Bibliometric and trend analysis of the top 100 most-cited articles on lateral interbody fusion (LIF).

PURPOSE: Lateral interbody fusion (LIF) is an increasingly popular minimally-invasive spine procedure. This study identifies notable trends in LIF literature and provides a detailed review of the bibliometric aspects of the top 100 most-cited articles. METHODS: Articles were queried from the Web of Science database. Inclusion criteria consisted of peer-reviewed articles, full-text availability, and LIF focus. Network analysis including co-authorship mapping and bibliographic coupling were complemented by trend analysis to determine prominent contributors and themes. Analyses were conducted using VOSviewer and Bibliometrix (RStudio). RESULTS: There has been a rapid increase in LIF publication and citation count since 1998. Leading journals were Spine (n = 24), Journal of Neurosurgery Spine (n = 22), and European Spine Journal (n = 12). NuVasive funded the most publications (n = 17), followed by DePuy Synthes Spine (n = 4). The United States was the most represented country (n = 81); however, trend analysis suggests a steadily growing international contribution. The most prolific author was J.S. Uribe (n = 16), followed by a tie in second place by E. Dakwar and L. Pimenta (n = 8). The most frequent keywords, "complication" (n = 34), "surgery" (n = 30), and "outcomes" (n = 24), demonstrated a patient-centric theme. CONCLUSIONS: This bibliometric analysis provides in-depth insights into the evolution and trends of LIF over the last two decades. The trends and themes identified demonstrate the innovative, collaborative, and patient-focused characteristics of this subfield. Future researchers can use this as a foundation for understanding the past and present state of LIF research while designing investigations.

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.

A multicenter, longitudinal survey of headaches and concussions among youth athletes in the United States from 2009 to 2019.

OBJECTIVE/ BACKGROUND: Chronic headaches and sports-related concussions are among the most common neurological morbidities in adolescents and young adults. Given that the two can overlap in presentation, studying the effects of one on another has proven difficult. In this longitudinal study, we sought to assess the relationship between chronic headaches and concussions, analyzing the role of historic concussions on chronic headaches, as well as that of premorbid headaches on future concussion incidence, severity, and recovery. METHODS: This multi-center, longitudinal cohort study followed 7,453 youth athletes who were administered demographic and clinical surveys as well as a total of 25,815 Immediate Post-concussion Assessment and Cognitive Testing (ImPACT) assessments between 2009 and 2019. ImPACT was administered at baseline. Throughout the season concussions were examined by physicians and athletic trainers, followed by re-administration of ImPACT post-injury (PI), and at follow-up (FU), a median of 7 days post-concussion. Concussion incidence was calculated as the total number of concussions per patient years. Concussion severity and recovery were calculated as standardized deviations from baseline to PI and then FU in Symptom Score and the four neurocognitive composite ImPACT scores: Verbal Memory, Visual Memory, Processing Speed, and Reaction Time. Data were collected prospectively in a well-organized electronic format supervised by a national research-oriented organization with rigorous quality assurance. Analysis was preformed retrospectively. RESULTS: Of the eligible athletes, 1,147 reported chronic headaches (CH) at the start of the season and 6,306 reported no such history (NH). Median age of the cohort was 15.4 ± 1.6 years, and students were followed for an average of 1.3 ± 0.6 years. A history of concussions (OR 2.31, P < 0.0001) was associated with CH. Specifically, a greater number of past concussions (r2 = 0.95) as well as concussions characterized by a loss of consciousness (P < 0.0001) were associated with more severe headache burden. The CH cohort had a greater future incidence of concussion than the NH cohort (55.6 vs. 43.0 per 100 patient-years, P < 0.0001). However, multivariate analysis controlling for demographic, clinical, academic, and sports-related variables yielded no such effect (OR 0.99, P = 0.85). On multivariable analysis the CH cohort did have greater deviations from baseline to PI and FU in Symptom Score (PI OR per point 1.05, P = 0.01, FU OR per point 1.11, P = 0.04) and Processing Speed (OR per point 1.08, P = 0.04), suggesting greater concussion severity and impaired symptomatic recovery as compared to the NH cohort. CONCLUSION: A history of concussions was a significant contributor to headache burden among American adolescents and young adults. However, those with chronic headaches were not more likely to be diagnosed with a concussion, despite presenting with more severe concussions that had protracted recovery. Our findings not only suggest the need for conservative management among youth athletes with chronic headaches, they also indicate a potential health care gap in this population, in that those with chronic headaches may be referred for concussion diagnosis and management at lower rates than those with no such comorbidity.

