Dichotomous frequency-dependent phase synchrony in the sensorimotor network characterizes simplistic movement.

It is hypothesized that disparate brain regions interact via synchronous activity to control behavior. The nature of these interconnected ensembles remains an area of active investigation, and particularly the role of high frequency synchronous activity in simplistic behavior is not well known. Using intracranial electroencephalography, we explored the spectral dynamics and network connectivity of sensorimotor cortical activity during a simple motor task in seven epilepsy patients. Confirming prior work, we see a "spectral tilt" (increased high-frequency (HF, 70-100 Hz) and decreased low-frequency (LF, 3-33 Hz) broadband oscillatory activity) in motor regions during movement compared to rest, as well as an increase in LF synchrony between these regions using time-resolved phase-locking. We then explored this phenomenon in high frequency and found a robust but opposite effect, where time-resolved HF broadband phase-locking significantly decreased during movement. This "connectivity tilt" (increased LF synchrony and decreased HF synchrony) displayed a graded anatomical dependency, with the most robust pattern occurring in primary sensorimotor cortical interactions and less robust pattern occurring in associative cortical interactions. Connectivity in theta (3-7 Hz) and high beta (23-27 Hz) range had the most prominent low frequency contribution during movement, with theta synchrony building gradually while high beta having the most prominent effect immediately following the cue. There was a relatively sharp, opposite transition point in both the spectral and connectivity tilt at approximately 35 Hz. These findings support the hypothesis that task-relevant high-frequency spectral activity is stochastic and that the decrease in high-frequency synchrony may facilitate enhanced low frequency phase coupling and interregional communication. Thus, the "connectivity tilt" may characterize behaviorally meaningful cortical interactions.

Subtemporal Approach for the Treatment of Ruptured and Unruptured Distal Basilar Artery Aneurysms: Is There a Contemporary Use?

BACKGROUND AND OBJECTIVES: Distal basilar artery aneurysms (DBAs) are high-risk lesions for which endovascular treatment is preferred because of their deep location, yet indications for open clipping nonetheless remain. The subtemporal approach allows for early proximal control and direct visualization of critical posterior perforating arteries, especially for posterior-projecting aneurysms. Our objective was to describe our clinical experience with the subtemporal approach for clipping DBAs in the evolving endovascular era. METHODS: This was a retrospective, single-institution case series of patients with DBAs treated with microsurgery over a 21-year period (2002-2023). Demographic, clinical, and surgical data were collected for analysis. RESULTS: Twenty-seven patients underwent clipping of 11 ruptured and 16 unruptured DBAs with a subtemporal approach (24 female; mean age 53 years). Ten patients had expanded craniotomies for treatment of additional aneurysms. The aneurysm occlusion rate was 100%. Good neurological outcomes as defined by the modified Rankin Scale score ≤2 and Glasgow Outcome Scale score ≥4 were achieved in 21/27 patients (78%). Two patients died before hospital discharge, one from vasospasm-induced strokes and another from an intraoperative myocardial infarction. CONCLUSION: These results demonstrate that microsurgical clip ligation of DBAs using the subtemporal approach remains a viable option for complex lesions not amenable to endovascular management.

Limited Efficacy of Empiric Antibiotics for Pediatric Facial Fractures.

BACKGROUND: Controversies exist regarding the role of perioperative antibiotic use in pediatric craniomaxillofacial fracture repair. PURPOSE: This study aims to identify factors associated with antibiotic prescribing patterns and measures the association between antibiotic exposure and postoperative infections. STUDY DESIGN, SETTING, SAMPLE: In this retrospective cohort study, TriNetX, a research database, was used to gather data on patients under 18 years of age who underwent repair of facial fractures. The records were obtained from 2003 to 2021. Current Procedural Terminology codes for facial fracture procedures were used to identify patients. PREDICTOR/EXPOSURE/INDEPENDENT VARIABLE: Antibiotic use, defined as a binary categorical variable of whether or not patients received perioperative antibiotics. The secondary predictor variable was timing of antibiotic administration, categorized by pre, intra, and postoperative administration. MAIN OUTCOME VARIABLES: Postoperative infection, determined by International Classification of Diseases, 9th and 10th Revision codes within patient charts. COVARIATES: Covariates included demographic variables such as age, sex, race, ethnicity, geographic location, and fracture characteristics, such as number of fractures and location of fracture. ANALYSES: χ2 analyses were used for categorical variables and two sample t tests for quantitative variables. Multivariable logistic regression was used to evaluate patient infection and antibiotic use with adjustment for covariates. P-values were 2-tailed and statistical significance was defined as P < .05. RESULTS: This cohort included 5,413 patients of which 70.4% were male, 74.4% identified as white, and 83.3% identified as non-Hispanic or Latino. There were no differences in postoperative infections in patients who received antibiotics compared to those who did not (0.9 vs 0.5%, respectively, P = .12). Nevertheless, antibiotic prescriptions have increased over the years. After controlling for relevant covariates, antibiotic use did not decrease the odds of infection (adjusted odds ratio 1.1, 95% CI 0.53 to 2.34, P = .79). There was a significant association between the timing of antibiotic use and infection (P = .044), with increased odds of infection when antibiotics were given postoperatively (adjusted odds ratio 3.8, 95% CI 1.2 to 12.07, P = .023). CONCLUSION AND RELEVANCE: While antibiotic prescriptions have increased over the years, this study demonstrates there is no difference in postoperative infection rates for pediatric patients prescribed antibiotics and those where were not.

