bluuebunny/crossref_metadata_2025 huggingface dataset:
453 Changed Innervation Upon Loss of Mandibular Division of Trigeminal Nerve to Muscles of Mastication
Authors: Wilson Nehemiah , Ziermann Janine
Published: March 2024

INTRODUCTION:

The gastrulation brain homeobox (Gbx) genes are essential for patterning and maintenance of neurons along the anteroposterior axis of the developing neural tube. Knockout (ko) of Gbx2 results in neonatal lethality associated with neurological and other defects. To understand pathologies, ko studies are not realistic as gene loss usually results in death before birth. Gbx2 neo/neo mutant mice express 6-10% of the wildtype Gbx2 expression levels. They have milder malformations than ko mice but lack the cerebellar vermis and mandibular division of the trigeminal nerve (3rd division of 5th cranial nerve = V3), among other defects. These Gbx2 neo/neo mutant mice die perinatally as they are unable to suckle due to lack of motor innervation via V3 to the muscles of mastication. Muscle cells develop largely without interaction with their motor nerve. However, the final differentiation of myocytes requires interactions with nerve fibers. Unexpectedly, the muscles of mastication appear normal in Gbx2 neo/neo mutant mice, despite the lack of V3.

METHODS:

We performed microdissections of neonate wildtype and Gbx2neo/neo mutant mice. Additionally, we embedded mutant and wildtype mouse embryos in paraffin, serial sectioned them (7 μm), stained the sections with Azan staining, and analyzed specimen microscopically.

RESULTS:

Current analysis of the data to identify where nerve fibers in the muscles of mastication originate is in process. We favor the origin of these fibers from the facial nerve (7th cranial nerve), which has several overlapping territories with the trigeminal nerve.

CONCLUSIONS:

Muscles require innervation for their final differentiation steps. The loss of a nerve can result in the invasion of another nerve into the territory of the lost one, which rescues muscle differentiation but not muscle function. IACUC Ziermann Med-20-02, Funding NSF #2000005 to Ziermann.
455 Distal Nerve Transfers in Treatment of Peripheral Nerve Lesions
Authors: Rasulic Lukas G. , Savić Andrija , Lepic Milan , Grujić Jovan , Radojević Stefan , Mićić Aleksa
Published: March 2024

INTRODUCTION:

Distal nerve transfers can be used in treating patients with irreparable high nerve lesions, aiming to regain hand function. The indications for these transfers include upper (C5-C6) and lower (C8-T1) brachial plexus palsy, isolated proximal extensive radial, median, or ulnar nerve lesion, or isolated axillary or musculocutaneous nerve lesion.

METHODS:

The selected cases (n = 5) included lower brachial plexus injury (n = 2), and isolated radial (n = 1), ulnar (n = 1), and median (n = 1) nerve injuries. The MRC grading was used to examine postoperative muscle strength. The DASH and PNSQoL questionnaires were used to assess the postoperative quality of life.

RESULTS:

The useful functional recovery (MRC = 4-5) was achieved in all presented cases. The DASH and PNSQoL scores indicated a satisfying quality of life in terms of the absence of postoperative disability.

CONCLUSIONS:

Distal nerve transfers are a valuable technique for treatment of the patients with irreparable proximal nerve lesions. This technique reduces the path necessary for the regenerative nerve fibers to pass, provides direct nerve coaptation without additional suture line, and facilitates faster and better recovery, with the final outcome as an increase in the patients’ quality of life.
467 Analysis of Surgical Smoke Generated by Electrocautery and Standard Surgical Mask Protection in a Simulated Neurosurgical Operating Room Using a Post-mortem Porcine Model for Laminectomy Exposures
Authors: Levy Bennett Reuben , Monteiro Andre , Jaikumar Vinay , Donnelly Brianna M. , Smolar David , Lim Jaims , Mullin Jeffrey Paul , Levy Elad I.
Published: March 2024

INTRODUCTION:

Electrocautery is a widely used tool to coagulate and separate tissue during neurosurgical procedures. Surgical smoke generated by electrocautery has harmful properties if inhaled over long-term. To our knowledge, no efforts have been made within the neurosurgery field to investigate the air quality of operating rooms (OR) where neurosurgical procedures are being performed.

METHODS:

Four freshly post-mortem porcine models were used to perform 4 laminectomy exposures measuring 20cm using electrocautery in a simulated neurosurgical OR. Air sampling media and pumps were connected to a 3D-printed human face model. In 2 models the face was covered with a standard surgical mask, and in 2 models no masks were placed. The models were positioned at 40 cm distance from the surgical field. Air samples were analyzed by an independent laboratory. Analyses of total amount of respirable dust and 31 VOCs were conducted. The mean total amount between each 2 samples of the masked vs non-masked models were compared.

RESULTS:

On all 2 masked and 2 non-masked models, all 31 VOCs were below the levels of quantitation. On the 2 non-masked models, the total amount of respirable dust were 8.2 times higher than in the 2 masked models.

