Effects of hours of sleep on ImPACT concussion testing: comparing baseline with postinjury scores.

OBJECTIVE: The influence of sleep on baseline and postconcussion neurocognitive performance prior to Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) is poorly understood. Since ImPACT is widely used in youth sport to assess neurocognitive performance before and after head injury, it is important to delineate factors that affect testing performance. While some have reported correlations between fewer hours of sleep and lower scores on baseline tests, others have not observed any such associations. Therefore, the authors sought to compare the relationship between sleep and neurocognitive performance on ImPACT at both baseline and postinjury. METHODS: The authors queried a database of 25,815 ImPACT tests taken from 2009 to 2019 by athletes aged 12-22 years. There were 11,564 baseline concussion tests and 7446 postinjury concussion ImPACT tests used in the analysis. Linear regression was used to model the effect of sleep on baseline and postconcussion ImPACT scores adjusting for sex, age, learning disability, attention-deficit/hyperactivity disorder, number of prior concussions, number of games missed, and strenuous exercise before testing. RESULTS: Mean composite scores expectedly were all significantly lower in the post-head injury group compared with the baseline group. In the multivariable analysis, at baseline, hours of sleep significantly affected symptom scores (ß = -1.050, 95% CI -1.187 to -0.9138; p < 0.0001). In the postinjury multivariable analysis, verbal memory (ß = 0.4595, 95% CI 0.2080-0.7110; p = 0.0003), visual memory (ß = 0.3111, 95% CI 0.04463-0.5777; p = 0.0221), impulse control (ß = -0.2321, 95% CI -0.3581 to -0.1062; p = 0.0003), and symptom scores (ß = -0.9168, 95% CI -1.259 to -0.5750; p < 0.0001) were all affected by hours of sleep. CONCLUSIONS: Hours of sleep did not alter neurocognitive metrics at baseline but did have an impact on post-head injury metrics. These findings suggest that individuals may be able to compensate for lack of sleep at baseline but not immediately after concussion. Concussions may reduce cognitive reserve or detract from the brain's resources, making sleep even more important for proper neurocognitive functioning postconcussion. Future work will analyze the effects of sleep on postconcussion test performance.

The Top 100 Cited Articles on Cervical Disc Arthroplasty: A Bibliometric Analysis.

STUDY DESIGN: Bibliometric analysis. OBJECTIVE: Cervical disc arthroplasty (CDA) has emerged as an effective surgical intervention for degenerative cervical disc disease with potential advantages over traditional cervical fusion. This bibliometric analysis aimed to assess the current state of research on CDA by analyzing the relevant literature using bibliometric indicators. SUMMARY OF BACKGROUND DATA: Web of Science Core Collection. METHODS: A comprehensive search was conducted using the Web of Science database, for articles related to CDA published in the last 19 years. The top 100 articles were reviewed using bibliometric analysis. Publication trends, citation patterns, authorship, and collaboration networks were analyzed using VOSviewer and the Bibliometrix package in RStudio. RESULTS: The results revealed a significant increase in the number of publications related to CDA over the past 2 decades, with most of the articles being published in orthopedic and spine surgery journals. The most frequently cited articles were related to clinical outcomes, complications, and biomechanical studies of CDA. Co-authorship analysis identified influential authors and collaborative networks, highlighting the multidisciplinary nature of CDA research involving neurosurgeons, orthopedic surgeons, and engineers. Overall, this bibliometric analysis provides a comprehensive overview of the current state of research on CDA, highlighting the key research themes, influential authors, and collaborative networks in the field. CONCLUSION: These findings can serve as a guide for researchers, clinicians, and policymakers to identify knowledge gaps, research trends, and future directions in the field of CDA.

The effect of age on baseline neurocognitive performance.

