Subdural Hematoma due to Dural Metastasis: A Systematic Review on Frequency, Clinical Characteristics, and Neurosurgical Management.

BACKGROUND: Subdural hematoma (SDH) occasionally accompanies dural metastasis and is associated with high recurrence rate, significantly impacting patient morbidity and mortality. This systematic review aims to evaluate the characteristics, management options, and outcomes of patients with SDH associated with dural metastasis. METHODS: A comprehensive search of the PubMed and Cochrane databases was conducted for English-language studies published from inception to March 20, 2023, adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The authors reviewed cases of histopathologically confirmed SDH with non-central nervous system (non-CNS) tumor metastasis, focusing on therapeutic management of SDH. Statistical analysis was performed using SPSS software, with a significance level set at 0.05. RESULTS: This review included 32 studies comprising 37 patients with 43 SDH cases associated with dural metastasis. Chronic SDH was the most frequently observed presentation (n = 28, 65.12%). The systemic malignancies most commonly associated with SDH due to dural metastasis were prostate carcinoma (n = 9, 24.32%) and gastric carcinoma (n = 5, 13.51%). A statistically significant association was found between metastatic melanoma and subacute SDH (p = 0.010). The majority of patients were treated with burr holes (n = 15, 40.54%) or craniotomies (n = 14, 37.84%), with no statistically significant difference in mortality rates between the two techniques (p = 0.390). Adjuvant therapy was administered to a limited number of patients (n = 5, 13.51%), including chemotherapy (n = 2, 5.41%), whole brain radiotherapy (n = 1, 2.70%), a combination of chemotherapy and whole brain radiotherapy (n = 1, 2.70%), and transcatheter arterial chemoembolization (n = 1, 2.70%). The overall recurrence rate was 45.95% (n = 17), with burr holes being the most common management approach (n = 4, 10.81%). Within a median of 8 days, 67.57% (n = 25) of patients succumbed, primarily due to rebleeding (n = 3, 8.11%), disseminated intravascular coagulation (n = 3, 8.11%), and pneumonia (n = 3, 8.11%). CONCLUSION: This review highlights the need for improving existing neurosurgical options and exploring novel treatment methods. It also emphasizes the importance of dural biopsy in patients with suspected metastasis to rule out a neoplastic etiology.

Contributions of Machine Learning in the Management of Stroke: A Bibliometric Analysis of the 50 Most Cited Articles.

BACKGROUND: Though currently considered a 'black box,' machine learning (ML) has a promising future to ameliorate the health-care burden of stroke which is the second leading cause of mortality worldwide. Through this study, we sought to review the most influential articles on the applications of ML in stroke. METHODS: Web of Sciences database was searched, and a list of the top 50 most cited articles, assessing the application of ML in stroke, was prepared by 2 authors, independently. Subsequently, a detailed analysis was performed to characterize the most impactful studies. RESULTS: The total number of citations to the top 50 articles were 2959 (range 35-243 citations) with a median of 47 citations. Highest number of articles were published in the journal Stroke and the United States was the major contributing country. The majority of the studies focused on the utilization of ML to improve stroke risk prediction, diagnosis, and outcome prediction. Statistical analysis revealed an insignificant association between the total and mean number of citations and the impact factor of the journal (P = 0.516 and 0.987, respectively). CONCLUSIONS: Recent years have witnessed a surge in the application of ML in stroke, with an enhancement in interest and funding over the years. ML has revolutionized the management of stroke and continues to aid in the neurosurgical decision-making and care in stroke patients.

Reoperation rate and risk factors of reoperation for ossification of the posterior longitudinal ligament (OPLL): a systematic review and meta-analysis.

