Early Exercise is Associated with Faster Concussion Recovery Among Collegiate Athletes: Findings from the NCAA-DoD CARE Consortium.

BACKGROUND: Growing evidence indicates early exercise may improve symptoms and reduce clinical recovery time after concussion, but research examining collegiate student-athletes is scarce. OBJECTIVE: The aim of this study was to compare symptom recovery time, clinical recovery time, and persisting post-concussion symptom (i.e., symptoms ≥ 28 days) prevalence by the timing of light exercise initiation before the graded return to play (RTP) protocol among concussed participants. METHODS: Collegiate student-athletes (n = 1228; age 18.4 ± 0.9 years; 56.5% male, 76.3% division I; 33.7% ≥ 1 prior concussion) across 30 institutions enrolled in the CARE Consortium completed post-concussion assessments and were monitored over time. Symptom recovery (days from injury to symptom resolution) and clinical recovery (days from injury to return to play protocol completion) was determined by the student-athletes' clinicians. Student-athletes were categorized by timing of light exercise initiation. Early (< 2 days post-concussion; n = 161), typical (3-7 days post-concussion; n = 281), and late exercise (≥ 8 days post-concussion; n = 169) groups were compared with the no-exercise group (n = 617; i.e., did not exercise prior to beginning the RTP protocol) for all analyses. Multivariable Cox regression models with hazard ratios (HR) and survival curves and a multivariable binomial regression model with prevalence ratios (PR) compared recovery outcomes between exercise groups while accounting for covariates. RESULTS: Compared to the no-exercise group, the early exercise group was 92% more probable to experience symptom recovery (HR 1.92; 95% CI 1.57-2.36), 88% more probable to reach clinical recovery (HR 1.88; 95% CI 1.55-2.28) and took a median of 2.4 and 3.2 days less to recover, respectively. The late exercise group relative to the no-exercise group was 57% less probable to reach symptom recovery (HR 0.43; 95% CI 0.35-0.53), 46% less probable to achieve clinical recovery (HR 0.54; 95% CI 0.45-0.66) and took 5.3 days and 5.7 days more to recover, respectively. The typical exercise group did not differ in hazard for symptom or clinical recovery (p ≥ 0.329) compared with the no-exercise group. The prevalence of persisting post-concussion symptoms in the combined sample was 6.6%. Early exercise had 4% lower prevalence (PR 0.96, 95% CI 0.94-0.99) and typical exercise had 3% lower prevalence (PR 0.97, 95% CI 0.94-0.99) of persisting post-concussion symptoms, while the late exercise group had an elevated prevalence (PR 1.11, 95% CI 1.04-1.18) compared with the no-exercise group. CONCLUSION: Exercise < 2 days post-concussion was associated with more probable and faster symptom and clinical recovery, and lower persisting post-concussion symptom prevalence. When considering our findings and existing literature, qualified clinicians may implement early exercise into their clinical practice to provide therapeutic treatment and improve student-athlete recovery.

Accurate classification of pain experiences using wearable electroencephalography in adolescents with and without chronic musculoskeletal pain.

Objective: We assessed the potential of using EEG to detect cold thermal pain in adolescents with and without chronic musculoskeletal pain. Methods: Thirty-nine healthy controls (15.2 ± 2.1 years, 18 females) and 121 chronic pain participants (15.0 ± 2.0 years, 100 females, 85 experiencing pain ≥12-months) had 19-channel EEG recorded at rest and throughout a cold-pressor task (CPT). Permutation entropy, directed phase lag index, peak frequency, and binary graph theory features were calculated across 10-second EEG epochs (Healthy: 292 baseline / 273 CPT epochs; Pain: 1039 baseline / 755 CPT epochs). Support vector machine (SVM) and logistic regression models were trained to classify between baseline and CPT conditions separately for control and pain participants. Results: SVM models significantly distinguished between baseline and CPT conditions in chronic pain (75.2% accuracy, 95% CI: 71.4%-77.1%; p < 0.0001) and control (74.8% accuracy, 95% CI: 66.3%-77.6%; p < 0.0001) participants. Logistic regression models performed similar to the SVM (Pain: 75.8% accuracy, 95% CI: 69.5%-76.6%, p < 0.0001; Controls: 72.0% accuracy, 95% CI: 64.5%-78.5%, p < 0.0001). Permutation entropy features in the theta frequency band were the largest contributor to model accuracy for both groups. Conclusions: Our results demonstrate that subjective pain experiences can accurately be detected from electrophysiological data, and represent the first step towards the development of a point-of-care system to detect pain in the absence of self-report.