CONCLUSIONS:

Total amount of VOCs appears to be low at the distance measured regardless of mask use, however further studies are needed to determine if even small amounts can still be harmful over time. Standard surgical masks seem to be efficient in protecting against the high amounts of respirable dust generated by surgical smoke.
486 Responsive Neurostimulation of the Centromedian Nucleus of the Thalamus in Adult Epilepsy: Multi-center Case Series
Authors: Gadot Ron , Shofty Ben , Giridharan Nisha , Banks Garrett P. , Sharma Himanshu , Gavvala Jay R. , Goldman Alica , Krishnan Vaishnav , Lin Lu , Rahimpour Shervin , Sheth Sameer A.
Published: March 2024

INTRODUCTION:

Responsive neurostimulation (RNS) is an FDA-approved therapy for focal drug-resistant epilepsy (DRE). Emerging evidence supports a role for RNS in DRE with regional, multifocal, or non-resectable seizure onset zones. The centromedian nucleus of the thalamus (CMT) is a promising target, although descriptions of predictors of longer-term response are lacking.

METHODS:

We retrospectively reviewed patients who underwent RNS implantation with at least one CMT electrode at Baylor College of Medicine (BCM) and the University of Utah (UoU) from 2019-2023. Patients with = 6 months of follow-up were assessed for changes in clinical seizure frequency following surgery, as well as changes in seizure severity and subjective quality-of-life (QoL).

RESULTS:

Sixteen patients underwent CMT RNS (n = 12 BCM, n = 4 UoU) at a median age of 30 years [range 20-51] with a median 19-year history of epilepsy. All patients were evaluated by a multidisciplinary team that recommended thalamic RNS. Thirteen underwent bilateral CMT implantation and 7 had a documented lesional effect (>50% reduction in seizures in the months following implantation). Thirteen patients had = 6-month follow-up with which to do subsequent seizure outcome analysis. In these patients, with a median follow-up of 18 months [6-40], median clinical seizure reduction was 80% [0-100%], 2 patients were seizure free for 6 months, and 1 was seizure free for 40 months. Patients with a lesional effect had a median 87% seizure reduction at last follow-up while those without a lesional effect had a 51% seizure reduction (two-tailed, two-sample t-test, p = 0.04). Subjective reduced seizure severity and increased QoL was documented in 92% of patients.

CONCLUSIONS:

RNS of the CMT can result in robust seizure frequency, severity, and QoL improvements in patients with DRE. Post-implantation lesional effect may be associated with longer-term improved response.
489 Increase in Broadband Power Is an Electrophysiologic Marker of Focal Thalamic Activity During Movement
Authors: Klassen Bryan T. , Valencia Gabriela Ojeda , Kaufmann Timothy , Miller Kai Joshua
Published: March 2024

INTRODUCTION:

The architecture of the human thalamus is currently indirectly inferred from human histopathologic and non-human animal studies. Given that movement-related increases in broadband power from electrocorticography recording have been previously shown to identify specific motor cortical subregions involved with a particular movement, we explored whether this phenomenon can also be used to localize motor subregions of thalamus.

METHODS:

We performed serial human thalamic local field potentials recordings using an electrode moved through the lateral thalamusduring deep brain stimulation surgery in 10 subjects. During the recording at each location, subjects alternated between 5 second epochs of rest and 5 second periods of contralateral hand movement. Power spectra were generated for each epoch using Welch’s overlapping periodogram method (1 second window, 50% overlap). Spectra from all movement and rest epochs were separately averaged. The difference between the power in the 65 to 95 Hz band during movement versus rest was used as a proxy for task-related change in broadband activity. Task-related differences in prominent low-frequency oscillations (patient-specific sub-ranges within 5 to 30 Hz) were analyzed per individual oscillation and in aggregate. Significance was determined using unpaired T tests at a threshold of p = 0.05.

RESULTS:

We find that recording sites showing statistically significant increases in broadband power during movement tend to tightly cluster in areas predicted to represent motor thalamus, whereas sites showing statistically significant reduction in the power (desynchronization) of low frequency oscillations are more diffusely distributed. This finding is replicated across all subjects.

CONCLUSIONS:

These results suggest that a task-dependent increase in broadband power is an electrophysiologic marker of focal thalamic activity and may be useful to delineate specific thalamic subregions on an individual subject basis.
501 Systemic Immunological Suppression in Glioblastoma Is Targeted by Concurrent VEGF and PD-1 Inhibition in a Dose-Dependent Manner: Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE-Seq) From a Randomized Controlled Trial
Authors: Ozair Ahmad , Alban Tyler J. , Grabowski Matthew M. , Otvos Balint , Bayik Defne , Bamashmos Anas , Rayman Pat , Diaz Marcella , Khosla Atulya , Bellur Shreyas , McDermott Michael William , Reardon David A. , Wen Patrick , Mohammadi Alireza M. , Peereboom David M. , Lathia Justin D. , Ahluwalia Manmeet
Published: March 2024

INTRODUCTION:

Anti-PD1 blockade has had poor efficacy in recurrent glioblastoma (rGBM) across three RCTs. VEGF, a proangiogenic factor that is upregulated in rGBM, contributes to tumor-associated immunosuppression and is widely targeted through bevacizumab. Preclinical data indicate a potential dose-dependent effect of anti-VEGF therapy on immunomodulation. Hence, a combination of anti-PD-1 and anti-VEGF agents is a promising approach for rGBM, for which an RCT was conducted.

METHODS:

Patients with rGBM were administered nivolumab (240mg IV q2weeks) plus either standard dose bevacizumab (10mg/kg) or low dose bevacizumab (3mg/kg) IV q2weeks, with 1:1 randomization. Stratification factors were age, performance status, extent of resection, and MGMT methylation status. Primary endpoint was overall survival (OS) at 12 months. CITE-Seq was performed on 16 patients across trial arms, both pre- and on-therapy, yielding total 32 immunological profiles. For control, CITE-seq was done on three patients receiving anti-VEGF therapy alone.

