A visual analog scale for patient-reported voice outcomes: The VAS voice.

OBJECTIVES: Although patient-reported outcome measures (PROMs) can be useful for assessing quality of life, they can be complex and cognitively burdensome. In this study, we prospectively evaluated a simple patient-reported voice assessment measure on a visual analog scale (VAS voice) and compared it with the Voice Handicap Index (VHI-10). STUDY DESIGN: Prospective survey. METHODS: An abbreviated voice measure was designed by a team of otolaryngologists, speech pathologists, and patients that consisted of four VAS questions related to (a) a global question of voice disturbance, (b) physical function of voice, (c) functional issues, and (d) emotional handicap. All English-speaking patients presenting to an academic laryngology clinic for a voice complaint were included. Internal consistency and validity were assessed with comparison to the VHI-10. RESULTS: A total of 209 patients were enrolled. Ninety-two percent of patients reported understanding the survey. The four-item VAS survey was highly correlated with VHI-10 score (Pearson correlation .81, P < .0001), and the Cronbach's alpha between all four VAS questions was .94. Age, gender, and diagnosis were not associated with either the global VAS or VHI-10 tool. CONCLUSION: Reducing the complexity of instruments assessing voice-related quality of life is feasible, and the VAS voice correlated with existing measures. Simplified assessments may offer advantages compared to more cumbersome PROMs. LEVEL OF EVIDENCE: 2c.

A Near-Peer Educational Model for Online, Interactive Learning in Emergency Medicine.

INTRODUCTION: The COVID-19 pandemic led to a large disruption in the clinical education of medical students, particularly in-person clinical activities. To address the resulting challenges faced by students interested in emergency medicine (EM), we proposed and held a peer-led, online learning course for rising fourth-year medical students. METHODS: A total of 61 medical students participated in an eight-lecture EM course. Students were evaluated through pre- and post-course assessments designed to ascertain perceived comfort with learning objectives and overall course feedback. Pre- and post-lecture assignments were also used to increase student learning. RESULTS: Mean confidence improved in every learning objective after the course. Favored participation methods were three-person call-outs, polling, and using the "chat" function. Resident participation was valued for "real-life" examples and clinical pearls. CONCLUSION: This interactive model for online EM education can be an effective format for dissemination when in-person education may not be available.

Measuring the impact of dysphonia on quality of life using health state preferences.

OBJECTIVES: Formal evaluation of health states related to dysphonia have not been rigorously evaluated in affected patients. The objective of this project was to evaluate the health states of mild, moderate, and severe dysphonia using formal health state preference evaluation, and to compare these outcomes with the degree of voice handicap. DESIGN: Prospective health state preference assessment. METHODS: A convenience sample of patients presenting with voice complaints were enrolled from an academic voice center. Demographic and voice handicap index (VHI-10) data were obtained, and an assessment of preference for five health states (monocular blindness, binocular blindness, mild dysphonia, moderate dysphonia, and severe dysphonia) was performed. Utility scores were calculated on a scale from 0 (death) to 1 (perfect health). Analysis was performed with ANOVA testing with post-hoc comparisons and correlation statistics. RESULTS: Of 209 assessments, 149 (75.6%) met quality criteria. Relative to monocular blindness (score 0.61 [CI 0.57-0.64]), moderate dysphonia (0.58 [0.54-0.62]) was rated equivalently, with severe dysphonia (0.33 [0.29-0.37]) ranking significantly worse and mild dysphonia (0.96 [0.95-0.98]) significantly better. Binocular blindness (0.18 [0.15-0.21]) was the worst-ranked health state. There was a weak inverse correlation of VHI-10 with dysphonia-related preference scores; with worsening reported voice handicap, scores decreased. CONCLUSION: This study demonstrated that dysphonia had a significant impact of quality of life, with moderate dysphonia ranking equivalently with monocular blindness. These numerical estimates may be used for ongoing research into the value and cost-effectiveness of medical, therapeutic, and surgical interventions for voice disorders. LEVEL OF EVIDENCE: 2c (outcomes research) Laryngoscope, 130:E177-E182, 2020.