Factors associated with hearing outcomes after a middle fossa approach in 131 consecutive patients with vestibular schwannomas.

OBJECTIVE: The middle fossa approach is an effective option for the treatment of small (Koos grade I and II) vestibular schwannomas (VSs) when the goal is hearing preservation. The authors evaluated the rates of hearing preservation and examined the factors associated with improved hearing outcomes after the middle fossa approach for VSs. METHODS: In this retrospective, single-center cohort study evaluating the clinical outcomes after resection of small VSs using the middle fossa approach, consecutive adult patients (> 18 years) who underwent surgery between January 2000 and December 2021 were included. Clinical and imaging characteristics were analyzed, including baseline hearing status, duration of surgery, anesthetic parameters, and imaging characteristics of the surgically treated tumors. RESULTS: Among the 131 included patients, 102 had valid and discoverable pre- and postoperative audiology assessments. The mean follow-up was 26 months (range 1-180 months). There were 85 patients with serviceable hearing preoperatively, defined as American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) class A or B, of whom 78% retained class A or B hearing at the last follow-up. Binary logistic regression demonstrated that preoperative hearing AAO-HNS class (OR 0.19, 95% CI 0.05-0.77; p = 0.02), overlap between fundus and cochlea (OR 0.32, 95% CI 0.11-0.96; p = 0.04), and duration of anesthesia (OR 0.98, 95% CI 0.97-0.99; p = 0.03) were independent predictors of hearing outcomes. Additionally, 75% of patients with high diffusion-weighted imaging signal in the tumor (p = 0.009) and 67% of patients with the tumor originating at the modiolus of the cochlea (p = 0.004) had poor hearing outcomes. CONCLUSIONS: The hearing preservation rates after microsurgical resection of small VSs using the middle fossa approach are high, with 78% of patients maintaining AAO-HNS class A or B hearing. Poor hearing status at baseline, longer duration of anesthesia, and large overlap between the fundus of the internal auditory canal and the cochlea were independently associated with unfavorable hearing outcomes. Imaging characteristics can be used to stratify patients' risk of hearing loss.

Policies Restricting Overlapping Surgeries Negatively Impact Access to Care, Clinical Efficiency, and Hospital Revenue: A Forecasting Model for Surgical Scheduling.

OBJECTIVE: To model the financial impact of policies governing the scheduling of overlapping surgeries, and to identify optimal solutions that maximize operating efficiency that satisfy the fiduciary duty to patients. BACKGROUND: Hospitals depend on procedural revenue to maintain financial health as the recent pandemic has revealed. Proposed policies governing the scheduling of overlapping surgeries may dramatically impact hospital revenue. To date, the potential financial impact has not been modeled. METHODS: A linear forecasting model based on a logic matrix decision tree enabled an analysis of surgeon productivity annualized over a fiscal year. The model applies procedural and operational variables to policy constraints limiting surgical scheduling. Model outputs included case and financial metrics modeled over 1000-surgeon-year simulations. case metrics included annual case volume, case mix, operating room (OR) utilization, surgeon utilization, idle time, and staff overtime hours. Financial outputs included annual revenue, expenses, and contribution margin. RESULTS: The model was validated against surgical data. case and financial metrics decreased as a function of increasingly restrictive scheduling scenarios, with the greatest contribution margin loses ($1,650,000 per surgeon-year) realized with the introduction of policies mandating that a second patient could not enter the OR until the critical portion of the first surgery was completed. We identify an optimal scheduling scenario that maximizes surgeon efficiency, minimizes OR idle time and revenue loses, and satisfies ethical obligations to patients. CONCLUSIONS: Hospitals may expect significant financial loses with the introduction of policies restricting OR scheduling. We identify an optimal solution that maximizes efficiency while satisfying ethical duty to patients. This forecast is immediately relevant to any hospital system that depends upon procedural revenue.

#Neurosurgery: A Temporal and Content Analysis of Academic Neurosurgery on Twitter.