RESULTS:

90 patients were enrolled with median age of 60.6 years and 45 patients per arm. Both arms had similar OS at 12 months (P = 0.14). Significantly higher OS was found in posthoc analysis for patients aged = 60 years with standard dose. Distinct immune cell populations were identified and differential changes in myeloid-derived suppressor cells (MDSCs) found across trial arms on-therapy. Network medicine approach identified VEGF as target to reduce MDSCs, with VEGF primarily expressed by responders’ MDSCs. Differential gene expression analysis identified increased pro-inflammatory signatures in standard dose arm.

CONCLUSIONS:

Standard dose bevacizumab was associated with increased inflammatory response and reduction of immunosuppressive MDSC. These mechanistic insights potentially explain survival benefit seen with concurrent VEGF and PD-1 inhibition in elderly rGBM patients.
706 Radial Versus Femoral Access for Diagnostic Cerebral Angiography: A Systematic Review and Meta-analysis of Randomized Trials
Authors: Lima Fonseca Rodrigues Amanda Cyntia , Tonetti Daniel
Published: March 2024

INTRODUCTION:

Radial artery access is the gold standard for percutaneous coronary procedures, desmonstrating benefits for patient safety and comfort, its adoption for diagnostic cerebral angiography has been limited by doctors’ concerns about achieving procedural success.

METHODS:

PubMed, Embase and Cochrane databases were searched through April 2023. Statistical analysis were performed using R version 4.2.3. Random-effects meta-analysis with risk ratio (RR) and 95% CI were estimated using the inverse variance and Mantel-Haenszel method for binary outcomes and DerSimonian-Laird estimator for continuous outcomes. The primary outcome was technical success, and the secondary outcomes were procedure time, radiation exposure and fluoroscopy.

RESULTS:

After reviewing 142 studies, were included 3 randomized trials involving 492 patients with 250 patients in radial group (50.81%) and 242 in femoral (49.19%). The total mean age of the patients was 57 years old, 249 males (50.61%) and 243 females (49.39%). There is no significant difference in technical success (RR 0.99, 95% CI 0.94 to 1.03, p = 0.555, I2 = 0%), procedure time (WMD 2.08 minutes, 95% CI -5.11 to 9.28, p = 0.570, I2 = 87%) and radiation exposure also showed no significant difference (WMD 27.87 mGy, 95% CI -21.43 to 77.17, p=0.268, I2 = 0%). Fluoroscopy time had high heterogeneity and a non-significant result (WMD 2.70 minutes, 95% CI -0.73 to 6.13, p = 0.123, I2 = 82%). The funnel plots showed roughly inverted symmetrical distributions among study points which indicated the lack of any preliminary publication bias. Leave-one-out sensitivity analysis determined that the final pooled results were unstable.

CONCLUSIONS:

The findings suggest that the procedures studied have similar technical success rates and radiation exposure. Studies are needed to explore the factors contributing to heterogeneity in procedure and fluoroscopy times to optimize safety and efficiency in radial or femoral access.
726 Changes of Reported Industry Payments to Neurosurgeons Pre- and Post-Covid-19 Epidemic
Authors: Elsamadicy Aladine A. , Cross James
Published: March 2024

INTRODUCTION:

Under the Affordable Care Act, the Physcian Patient Sunshine Act was implemented in 2010, providing public transparency of industry relationships with physcians. Open Payments Data (OPD) was released in 2014, and annually since. Payments to Neurosurgeons have been found to be amongst the highest. However, the implications Covid-19 in 2020 had on payments has not been reported.

METHODS:

A retrospective study was performed from January 1, 2017 to December 31, 2021 of the Open Payments Database. Collected data included the total number of industry payments, the aggregate value of industry payments, and the mean value of each industry payment made to neurosurgeons per year over the 5-year period.

RESULTS:

A total of 7,985 unique neurosurgeons recieved payments, totaling $451,610,410, There was a decreasing trend in the number of Neurosurgeons recieving payments during Covid-19 (2020): 5,478 (2017), 5,286 (2018), 5,146 (2019), 4,330 (2020), and 4,880 (2021). Additionally, there was decline in the total amount of payments made in 2020, compared to the other years: 80,358 (2017), 82,143 (2018), 85,026 (2019), 46,762 (2020), and 67,507 (2021). Among the types of payments, year 2020 was lower than the other years in Food and Beverage, Travel and Lodging, Services other than Consulting, and Eduction. Interestingly, year 2020 had higher number of payments for Consulting Fee and Royalty/License payments compared to pre-Covid-19 years.

CONCLUSIONS:

Our study shows that over the 5-year period (2017-2021) of the Centers for Medicare and Medicaid Services OPD, there was decrease in number of Neurosurgeons recieving payments and the number of payments made to Neurosurgeons compared to Pre-Covid. However, 2021 demonstrated an increasing trend similar to Pre-Covid.
755 Pathology in the Digital Era of Neuro-oncology: A Pathomics-Based Approach to Modeling Outcomes in Medulloblastoma
Authors: Mahtabfar Aria , Familiar Ariana , Kazerooni Anahita Fathi , Khanna Omaditya , Kiani Mahsa , Haldar Debanjan , Viswanathan Karthik , Resnick Adam C. , Viaene Angela , Storm Phillip B. , Nabavizadeh Ali
Published: March 2024

INTRODUCTION:

Pathomics is an emerging data science technique that may be used to extract intricate, sub-visual histopathologic features using high-throughput digital image analysis.