Investigation of Skull-Based Cerebrospinal Fluid Leak Repair: A Single-Institution Comprehensive Study of 116 Cases Over 10 Years.

BACKGROUND: Cerebrospinal fluid (CSF) leaks have been historically difficult to diagnose and treat because their cause can widely vary. There are insufficient diagnostic predictors and no clinically accepted standards for their treatment. This large institutional study reports on the diagnosis, management, and outcomes of patients presenting with CSF leak over 10 years and aims to identify potential comorbidities and risk factors for primary and recurrent leaks. METHODS: Patients diagnosed with CSF leak from 2007 to 2017 were analyzed retrospectively. The data included medical history, body mass index, surgical treatment, and postoperative outcomes. RESULTS: A total of 116 cases were identified. The location of leaks was 91 CSF rhinorrhea and 28 CSF otorrhea (3 both). The average BMI for females was greater than that of males (P = 0.01). Causes of leak were 64 noniatrogenic, 47 iatrogenic, and 9 traumatic. A total of 108 patients underwent surgical treatment. Sixty-nine were treated by endoscopic approaches, 42 involved open approaches, and 83 involved the placement of a lumbar drain. Eighteen patients had a ventriculoperitoneal shunt and 6 had a lumbar-peritoneal shunt. A total of 78 patients (72.22%) had an associated encephalocele with the CSF leak. The average length of stay was 7.73 days (0.76). The average length of follow-up was 1.58 years (0.22). The primary repair rate was 80.17% (n = 93) and the overall repair outcome was 99.14% (n = 115). CONCLUSIONS: The overall CSF repair outcome was 99.14% over 10 years at a single institution. Despite this high percentage, CSF leaks continue to be a complex problem and require vigorous multidisciplinary work with close follow-up and use of multiple imaging strategies.

Dynamic Cervical Cord Compression Post-laminectomy Visualized by Flexion-extension Magnetic Resonance Imaging: Case Report.

Flexion-extension magnetic resonance imaging (MRI) in the cervical spine is not universally used in cervical spine surgery. However, flexion-extension MRIs can identify previously undetected spinal stenosis, improve surgical decision-making, and maybe a better tool to evaluate postoperative outcomes. One uncommon complication after laminectomy, to treat cervical spinal stenosis, is muscle weakness due to subsequent dynamic cord compression by posterior paraspinal musculature. We present a case of a 41-year-old male who underwent posterior cervical decompression and developed subsequent neurological deficits and muscle weakness. MRI with neutral cervical positioning did not show spinal stenosis necessitating surgical intervention. However, given the patient's increasing tetraparesis, flexion-extension MRI was performed and it revealed significant spinal stenosis in both flexion and extension positions due to spondylosis and compression from paraspinal muscles. This case demonstrates the utility of flexion-extension MRI in identifying pathologies such as cord compression by paraspinal muscles. Exclusive use of a neutral-position MRI scan may not be sufficient to provide proper diagnoses for cervical spine pathologies. Flexion-extension MRI should be considered when the degree of neurological symptoms outweighs minimal or absent pathology seen on neutral-position sagittal MRI.

Detection of Cerebrospinal Fluid Leaks: Is There a Radiologic Standard of Care? A Systematic Review.