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.

A Multivariable Analysis to Evaluate the Presence or Absence of Gender Differences in Baseline ImPACT Composite Scores and Symptom Severity Ratings in Student-Athletes Ages 12-18 Years.

INTRODUCTION: Gender differences in neurocognitive function have been reported over the past few decades. However, multiple studies that report gender differences in Immediate Post-Concussion Assessment and Cognitive Tests composite scores ignore potential confounders which may lead to inaccurate results. METHODS: A total of 4829 male and 2477 female baseline Immediate Post-Concussion Assessment and Cognitive Tests from 2009 to 2019 of subjects ages 12-18 years were used to evaluate gender differences in baseline neurocognitive scores and symptom severity ratings. Regression analyses were used to assess the effects of gender on neurocognitive performance at baseline while controlling for a number of potential confounders including symptom burden at the time of testing. RESULTS: Differences in 3 of 5 composite scores as well as severity rating scores were maintained in multivariate analysis. Females had increased Post-Concussion Symptom Scale (ß = 3.54, 95% confidence interval, 2.91 to 4.16, P < .0001) along with higher verbal memory (ß = 1.82, 95% confidence interval, 1.15 to 2.50, P < .0001) and visual motor (ß = 1.29, 95% confidence interval, 0.85-1.72, P < .0001) scores. CONCLUSIONS: Statistically significant gender differences were found in baseline neurocognitive function. This study clarifies for the first time that gender differences in these neurocognitive domains are not simply an artifact of differences in symptom burden. However, the small effect sizes call into question the clinical relevance of these differences.

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.

Effects of Recurrent Mild Traumatic Brain Injuries on Incidence, Severity, and Recovery of Concussion in Young Student-Athletes.

OBJECTIVE: To examine the effects of recurrent concussions on the incidence, severity, and recovery of significant neurocognitive dysfunction (SND) in young athletes. SETTING: Various US youth sports organizations that utilize Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) for baseline and postinjury concussion testing. PARTICIPANTS: Data from 11 563 ImPACT baseline evaluations of US student-athletes aged 12 to 22 years were separated into 2 cohorts: subjects reporting 2 or more previous concussions (PC; n = 976 baseline evaluations) at baseline and a control group reporting zero previous concussions (CT; n = 7743 baseline evaluations). Subjects reporting 1 prior concussion were excluded. DESIGN: Retrospective cohort. MAIN MEASURES: Differences in SND incidence, severity, and recovery between the 2 cohorts were assessed using chi-squared tests, t tests, survival analyses, and multivariate regressions. RESULTS: The PC cohort had a higher incidence of head injury leading to ImPACT (436.7 per 1000 person-years vs 194.4 per 1000 person-years, P < .0001) and a higher incidence of SND (140.4 vs 71.8, P < .0001) than controls. However, the Severity Index (SI) demonstrated that SND severity was lower in the PC group (7.55 vs 8.59, P = .04). Adjusted analyses similarly demonstrated that the PC cohort had increased SND incidence (odds ratio = 1.93; 95% CI, 1.61 to 2.31; P < .0001), decreased SI (ß = -1.37; 95% CI, -2.40 to -0.34; P = .009), and equivalent recovery (hazard ratio = 0.98; 95% CI, 0.76 to 1.72; P = .90). CONCLUSION: Participants with a history of concussion have a higher incidence of SND but present with lower severity SND, which may be a result of increased concussion education or symptom awareness. Recurrent concussion has no significant impact on acute neurocognitive recovery. Together, these results provide evidence against the supposition that a history of concussion increases the severity of future SND.