METHODS:

Using the Children’s Brain Tumor Network database, pediatric medulloblastoma patients were evaluated for inclusion in the study. After tumor segmentation, 49 quantitative pathomic features were extracted using a digital pathology software package (Qupath). LASSO cox proportional hazard model with stratified 5-fold cross-validation was used to identify high-performing features and create a predictive survival model by identifying low-, medium- and high-risk OS cohorts. A classification model was developed using histogram gradient boosting classifier to perform binary classification of Group3/4 vs. SHH/WNT with leave-one-subject-out cross validation.

RESULTS:

84 patients with median age at diagnosis of 8.61 years (range 0.31-21.72), and median OS of 45.6 months (range 0.76-195.87) were included in the study. A survival model built using only clinical features yielded a concordance index (c-index) of 0.76 compared to actual outcomes (stratification: p < 0.001). However, a survival model built by combining clinical and high-performing pathomic features yielded the best performance, showing disparate outcomes between low-, medium- and high-risk groups (p < 0.001) with resultant c-index of 0.85. Furthermore, pathomic features classified subjects into Group 3/4 or SHH/WNT with classification accuracy of 71% (SEM = 0.06), and t-test against stratified chance accuracy (57%) showed significantly above-chance performance (p = .019).

CONCLUSIONS:

This study represents the largest pathomic-based machine learning analysis for predicting survival and molecular subtypes in medulloblastoma. The results demonstrate success in pathomic analysis using machine learning-based modeling to predict survival and molecular subtypes for patients with medulloblastoma. Further work will aim to perform our analysis on an external validation dataset to enhance model performance and improve its clinical applicability.
757 Machine Learning-Driven Web Application for Enhanced Clinical Decision Support in Thoracolumbar Spinal Cord Injuries
Authors: Karabacak Mert , Jagtiani Pemla , Margetis Konstantinos
Published: March 2024

INTRODUCTION:

Thoracolumbar spinal cord injuries (tlSCI) can result in negative short-term in-hospital outcomes, underscoring the importance of precise prediction tools.

METHODS:

This retrospective cohort study included 147,826 patients from the American College of Surgeons Trauma Quality Program database. XGBoost, LightGBM, CatBoost, and Random Forest algorithms were utilized in combination with the Optuna optimization library for hyperparameter tuning. Models were evaluated graphically with receiver operating characteristic (ROC) curves, precision-recall curves, and numerically with precision, recall, F1 score, accuracy, area under ROC (AUROC), and area under PRC. The best-performing models were integrated into an open-access web application for individualized predictions.

RESULTS:

The best-performing models for each outcome were as follows: for predicting mortality, Random Forest achieved the highest AUROC (0.865, 95% CI 0.848-0.879); in predicting non-home discharges, LightGBM had the highest AUROC (0.801, 95% CI 0.794-0.804); and for predicting major complications, Random Forest performed best with an AUROC of 0.733 (95% CI 0.642-0.808). Algorithms' receiver operator curves for the outcomes: (A) mortality, (B) non-home discharges, and (C) major complications.

CONCLUSIONS:

This study successfully developed ML models to predict critical in-hospital outcomes for patients with tlSCI. By incorporating the top-performing algorithms into a user-friendly web application, these models have the potential to improve clinical decision-making and management strategies for tlSCI patients, ultimately enhancing patient care and outcomes.
758 An Appraisal of the Quality of Development and Reporting of Predictive Models in Neurosurgery
Authors: Khalid Syed Ibad , Massaad Elie , Roy Joanna , Thomson Kyle , Kiapour Ali , Shin John H.
Published: March 2024

INTRODUCTION:

Overwhelming evidence indicates that the quality of reporting of predictive models is poor, often being confounded by small datasets, inappropriate statistical methods, a lack of validation, and reproducibility.

METHODS:

Articles reporting prediction models published in the top five neurosurgery journals by SJR2-rank (Neurosurgery, Journal of Neurosurgery, Journal of Neurosurgery: Spine, Journal of NeuroInterventional Surgery, and Journal of Neurology, Neurosurgery, and Psychiatry) between January 1st, 2018, and January 1st, 2023, were identified via a PubMed search strategy that combined terms related to machine learning and prediction models. The identified original research articles were analyzed against the TRIPOD criteria.

RESULTS:

110 articles were included and analyzed against the TRIPOD checklist. Among the articles screened, the median compliance was 57.4% (50.0-66.7%). Models utilizing machine learning-based models exhibited lower compliance on average compared to conventional learning-based models (57.1%, 50.0-66.7% vs. 68.1%, 50.2-68.1%, p = 0.472). Among the TRIPOD criteria, the lowest compliance was observed in blinding the assessment of predictors and outcomes (n = 7, 12.7% and n = 10, 16.9%, respectively), including an informative title (n = 17, 15.6%) and reporting model performance measures including confidence intervals (n = 27, 24.8%). Few studies provided sufficient information to allow for the external validation of results (n = 26, 25.7%).

CONCLUSIONS:

Published machine learning models predicting outcomes in neurosurgery often fall short of meeting the established guidelines laid out by TRIPOD for their development, validation, and reporting. This lack of compliance may indicate the extent to which these models have been subjected to external validation or adopted into routine clinical practice in neurosurgery.
817 Promoting Durable Well-Being Among Neurosurgical Professionals via an Interactive, Online, Wellness Educational Initiative
Authors: Kazemi Foad , Mukherjee Debraj Raj
Published: March 2024

INTRODUCTION:

Burnout is increasingly recognized as a source of worse job satisfaction and well-being within neurosurgery. We initiated a 10-week department-wide wellness course (Peace Education Program, PEP) with the goal of improving well-being.