INTRODUCTION: Diagnosis of cerebrospinal fluid (CSF) leaks traditionally involves laboratory testing of markers and appropriate imaging. Surgical localization can be difficult, and the inability to accurately localize skull base defects leads to increased rates of repair failure and complications. Many imaging techniques localizing and identifying CSF leaks have been proposed. Comparisons of current and investigational imaging techniques used to localize CSF leaks are reviewed. METHODS: A comprehensive and systematic search through PubMed, Scopus, and reference lists from relevant articles was completed to identify literature on sensitivities of different imaging methods for localization and detection of CSF leaks. Prospective, retrospective, and case series published since 1995 that addressed imaging techniques for CSF leaks confined to the skull base were included. Sensitivities of each major imaging technique proposed were recorded and analyzed. RESULTS: In total, 133 studies initially were screened from 2125 studies on preliminary search. Of these, 38 studies were included based on inclusion criteria. Studies were segregated by imaging modality. A total of 1000 patients with CSF leaks subsequently were evaluated. CONCLUSIONS: Although radionuclide cisternography has been the historical standard, recent imaging techniques have emerged considering the low sensitivity. Computed tomography cisternography with contrast also has low sensitivity, even in active leaks. Although high-resolution computed tomography is commonly the initial study of choice, magnetic resonance imaging methods, particularly 3-dimensional imaging, may prove to be a more sensitive study of choice. Computed tomography/magnetic resonance imaging combination methods may show promise in localizing CSF leaks. Stratifying by status and etiology may be an important determinant. Further studies investigating various imaging techniques for localizing CSF leaks are needed.

Workforce Analysis of Spine Surgeons Involved with Neurological and Orthopedic Surgery Residency Training.

OBJECTIVE: Spinal surgery is taught and practiced within 2 different surgical disciplines: neurological surgery and orthopedic surgery. We have provided a unified analysis of spine-focused faculty at U.S. residency programs. METHODS: A total of 278 Accreditation Council for Graduate Medical Education training programs were assessed to identify 923 full-time faculty members with a spinal surgery designation, defined by spine fellowship training or surgeon case volume >75% spine surgeries. Faculty were assessed with respect to parent discipline, years of fellowship training, academic rank, gender, and academic productivity (h-index). RESULTS: The spine-teaching workforce contains 55% orthopedic surgeons and 45% neurosurgeons with wide gender asymmetry overall and at all faculty ranks. Of the female spine surgeons, those with neurosurgical training (64.44%) nearly doubled the number with orthopedic training (35.56%). Academic productivity increased with academic rank similarly for both genders and subspecialties. Orthopedic spine surgeons had a greater mean fellowship number compared with the neurological spine surgeons. Fellowship time of completion (intraresidency/infolded vs. postresidency) did not significantly affect the h-indexes. Addition of fellowship conferred academic productivity benefit for orthopedic surgeons only. CONCLUSIONS: Neurological and orthopedic spine surgery showed similar patterns for the spread of faculty across academic ranks and trends in academic productivity. Marked gender disparity was seen in both neurosurgical and orthopedic surgery, with fewer female spine surgeons seen at every academic rank. Orthopedic spine surgeons had a greater mean fellowship number than did their neurosurgical counterparts, and a lack of fellowship correlated with lower academic productivity in orthopedic, but not neurological, spine surgery.

Academic Productivity of Spine Surgeons at United States Neurological Surgery and Orthopedic Surgery Training Programs.

OBJECTIVE: Spinal surgery is taught and practiced within 2 different surgical disciplines, neurological surgery and orthopedic surgery. We have provided a unified analysis of academic productivity measured using the h-index attributable to spine-focused faculty at U.S. residency programs. METHODS: A total of 278 Accreditation Council for Graduate Medical Education training programs were assessed to identify 923 full-time faculty members with a spinal surgery designation, as defined by spine fellowship training or case volume >75% in spine surgery. The faculty were assessed with respect to academic rank, duration of practice in years, and academic productivity (h-index). RESULTS: The comparison showed a significantly greater mean h-index for neurological spine surgeons. The mean h-index for both disciplines increased significantly as faculty rank increased. Within the academic ranks of assistant and associate professor, neurological spine surgeons had significantly greater mean h-indexes. Neurological spine surgeons had a significantly lower practice duration. At all ranks except for assistant professor, the mean practice duration was not significantly different statistically between the neurological spine and orthopedic spine surgeons. A positive correlation between the h-index and practice duration was found for both spine surgical disciplines. The proportional odds models for neurological and orthopedic spine surgeons were moderately successful at predicting faculty rank according to the h-index. CONCLUSIONS: We present a unified view of academic productivity as measured by the h-index among neurosurgical and orthopedic surgery spine faculty, with some noticeable differences. These results can be used for benchmark purposes to assess the relative productivity of its faculty and could be of interest to those pursuing academic opportunities in spine surgery.