OBJECTIVE: Evaluate the independent effect of age on baseline neurocognitive performance. STUDY DESIGN: Baseline ImPACT scores from tests taken by 7454 athletes aged 12-22 from 2009 to 2019 were split into three age cohorts: 12-14 years (3244), 15-17 years (3732), and 18-22 years (477). Linear regression analyses were used to evaluate the effect of age on ImPACT composite scores while controlling for demographic differences, medication-use, and symptom burden. Significance values have been set at p < 0.05. RESULTS: Linear regression analyses demonstrated that increased age does not significantly affect symptom score (ß = 0.06, p = 0.54) but does improve impulse control (ß = -0.45, p < 0.0001), verbal memory (ß = 0.23, p = 0.03), visualmotor (ß = 0.77, p < 0.0001), and reaction time (ß = -0.008, p < 0.0001) scores.  However, age did not have an effect on visual memory scores (ß = -0.25, p = 0.07). CONCLUSIONS: Age was shown to be an independent modifier of impulse control, verbal memory, visual motor, and reaction time scores but not visual memory or symptom scores.  This underscores the previous literature showing developmental differences as age increases among the adolescent athlete population.  This data also indicates the need for repeat neurocognitive baseline testing every other year as baseline scoring is likely to change as athletes become older.

Bibliometric Analysis of the Top 100 Cited Articles and Author H-Indexes on the Surgical Treatment of Trigeminal Neuralgia.

INTRODUCTION: Medically refractory cases of trigeminal neuralgia often require treatment escalation. Surgical options include microvascular decompression and percutaneous ablation. This paper provides a bibliometric analysis of the most influential articles on the surgical management of trigeminal neuralgia. METHODS: The Web of Science database was queried to identify the top 100 cited articles concerning surgical treatment of trigeminal neuralgia. The search terms used included ALL=(("trigeminal neuralgia" OR "tic douloureux" OR "Fothergill's disease" OR "Trifacial neuralgia") AND ("surgical treatment" OR "surgical management" OR "surgery" OR "neurosurgery") NOT ("radiosurgery" OR "gamma knife")). The extracted variables included the first and senior author names, journal, publication year, institution, and surgical modality. RESULTS: Our bibliometric search yielded 2104 studies, with 41,502 citations overall. Within the top 100 articles, Zakrzewska had the most first author papers (n = 5), and Burchiel had the most senior author papers (n = 6). The Massachusetts General Hospital was the most represented institution (n = 5). The United States was the most represented country (51%). Microvascular decompression was the most studied surgical strategy (51%), followed by percutaneous radiofrequency coagulation (9%), balloon/nerve compression (7%), and glycerol rhizolysis (7%). Some studies assessed multiple treatment modalities (22%). The types of studies included retrospective articles (58%), prospective articles (26%), reviews (10%), anatomic studies (2%), and basic science (1%). Neurosurgery (35%) and the Journal of Neurosurgery (33%) were the most represented journals. CONCLUSIONS: The current literature consists of retrospective reviews and mostly describes microvascular decompression for trigeminal neuralgia. Future studies should include further characterization of other surgical modalities such as percutaneous radiofrequency thermocoagulation, glycerol injection, and balloon compression.

Clinical Considerations and Outcomes for Spine Surgery Patients with a History of Transplant: A Systematic Scoping Review.

OBJECTIVE: The objective of this study was to investigate the perioperative management and outcomes of patients with a prior history of successful transplantation undergoing spine surgery. METHODS: We searched Medline, Embase, and Cochrane Central Register of Controlled Trials for matching reports in July 2021. We included case reports, cohort studies, and retrospective analyses, including terms for various transplant types and an exhaustive list of key words for various forms of spine surgery. RESULTS: We included 45 studies consisting of 34 case reports (published 1982-2021), 3 cohort analyses (published 2005-2006), and 8 retrospective analyses (published 2006-2020). The total number of patients included in the case reports, cohort studies, and retrospective analysis was 35, 48, and 9695, respectively. The mean 1-year mortality rate from retrospective analyses was 4.6% ± 1.93%, while the prevalence of perioperative complications was 24%. Cohort studies demonstrated an 8.5% ± 12.03% 30-day readmission rate. The most common procedure performed was laminectomy (38.9%) among the case reports. Mortality after spine surgery was noted for 4 of 35 case report patients (11.4%). CONCLUSIONS: This is the first systematic scoping review examining the population of transplant patients with subsequent unrelated spine surgery. There is significant heterogeneity in the outcomes of post-transplant spine surgery patients. Given the inherent complexity of managing this group and elevated mortality and complications compared to the general spine surgery population, further investigation into their clinical care is warranted.

Baseline ImPACT Composite Scores in Student-Athletes With Attention-Deficit/Hyperactivity Disorder.