METHODS:

We utilized PEP, a free, interactive, online wellness course focusing on 10 domains (hope, appreciation, inner strength, self-awareness, clarity, understanding, dignity, choice, peace, and contentment). Two weeks before and 6 months after the course, we distributed de-identified surveys based upon the validated Schwartz Outcome Scale-10 (SOS) with Likert scale scores 0-6 to assess participant wellness. Completion of the course was defined as attending >7 of 10 sessions. Mann-Whitney U testing analyzed statistical differences between post-and pre-course data. p-values <0.05 were considered statistically significant.

RESULTS:

Sixty-nine faculty, trainees, and staff registered to participate, 41 joined >1 session, and 15 completed the course. Twenty-one and ten participants completed the pre- and post-course survey, respectively. Pre-course mean(+SD) SOS-10 score was 4.32 ± 1.23, which improved to 5.10 ± 0.75 post-course (p < 0.001). Pre-course, the lowest domain score related to “appreciation” (3.95 ± 1.46); post-course the highest domain score related to “hope” (5.30 ± 0.48). Overall, all 10 domains demonstrated improved mean scores over time, with 5 domains [“inner strength” (p = 0.008), “understanding” (p = 0.030), “hope” (p = 0.020), “choice” (p = 0.026), and “peace” (p = 0.048)] demonstrating statistically significant score improvements six months after course completion. Focusing on participants who completed >7 sessions, we additionally found statistically significant score improvements in the domains of “clarity” (p = 0.019), “contentment” (p = 0.030), and “appreciation” (p = 0.029) six months after course completion.

CONCLUSIONS:

Our findings demonstrate improved wellness in participants up to 6 months after wellness course completion. Participants attending >7 sessions benefited more than counterparts. This free, interactive, online course can be utilized at other neurosurgical training programs to combat burnout and improve wellness.
818 Prevalence of and Risk Factors for Depression, Anxiety, and Burnout in U.S. Neurosurgical Residents
Authors: Tavakol Sherwin , Nawaz Samia , Oumar Coulibaly Nangorgo Jean , Shakir Hakeem Jon
Published: March 2024

INTRODUCTION:

Rates of mental illness are disproportionately higher among medical residents. Neurosurgical trainees are no exception and may be more likely to suffer from depression, anxiety, and/or burnout than other residents. An assessment of the prevalence of mental illness in U.S. neurosurgical residents in the post-COVID-19 era is lacking in the literature and understanding the risk factors is vital to combating these mental health disorders.

METHODS:

Cross-sectional study analyzing responses to a 28-question survey from March-May 2023 distributed to U.S. neurosurgery residents. The survey included demographic and program-specific information, as well as Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) screening questions. PHQ-9 and GAD-7 scores >5 represent at least mild depression and anxiety, respectively.

RESULTS:

Forty-eight responses were included in the analysis, which consisted of 35 males (74%), 36 married respondents (77%), and 27 junior residents (56%, PGY-1 to 4). Twenty-four residents (50%) screened positive for depression, 19 residents (40%) screened positive for anxiety, and 26 residents (54%) reported feeling burned out. Depressed residents were highly more likely to also suffer from anxiety (70%, p < 0.0001) and burnout (79%, p = 0.001). Further, junior residents (63%, p = 0.042), female residents (83%, p = 0.008), and residents on a neurosurgical rotation (60%, p = 0.036) were more likely to screen positive for depression. However, being married (p = 0.318), practicing in one’s home state (p = 0.724), having a 24-hour call system (0.188), having formal didactic time (p = 0.125), and having program-led wellness initiatives (p = 0.069) were not protective.

CONCLUSIONS:

Half of U.S. neurosurgery residents who responded screened positive for depression, 40% screened positive for anxiety, and 54% felt burned out. Depression was strongly correlated with both anxiety and burnout. Neurosurgery residents who were female, in their junior years, and on-service were at particularly high risk for depression.
819 Pre-residency Research Output Amongst U.S. Neurological Surgery Residents
Authors: Gupta Rishabh , Chen Jeffrey , Roth Steven G. , Kamal Naveed , Reisen Breanne , Ortiz Alex , Feldman Michael , Mummareddy Nishit , Jo Jacob , Chambless Lola Blackwell
Published: March 2024

INTRODUCTION:

Research productivity is often used in evaluating candidates for neurosurgery residency. Official Match data report successful candidates have on average ∼25 pre-residency research products; however, average number of indexed publications, the highest-valued research product, is not reported separate from other research products.

METHODS:

A list of all US neurosurgery residents who successfully matched between 2017-2021 was generated and narrowed to US MD seniors who applied to the authors’ institution. Each resident’s pre-residency publication quantity was extracted using Scopus. Additional variables were extracted from residency applications.

RESULTS:

93.2% of all matched neurosurgery applicants from 2017 through 2021 were captured. Distribution of publication quantity was right skewed. Mean ± SD total, neuroscience-specific, and first-author pre-residency publications for applicants who matched in 2021 were 8.1 ± 10.0, 6.6 ± 8.7, and 2.3 ± 3.8 respectively. Median (IQR) total, neuroscience-specific, and first-author pre-residency publications were 5.0 (2.0, 11.0), 4.0 (1.5, 9.0), and 1.0 (0.0, 3.0) respectively. There was a statistically significant increase in average total, neuroscience-specific, and first-author publications from 2017 to 2021 (p < 0.001). Multivariable analysis demonstrated an independent, positive association between class year and publication quantity (1.07 (0.71-1.42), p < 0.001).