The Effect of Sex, Sport, and Preexisting Histories on Baseline Concussion Test Performance in College Lacrosse and Soccer Athletes.

OBJECTIVE: To study sex and sport differences in baseline clinical concussion assessments. A secondary purpose was to determine if these same assessments are affected by self-reported histories of (1) concussion; (2) learning disability; (3) anxiety and/or depression; and (4) migraine. DESIGN: Prospective cohort. SETTING: National Collegiate Athletic Association D1 Universities. PARTICIPANTS: Male and female soccer and lacrosse athletes (n = 237; age = 19.8 ± 1.3 years). ASSESSMENT OF RISK FACTORS: Sport, sex, history of (1) concussion; (2) learning disability; (3) anxiety and/or depression; and (4) migraine. MAIN OUTCOME MEASURES: Sport Concussion Assessment Tool 22-item symptom checklist, Standardized Assessment of Concussion, Balance Error Scoring System (BESS), Generalized Anxiety Disorder 7-item scale, and Patient Health Questionnaire. RESULTS: Female athletes had significantly higher total symptoms endorsed (P = 0.02), total symptom severity (P < 0.001), and BESS total errors (P = 0.01) than male athletes. No other sex, sport, or sex-by-sport interactions were observed (P > 0.05). Previous concussion and migraine history were related to greater total symptoms endorsed (concussion: P = 0.03; migraine: P = 0.01) and total symptom severity (concussion: P = 0.04; migraine: P = 0.02). Athletes with a migraine history also self-reported higher anxiety (P = 0.004) and depression (P = 0.01) scores. No other associations between preexisting histories and clinical concussion outcomes were observed (P > 0.05). CONCLUSIONS: Our findings reinforce the need to individualize concussion assessment and management. This is highlighted by the findings involving sex differences and preexisting concussion and migraine histories. CLINICAL RELEVANCE: Clinicians should fully inventory athletes' personal and medical histories to better understand variability in measures, which may be used to inform return-to-participation decisions following injury.

The magnitude of parental stress is highly variable following pediatric concussion: using the transactional model of stress to understand parent experiences.

OBJECTIVES: To use the Transactional Model of Stress to understand variations in parental stress following pediatric concussion. METHODS: Mixed-methods design. 49 children with concussion (13.8 ± 2.3 years, nfemales = 27) and their parent (nfemales = 40) were recruited from a specialty clinic. Quantitative data were collected via surveys at the child's initial clinic visit. Qualitative data were collected through an eleven-question, semi-structured interview with 12 parents. Interview questions focused on post-concussion stressors and data were analyzed using thematic analysis. Multivariable linear regression analyzed predictors of parental stress . RESULTS: Ten of the parents interviewed (83%) described the concussion as having a negative overall effect on their stress, while two parents described the overall experience as positive. Coping abilities and other life stressors were described as reasons for varying stress levels. Neurotic and conscientious personality factors and the child's quality of life total score accounted for 45% of the variance in parental stress (R2 = 0.451, F(3,33) = 9.03, p < 0.001). CONCLUSIONS: Parental stress following pediatric concussion is highly variable. The Transactional Model of Stress appears useful to understand this phenomenon. Future studies should investigate interventions to reduce stress for parents experiencing high levels following their child's concussion.

