income countries than in high-income countries, highlighting possible gaps in treatment access. Quantification of macroeconomic losses related to CNS cancer can help to justify the spending of finite resources to improve outcomes for neuro-oncological patients globally.

Utility of a Pilot Neurosurgical Operative Skills Boot Camp in Medical Student Training.

OBJECTIVE: The neurosurgical sub-internship is a crucial step for prospective neurosurgeons. However, the expectations for sub-interns, particularly the technical skills required by residents and attendings, often are unclear. We present survey data on what medical students, residents, and attendings believe are important procedural proficiencies for neurosurgical sub-internships. We incorporated these tasks into a pilot skills-based craniotomy workshop, and here we report on the impact of the session on the neurosurgical training of medical students. METHODS: A 1-day craniotomy lab using cadaveric cranial specimens was conducted for medical students. Surveys querying important competencies for sub-internships were answered by residents and attendings at affiliated hospitals. Pre- and postlab surveys querying interest in and perceptions of neurosurgery, self-assessment of skills, and important competencies for sub-internship preparation were answered by attendees. RESULTS: Medical students, residents, and attendings agreed that burr-hole placement, bone replating, and galea and skin closure were of high importance for sub-interns. There was significant disagreement on the importance of dural opening and closure, establishing a craniotomy, and neuronavigation. The workshop altered perceptions of neurosurgery, with significant changes in recognizing the value of peer mentorship. Students also expressed increased confidence in technical skills, with significant improvements shown in understanding of neurosurgical high-speed drill use (P < 0.001). CONCLUSIONS: Although the expectations for sub-interns may be heterogeneous, there is general agreement that proficiency in the initial and final steps of craniotomies, as well as minor procedures, is recommended. Cadaveric labs can improve student engagement in neurosurgery, facilitate interactions with neurosurgical departments, and enhance technical skills.

"Recycling" A Failed Superficial Temporal Artery Indirect Bypass into a Double Barrel Direct Bypass in Moyamoya Disease.

OBJECTIVES: Moyamoya disease is an idiopathic cerebrovascular disorder in which patients experience recurrent transient ischemic attacks, ischemic or hemorrhagic strokes, headaches, and seizures from progressive stenosis of the vessels of the anterior circulation. The mainstay of treatment in symptomatic patients is surgical revascularization. Here, we present the case of a moyamoya patient in which a failed encephaloduroarteriosynangiosis, after new strokes, is recycled and converted into a combined "double barrel" direct superficial temporal artery to middle cerebral artery bypass with included video. CASE REPORT/RESULTS: We describe a 37-year-old woman with a history of hypertension, obstructive sleep apnea, celiac disease, and moyamoya disease complicated by multiple ischemic strokes who presented with progressive dysarthria, dysphagia, and new left-sided ischemic infarcts. The patient had previously undergone right-sided direct bypass and left-sided encephaloduroarteriosynangiosis in the setting of multiple ischemic strokes. After more strokes, the patient underwent a left-sided frontotemporoparietal craniotomy for conversion of the failed indirect bypass into a "double barrel" direct bypass. CONCLUSIONS: The literature is divided over which revascularization procedure should be preferred. Irrespectively, most failed bypass grafts are repaired via direct bypasses, to good effect. We highlight a case in which a failed indirect bypass is directly incorporated into a combined direct bypass with resulting restoration of blood flow. In the case of a failed indirect bypass in an adult patient with moyamoya disease, this method provides the operator with an additional option for restoration of perfusion, especially in patients without other viable vessels available for anastomosis.