CONCLUSIONS:

Indexed publications constitute a small portion of total research products successful neurosurgery candidates apply with. A high number of publications is not necessary to match with approximately 50% of all applicants who successfully matched having fewer than five publications and 25% having fewer than two. That said, average pre-residency publication quantity is increasing over time at a rate of approximately one publication per year.
870 Middle Meningeal Artery Embolization Does Not Confer Protection Against Symptomatic Recurrence in Patients With Early Anticoagulation Following Surgery for Chronic Subdural Hematomas
Authors: Zeineddine Hussein A. , Dawes Bryden Hugh , Martinez-Gutierrez Juan Carlos , Wroe William , Blackburn Spiros L. , Chen Peng Roc , Ciavarra Bronson , Chen Ching-Jen , Kitagawa Ryan Seiji
Published: March 2024

INTRODUCTION:

Chronic subdural hematoma (cSDH) is a prevalent condition that carries a significant burden. Middle meningeal artery embolization (MMAE) has emerged as a promising treatment both as an adjunct to surgery and as a primary treatment. A number of patients suffering from cSDH have concurrent comorbidities necessitating early introduction of antithrombotic medications. The question of whether adding MMAE to surgically evacuated cSDH confers protection against recurrence in this subgroup of patients is unclear.

METHODS:

This a single center study. Patients in the surgery + MMAE cohort were identified from a prospectively collected MMAE registry and compared to a historical surgery cohort presenting over a 2-year period prior to the introduction of MMAE in our institution. Included patients had evacuation of cSDH with either burrholes or craniotomy. Patients were included if they had a clinical indication requiring early antithrombotics within 5 days of surgery. The primary outcome was reoperation.

RESULTS:

A total of 16 cSDHs in 13 patients (MMAE + surgery) and 32 cSDHs in 27 patients (surgery) met the inclusion criteria. No significant differences of baseline characteristics was identified. There was a total of 2 recurrences in the group that underwent MMAE with no reoperation. In the group of surgery alone, there was 4 recurrence and 3 reoperations. The rate of reoperation however was not significantly different in the two cohort neither was the rate of recurrence. (p = 0.54 and 0.7 respectively).

CONCLUSIONS:

This study analyzed a specific subset of patients requiring ultra-early administration of antithrombotic medications. While MMAE is gaining momentum as an adjunct to surgery, or even as sole treatment, it is unclear whether addition of MMAE to surgery confers any protection against recurrence or surgery in this particular subset.
880 Extraction of a Metal Arrow Entering the Skull Base Using a Three-Surgeon Combined Microscopic and Endoscopic Approach
Authors: Gatdula Francis James , Piatos del Rosario Jose Nicanor
Published: March 2024

INTRODUCTION:

Low velocity penetrating brain injuries (PBI) present both a diagnostic and therapeutic challenge in management particularly in operative planning for the extraction of the impaled foreign body.

METHODS:

A 3-surgeon combined microscopic-endoscopic approach with the use of intraoperative ultrasound, angiogram, and C-arm localization was done. This involved a 5-part procedure: internal carotid angiography; parieto-occipital vertex craniotomy with ultrasound-guided localization; right transciliary cranio-orbito-zygomatic osteotomy transciliary approach; endoscopic guided advancement and extraction of foreign body and endoscopic endonasal transsphenoidal repair of skull base defect.

RESULTS:

The rationale for the procedures borders on obtaining information on the relationship of the arrow to the major vessels at the base of the brain, visualization of the arrow’s entry into the skull, guidance on the point of exit as the arrow was pushed upwards towards cortex and extracted it from the surface, and the integrated use of a basal approach for actual visualization of the shaft of the arrow. The patient remained clinically and neurologically stable post-operatively and was discharged after 10 days. He was back to pre-morbid functional status during follow-up at the outpatient two weeks after surgery.

CONCLUSIONS:

Presented is a successfully managed case of low-velocity PBI. The knowledge of surgical anatomy combined with the different concepts and principles of neurosurgery led to the development of combined techniques that can be used and may further be improved in the management of these injuries.
892 Pain Intensity Is Characterized by Theta Band Dynamics and Opioid Pain Medication Effect at Gamma Band Dynamics Within the Human Subcortical Structures
Authors: Ryu Jihye , Bari Ausaf A.
Published: March 2024

INTRODUCTION:

Chronic pain is a multifaceted condition that involves processes of sensation, cognition, and emotion. Given its complexity, characterizing the dynamic changes in pain intensity for patients with chronic pain has remained a challenge. Several EEG studies have shown chronic pain patients to exhibit an increased theta and alpha band power, and acute pain to induce an increased gamma power. However, these do not inform the dynamical changes in pain fluctuations, and critically at the subcortical hubs that modulate the processes of sensation, cognition, and emotion.

METHODS:

The patients continuously rated their pain level for approximately 10 minutes, and we characterized the pain reduction that occurred spontaneously and that occurred via opioid pain medication. We used a novel method coined variance of auto-information (VAI), that would parameterize the stochasticity (i.e., randomness) of the theta and gamma bandpass filtered LFP.

RESULTS:

In all four patients, the theta VAI (randomness) was found to be lower as pain was relieved both spontaneously (p = 0.01) and via fentanyl (p = 0.03). The gamma VAI was higher when pain was relieved via fentanyl (p = 0.03).