BACKGROUND: Athletes who are diagnosed with attention-deficit/hyperactivity disorder (ADHD) are at increased risk of concussion compared to other athletes. Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) is a widely used concussion tool, but it relies on pre-injury baseline testing that can be affected by psychiatric conditions. This research aims to determine if there are differences in pre-injury testing composite scores in student-athletes with ADHD compared to those without ADHD diagnosis. METHODS: We obtained 11,563 pre-season ImPACT assessments of 7,454 student-athletes (ages: 12-22) from 2009 to 2019. After exclusions, there were 6,920 control and 276 ADHD subjects. Multivariable linear regression analyses compared the independent effect of ADHD on the six ImPACT composite score metrics with Bonferroni correction for multiple comparisons with a = 0.008. RESULTS: Univariate analyses indicated ADHD is associated with more symptoms as measured by the Post-Concussion Symptom Scale (PCSS) (ß = 2.67, 95% CI: 1.47-3.87, p < .0001) and worse Impulse Control scores (ß = 0.93, 95% CI: 0.33-1.53, p = .002). In multivariate analysis, this association was the same for symptom score (ß = 2.48, 95% CI: 1.22-3.74, p < .0001), but Impulse Control was not significantly different after multiple comparison adjustment (ß = 0.87, 95% CI: 0.22-1.15, p = .009). CONCLUSIONS: The ADHD subjects reported worse symptoms at baseline and had worse Impulse Control in univariate analysis, but not multivariate analysis. These results can further guide clinicians in concussion diagnosis and test interpretations for student-athletes with ADHD, considering the symptom burden at baseline.

Bibliometric Analysis of International Medical Graduates and Professorship Promotion in Neurosurgery.

BACKGROUND: International medical graduates (IMGs) comprise ∼25% of physicians in the United States. Differences in promotion rates from assistant to associate to full professorship based on medical school location have been understudied. We aim to stratify odds of professional advancement by 3 categories: IMG with U.S. residency, IMG with international residency, and U.S. medical with U.S. residency training. METHODS: We created and queried a database after exclusions of 1334 neurosurgeons including multiple demographic factors: academic productivity and promotion rates. Stratified logistic regression modeled odds of promotion including the variables: decades out of training, Scopus h-index, gender, and training location. Odds ratios (ORs) and 95% confidence intervals (CIs) for each variable were calculated. RESULTS: Significant predictors of increased associate versus assistant professorship included decades out of training (OR = 2.519 [95% CI: 2.07-3.093], P < 0.0001) and Scopus h-index (OR = 1.085 [95% CI: 1.064-1.108], P < 0.0001) while international medical school with U.S. residency (OR = 0.471 [95% CI: 0.231-0.914], P = 0.0352) was associated with decreased promotion. Significant predictors of associate versus full professorship were decades out of training (OR = 2.781 [95% CI: 2.268-3.444], P < 0.0001) and Scopus h-index (OR = 1.064 [95% CI: 1.049-1.080], P < 0.0001). Attending medical school or residency internationally was not associated with odds of full professorship. CONCLUSIONS: Time out of residency and Scopus h-index were associated with higher academic rank regardless of career level. Attending medical school internationally with U.S. residency was associated with lower odds of associate professorship promotion over 10 years. There was no relationship between IMG and full professorship promotion. IMGs who attended residency internationally did not have lower promotion rates. These findings suggest it may be harder for IMGs to earn promotion from assistant to associate professor in neurosurgery.

Effects of repetitive head trauma on symptomatology of subsequent sport-related concussion.

