OBJECTIVE: It is unknown whether efforts to expand access to neurosurgery worldwide have translated to an increase in the global neurosurgery workforce, particularly in low- and middle-income countries. The main objective of this study was to quantify the number and distribution of consultant neurosurgeons worldwide, while also identifying temporal and geographic trends in the neurosurgery workforce in different income levels and WHO regions, and analyzing what factors might contribute to the growth of a national workforce. METHODS: This study was a subanalysis of an electronic cross-sectional survey administered to participants identified through neurosurgery societies, personal contacts, and online searches of all 193 countries and 26 territories, independent states, and disputed regions as defined by the World Bank (WB) and United Nations between October 2022 and March 2023. Population-weighted statistics for the consultant neurosurgery workforce and resource availability were estimated, and linear regression analysis was conducted to identify correlations with growth in the workforce. RESULTS: Data were obtained for 192 countries (99.5%) and 25 additional territories, states, and disputed regions (96.2%). One hundred seventy-seven respondents participated in the survey. There were an estimated 72,967 neurosurgeons worldwide, representing a global pooled density of 0.93 neurosurgeons per 100,000 people and a median country density of 0.44 neurosurgeons per 100,000 people. The authors found an increasing density of consultant neurosurgeons, from low-income countries (0.12 per 100,000 people), to lower-middle-income countries (LoMICs; 0.37), to upper-middle-income countries (UpMICs; 1.13), and to high-income countries (2.44). The WHO African and Southeast Asia regions had the lowest pooled neurosurgeon density, while the Western Pacific region (WPR) had the highest density. There were 29 countries, 14 territories, and 1 independent state with no neurosurgeons. Neurosurgeons in countries with higher income–level designations had more frequent access to resources and equipment. The annual growth rates in workforce density were highest in LoMICs (26.0%) and UpMICs (21.3%), and the most rapid annual growth was in the Southeast Asia region (33.0%). Regression analysis revealed that an increasing population quartile, the Eastern Mediterranean region (relative to the WPR), the presence of a national neurosurgery society, increasing global development aid, and national gross domestic product were associated with relative growth in national neurosurgeon density. CONCLUSIONS: The authors estimate a global consultant neurosurgeon workforce of nearly 73,000 neurosurgeons, with stark disparities in the density and growth of the workforce in different WB income-level groups and WHO regions. The presence of a neurosurgery society was correlated with the growth of the workforce, and this study identified several regional targets for further intervention to expand access to neurosurgery.

Glioblastoma is the most common and lethal central nervous system malignancy with a median survival after progression of only 6–9 months. Major biochemical mechanisms implicated in glioblastoma recurrence include aberrant molecular pathways, a recurrence-inducing tumor microenvironment, and epigenetic modifications. Contemporary standard-of-care (surgery, radiation, chemotherapy, and tumor treating fields) helps to control the primary tumor but rarely prevents relapse. Cytoreductive treatment such as surgery has shown benefits in recurrent glioblastoma; however, its use remains controversial. Several innovative treatments are emerging for recurrent glioblastoma, including checkpoint inhibitors, chimeric antigen receptor T cell therapy, oncolytic virotherapy, nanoparticle delivery, laser interstitial thermal therapy, and photodynamic therapy. This review seeks to provide readers with an overview of (1) recent discoveries in the molecular basis of recurrence; (2) the role of surgery in treating recurrence; and (3) novel treatment paradigms emerging for recurrent glioblastoma.

Discogenic back pain, a subset of chronic back pain, is caused by intervertebral disc (IVD) degeneration, and imparts a notable socioeconomic health burden on the population. However, degeneration by itself does not necessarily imply discogenic pain. In this review, we highlight the existing literature on the pathophysiology of discogenic back pain, focusing on the biomechanical and biochemical steps that lead to pain in the setting of IVD degeneration. Though the pathophysiology is incompletely characterized, the current evidence favors a framework where degeneration leads to IVD inflammation, and subsequent immune milieu recruitment. Chronic inflammation serves as a basis of penetrating neovascularization and neoinnervation into the IVD. Hence, nociceptive sensitization emerges, which manifests as discogenic back pain. Recent studies also highlight the complimentary roles of low virulence infections and central nervous system (CNS) metabolic state alteration. Targeted therapies that seek to disrupt inflammation, angiogenesis, and neurogenic pathways are being investigated. Regenerative therapy in the form of gene therapy and cell-based therapy are also being explored.

Introduction: Brain metastases are the most common brain tumors in adults, whose management remains nuanced. Improved understanding of risk factors for surgical complications and mortality may guide treatment decisions. Methods: A nationwide, multicenter analysis was conducted with a retrospective cohort. Adult patients in the 2012-2015 American College of Surgeons National Surgical Quality Improvement Project (ACS NSQIP) databases who received a craniotomy for resection of brain metastasis were included. Results: 3500 cases were analyzed, of which 17% were considered frail and 24% were infratentorial. The most common 30-day medical complications were venous thromboembolism (3%, median time-to-event [TTE] 4.5 days), pneumonia (4%, median TTE 6 days), and urinary tract infections (2%, median TTE 5 days). Reoperation and unplanned readmission occurred in 5% and 12% of patients, respectively. Infratentorial approach and frailty were associated with reoperation before discharge (OR 2.0 for both; p=0.01 and p=0.03 respectively), but not after discharge. Infratentorial approaches conferred heightened risk for readmission for hydrocephalus (OR 5.1, p=0.02) and reoperation for cerebrospinal fluid diversion (OR 7.1, p<0.001).Overall 30-day mortality was 4%, with nearly three-quarters occurring after discharge. Pre-frailty and frailty were associated with increased odds for post-discharge mortality (OR 1.7 and 2.7, p<0.05), but not pre-discharge mortality. We developed a model to identify pre-/peri-operative variables associated with death, including frailty, thrombocytopenia, and high American Society of Anesthesiologists score (AUROC 0.75). Conclusions: Optimization of metrics contributing to patient frailty and heightened surveillance in patients with infratentorial metastases may be considered in the peri-operative period.

Despite advances in surgical resection and chemoradiation, high-grade brain tumors continue to be associated with significant morbidity/mortality. Novel therapeutic strategies and approaches are, therefore, desperately needed for patients and their families. Given the success experienced in treating multiple other forms of cancer, immunotherapy and, in particular, immunovirotherapy are at the forefront amongst novel therapeutic strategies that are currently under investigation for incurable brain tumors. Accordingly, herein, we provide a focused mini review of pertinent oncolytic herpes viruses (oHSV) that are being investigated in clinical trials.