Spontaneous Arrest of Sporadic Spinal Hemangioblastoma Growth after Postoperative Nodular Recurrence: Case Report.

Hemangioblastomas are rare, slow-growing, highly vascularized tumors of the central nervous system which often occur in the spinal cord. When presenting as sporadic, isolated tumors without Von-Hippel Lindau disease, they are curable through surgery with a low rate of recurrence. Tumor recurrence in these cases is usually associated with prior subtotal resection. However, to the best of our knowledge, cases of recurrent, sporadic spinal hemangioblastoma have not been reported to spontaneously arrest without intervention or symptoms. We report a patient who underwent an initial complete resection of a cervical spinal hemangioblastoma, a subtotal resection of tumor recurrence four and a half years later, and nine years of neurologic and radiographic stability with no additional interventions.

Evaluation of Concussion Incidence and Modulating Factors in the 2013-2017 Australian Football League.

Introduction The increasing awareness and popularization of concussions in the research realm over the last few years have begun to shed more light on the detrimental effects associated with repetitive head trauma. While the majority of the current literature focuses on the National Football League (NFL) and National Hockey League (NHL), several other high-impact sports have been implementing concussion management protocols to protect their players. The Australian Football League (AFL) is a prime example of a major contact sport that has undertaken recent changes to its concussion assessment and management modalities. We recognize the benefit of reporting potential changes in concussion rates over the 2013-2017 AFL seasons. We were interested in some of the factors not yet evaluated before, which may contribute to the overall concussion incidence such as "style-of-play" factors" (home/away, win/loss, points scored, time of season). We hope the results of this analysis shed light on the mechanisms by which concussion rates can be mitigated across major contact sports. Methods Data were obtained from the weekly injury list published by the AFL, a publicly available website. Details of players listed with concussions were collected from regular season games (890 games total) of 18 AFL teams from 2013 to 2017. Weekly injury lists were retrospectively compared using THE AGE, a publicly available newspaper published and owned by Fairfax Media. Data were analyzed utilizing GraphPad Prism 6 (GraphPad Software Inc., CA, US). In addition to descriptive statistics, Fisher's exact tests, Welch's two-tailed t-tests, and correlation tests were used. Alpha level < 0.05 was considered significant for all tests. Results The dataset comprised 236 total concussions between the 2013 and 2017 AFL seasons. We noted a significant increase in the concussion rate (p = 0.0010) between the 2013 and 2017 seasons. This result was complemented by a significant increase in average games missed between the 2014 and 2015 seasons (p = 0.0002); however, this trend was not significant when evaluating the 2013 and 2017 seasons directly (p = 0.0951). Further analysis into the "style of play" factors on concussion incidence, such as average points scored, win/loss, home/away, and time of season, produced non-significant results. Conclusion Our study identified a significant increasing trend in concussion rate and average games missed that correlate to the data analysis in other high-impact sports such as the NFL and NHL. However, further research is necessary to determine if these findings indicate the improvement in concussion management and player safety measures beginning to develop in high-impact sports. We also noted that certain "style of play" factors (points scored, win/loss, home/away, and time of season) have no significant implication on concussion rate during the 2013-2017 AFL seasons. While we consider our data source to be reliable in the reporting of concussions from the AFL, the ideal data set would comprise a medical diagnosis from the team of doctors. It may be possible that our data set is underreporting the total amount of concussions between the 2013 and 2017 AFL seasons. Return-to-play times were not ascertained directly from the team doctor for the clearance date. It may be possible that this data collection modality led to missed cases of head injury or return to play times, which could impact the reliability of our dataset.

c-index and Subindices of the h-index: New Variants of the h-index to Account for Variations in Author Contribution.