OBJECTIVE: Adolescent participation in athletics continues to grow, leading to an increasing incidence of sports-related concussion (SRC). The current literature suggests that a greater number of prior concussions positively correlates with a greater number of total symptoms, but the specific concussion-related symptoms are not as well defined. The current study investigated the effects of prior recurrent head injury on the symptom profiles of student-athletes after another suspected concussion. METHODS: A multicenter database consisting of 25,815 Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) results was filtered for student-athletes aged 12-22 years old who competed in 21 different sports. Patients were separated into 2 cohorts: athletes reporting a single prior concussion (SRC1) and athletes reporting 2 or more prior concussions (SRC2+). Comparisons were assessed for differences in 22 symptoms and 4 symptom clusters at baseline, first postinjury test (PI1), and second postinjury test (PI2) by using univariate and multivariate analyses. RESULTS: No differences were seen between SRC1 (n = 2253) and SRC2+ (n = 976) at baseline. At PI1, the SRC2+ group (n = 286) had lower severity of headaches (p = 0.04) but increased nervousness (p = 0.042), irritability (p = 0.028), sadness (p = 0.028), visual problems (p = 0.04), and neuropsychiatric symptoms (p = 0.009) compared with SRC1 (n = 529). Multivariate analysis revealed decreased headache severity with increased prior concussion (ß = -0.27,95% CI -0.45 to -0.09, p = 0.003). Multivariate analysis at PI2 demonstrated the SRC2+ cohort (n = 130) had increased cognitive (ß = 1.22, 95% CI 0.27-2.18, p = 0.012), sleep (ß = 0.63, 95% CI 0.17-1.08, p = 0.007), and neuropsychiatric (ß = 0.67,95% CI 0.14-1.2,0.014) symptoms compared with SRC1 (n = 292). CONCLUSIONS: At longitudinal follow-up, patients with a history of recurrent concussions reported greater symptom burden in cognitive, sleep, and neuropsychiatric symptom clusters but not migraine symptoms. This is an important distinction because migraine symptoms are often more easily distinguishable to patients, parents, and physicians. Careful assessment of specific symptoms should be considered in patients with a history of recurrent head injury prior to return to play.

Novel Grading Scales for Static and Flexion-Extension Magnetic Resonance Imaging in Patients with Cervical Spondylotic Myelopathy.

BACKGROUND: Flexion-extension magnetic resonance imaging (MRI) has potential to identify cervical pathology not detectable on conventional static MRI. Our study evaluated standard quantitative and novel subjective grading scales for assessing the severity of cervical spondylotic myelopathy in dynamic sagittal MRI as well as in static axial and sagittal images. METHODS: Forty-five patients underwent both conventional and flexion-extension MRI prior to anterior cervical discectomy and fusion from C4 through C7. In addition to measuring Cobb angles and cervical canal diameter, grading scales were developed for assessment of vertebral body translation, loss of disc height, change in disc contour, deformation of cord contour, and cord edema. Data were collected at all levels from C2-C3 through C7-T1. Variations in measurements between cervical levels and from flexion through neutral to extension were assessed using Mann-Whitney, Kruskal-Wallis, and two-way ANOVA tests. RESULTS: Cervical canal diameter, vertebral translation, and posterior disc opening changed significantly from flexion to neutral to extension positions (P < 0.01). When comparing operative versus nonoperative cervical levels, significant differences were found when measuring sagittal cervical canal dimensions, vertebral translation, and posterior disc opening (P < 0.01). Degenerative loss of disc height, disc dehydration, deformation of ventral cord contour, and cord edema were all significantly increased at operative levels versus nonoperative levels (P < 0.01). CONCLUSIONS: Flexion-extension MRI demonstrated significant changes not available from conventional MRI. Subjective scales for assessing degenerative changes were significantly more severe at levels with operative cervical spondylotic myelopathy. The utility of these scales for planning surgical intervention at specific and adjacent levels is currently under investigation.

The Effect of Multiple Scopus Profiles on the Perceived Academic Productivity of Neurosurgeons in the United States.