Developing a conceptual framework to identify and classify sources of parental stress following pediatric concussion.

OBJECTIVES: To create a conceptual framework that classifies the various stresses parents experience following their child's concussion. METHODS: Twelve parents of children with concussion completed a semi-structured interview with the lead author. Questions broadly focused on post-concussion stress, with specific probes for caregiving responsibilities, concussion knowledge, and athletic participation. Data were analyzed using thematic analysis. RESULTS: Ten mothers and 2 fathers participated. Five themes stemmed from our analysis: 1) Concussion Knowledge (central theme): stressors related to sources of concussion information; 2) Child Health Factors: stressors related to injury and illness, including concussion; 3) Activity Factors: stressors related to academic and athletic performance; 4) Parent-Injured Child Relationship Factors: stressors related to providing care to the child; and 5) Personal Factors: stressors unrelated to the concussion (e.g. family, social, career, etc.). Child Health Factors was most frequently identified as the primary stressor (n = 9). CONCLUSIONS: Sources of parental stress were varied following pediatric concussion. Issues relating to the child's post-injury dysfunction and the uncertain recovery from concussion were key stressors identified by parents. Moving forward, this framework can be used to ground the development of specific parental stress screening tools and interventions, which may benefit the parent's mental health and the child's clinical recovery.

Higher parental stress is significantly related to longer clinical recovery times in concussed children: A mixed-methods study.

OBJECTIVES: Parental stress and anxiety negatively influences a child's recovery following traumatic brain injury, but these relationships are largely unexplored in a concussion-specific sample. We hypothesized that children with parents experiencing high stress or with pre-existing anxiety would take significantly longer to recover from concussion. DESIGN: Mixed-methods. METHODS: Forty-nine concussed children (13.8 ±â€¯2.3 years, nfemales = 27) and their parents were recruited. Quantitative data were collected using the Perceived Stress Scale (10-item). Qualitative data (n = 12) were collected through a semi-structured interview with the parent. Kaplan-Meier curves and Cox proportional hazard models analyzed the effect of parental stress and anxiety on time in clinic (days between clinic presentation and discharge) and recovery time (days between concussion and clinic discharge). Thematic analysis was used to analyze interview data. RESULTS: Parental anxiety was not significantly related to either the child's time in clinic (P = 0.27) or recovery time (P = 0.41). Conversely, higher perceived parental stress was related to longer recovery time (Hazard Ratio: 2.162, 95% CI: 1.075, 4.348; p = 0.03) for the injured child, with similar results for time in clinic (Hazard Ratio: 1.883, 95% CI: 0.966, 3.668, p = 0.06). During the interview, parents expressed their stress was directly tied to their child's symptoms and overall functioning and varied throughout recovery. CONCLUSIONS: Recovery time is significantly longer in concussed children whose parents are experiencing higher levels of stress, but not pre-existing anxiety, following injury. Parental stress varies throughout recovery, with stress generally higher in the acute post-injury period. Clinicians should monitor parental stress post-concussion when possible.

Electroencephalographic characteristics of children and adolescents with chronic musculoskeletal pain.

Introduction: The pathophysiology of pediatric musculoskeletal (MSK) pain is unclear, contributing to persistent challenges to its management. Objectives: This study hypothesizes that children and adolescents with chronic MSK pain (CPs) will show differences in electroencephalography (EEG) features at rest and during thermal pain modalities when compared with age-matched controls. Methods: One hundred forty-two CP patients and 45 age-matched healthy controls (HCs) underwent a standardized thermal tonic heat and cold stimulations, while a 21-electrode headset collected EEG data. Cohorts were compared with respect to their EEG features of spectral power, peak frequency, permutation entropy, weight phase-lag index, directed phase-lag index, and node degree at 4 frequency bands, namely, delta (1-4 Hz), theta (4-8 Hz), alpha (8-13 Hz), and beta (13-30 Hz), at rest and during the thermal conditions. Results: At rest, CPs showed increased global delta (P = 0.0493) and beta (P = 0.0002) power in comparison with HCs. These findings provide further impetus for the investigation and prevention of long-lasting developmental sequalae of early life chronic pain processes. Although no cohort differences in pain intensity scores were found during the thermal pain modalities, CPs and HCs showed significant difference in changes in EEG spectral power, peak frequency, permutation entropy, and network functional connectivity at specific frequency bands (P < 0.05) during the tonic heat and cold stimulations. Conclusion: This suggests that EEG can characterize subtle differences in heat and cold pain sensitivity in CPs. The complementation of EEG and evoked pain in the clinical assessment of pediatric chronic MSK pain can better detect underlying pain mechanisms and changes in pain sensitivity.