Revision surgery for OPLL is undesirable for both patients and physicians. However, the risk factors for reoperation are not clear. Thus, we sought to review the existing literature and determine the factors associated with higher reoperation rates in patients with OPLL. A search was performed using Pubmed, Embase, Web of Sciences, and Ovid to include studies regarding the risk factors of reoperation for OPLL. RoBANS (Risk of Bias Assessment tool for Nonrandomized Studies) was used for risk of bias analysis. Heterogeneity of studies and publication bias was assessed, and sensitivity analysis was performed. Statistical analysis was performed with a p-value < 0.05 using SPSS software (version 23). Twenty studies with 129 reoperated and 2,793 non-reoperated patients were included. The pooled reoperation rate was 5% (95% CI: 4% to 7). The most common cause of reoperation was residual OPLL or OPLL progression (n = 51, 39.53%). An increased risk of additional surgery was found with pre-operative cervical or thoracic angle (Standardized mean difference = -0.44; 95% CI: -0.69 to -0.19; p = 0.0061), post-operative CSF leak (Odds ratio, OR = 4.97; 95% CI: 2.48 to 9.96; p = 0.0005), and graft and/or hardware failure (OR = 192.09; 95% CI: 6.68 to 5521.69; p = 0.0101). Apart from the factors identified in our study, the association of other variables with the risk of second surgery could not be ruled out, owing to the complexity of the relationship and significant bias in the current literature.

The Call for Neuroendoscopy Cadaveric Workshops in Lower-Middle Income Countries.

OBJECTIVE: This study aims to assess the impact of the workshops organized during Neuroendocon 23 on the perspective and confidence of neurosurgeons toward endoscopy in a lower-middle income country. METHODS: Neuroendocon 23 had cranial and spinal endoscopy cadaveric workshops with 30 delegates each. A pre and postworkshop survey was disseminated among the delegates, and statistical analysis was performed with SPSS (version 26) using P < 0.05. RESULTS: A total of 24 delegates (40%) consented to participate in the study, with only 1 female respondent (4.17%). After the cranial endoscopy workshop, there was an increase in the level of confidence of delegates in cranial endoscopic approaches (P < 0.001). Similarly, after the spine endoscopy workshop, the respondents had increased confidence in managing spine conditions with the endoscopic approach (P = 0.040), to the extent that they preferred the endoscopic over the microsurgical technique (P < 0.001). All respondents (n = 24, 100%) believed that endoscopy should be promoted in lower-middle income countries and integrated into residency curricula. CONCLUSIONS: Cranial and spinal endoscopy cadaveric workshops could be the first step in stimulating the interest of neurosurgeons in endoscopy.

Learnings from Asia's first ever medical student neurosurgery Conference: NEUROFEST, 2022.

The study lays out the design and learnings of Neurofest, Asia's first ever medical student Neurosurgery conference organized by Walter E Dandy Medical Student Neurosurgery Club, India. Neurofest was conducted in October 2022 inclusive of various events: workshops, talks and contests. An online post-conference questionnaire was disseminated among the delegates to record their experience and feedback for the conference. Statistical analysis was performed using SPSS with a level of significance p < 0.05. Of the 158 total delegates, 65.2% (n = 103) participated in this study. The majority of the responders were satisfied with the events at the conference. 85.4% (n = 88) of the respondents reported an increased interest in neurosurgery, probably due to the quality of workshops (p = 0.004), talks by faculty (p = 0.023), contacts with the faculty (p = 0.025) and confidence in approaching a faculty (p < 0.001). 92.2% (n = 95) of the respondents claimed to recommend Neurofest to their colleagues. The reasons for this were found to be the quality of workshops (p = 0.001) and confidence in approaching a faculty (p = 0.030). Nearly all respondents believed that such conferences are important in empowering medical students (n = 100, 97.1%). Similar conferences are required to provide medical students with early exposure to neurosurgery. In the future, continued research is required to optimize neurosurgical conferences and endorse the prospect of neurosurgery as a career option in Lower-Middle Income countries.

Utility of Machine Learning in the Management of Normal Pressure Hydrocephalus: A Systematic Review.