OBJECTIVE: Bibliometrics assessing academic productivity plays a significant role in neurosurgeons' career advancement. This study aimed to evaluate the influence of multiple author profiles on Scopus on neurosurgeon author-level metrics (h-index, document number, citation number). METHODS: A list of 1671 academic neurosurgeons was compiled through public searches of hospital and faculty websites for 115 neurosurgical residency training programs. The h-index, document number, and citation number for each neurosurgeon were collected using the Scopus algorithm. For surgeons with multiple profiles, total document number and citation number were calculated by summing results of each profile. Cumulative h-indices were calculated manually. Comparisons were made between surgeons with a single Scopus profile and surgeons with multiple profiles. RESULTS: A total of 124 neurosurgeons with multiple profiles were identified. Gender distribution (P = 0.47), years in practice (P = 0.06), subspecialty (P = 0.32), and academic rank (P = 0.16) between neurosurgeons with a single profile versus multiple profiles were similar. Primary profile h-index median was 16 (interquartile range [IQR]: 8-34), combined profiles median was 20 (IQR: 11-36), and percent loss median was 17.3% (IQR: 3%-33%) (P < 0.001). For document number, primary profile median was 46 (IQR: 16-127), combined profiles median was 55 (IQR: 22-148), and percent loss median was 16.2% (IQR: 7%-36%) (P < 0.001). For citation number, primary profile median was 1030 (IQR: 333-4082), combined profiles median was 1319 (IQR: 546-4439), and percent loss median was 14.1% (IQR: 4%-32%) (P < 0.001). CONCLUSIONS: U.S. academic neurosurgeons with multiple existing profiles on Scopus experience a 17.3% loss in h-index, a 16.2% loss in document number, and a 14.1% loss in citations, heavily undercounting their perceived academic productivity.

Seasonal Effects on Postoperative Complications After Spinal Surgery: A National Database Analysis.

OBJECTIVE: To investigate the role of seasonality on postoperative complications after spinal surgery. METHODS: Data were obtained from the American College of Surgeons National Surgical Quality Improvement Program database from 2011 to 2018. Current Procedural Terminology codes were used to identify the following procedures: posterior cervical decompression and fusion, cervical laminoplasty, posterior lumbar fusion, lumbar laminectomy, and spinal deformity surgery. The database was queried for deep vein thrombosis (DVT), pulmonary embolism, pneumonia, sepsis, septic shock, Clostridium difficile infection, stroke, cardiac arrest, myocardial infarction, urinary tract infection (UTI), and early unplanned hospital readmission (readmission). Warm season was defined as April-September, whereas cold season was defined as October-March. Statistical analysis included computing overall complication rates and comparison between seasons using univariate analysis and multivariable logistic regression. RESULTS: A total of 208,291 individuals underwent spinal surgery from 2011 to 2018. There was a statistically significant increase in UTI (odds ratio [OR], 1.16; 95% confidence interval [CI], 1.07-1.26; P = 0.0002) and readmission (OR, 1.06; 95% CI, 1.02-1.11, P = 0.007) in the warm season compared with the cold season. An investigation into the July effect showed increases in DVT (OR, 1.24; 95% CI, 1.03-1.48; P = 0.020) and thromboembolic events (OR 1.17; 95% CI, 1.01-1.35; P = 0.032) in July-September compared with the preceding 3 months. CONCLUSIONS: The results showed a higher incidence of UTI and readmission among spine surgery patients in the warm season and a higher incidence of DVT and thromboembolic events from July to September. In both cases, the effect of seasonality is statistically significant, but the absolute difference is small and may not suggest policy changes.

International Survey of Antiseizure Medication Use in Patients with Complicated Mild Traumatic Brain Injury: A New York Neurotrauma Consortium Study.

BACKGROUND: Seizures and epilepsy after traumatic brain injury (TBI) negatively affect quality of life and longevity. Antiseizure medication (ASM) prophylaxis after severe TBI is associated with improved outcomes; these medications are rarely used in mild TBI. However, a paucity of research is available to inform ASM use in complicated mild TBI (cmTBI) and no empirically based clinical care guidelines for ASM use in cmTBI exist. We aim to identify seizure prevention and management strategies used by clinicians experienced in treating patients with cmTBI to characterize standard care and inform a systematic approach to clinical decision making regarding ASM prophylaxis. METHODS: We recruited a multidisciplinary international cohort through professional organizational listservs and social media platforms. Our questionnaire assessed factors influencing ASM prophylaxis after cmTBI at the individual, institutional, and health system-wide levels. RESULTS: Ninety-two providers with experience managing cmTBI completed the survey. We found a striking diversity of ASM use in cmTBI, with 30% of respondents reporting no/infrequent use and 42% reporting frequent use; these tendencies did not differ by provider or institutional characteristics. Certain conditions universally increased or decreased the likelihood of ASM use and represent consensus. Based on survey results, ASMs are commonly used in patients with cmTBI who experience acute secondary seizure or select positive neuroimaging findings; we advise caution in elderly patients and those with concomitant neuropsychiatric illness. CONCLUSIONS: This study is the first to characterize factors influencing clinical decision making in ASM prophylaxis after cmTBI based on multidisciplinary multicenter provider practices. Prospective controlled studies are necessary to inform standardized guideline development.