Objectives Bibliometrics are used to assess or compare the academic productivity of individuals or groups. Most of these metrics, including the widely used h-index, do not recognize the added contribution that is generally provided by authors listed first, second, second-to-last and last (enhanced positions) in a publication citation. We propose the c-index as a novel modification to the h-index that will better reflect an individual's academic output, incorporating authorship position. Methods One hundred and sixty-six academic neurosurgeons in eight New York City (NYC) metropolitan region training programs were identified through department websites. Using the Scopus citation database, bibliometric profiles were created for each surgeon. Once an individual's h-index was calculated, the h-core articles (those with h or more citations) were specifically assessed to determine citation author position. Novel bibliometric indices were created to reflect the number of h-core articles that accounted for primary (hp), senior (hs) or internal authorship (hi) position. Weighted "involvement factors" for primary (ip) and senior (is) author contribution were created to reflect the added value of "enhanced position" authorship in an individual's h-core publications. c-indices were created to reflect the author's h-index once augmented by primary (cp), senior (cs), and overall (co) "enhanced position" authorship. Comparisons were made within each institution and across institutions, according to academic rank (assistant professor, associate professor, professor and chairperson). Results Breakdown by academic rank showed an increasing average h-index progressing from assistant professor through professor rank with no significant difference demonstrated between professor and chair status. This pattern was seen across all departments (aggregate) but with fewer instances of significance at the level of individual departments. After h-index modification, cp, cs, and co indices showed a similarly significant trend. As faculty rank increased, there was a significant trend toward increasing numbers of articles with authors in enhanced positions and a higher percentage of articles with the author in a senior position. Academic faculty had higher h, cp, and cs indices than clinical faculty. Evaluation of each individual department revealed no significant trend regarding a department's higher average cp or cs. Average c-index for a department paralleled the average h-index of that department, with larger departments tending to have larger cumulative h, cp, cs, and co indices. No consistent correlation was seen between mean h-indices and academic rank at an individual departmental level. Conclusions This study examines the academic productivity of a subset of neurosurgical programs in the NYC metropolitan area as a test bed for novel bibliometric indices. hp, hi, and hs represent the respective number of primary, internal and senior authorship papers that comprise an individual's h-core papers. cp, cs, and co, variations of the h-index metric, are designed to more accurately reflect the contributions by primary, secondary and senior authors. Increasing academic rank was associated with an increased number of articles with the author in enhanced positions and a higher percentage of articles in a senior position.

High-throughput Screening in Larval Zebrafish Identifies Novel Potent Sedative-hypnotics.

WHAT WE ALREADY KNOW ABOUT THIS TOPIC: WHAT THIS ARTICLE TELLS US THAT IS NEW: BACKGROUND:: Many general anesthetics were discovered empirically, but primary screens to find new sedative-hypnotics in drug libraries have not used animals, limiting the types of drugs discovered. The authors hypothesized that a sedative-hypnotic screening approach using zebrafish larvae responses to sensory stimuli would perform comparably to standard assays, and efficiently identify new active compounds. METHODS: The authors developed a binary outcome photomotor response assay for zebrafish larvae using a computerized system that tracked individual motions of up to 96 animals simultaneously. The assay was validated against tadpole loss of righting reflexes, using sedative-hypnotics of widely varying potencies that affect various molecular targets. A total of 374 representative compounds from a larger library were screened in zebrafish larvae for hypnotic activity at 10 µM. Molecular mechanisms of hits were explored in anesthetic-sensitive ion channels using electrophysiology, or in zebrafish using a specific reversal agent. RESULTS: Zebrafish larvae assays required far less drug, time, and effort than tadpoles. In validation experiments, zebrafish and tadpole screening for hypnotic activity agreed 100% (n = 11; P = 0.002), and potencies were very similar (Pearson correlation, r > 0.999). Two reversible and potent sedative-hypnotics were discovered in the library subset. CMLD003237 (EC50, ~11 µM) weakly modulated γ-aminobutyric acid type A receptors and inhibited neuronal nicotinic receptors. CMLD006025 (EC50, ~13 µM) inhibited both N-methyl-D-aspartate and neuronal nicotinic receptors. CONCLUSIONS: Photomotor response assays in zebrafish larvae are a mechanism-independent platform for high-throughput screening to identify novel sedative-hypnotics. The variety of chemotypes producing hypnosis is likely much larger than currently known.

