The National Institute of Neurological Disorders and Stroke and Department of Defense Sport-Related Concussion Common Data Elements Version 1.0 Recommendations

Aim: Through a partnership with the National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), and Department of Defense (DoD), the development of Sport-Related Concussion (SRC) Common Data Elements (CDEs) was initiated. The aim of this collaboration was to increase the efficiency and effectiveness of clinical research studies and clinical treatment outcomes, increase data quality, facilitate data sharing across studies, reduce study start-up time, more effectively aggregate information into metadata results, and educate new clinical investigators. Materials/Methods: The SRC CDE Working Group consisted of 34 worldwide experts in concussion from varied fields of related expertise, divided into three Subgroups: Acute (3 months post-concussion). To develop CDEs, the Subgroups reviewed various domains, and then selected from, refined, and added to existing CDEs, case report forms and field-tested data elements from national registries and funded research studies. Recommendations were posted to the NINDS CDE Website for Public Review from February 2017 to April 2017. Results: Following an internal Working Group review of recommendations, along with consideration of comments received from the Public Review period, the first iteration (Version 1.0) of the NINDS SRC CDEs was completed in June 2017. The recommendations include Core and Supplemental ? Highly Recommended CDEs for cognitive data elements and symptom checklists, as well as other outcomes and endpoints (e.g., vestibular, oculomotor, balance, anxiety, depression) and sample case report forms (e.g., injury reporting, demographics, concussion history) for domains typically included in clinical research studies. Interpretation: The NINDS SRC CDEs and supporting documents are publicly available on the NINDS CDE website https://www.commondataelements.ninds.nih.gov/. Widespread use of CDEs by researchers and clinicians will facilitate consistent SRC clinical research and trial design, data sharing, and metadata retrospective analysis

Persistent effects of playing football and associated (subconcussive) head trauma on brain structure and function: a systematic review of the literature

Aim/objectiveThere is ongoing controversy about persistent neurological deficits in active and former football (soccer) players. We reviewed the literature for associations between football activities (including heading/head injuries) and decline in brain structure/function.DesignSystematic literature review.Data sourcesMEDLINE, Embase, PsycINFO, CINAHL, Cochrane-CRCT, SportDiscus, Cochrane-DSR=4 (accessed 2 August 2016).Eligibility criteria for selecting studiesOriginal studies reporting on football-related persistent effects on brain structure/function. Results from neurocognitive testing, neuroimaging and EEG were compared with controls and/or correlated with heading frequency and/or head injuries. Methodological quality was rated for risk-of-bias, including appropriateness of controls, correction for multiple statistical testing and assessment of heading frequency and head injuries.Results30 studies with 1691 players were included. Those 57% (8/14) of case–control studies reporting persistent neurocognitive impairment had higher odds for inappropriate control of type 1 errors (OR=17.35 (95% CI (10.61 to 28.36)) and for inappropriate selection of controls (OR=1.72 (1.22 to 2.43)) than studies observing no impairment. Studies reporting a correlation between heading frequency and neurocognitive deficits (6/17) had lower quality of heading assessment (OR=14.20 (9.01 to 22.39)) than studies reporting no such correlation. In 7 of 13 studies (54%), the number of head injuries correlated with the degree of neurocognitive impairment. Abnormalities on neuroimaging (6/8 studies) were associated with subclinical neurocognitive deficits in 3 of 4 studies.Summary/conclusionsVarious methodological shortcomings limit the evidence for persistent effects of football play on brain structure/function. Sources of bias include low-quality assessment of heading frequency, inappropriate control for type 1 errors and inappropriate selection of controls. Combining neuroimaging techniques with neurocognitive testing in prospective studies seems most promising to further clarify on the impact of football on the brain.</jats:sec

Non-linearity in gaze holding: Experimental results and possible mechanisms

Cerebellar impairment may cause deficits in horizontal gaze holding, leading to centrifugal gaze-evoked nystagmus during fixation of eccentric targets. Healthy individuals show a weak drift leading to physiological nystagmus only at large gaze angles. These drifts are due to imperfect memory of the neural circuitry generating the eye position signals by integration of velocity signals. The cerebellum plays a crucial role in reducing the "leakiness" of this neural integrator. This neural integrator has been traditionally modeled as a first order low-pass filter, implying a linear relation between drift velocity and eye eccentricity. Evidences of a nonlinear behavior, however, can be found in the literature. In a recent series of papers we showed that the eye drift velocity (V) can be descriptively modeled as a tangent function of gaze eccentricity (P) with the following equation: V= k(2)/k(1) tan (k(1)P). Notably, the two parameters have distinct roles: k(1) regulates the rate of compression of the tangent, exclusively determining the non-linearity; k(2) is a pure scaling factor. This descriptive model robustly fitted the data of healthy individuals both at baseline (n = 50) and following transient cerebellar impairment induced by controlled amounts of alcohol [blood alcohol content 0.06% (n 15) and 0.1% (n = 15)] and of patients with chronic cerebellar impairment of various origin (n = 20). Interestingly, alcohol selectively changed the scaling factor k(2) , evidencing that an overall, transient cerebellar impairment does not impact the non-linear behavior. Patients with cerebellar degeneration, on the other hand, showed a change in both k(1) and k(2) , implying a role of the cerebellum in limiting the range of eye positions where the non-linearity becomes relevant. Non-linearity has been reported in literature for both the neural integrator and the eye plant. While previous models using a neural network attempted to reproduce the non-linear behavior of the brainstem, we propose a block diagram reproducing the observed PV tangent relation by introducing a position dependency in the parameters of the cerebellar feedback loop