Effects of a history of headache and migraine treatment on baseline neurocognitive function in young athletes.

OBJECTIVE/BACKGROUND: Despite the prevalence of concussions in young athletes, the impact of headaches on neurocognitive function at baseline is poorly understood. We analyze the effects of a history of headache treatment on baseline ImPACT composite scores in young athletes. METHODS: A total of 11,563 baseline ImPACT tests taken by 7,453 student-athletes ages 12-22 between 2009 and 2019 were reviewed. The first baseline test was included. There were 960 subjects who reported a history of treatment for headache and/or migraine (HA) and 5,715 controls (CT). The HA cohort included all subjects who self-reported a history of treatment for migraine or other type of headache on the standardized questionnaire. Chi-squared tests were used to compare demographic differences. Univariate and multivariate regression analyses were used to assess differences in baseline composite scores between cohorts while controlling for demographic differences and symptom burden. RESULTS: Unadjusted analyses demonstrated that HA was associated with increased symptoms (ß=2.30, 95% CI: 2.18-2.41, p<.0001), decreased visual memory (ß=-1.35, 95% CI: -2.62 to -0.43, p=.004), and increased visual motor speed (ß=0.71, 95% CI: 0.23-1.19, p=.004) composite scores. Baseline scores for verbal memory, reaction time, and impulse control were not significantly different between cohorts. Adjusted analyses demonstrated similar results with HA patients having greater symptom burden (ß=1.40, 95% CI: 1.10-1.70, p<.0001), lower visual memory (ß=-1.25, 95% CI: -2.22 to -0.27, p=.01), and enhanced visual motor speed (ß=0.60, 95% CI: 0.11-1.10, p=.02) scores. CONCLUSION: HA affected symptom, visual motor speed, and visual memory ImPACT composite scores. Visual memory scores and symptom burden were significantly worse in the HA group while visual motor speed scores were better, which may have been due to higher stimulant use in the HA group. The effects of HA on visual motor speed and visual memory scores were independent of the effects of the increased symptom burden.

Clinical Considerations and Outcomes for Spine Surgery Patients with a History of Transplant: A Systematic Scoping Review Protocol.

Spine surgery patients with a history of organ transplantation are a complex population due to their unique anesthetic considerations, immunologic profiles, drug interactions, and potential organ dysfunction. It is common for these patients to develop neck/back pain and pathology that warrants surgical intervention. However, there is a relative dearth of literature examining their outcomes and clinical considerations. The purpose of this protocol is to investigate their clinical outcomes following spine surgery and medical management. We perform a systematic literature search using PRISMA-ScR guidelines to include case reports, cohort studies, and retrospective analyses. The search terms include kidney, liver, heart, pancreas, lung, and bone marrow for transplants of interest and contain an extensive list of terms covering spine surgery. The search is conducted using Medline, Embase, and the Cochrane Central Register of Controlled Trials. A thorough examination of titles and abstracts is performed followed by data extraction. The data points include patient demographics, past medical history, spine procedural information, and clinical outcomes. This systematic review will aid clinicians in identifying demographics, medical management, and clinical outcomes for spine surgery patients with a previous organ transplant. These findings will highlight the gaps in the knowledge of this complex population and stimulate further research.

Subspecialty and Training Preferences for U.S. Neurosurgery Faculty with International Training.