Sex and Sport Differences in College Lacrosse and Soccer Head Impact Biomechanics.

PURPOSE: Sport-related head impact biomechanics research has been male-centric and focused primarily on American football and ice hockey, which do not address popular sports in which both sexes participate. The purpose of this study was to quantify college female and male lacrosse and soccer head impact biomechanics. METHODS: Head impact biomechanics were collected from college lacrosse and soccer players across two Division 1 college athletic programs (96 female athletes, 141 male athletes; age, 19.8 ± 1.3 yr; height, 174.8 ± 9.2 cm; mass, 72.4 ± 11.7 kg). We deployed helmetless head impact measurement devices (X2 Biosystems xPatch) before each event. Peak linear and rotational accelerations were log-transformed for random intercepts general linear mixed models, and subsequently categorized based on impact magnitude for additional categorical analyses. RESULTS: Most linear (69.4%) and rotational (72.3%) head impact accelerations sustained by our study cohort were categorized as mild. On average, male athletes sustained impacts with higher linear accelerations than females (P = 0.04), and lacrosse athletes sustained higher linear acceleration impacts than soccer athletes (P = 0.023). Soccer athletes sustained significantly higher-magnitude impacts during competitions versus practices (linear, P < 0.001, rotational, P < 0.001), whereas lacrosse athletes sustained higher-magnitude impacts during practices versus competition (linear, P < 0.001; rotational, P < 0.001). Male athletes sustained higher accelerations in competitions versus practice (linear, P = 0.004; rotational, P < 0.001), whereas female athletes sustained higher accelerations in practice versus competitions (linear, P < 0.001; rotational, P = 0.02). There were no interactions between sex and sport on impact magnitude. CONCLUSIONS: Male athletes and lacrosse athletes experience higher-magnitude head impacts. Given the limited literature in this area, future research should continue characterizing head impact biomechanics in women's and nonhelmeted sports as well as validate nonhelmeted head impact technologies.

Comparison of Concussion Sideline Screening Measures Across Varying Exertion Levels Within Simulated Games.

CONTEXT: Currently, there is no gold standard to evaluate the effect of varying game-like exertion states on Sport Concussion Assessment Tool 3rd Edition (SCAT-3) outcomes. Baseline assessments may occur before, during, or after physical activity, while postinjury evaluations predominantly occur following physical activity. Thus, clinicians may be comparing postinjury evaluations completed following exertion to baseline evaluations completed following varying levels of rest or exertion, which may not be a valid method for clinical decision making. OBJECTIVE: To determine the effect of various physical exertion levels on sideline concussion assessment outcomes and reliability. DESIGN: Within-subjects, repeated measures. SETTING: Field. PARTICIPANTS: Physically active participants (N = 36) who regularly participate in basketball activity. INTERVENTION: Subjects participated in 2 simulated basketball games, completing a symptom checklist, Standardized Assessment of Concussion, and Balance Error Scoring System before game play, during halftime, and at the completion of each simulated game. Pulse rate was assessed as a proxy of physical exertion. MAIN OUTCOME MEASURES: Total symptom, Standardized Assessment of Concussion, and Balance Error Scoring System scores. RESULTS: Physical exertion did not significantly predict symptom, Standardized Assessment of Concussion, or Balance Error Scoring System scores, although a trend toward higher symptom scores was observed for females (ß = 0.03, P = .09). All assessments had poor to moderate reliability across sessions (.15 < interclass correlation coefficient [2,1] < .60). CONCLUSION: Low- to moderate-intensity physical activity did not have a significant effect on clinical concussion sideline assessments; however, the low test-retest reliability observed prevents strong conclusions on these relationships. The poor overall reliability does not allow for clear recommendations for what state of baseline physical exertion (ie, rested or exerted) provides optimal data to make postinjury clinical decisions, although baseline concussion assessments completed at rest have the most valid and conservative normative values for injury comparison.