BACKGROUND: Social media has become ubiquitous in modern medicine. Academic neurosurgery has increased adoption to promote individual and departmental accomplishments, engage with patients, and foster collaboration. We sought to quantitatively evaluate the adoption of one of the most used social media platforms, Twitter, within academic neurosurgery. METHODS: A quantitative and qualitative analysis of Twitter use across 118 academic neurosurgery departments with residency programs in the United States was performed in March 2019 and March 2021. We collated Twitter handles, Doximity residency ranking (a peer-determined ranking system), geographic location, and Twitter demographics (tweets, followers, likes, and tweet content) from before and after the coronavirus disease 2019 (COVID-19) pandemic. Tweet content was characterized by reviewers over a predetermined 6-month period. Linear regression and parametric/nonparametric tests were used for analysis. RESULTS: Departmental accounts grew 3.7 accounts per year between 2009 and 2019 (R2 = 0.96), but 43 accounts (130%) were added between 2019 (n = 33) and 2021 (n = 76). This growth, coinciding with the COVID-19 pandemic, changed the model from linear to exponential growth (R2 = 0.97). The highest-ranking programs based on Doximity were significantly more likely to have an account (P < 0.001) and have more followers (P < 0.0001). Tweet content analysis revealed prioritization of faculty/resident activity (mean 49.9%) throughout the quartiles. CONCLUSIONS: We demonstrate rapid uptake in Twitter use among U.S. academic neurosurgical departments, accelerated by COVID-19. With the impact of COVID-19, it is clear that there will be continued rapid adoption of this platform within neurosurgery, and future studies should explore the outcomes of peer collaboration, patient engagement, and dissemination of medical information.

Theta Synchrony Is Increased near Neural Populations That Are Active When Initiating Instructed Movement.

Theta oscillations (3-8 Hz) in the human brain have been linked to perception, cognitive control, and spatial memory, but their relation to the motor system is less clear. We tested the hypothesis that theta oscillations coordinate distributed behaviorally relevant neural representations during movement using intracranial electroencephalography (iEEG) recordings from nine patients (n = 490 electrodes) as they performed a simple instructed movement task. Using high frequency activity (HFA; 70-200 Hz) as a marker of local spiking activity, we identified electrodes that were positioned near neural populations that showed increased activity during instruction and movement. We found that theta synchrony was widespread throughout the brain but was increased near regions that showed movement-related increases in neural activity. These results support the view that theta oscillations represent a general property of brain activity that may also play a specific role in coordinating widespread neural activity when initiating voluntary movement.

Network Brain-Computer Interface (nBCI): An Alternative Approach for Cognitive Prosthetics.

Brain computer interfaces (BCIs) have been applied to sensorimotor systems for many years. However, BCI technology has broad potential beyond sensorimotor systems. The emerging field of cognitive prosthetics, for example, promises to improve learning and memory for patients with cognitive impairment. Unfortunately, our understanding of the neural mechanisms underlying these cognitive processes remains limited in part due to the extensive individual variability in neural coding and circuit function. As a consequence, the development of methods to ascertain optimal control signals for cognitive decoding and restoration remains an active area of inquiry. To advance the field, robust tools are required to quantify time-varying and task-dependent brain states predictive of cognitive performance. Here, we suggest that network science is a natural language in which to formulate and apply such tools. In support of our argument, we offer a simple demonstration of the feasibility of a network approach to BCI control signals, which we refer to as network BCI (nBCI). Finally, in a single subject example, we show that nBCI can reliably predict online cognitive performance and is superior to certain common spectral approaches currently used in BCIs. Our review of the literature and preliminary findings support the notion that nBCI could provide a powerful approach for future applications in cognitive prosthetics.

Topical Vancomycin Reduces Surgical-Site Infections After Craniotomy: A Prospective, Controlled Study.

BACKGROUND: Surgical-site infections (SSIs) are an important cause of morbidity and mortality in neurosurgical patients. Topical antibiotics are one potential method to reduce the incidence of these infections. OBJECTIVE: To examine the efficacy of topical vancomycin applied within the wound during craniotomy in a large prospective cohort study at a major academic center. METHODS: Three hundred fifty-five patients were studied prospectively in this cohort study; 205 patients received 1 g of topical vancomycin powder in the subgaleal space while 150 matched control patients did not. Patients otherwise received identical care. The primary outcome variable was SSI rate factored by cohort. Secondary analysis examined cost savings from vancomycin usage estimated from hospital costs associated with SSI in craniotomy patients. RESULTS: The addition of topical vancomycin was associated with a significantly lower rate of SSI than standard of care alone (0.49% [1/205] vs 6% [9/150], P = .002). Based on the costs of revision surgery for infections, topical vancomycin usage was estimated to save $1367 446 per 1000 craniotomy patients. No adverse reactions occurred. CONCLUSION: Topical vancomycin is a safe, effective, and cost-saving measure to prevent SSIs following craniotomy. These results have broad implications for standard of care in craniotomy.