Concussion in community Australian football – epidemiological monitoring of the causes and immediate impact on play

BACKGROUND: Head injuries, particularly concussion, are a major cause of concern in many sports, particularly the football codes, driving a need to better understand injury mechanisms and potential methods of prevention. The aim of this study was to describe the mechanisms and follow up care of concussion injuries sustained in adult male community Australian football to identify target areas for prevention and management. METHODS: Secondary analysis of injury data collected in a cluster randomised controlled trial in community Australian football across two states of Australia in 2007 and 2008. There were 1564 players from 18 clubs. The main outcome measures were the number and rate of head/neck/face (HNF) injuries and concussion sustained in games. A specific description of the mechanisms of the concussion injuries is presented along with the immediate return-to-play status of concussion cases. RESULTS: 143 HNF injuries were sustained by 132 players. The game HNF injury incidence was 4.9 per 1000 game hours (n = 138; 95 % confidence interval 4.1; 5.7). Just under a quarter (n = 34) of all HNF injuries were recorded as concussion. All concussions occurred during games (none in training), with all but one related to body contact with other players. Overall, 68 % of the concussions were considered within game rules, while 32 % were either outside of the rules or unclear. Most (88 %) players left the field immediately following concussion but 47 % later returned to play in the same game. CONCLUSIONS: Prevention strategies for concussion need to be based on knowledge of the mechanisms of injury. Most concussions in community Australian football occurred through body contact with other players or during tackling. Management of players post-concussion was generally poor with over half of the cases continuing to play in the same game. Therefore, new primary prevention strategies that target body-contact/tackling skills and improved secondary prevention measures relating to compliance with return-to-play protocols would be valuable

Higher frequency of hamstring injuries in elite track and field athletes who had a previous injury to the ankle - a 17 years observational cohort study

Abstract Background Inversion injury to the ankle and hamstring injuries are common problems in most sports. It is not known whether these injuries constitute a predisposing factor or a precursor of injury or re-injury of these anatomical locations. Therefore, we wished to test the hypothesis that a previous inversion ankle injury exerted a significant effect on the chance of an athlete suffering from a subsequent ipsilateral hamstring injury and vice versa. Methods In an observational cohort study over 17 years (1998–2015), 367 elite track and field athletes, were grouped according to their first traumatic isolated ankle or hamstring injury. Fifty athletes experienced both injuries. The Mann-Whitney U and Chi-square tests (p < 0.05) were performed to test possible associations of ankle and hamstring injury with age, gender, athletics discipline, grade, and type of antecedent injury. Results Athletes with a preceding ankle injury had a statistically significantly higher chance of experiencing a subsequent hamstring injury compared with athletes who had experienced a hamstring injury as their first traumatic event (x2 = 4.245, p = 0.039). The proportion of both ankle and hamstring injury events was not statistically different between female (18%) and male (11%) athletes. Age and grade of injury did not influence the proportion of ankle and/or hamstring injury events. Conclusion There is a statistically significantly higher frequency of hamstring injuries in elite track and field athletes having experienced a previous ankle ligament injury

Muscle injuries in sports: a new evidence-informed and expert consensus-based classification with clinical application

Muscle injuries are among the most common injuries in sport and continue to be a major concern because of training and competition time loss, challenging decision making regarding treatment and return to sport, and a relatively high recurrence rate. An adequate classification of muscle injury is essential for a full understanding of the injury and to optimize its management and return-to-play process. The ongoing failure to establish a classification system with broad acceptance has resulted from factors such as limited clinical applicability, and the inclusion of subjective findings and ambiguous terminology. The purpose of this article was to describe a classification system for muscle injuries with easy clinical application, adequate grouping of injuries with similar functional impairment, and potential prognostic value. This evidence-informed and expert consensus-based classification system for muscle injuries is based on a four-letter initialism system: MLG-R, respectively referring to the mechanism of injury (M), location of injury (L), grading of severity (G), and number of muscle re-injuries (R). The goal of the classification is to enhance communication between healthcare and sports-related professionals and facilitate rehabilitation and return-to-play decision making