Near Point of Convergence Deficits and Treatment Following Concussion: A Systematic Review.

CONTEXT: Convergence dysfunction following concussion is common. Near point of convergence (NPC) is a quick and easy assessment that may detect oculomotor dysfunction such as convergence insufficiency (CI), but NPC measurements are rarely reported. Convergence dysfunction is treatable in otherwise healthy patients; the effectiveness of oculomotor therapy following concussion is unclear. OBJECTIVES: The purpose of this article was to systematically review the literature and answer the following clinical questions: (1) Is performance on NPC negatively affected in patients diagnosed with a concussion compared with pre-injury levels or healthy controls? (2) In patients diagnosed with concussion, what is the effect of oculomotor/vision therapy on NPC break measurements? EVIDENCE ACQUISITION: The search was conducted in CINAHL, SPORTDiscus, MEDLINE, and PubMed using terms related to concussion, mild traumatic brain injury, convergence, vision, and rehabilitation. Literature considered for review included original research publications that collected measures of NPC break in concussion patients, with a pretest-posttest comparison or comparison with a healthy control group. A literature review was completed; 242 relevant articles were reviewed, with 18 articles meeting criteria for inclusion in the review. EVIDENCE SYNTHESIS: Articles were categorized according to the clinical question they addressed. The patient or participant sample (number, sex, age, and health status), study design, instrumentation, or intervention used, and main results were extracted from each article. CONCLUSIONS: The authors' main findings suggest that there is a moderate level of evidence that patients have impaired NPC up to several months postconcussion, and a low level of evidence that impairments can be successfully treated with oculomotor therapy. These findings should be cautiously evaluated; the studies are limited by weak/moderate quality, small sample sizes, varied methodology, and nonrandomized treatment groups. Future research should explore factors affecting convergence postconcussion and include randomized, controlled studies to determine if performing vision therapy improves visual measures and promotes recovery.

Head Impact Biomechanics Differ Between Girls and Boys Youth Ice Hockey Players.

The influence of sex on head impact biomechanics is unknown for youth ice hockey. We sought to determine sex differences in head impact severity and frequency in youth ice hockey players. Male (n = 110) and female (n = 25) players (13-16 years old) were recruited from a local hockey organization. Players wore helmets instrumented with the Head Impact Telemetry System for all competitions and practices throughout the season. Seven team-seasons were captured. Random intercepts general mixed linear models determined whether linear acceleration and rotational acceleration differed by sex. Linear regression models evaluated the relationship between sex and impact frequency. All head impact biomechanics were natural log-transformed as their distributions were right-skewed. Females sustained fewer impacts per player than males (27 fewer impacts per player-season, p < 0.0001) even when analysis was limited to games only (21 fewer impacts per player-season, p < 0.0001). The linear acceleration was higher among females (1.07 g; 95% CI 1.00, 1.13; p = 0.04). There were no other meaningful sex differences in head impact severity. Female players are not permitted to body check, and this likely explains why they sustain fewer head impacts than males. However, as a result, females likely sustain a higher proportion of head impacts through illegal or unintentional head contact, and these impacts may result in more force being delivered to the head.

The Stability of Retrospective Pre-injury Symptom Ratings Following Pediatric Concussion.