CONCLUSIONS:

The results demonstrate characterizing pain intensity using the human neuronal oscillatory activity from the subcortical structures. We also introduce the VAI method that consistently characterize pain relief among chronic pain patients. These findings may help to identify biomarkers for pain intensity, and potentially guide stimulation targets for closed-loop neuromodulatory treatment.
894 Comparison of Intraoperative Neural Changes During Tonic Versus High-Frequency Spinal Cord Stimulation in Chronic Pain Patients
Authors: Gopal Jay , Bao Jonathan , Paniccioli Steven , Grey Rachael , Briotte Michael , McCarthy Kevin , Pilitsis Julie G. , Telkes Ilknur
Published: March 2024

INTRODUCTION:

Chronic pain is a prevalent issue that may affect up to 34% of US adults, and spinal cord stimulation (SCS) is a promising therapy. However, SCS device selection remains a challenge because there are currently no objective biomarkers to evaluate chronic pain, or to predict which patients will be responders.

METHODS:

Intraoperative EEG signals were recorded in 24 chronic pain patients (14 women) during permanent SCS electrode placement surgery. Neural responses were captured with respect to tonic (60 Hz/300 µs) and high-frequency (1 kHz/30 µs) SCS paradigms in a randomized manner and correlated to Numeric Rating Scale (NRS) scores. All data were analyzed offline in MATLAB and SPSS v28.0.1.1.

RESULTS:

Our analyses for the main effects demonstrated a significant difference between cortical regions (F(2.88,57.7) = 7.60 , p < 0.001) and a marginal difference between stimulation conditions (F(2,40) = 2.970, p = 0.063). The post hoc analysis for these factors revealed that alpha/theta peak power ratio was significantly different between in central regions (C3-C4) between tonic and HF stimulation (p = 0.006) and temporal regions (T3-T4) between baseline and HF stimulation (p = 0.049). The comparison of NRS scores before and 3 months after surgery indicated a significant improvement in pain intensity (p < 0.001) at the group level. The neural features found to be significantly correlated with preoperative NRS scores in PFC (p = 0.036 and p = 0.025) and temporal regions (p = 0.041 and p = 0.012) under both stimulations.

CONCLUSIONS:

Our preliminary results support the possibility that different stimulation patterns affect the electrophysiological activity differently in various cortical regions. Such differences might account for the variability in pain suppression in patients with chronic pain treated with SCS. Future work will utilize this dataset to develop a machine learning classifier to support objective device selection strategies.
929 Outcomes in Pediatric Spinal Cord Injuries Based on Time to Surgery
Authors: Deaver Courtney , Nosova Kristin , Pico Annemarie Campbell , Bauer Isabel L. , Bates Bryan , He Jack , Keric Natasha , Nakaji Peter , Bina Robert Wagner
Published: March 2024

INTRODUCTION:

Early surgery in individuals with traumatic spinal cord injury (SCI) has been associated with improved neurological recovery, lower risk of complications, and reduced resource utilization. Patient and healthcare-related factors may contribute to delay in surgery. This study aimed to determine factors contributing to longer time-to-surgery in pediatric patients with complete and incomplete SCI.

METHODS:

Patients with SCI were identified in the National Trauma Data Bank based on AIS codes. Patients who died in the ED or were transferred to another hospital were excluded. Procedure codes were used to identify patients who underwent spinal surgery. Patients were grouped by time to surgery less than or greater than 12 hours.

RESULTS:

549 patients were identified with 235 incomplete and 314 complete SCI. 399 patients underwent surgery (177 incomplete; 222 complete). Of patients who underwent surgery, 55% of incomplete and 52% of complete SCI went to surgery after 12 hours. SCI patients with greater than 12-hour time-to-surgery had worse injury severity scores (32 vs 28, p < 0.05). Additionally, ICU LOS, total ventilation days, and total LOS were longer. Time-to-surgery greater than 12 hours was statistically associated with unplanned ICU stay (incomplete), unplanned OR (complete), ventilator associated pneumonia (complete), and delirium (incomplete). Time-to-surgery was not significantly associated with race, gender, or mechanism of injury. pneumonia (complete), and delirium (incomplete). Time-to-surgery was not significantly associated with race, gender, or mechanism of injury.

CONCLUSIONS:

Greater time-to-surgery is associated with higher risk of complications and longer hospital stays in patients with complete and incomplete SCI in the pediatric population. This data raises the question as to whether earlier surgery could reduce complications.
Grade 3 Meningiomas Following 2021 WHO Guidelines—A Dual Center Retrospective Study on Clinical Characteristics and Outcomes
Authors: English Collin , Pugazenthi Sangami , Leidig Will , MgGeehan Kyle , Khan Basit , Gadot Ron , Kim Albert H. , Patel Akash J.
Published: March 2024

INTRODUCTION:

In their updated 2021 guidelines, the World Health Organization (WHO) for the first time included molecular markers in the classification of Grade 3 meningiomas (G3Ms). Now, homozygous deletion of CDKN2A/B or TERT Promoter (TERTp) mutations independently qualify a meningioma as Grade 3 [1].

METHODS:

We performed a dual-center retrospective review from 2005 to 2021 on primary G3Ms. To adhere to guidelines, tumors were regraded when RNA sequencing, methylation profiling, or DNA microarray was available. Tumor recurrence was the outcome metric.