BACKGROUND: Academic neurosurgeons with international medical training play a large role in the U.S. neurosurgical workforce. We aimed to compare U.S.-trained neurosurgeons with internationally trained neurosurgeons to reveal differences in subspecialty preferences and training opportunities abroad. METHODS: We identified 1671 neurosurgeons from 115 Accreditation Council for Graduate Medical Education (ACGME)-accredited neurosurgical residency programs. Data on demographics, institution characteristics, and chosen subspecialty were collected, and faculty were divided based on location of training. Univariate analysis and multivariable logistic regression compared faculty characteristics between training locations. RESULTS: Compared with the U.S. medical school + U.S. residency group, the international medical graduate + U.S. residency group was more likely to subspecialize in oncology/skull base and vascular neurosurgery and complete a fellowship in the United States or internationally (P < 0.05). The international medical graduate + international residency group was more likely to subspecialize in oncology/skull base neurosurgery, more likely to complete an international fellowship, and less likely to practice general neurosurgery (P < 0.05). Neurosurgeons in pediatrics, radiosurgery, and vascular subspecialties were more likely to receive fellowship training in any location (P < 0.05). Additionally, functional neurosurgeons were more likely to complete fellowships internationally, spinal neurosurgeons were less likely to pursue international fellowships, and peripheral nerve neurosurgeons were more likely to have dual fellowship training in both the United States and abroad (P < 0.05). CONCLUSIONS: International medical training affected subspecialty choice and fellowship training. Internationally trained neurosurgeons more often specialized in oncology and vascular neurosurgery. Functional neurosurgeons were more likely to complete international fellowships, spine neurosurgeons were less likely to complete international fellowships, and peripheral nerve neurosurgeons more often had both U.S. and international fellowships.

High altitude modulates concussion incidence, severity, and recovery in young athletes.

BACKGROUND: High altitude may affect concussion, but prior studies are limited . We tested whether high altitude affects sport-related concussion (SRC) incidence, severity, and recovery. METHODS: Twenty-five thousand eight hundred fifteen baseline and post-injury Immediate Post-Concussion Assessment and Cognitive Testing results were compiled from Florida and Colorado, low (27 m or 62 m) and high (1,640 m or 1,991 m) altitude locations, respectively. Incidence, severity, and recovery of injury were compared between altitudes. RESULTS: High altitude was associated with increased suspected concussion incidence (adjusted OR, 2.04 [95% CI, 1.86 to 2.24];P < .0001). However, high altitude was associated with lower concussion severity measured by Severity Index (SI) (adjusted OR, 0.42 [95% CI, 0.37 to 0.49];P < .0001). High altitude was associated with decreased recovery from post-concussive symptoms in the migraine (ß, -2.72 [95% CI, -3.31 to -2.13]; P < .0001), cognitive (ß, -1.88 [95% CI, -2.40 to -1.36]; P < .0001), and sleep symptom clusters (ß, -0.30 [95% CI, -0.52 to -0.08]; P = .007). Athletes with initial SI≥8 showed prolonged neurocognitive dysfunction at high altitude (HR, 1.38 [95% CI, 1.06 to 1.81]; P = .02). CONCLUSIONS: High altitude was associated with increased suspected concussions and prolonged recovery but less severe initial injury.

Seasonal Effects on Surgical Site Infections Following Spine Surgery.

BACKGROUND: Studies investigating seasonality as a risk factor for surgical site infections (SSIs) after spine surgery show mixed results. This study used national data to analyze seasonal effects on spine surgery SSIs. METHODS: National Surgical Quality Improvement Program data (2011-2018) were queried for posterior cervical fusions (PCFs), cervical laminoplasties, posterior lumbar fusions (PLFs), lumbar laminectomies, and deformity surgeries. Patients aged >89 and procedures for tumors, fractures, infections, and nonelective indications were excluded. Patients were divided into warm (admitted April-September) and cold (admitted October-March) seasonal groups. End points were SSIs and reoperations for wound débridement/drainage. Stratified analyses were performed by surgery type and pre-versus postdischarge infections. RESULTS: Overall (N = 208,291), SSIs were more likely in the warm season (odds ratio [OR] 1.15, 95% confidence interval [CI] 1.08-1.23, P < 0.0001) and for PCFs (OR 1.40, 95% CI 1.08-1.80, P = 0.011), PLFs (OR 1.15, 95% CI 1.04-1.28, P = 0.006), and lumbar laminectomies (OR 1.13, 95% CI 1.03-1.25, P = 0.014). Postdischarge infections were also more likely in the warm season overall (OR 1.15, 95% CI 1.07-1.23, P < 0.0001) and for PCFs (OR 1.32, 95% CI 1.01-1.73, P = 0.041), PLFs (OR 1.14, 95% CI 1.03-1.27, P = 0.014), and lumbar laminectomies (OR 1.15, CI 1.04-1.27, P = 0.007). In-hospital infections were more likely during the warm season only for PCFs (OR 2.54, 95% CI 1.06-6.10, P = 0.037). Reoperations for infection were more likely during the warm season for PLFs (OR 1.29, 95% CI 1.08-1.54, P = 0.005). CONCLUSIONS: PCF, PLF, and lumbar laminectomy performed during the warm season had significantly higher odds of SSI, especially postdischarge SSIs. Reoperation rates for wound management were significantly increased during the warm season for PLFs. Identifying seasonal causes merits further investigation and may influence surgeon scheduling and expectations.