BACKGROUND: In the past decade, many machine learning (ML) models have been used in the management of normal pressure hydrocephalus (NPH). This study aims at systematically reviewing those ML models. METHODS: The PubMed, Embase, and Web of Science databases were searched for studies reporting applications of ML in NPH. Quality assessment was performed using Prediction model Risk Of Bias ASsessment Tool (PROBAST) and Transparent Reporting of a multivariable predication model for Individual Prognosis Or Diagnosis (TRIPOD) adherence reporting guidelines, and statistical analysis was performed with the level of significance of <0.05. RESULTS: A total of 22 studies with 53 models were included in the review, of which the convolutional neural network was the most used model. Inputs used to train various models included clinical features, computed tomography scan, magnetic resonance imaging, intracranial pulse waveform characteristics, and perfusion infusion. The overall mean accuracy of the models was 77% (highest for the convolutional neural network, 98%, while lowest for decision tree, 55%; P = 0.176). There was a statistically significant difference in the accuracy and area under the curve of diagnostic and interventional models (accuracy: 83.4% vs. 69.4%, area under the curve: 0.882 vs. 0.729; P < 0.001). Overall, 59.09% (n = 13) and 81.82% (n = 18) of the studies had high-risk bias and high-applicability, respectively, on PROBAST assessment; however, only 55.15% of the studies adhered to the TRIPOD statement. CONCLUSIONS: Though highly accurate, there are many challenges to current ML models necessitating the need to standardize the ML models to enable comparison across the studies and enhance the NPH decision-making and care.

Macrophages in Recurrent Glioblastoma as a Prognostic Factor in the Synergistic System of the Tumor Microenvironment.

Glioblastoma (GBM) is a common and highly malignant primary tumor of the central nervous system in adults. Ever more recent papers are focusing on understanding the role of the tumor microenvironment (TME) in affecting tumorigenesis and the subsequent prognosis. We assessed the impact of macrophages in the TME on the prognosis in patients with recurrent GBM. A PubMed, MEDLINE and Scopus review was conducted to identify all studies dealing with macrophages in the GBM microenvironment from January 2016 to December 2022. Glioma-associated macrophages (GAMs) act critically in enhancing tumor progression and can alter drug resistance, promoting resistance to radiotherapy and establishing an immunosuppressive environment. M1 macrophages are characterized by increased secretion of proinflammatory cytokines, such as IL-1ß, tumor necrosis factor (TNF), IL-27, matrix metalloproteinase (MMPs), CCL2, and VEGF (vascular endothelial growth factor), IGF1, that can lead to the destruction of the tissue. In contrast, M2 is supposed to participate in immunosuppression and tumor progression, which is formed after being exposed to the macrophage M-CSF, IL-10, IL-35 and the transforming growth factor-ß (TGF-ß). Because there is currently no standard of care in recurrent GBM, novel identified targeted therapies based on the complex signaling and interactions between the glioma stem cells (GSCs) and the TME, especially resident microglia and bone-marrow-derived macrophages, may be helpful in improving the overall survival of these patients in the near future.

Endoscopic versus microscopic discectomy for pathologies of lumbar spine: A nationwide cross-sectional study from a lower-middle-income country.

Objective: We conducted a cross-sectional study to assess the preference of spine surgeons between MD for microdiscectomy and endoscopic discectomy (ED) surgery for the management of lumbar pathologies in a lower-middle-income country (LMIC). Methodology: An online survey assessing the preference of spine surgeons for various lumbar pathologies was developed and disseminated in "Neurosurgery Cocktail" a social media platform. Statistical analyses were performed using SPSS software with a level of significance <0.05. Results: We received responses from 160 spine surgeons having a median experience of 6.75 years (range 0-42 years) after residency. Most of the spine surgeons preferred MD over ED, preference being homogeneous across all lumbar pathologies. In ED, the interlaminar approach was preferred more frequently than the transforaminal approach. The most commonly chosen contraindication for the interlaminar approach and transforaminal approach was ≥ 3 levels lumbar disc herniation (LDH) (n = 117, 73.1%) and calcified LDH (n = 102, 63.8%), respectively. There was no significant association between the type of approach preferred (MD vs. ED; and interlaminar vs. translaminar endoscopic approach) with the type of workplace and the level of experience. Conclusion: Spine surgeons were inclined toward MD over ED, due to various reasons, such as a steep learning curve, lack of training opportunities, and upfront expenses. There is a pressing need for the upliftment of ED in LMICs which requires global action.