Objective: To determine the stability of children's retrospective ratings of pre-injury levels of symptoms over time following concussion. Methods: Children and adolescents (n = 3,063) between the ages of 5-17 diagnosed with a concussion by their treating pediatric emergency department (PED) physician within 48 h of injury completed the Post-Concussion Symptom Inventory (PCSI) at the PED and at 1, 2, 4, 8, and 12-weeks post-injury. At each time point, participants retrospectively recalled their pre-injury levels of post-injury symptoms. The PCSI has three age-appropriate versions for children aged 5-7 (PCSI-SR5), 8-12 (PCSI-SR8), and 13-18 (PCSI-SR13). Total scale, subscales (physical, cognitive, emotional, and sleep), and individual items from the PCSI were analyzed for stability using Gini's mean difference (GMD). Results: The mean GMD for total score was 0.31 (95% CI = 0.28, 0.34) for the PCSI-SR5, 0.19 (95% CI = 0.18, 0.20) for the PCSI-SR8, and 0.17 (95% CI = 0.16, 0.18) for the PCSI-SR13. Subscales ranged from mean GMD 0.18 (physical) to 0.31 (emotional) for the PCSI-SR8 and 0.16 (physical) to 0.31 (fatigue) for the PCSI-SR13. At the item-level, mean GMD ranged from 0.13 to 0.60 on the PCSI-SR5, 0.08 to 0.59 on the PCSI-SR8, and 0.11 to 0.41 on the PCSI-SR13. Conclusions: Children and adolescents recall their retrospective pre-injury symptom ratings with good-to-perfect stability over the first 3-months following their concussion. Although some individual items underperformed, variability was reduced as items were combined at the subscale and full-scale level. There is limited benefit gained from collecting multiple pre-injury symptom queries. Clinical Trial Registration: Clinicaltrials.gov through the US National Institute of Health/National Library of Medicine. (NCT01873287; http://clinicaltrials.gov/ct2/show/NCT01873287).

A Randomized Controlled Trial Investigating the Feasibility and Adherence to an Aerobic Training Program in Healthy Individuals.

CONTEXT: Concussion management is moving from passive rest strategies to active interventions, including aerobic exercise therapy. Little information is available regarding the feasibility and adherence of these programs. OBJECTIVES: To determine whether an aerobic exercise training program intended for rehabilitation in people with concussion is feasible. Healthy, nonconcussed subjects were studied in this phase 1 trial. DESIGN: Phase 1 parallel-group, randomized controlled trial in a sample of healthy (nonconcussed), recreationally active university students. SETTING: Laboratory. PATIENTS: 40 healthy university students. METHODS: Participants were equally randomized to acute concussion therapy intervention (ACTIVE) training or nontraining groups. All participants completed maximal cardiopulmonary exercise tests on a stationary cycle ergometer at 2 test sessions approximately 14 days apart. During this 2-week study period, ACTIVE training participants completed six 30-minute cycling sessions, progressing from 60% to 80% of the participant's individualized maximal oxygen consumption. A subset of participants (NACTIVE = 12, Nnontraining = 11) wore physical activity monitors throughout the 2-week study period. MAIN OUTCOMES MEASURES: Study protocol and randomization effectiveness, exercise safety and adherence, and progressive intensity of the ACTIVE training procedures. RESULTS: No adverse events occurred during any exercise sessions. Twelve ACTIVE training participants (60%) completed all training sessions, and every participant completed at least 4 sessions. Heart rate increased throughout the training period (P < .001), but symptom changes and training adherence remained stable despite the progressively increasing workload. ACTIVE training participants completed approximately 30 additional minutes of physical activity on training sessions days, although that was not statistically significant (P = .20). CONCLUSIONS: University-aged students were adherent to the ACTIVE training protocol. Future research should investigate the safety and feasibility of aerobic training programs in acutely concussed individuals to determine their appropriateness as a clinical rehabilitation strategy.

Randomized Controlled Trial Evaluating Aerobic Training and Common Sport-Related Concussion Outcomes in Healthy Participants.