Ability to modulate birdsong across social contexts develops without imitative social learning.

Many important behaviours are socially learned. For example, the acoustic structure of courtship songs in songbirds is learned by listening to and interacting with conspecifics during a sensitive period in development. Signallers modify the spectral and temporal structures of their vocalizations depending on the social context, but the degree to which this modulation requires imitative social learning remains unknown. We found that male zebra finches (Taeniopygia guttata) that were not exposed to context-dependent song modulations throughout development significantly modulated their song in ways that were typical of socially reared birds. Furthermore, the extent of these modulations was not significantly different between finches that could or could not observe these modulations during tutoring. These data suggest that this form of vocal flexibility develops without imitative social learning in male zebra finches.

EGR-1 Expression in Catecholamine-synthesizing Neurons Reflects Auditory Learning and Correlates with Responses in Auditory Processing Areas.

Distinguishing between familiar and unfamiliar individuals is an important task that shapes the expression of social behavior. As such, identifying the neural populations involved in processing and learning the sensory attributes of individuals is important for understanding mechanisms of behavior. Catecholamine-synthesizing neurons have been implicated in sensory processing, but relatively little is known about their contribution to auditory learning and processing across various vertebrate taxa. Here we investigated the extent to which immediate early gene expression in catecholaminergic circuitry reflects information about the familiarity of social signals and predicts immediate early gene expression in sensory processing areas in songbirds. We found that male zebra finches readily learned to differentiate between familiar and unfamiliar acoustic signals ('songs') and that playback of familiar songs led to fewer catecholaminergic neurons in the locus coeruleus (but not in the ventral tegmental area, substantia nigra, or periaqueductal gray) expressing the immediate early gene, EGR-1, than playback of unfamiliar songs. The pattern of EGR-1 expression in the locus coeruleus was similar to that observed in two auditory processing areas implicated in auditory learning and memory, namely the caudomedial nidopallium (NCM) and the caudal medial mesopallium (CMM), suggesting a contribution of catecholamines to sensory processing. Consistent with this, the pattern of catecholaminergic innervation onto auditory neurons co-varied with the degree to which song playback affected the relative intensity of EGR-1 expression. Together, our data support the contention that catecholamines like norepinephrine contribute to social recognition and the processing of social information.

Effects of Game Characteristics and Player Positions on Concussion Incidence and Severity in Professional Football.

BACKGROUND: Increasing efforts have been made to reduce the incidence and severity of concussion in high-contact sports. Despite these efforts, a relative lack of knowledge is available regarding modulating factors affecting concussion injury. PURPOSE: To analyze the potential influence of game characteristics and outcomes on concussion incidence and severity in professional football. STUDY DESIGN: Descriptive epidemiology study. METHODS: PBS Frontline Concussion Watch was used to collect concussion injury data from regular-season games of 32 National Football League (NFL) teams from 2012 to 2015. Game characteristic variables such as rushing and passing attempts, turnovers, and margin of victory were collected from ESPN. Analysis included descriptive statistics, analysis of variance, t tests, and correlation tests. RESULTS: Away teams demonstrated a significantly greater concussion incidence per game than home teams. Losing teams had a significantly greater concussion incidence per game than winning teams. Being both the away team and the losing team appeared to have an additive effect. The home-versus-away and win-versus-loss effects were significant for offensive but not defensive positions. Within individual positions, significantly greater concussion incidence was associated with tight ends, running backs, wide receivers, and cornerbacks. When running versus passing positions were compared, passing positions (wide receiver, tight end, cornerback, safety) had significantly greater concussion incidence. A total of 626 games were missed as a result of reported concussions. Away teams had significantly more games missed due to concussion when they lost. Play time did not significantly differ before or after concussion injury. Other game characteristic variables did not significantly affect concussion frequency or intensity. CONCLUSION: Position, game location, and game outcome affect concussion incidence for professional football players. In a subset of analyses, the number of games missed aligned with concussion incidence, but this appeared to be an imperfect measure. These findings highlight new factors that may modulate concussion incidence and merit further study on how they may influence concussion evaluation.

