Bauman, Megan

Extracellular vesicles (EVs) are membrane-bound particles released by all cells. Previous research has found that these microscopic vesicles contribute to intercellular signaling and communication. EVs carry a variety of cargo, including nucleic acids, proteins, metabolites, and lipids. The composition of EVs varies based on cell of origin. Therefore, EVs can serve as an important biomarker in the diagnosis and treatment of various cancers. EVs derived from glioblastoma (GBM) cells carry biomarkers, which could serve as the basis for a potential diagnostic strategy known as liquid biopsy. Multiple EV isolation techniques exist, including ultrafiltration, size exclusion chromatography, flow field-flow fractionation, sequential filtration, differential ultracentrifugation, and density-gradient ultracentrifugation. Recent and ongoing work aims to identify cellular markers to distinguish GBM-derived EVs from those released by noncancerous cells. Strategies include proteomic analysis of GBM EVs, identification of GBM-specific metabolites, and use of Food and Drug Administration-approved 5-aminolevulinic acid—an oral agent that causes fluorescence of GBM cells—to recognize GBM EVs in a patient's blood. In addition, accurately and precisely monitoring changes in EV cargo concentrations could help differentiate between pseudoprogression and GBM recurrence, thus preventing unnecessary surgical interventions.

Abstract Background Hemangioblastomas pose an inherent surgical risk due to the potential for high intraoperative blood loss, especially in larger tumors. One approach to minimize this risk is to use preoperative embolization. Herein, we present our institutional experience treating large and giant cerebellar hemangioblastomas. Methods We performed a retrospective chart review of 19 patients with cerebellar hemangioblastomas that had a maximal diameter of >3 cm. We performed a literature review and included individual patient-level data that met our >3 cm diameter cerebellar hemangioblastoma inclusion criteria. Results Our cohort consisted of 19 patients that received a total of 20 resections for their cerebellar hemangioblastomas. Preoperative embolization was utilized in eight cases (38.1%). One patient experienced transient neurological complications after embolization (12.5%). Tumors of patients in the embolization group had larger median total, solid, and cystic volumes and were more likely to involve the cerebellopontine angle than those in the non-embolized group. Compared with non-embolized patients, embolized patients had less decrease in their hemoglobin, lower volumes of estimated blood loss, reduced rates of postoperative complications and permanent deficits, and greater instances of neurological improvement. The larger cohort (obtained from the combining our cohort with patients identified during a literature review) consisted of 99 patients with 39 receiving preoperative embolization. Conclusion It is important to examine individual patient characteristics when determining eligibility for preoperative embolization. However, improvements in endovascular techniques have made preoperative embolization a safe and effective procedure with minimal risks that can be performed in many patients.

OBJECTIVE At present, females constitute less than 10% of neurosurgeons in the US, despite representing approximately half of all medical students. Multiple barriers have been described for females entering the neurosurgical field, particularly academic neurosurgery. Understanding the environment that female neurosurgeons face and any potential barriers preventing career advancement is needed to recruit, promote, and retain females in neurosurgery. METHODS The gender composition of editorial boards for 5 high-impact neurosurgery journals was analyzed from 2000 to 2020. The names of editorial board members were obtained directly from the journal administration, physical copies of the published journal, or publicly available data through each journal’s website. The gender, degrees, academic titles, H-index, and country were determined for each individual and statistical tests were performed to identify significant differences. RESULTS Of the 466 identified individuals that served on at least one editorial board between 2000 and 2020, there were 36 females (7.7%) and 430 males (92.3%). There were no significant differences between males and females serving on multiple editorial boards. Most females possessed an additional graduate degree (58.3%), while only one-third of males (33.5%) obtained such a degree (p = 0.002). In addition, males had significantly higher average H-indices than females (p = 0.002). These trends were also observed when analyzing only US-based editorial board members. Although females were more likely overall to be identified as associate professors, males were more likely to be appointed as full professors (p = 0.001); this trend did not remain true in the US-based cohort. When analyzing the editorial boards for individual journals, all 5 journals experienced an increase of female representation since 2000 or since their inception after 2000. The highest proportion of females for a single journal was 27.3% in 2020. All other journals ranged from 11.0% to 13.5% in 2020. CONCLUSIONS When entering the field of neurosurgery, females continue to face significant social and academic barriers. While the proportion of females on editorial boards for neurosurgery journals in 2020 is consistent with the proportion of practicing female neurosurgeons, there is a statistically significantly higher likelihood that females possess additional graduate degrees and lower H-indices compared to their male counterparts. The authors encourage neurosurgical journals to continue expanding female representation on editorial boards.

Heparin-induced thrombocytopenia (HIT) is a prothrombotic state caused by autoantibodies against platelet factor 4 (PF4)-heparin complexes. Although HIT typically presents 5-10 days after the initiation of heparin, thrombosis and thrombocytopenia may occur up to several weeks following heparin withdrawal, so-called delayed-onset HIT. Although rare, there have been isolated reports of HIT-induced cerebral venous sinus thrombosis (CVST), which carry high rates of morbidity and mortality. There is a need to further characterize the etiology, clinical presentation, treatment paradigms, and outcomes of patients with HIT-induced CVST. Here, we present the case of a 57-year old female who presented to the emergency department with a headache and seizure 11 days following a right total knee arthroplasty for which she received 3 post-operative doses of enoxaparin. Work-up demonstrated acute intracerebral hemorrhage (ICH), CVST, and thrombocytopenia. Intravenous heparin resulted in rapidly deteriorating platelet count and subsequent serologic testing confirmed the diagnosis of HIT. Treatment with bivalirudin was initiated, the HIT resolved, and the patient was discharged home on hospital day 19 with long-term anticoagulation mediated by warfarin. At 3-month follow up, the patient had mild upper motor neuron pattern weakness and was living independently. This case depicts a rare case of delayed-onset HIT and CVST, highlights the importance of establishing a fluid treatment plan for managing HIT-induced CVST, and illustrates the importance of employing rapid anticoagulation despite acute ICH to achieve a desirable clinical outcome.