Incidence and Severity of Concussions Among Young Soccer Players Based on Age, Sex, and Player Position.

BACKGROUND: Previously studied risk factors for sports-related concussion in soccer players include sex, age, and player position. However, prior studies were limited in number, they reported conflicting results, and most did not assess initial concussion severity. PURPOSE/HYPOTHESIS: The purpose of this study was to conduct an in-depth analysis of soccer players across key demographic groups (sex, age, position) for both concussion incidence and severity. It was hypothesized that concussion incidence and severity would be higher among male players, players aged ≥17 years, and goalkeepers. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: The authors analyzed baseline and postinjury ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing) scores for athletes aged 12 to 22 years between July 2009 and June 2019. Players were assigned to an age group based on when they had their most recent baseline test. Concussion incidence and concussion severity index were compared using t tests and multivariate logistic regression. RESULTS: For 1189 individuals who reported soccer as their primary sport, 1032 contributed 1754 baseline ImPACT tests (some individuals had multiple baseline tests), whereas 445 individuals were suspected of sustaining a concussion and then referred for a postinjury 1 test. Of these players, 254 (24.6%) had both a baseline and a postinjury test and were analyzed for concussion severity. Linear regression showed that forwards had a lower incidence of ImPACT-proxied concussions than goalkeepers had (P = .008). Female players had a significantly higher incidence of ImPACT concussions compared with male players (mean, 0.07 [female] vs 0.04 [male] concussions per person-year; P = .05). Players in the ≥17-year age group had a higher incidence of ImPACT concussions than players in the 15- to 16-year age group (P = .04), although the 15- to 16-year age group had more severe concussions than the ≥17-year age group (mean severity index, 2.91 [age 15-16 years] vs 1.73 [age ≥17 years]; P = .001). CONCLUSION: Female soccer players experienced a higher incidence of concussion than did male players, and goalkeepers experienced a greater incidence of ImPACT concussions than did forwards. Players of both sexes and all positions in the 15- to 16-year age group showed increased initial concussion severity compared with the ≥17-year age group, despite a lower comparative incidence of ImPACT concussions. Further study is needed to understand whether sex and player position affect concussion severity.

Sport Contact Level Affects Post-Concussion Neurocognitive Performance in Young Athletes.

OBJECTIVE: Contact level affects the incidence of sports-related concussion. However, the effects of contact level on injury severity and recovery are less clear and are the focus of this study. METHOD: Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) for athletes aged 12-22 was performed at baseline (n = 10,907 for 7,058 athletes), after suspected concussion determined by physicians or athletic trainers (n = 5,062 for 4,419 athletes), and during follow-up visits (n = 3,264 for 2,098 athletes). Athletes played contact/collision (CC), limited contact (LC), and noncontact (NC) sports. Injury incidence, severity, and recovery were measured using raw and change from baseline neurocognitive test scores. Comparisons between groups used univariate analysis and multivariable regression controlling for demographic variables. RESULTS: Compared to CC athletes, LC and NC athletes showed decreased suspected concussion incidence. At initial post-injury testing, all neurocognitive test scores were similar between groups except changes from baseline for processing speed were improved for LC compared to CC athletes. Upon follow-up testing, raw neurocognitive scores were better for NC compared to the contact collision athletes in verbal memory, processing speed, total symptom score, migraine cluster, cognitive cluster, and neuropsychiatric cluster scores. For change from baseline scores, LC athletes exhibited better performance on verbal memory, processing speed, and reaction time but also showed higher neuropsychiatric scores than CC athletes. CONCLUSION: Neurocognitive scores between contact levels were similar at the first post-injury test. However, follow up showed many improved scores and symptoms for limited and NC sports compared to CC sports, which may indicate faster recovery.