Modifying Factors for Concussion Incidence and Severity in the 2013-2017 National Hockey League Seasons.

Introduction In the past few years, there has been a rising interest in both the prevalence and the short- and long-term consequences of concussions. While the main focus of concussion-based research revolves around the National Football League (NFL), attention is now shifting to other high contact leagues like the National Hockey League (NHL), where there is constant player-to-player contact as well as collisions with the perimeter boards. While the body of evidence surrounding injury and concussion rates in the NHL has substantially grown in size over the previous few years, there is still a void pertaining to the in-game effects that could modulate concussion incidence. Our study takes a novel approach to evaluate several "style of play" factors such as home/away perspective, win/loss outcome, points scored, real time length of game, time of season, and player position in modulating concussion rates. Methods Data on concussion incidence for the 2013-2017 National Hockey League seasons was collected utilizing FOX Sports injury tracker. Only injuries specifically diagnosed as concussions during regular and postseason games were utilized in our data set. A Google search on the reported injury was performed in order to correlate the concussion to the correct game in which the player sustained it. NHL season schedules were acquired through the online source "Hockey Reference." There were a total of 5281 games when considering the regular and postseason games between the 2013-2017 seasons. Concussions sustained during team practices and preseason contests were not accounted for in our data set to control for inconsistent reporting. Our data set does not account for the current 2017-2018 NHL expansion with the addition of a Las Vegas team to the league. Results Statistical analysis of several "Style of Play" factors such as home/away perspective, win/loss outcome, points scored, real time length of game and time of season produced non-significant results pertaining to modulating concussion rate during the 2013-2017 NHL seasons. When evaluating on-ice position we noted offensive players combined to have the highest rate of concussion. Forwards (left wing (LW), right wing (RW)) demonstrated similar concussion rates, while goalies encountered the lowest concussion rate. Conclusion The results of our analysis demonstrated non-significance for home/away effects, win/loss results, average points scored, real time length of game, and time of season on influencing concussion rates. We noted offensive players combined to have the highest rate of concussions, while goalies encountered the least. The key limitation in our data set is the lack of reliable and publicly available data surrounding concussion incidence in the National Hockey League. Due to this drawback, our data set should be considered as an under-reported representation of the total amount of concussions spanning the 2013-2017 seasons.

Does the Environment Influence the Frequency of Concussion Incidence in Professional Football?

Background Sports-related concussion is a major cause of mild traumatic brain injury (mTBI). It is possible that environmental factors, such as temperature, humidity, and stadium's altitude, may influence the overall incidence of concussions during a game. Purpose To examine the impact of environmental factors, such as temperature, humidity, barometric pressure, and dew point, on concussion incidence. Methods Public Broadcasting Service (PBS) FRONTLINE Concussion Watch was used to collect injury data on 32 NFL teams during regular season games from 2012 to 2015. Weather data points were collected from Weather Underground. Concussion incidence per game, the probability of a concussion during a game, and a difference in mean game-day temperature, humidity, dew point, and barometric pressure between concussion and concussion-free games were calculated. Our analysis included t-tests, analysis of variance (ANOVA), multivariate correlation tests, and logistic and Poisson regression.  Results Overall, 564 concussions were reported. There were 411 games with concussions and 549 games without concussions. We observed a significant decrease in concussion incidence with increasing temperature, both when the temperature was divided into 20oF increments or into quartiles (p = 0.005 and p = 0.002, respectively). We identified a statistically significant lower mean-game day temperature in concussion games compared to concussion-free games (p < 0.0006). We also observed a significant decrease in the incidence of concussion per game with increasing dew point. There was no significant difference in concussion incidence in barometric pressure and humidity. The logistic regression model predicted a decrease in the probability of a concussion in games with higher temperatures and dew points. Conclusions National Football League (NFL) players experienced an increased risk of concussion during football games played in colder temperatures and at lower dew points. Further research on environmental effects on concussions may aid in improving player safety in football leagues.