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.

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.

Return to play after head injury in adolescent sports: evaluating football versus other sports.

OBJECTIVE: Increased adolescent sports participation has raised concerns about higher rates of concussions, a prevalent injury among young athletes with potential long-term effects. Discrepancies in concussion recovery and management protocols across various sports underscore a critical issue in youth athletics. This study aimed to examine the relationship between sport type and the number of games missed following a concussion to inform targeted management strategies. METHODS: Data from 7445 postinjury ImPACT tests for athletes aged 12-22 years, collected from 2009 to 2019, were analyzed across different sports: baseball, basketball, cheerleading, football, ice hockey, lacrosse, soccer, softball, swimming, track and field, volleyball, and wrestling. The number of days and normalized missed games (NMG), a metric accounting for the different number of games in a season for different sports, were used to evaluate the effect of concussions across different sports. ANOVA, t-tests, and linear regression analyses were performed to model the effect of sport type on games missed in a season while controlling for sex, age, concussion history, diagnosed learning disability (DLD), and attention-deficit/hyperactivity disorder (ADHD). RESULTS: Multivariable linear regression analysis demonstrated that football participation significantly increased NMG (ß 1.681, 95% CI 0.807-2.554; p < 0.001) and days missed (ß 1.637, 95% CI 1.044-2.231; p < 0.001) after head injury. Concussion diagnoses were also found to significantly increase NMG (ß 2.344, 95% CI 1.629-3.059; p < 0.001) and days missed (ß 1.560, 95% CI 1.074-2.045; p < 0.001), as well as history of prior concussion (NMG: ß 7.791, 95% CI 7.368-8.215; p < 0.001; days missed: ß 5.232, 95% CI 4.945-5.520; p < 0.001). In contrast, factors such as age, sex, DLD, ADHD, and concussions causing loss of consciousness did not significantly affect NMG or days missed. ANOVA with Tukey Honest Significant Difference indicated that compared with football, ice hockey (mean difference [MD] 5.4 days, p = 0.011) and track and field (MD 4.1 days, p = 0.006) were associated with significantly more days being missed after head injury. Conversely, basketball (MD -3.0, p < 0.001) and volleyball (MD -2.6, p = 0.005) were associated with fewer missed games. CONCLUSIONS: Adolescents playing football missed fewer days and games after concussion than other contact and noncontact sports, including ice hockey and track and field, raising questions about variations in return-to-play protocols and cultural attitudes within sports. Further research is needed to determine the factors affecting games missed across sport types in adolescent athletics and return-to-play protocols.

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.

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 100 Top-Cited Articles on Robotic Neurosurgery: A Bibliometric Analysis.

BACKGROUND: Robotic neurosurgery is a rapidly advancing field with numerous applications in various subspecialties, including spine, functional, skull base, and cerebrovascular. This study aims to provide a comprehensive analysis of the most-cited articles on robotic neurosurgery. METHODS: The Web of Science database was used to collect data, and bibliometric analysis was performed using VOSviewer and RStudio. Network analysis techniques such as co-occurrence, coauthorship, bibliographic coupling, and thematic mapping analyses were used to identify the top 100 most cited articles, major contributors, emerging trends, and noteworthy themes in the field. RESULTS: The results showed that there has been a steady increase in the number of publications on robotic neurosurgery since 1991, with an exponential growth in the number of citations. The United States was the most common country of origin for articles, followed by Canada. The most productive authors in this field were Burton S.A. and Gerszten P.C., while the University of Pittsburgh was the most productive institution, and Neurosurgery was the most productive journal. Themes such as robotics, back pain, and prostate cancer, as well as trends in developing new technologies and improving the precision of surgical procedures, were identified. CONCLUSIONS: This study provides a comprehensive analysis of the most-cited articles on robotic neurosurgery. The broad range of topics and techniques explored emphasize the importance of continued innovation and investigation. Ultimately, the study's findings provide valuable guidance for future research and contribute to advancing our understanding of this critical area of study.

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.

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.

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.

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.

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.

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.