RESULTS:

A total of 1358 patients were reviewed with 31 (2.3%) primary tumors meeting criteria for Grade 3 and 4/31 (13%) meeting only molecular criteria. Among the 31 patients, 16 (52%) were female with a median age of 65. Upon regrading, 25 (81%) met only histological criteria, 3 (9.7%) had only TERTp mutations, 1 (3.1%) had only CDKN2A deletion, 1 (3.1%) met histological criteria and had TERT mutation, and 1 (3.1%) met histological criteria and had CDKN2A deletion. Molecular profiling of 18 G3Ms demonstrated chromosomal deletions in 1p (16/18, 89%), 14q (10/18, 56%), and 22q (16/18, 89%). Common locations were frontal (11/31, 35%) and parietal convexity (6/31, 23%). Histological findings included necrosis (24/31, 77%), hypercellularity (23/31, 74%), and prominent nucleoli (21/31, 68%). Tumors recurred in 9/31 (29%) and 8/31 (26%) recurred multiple times.

CONCLUSIONS:

Here we present the first description of G3Ms following the updated 2021 WHO guidelines.
Where Do Surgical Resection and Radiosurgery Fall Short for Large Metastatic Brain Lesions?
Authors: Mishra Akash , Koffler Daniel , Calugaru Emel , Viswanatha Sirisha Devi , Rowe Niara , Bajaj Vikram , Goenka Anuj , Schulder Michael
Published: March 2024

INTRODUCTION:

Stereotactic radiosurgery is established as the optimal treatment modality for metastatic disease of the brain, but there is ongoing debate about the optimal treatment for larger brain metastases. There have been few studies identifying and quantifying lesion characteristics where efficacy and local control of these lesions suffer.

METHODS:

We retrospectively identified patients who received surgical resection and/or hypofractionated Gamma Knife radiosurgery (HF-GKRS) between 2017 and 2022 for the treatment of metastatic brain tumors greater than 10cc. Clinical, treatment, and radiological data was collected. Local failure (LF) events were examined, and independent factors associated with subsequent local failure were identified.

RESULTS:

105 lesions greater than 10cc (in 97 patients) were treated and the median patient follow-up was 10.1 months. The median gross tumor volume was 15.8cc (range 10.1-62.4). Prior surgical resection was performed on 49 lesions (54%). Tumor volume larger than 33.5cc (p = 0.029, 12-month LF rate 38%) and radioresistant histology (p=0.047, 12-month LF rate 54%) were associated with increased risk of LF (p=0.018) whereas surgical resection did not correlate with increased LC (p = 0.642, 12-month LF rate 19%).

CONCLUSIONS:

Patients with brain metastases that are greater than 4cm in diameter or are of radioresistant histology (primary origin of gastrointestinal adenocarcinoma, melanoma, or renal cell carcinoma) are especially prone to local failure despite aggressive surgical resection, stereotactic radiosurgery, and systemic chemotherapy. In these cases, the optimal management needs to be further elucidated and may involve preoperative stereotactic radiosurgery or intraoperative brachytherapy.
Reliability and Predictors of Intraoperative Neuromonitoring Changes During Intramedullary Tumor Resection: A Multicenter Experience
Authors: Otamendi-Lopez Andrea , Akinduro Oluwaseun O. , de Macedo Filho Leonardo , Goyal Anshit , De Biase Gaetano , Ghaith Abdul Karim , McKevitt Chase , Kalani Maziyar A. , Meyer Fredric B. , Marsh W. Richard , Clarke Michelle J. , Krauss William E. , Bydon Mohamad , Quinones-Hinojosa Alfredo
Published: March 2024

INTRODUCTION:

Intraoperative neuromonitoring (IONM) is used in real-time to alert neurosurgeons of potential neurological changes when resecting intramedullary spinal cord tumors (IMSCTs). Previous studies have reported variable reliability of IONM.

METHODS:

A multicenter retrospective study was performed on patients undergoing IMSCTs surgery with neuromonitoring at the three Mayo Clinic sites between 2005 to 2022. Demographics, SSEP, MEP changes and postoperative outcomes were recorded. Specificity, sensitivity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Variables found significant on univariate analysis (p < 0.05) were applied to a multivariate model to identify predictors for IONM SSEP and MEP changes.

RESULTS:

135 patients underwent surgical resection for IMSCTs using IONM. The mean age at diagnosis was 45 ± 17.9 years. Laminectomy was the most frequent index operation (96.3%). A total of 8.9% of patients presented with short-term improvement, while 70.4% presented long-term improvement on their baseline McCormick Scale. Sensitivity, specificity, PPV, NPV, accounted for 86.2%, 51%, 5.2%, 99.2% for MEP; 77.8%, 48.2%, 4.4%, 98.6% for SSEP. We found predictors of IONM changes: poorly defined MEP baseline (OR 3.004, 95% CI 1.22-7.397, p = 0.017), WHO grade II tumors (OR 2.334, 95% CI 1.043-5.223, p = 0.039), cervicomedullary junction location (OR 0.103, 95% CI 0.011-0.983, p = 0.048). Only WHO grade II tumors (OR 2.85, 95% CI 1.208-6.727, p = 0.017) was a predictor for SSEP changes.

CONCLUSIONS:

Our study represents the largest cohort describing sensitivity, specificity, and predictive factors for intraoperative changes and postoperative outcomes of resection of IMSCTs. A poorly defined baseline and cervicomedullary tumor location were predictors of IONM MEP changes, whiIe WHO grade II tumors were a predictor for both IONM SSEP and MEP changes.