CONTEXT: Aerobic exercise interventions are increasingly being prescribed for concussion rehabilitation, but whether aerobic training protocols influence clinical concussion diagnosis and management assessments is unknown. OBJECTIVE: To investigate the effects of a brief aerobic exercise intervention on clinical concussion outcomes in healthy, active participants. DESIGN: Randomized controlled clinical trial. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Healthy (uninjured) participants (n = 40) who exercised ≥3 times/week. INTERVENTION(S): Participants were randomized into the acute concussion therapy intervention (ACTIVE) training or nontraining group. All participants completed symptom, cognitive, balance, and vision assessments during 2 test sessions approximately 14 days apart. Participants randomized to ACTIVE training completed six 30-minute exercise sessions that progressed from 60% to 80% of individualized maximal oxygen consumption (V˙o2max) across test sessions, while the nontraining group received no intervention. MAIN OUTCOME MEASURE(S): The CNS Vital Signs standardized scores, Vestibular/Ocular Motor Screening near-point convergence distance (cm), and Graded Symptom Checklist, Balance Error Scoring System, and Standardized Assessment of Concussion total scores. RESULTS: An interaction effect was found for total symptom score ( P = .01); the intervention group had improved symptom scores between sessions (session 1: 5.1 ± 5.8; session 2: 1.9 ± 3.6). Cognitive flexibility, executive functioning, reasoning, and total symptom score outcomes were better but composite memory, verbal memory, and near-point convergence distance scores were worse at the second session (all P values < .05). However, few changes exceeded the 80% reliable change indices calculated for this study, and effect sizes were generally small to negligible. CONCLUSIONS: A brief aerobic training protocol had few meaningful effects on clinical concussion assessment in healthy participants, suggesting that current concussion-diagnostic and -assessment tools remain clinically stable in response to aerobic exercise training. This provides normative data for future researchers, who should further evaluate the effect of ACTIVE training on clinical outcomes among concussed populations. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov : NCT02872480.

Predicting Recovery Patterns After Sport-Related Concussion.

CONTEXT: Clinicians sometimes treat concussed individuals who have amnesia, loss of consciousness (LOC), a concussion history, or certain symptom types more conservatively, but it is unclear whether recovery patterns differ in individuals with these characteristics. OBJECTIVE: To determine whether (1) amnesia, LOC, and concussion history influence the acute recovery of symptoms, cognition, and balance; and (2) cognition and balance are influenced by acute symptom type. DESIGN: Cohort study. SETTING: Seven sports at 26 colleges and 210 high schools. PATIENTS OR OTHER PARTICIPANTS: A total of 8905 collegiate (n = 1392) and high school (n = 7513) athletes. MAIN OUTCOME MEASURE(S): The Graded Symptom Checklist, Standardized Assessment of Concussion, and Balance Error Scoring System were administered to all athletes during the preseason. To allow us to track recovery patterns, athletes diagnosed with a concussion (n = 375) repeated these assessments immediately after the injury, 3 hours postinjury, 1 day postinjury, and at 2, 3, 5, 7, and 90 days after injury. RESULTS: Athletes who experienced amnesia had markedly greater deficits in and a slower recovery trajectory on measures of symptoms, cognition, and balance. Athletes with 2 or more prior concussions demonstrated poorer balance than those with no previous history. Otherwise, LOC and concussion history largely did not affect symptoms, cognition, or balance. Greater deficits in balance scores were observed in athletes with all symptom types. Regardless of these characteristics, most athletes recovered within 7 to 10 days. CONCLUSIONS: Athletes who experienced amnesia had more symptoms and greater deficits in cognition and balance. Symptoms and cognitive or balance deficits were not consistently associated with LOC or concussion history. Acute symptoms had a strong influence on balance scores and, to a lesser extent, on cognition. However, we found no evidence to support more cautious return-to-play decisions for athletes with these characteristics, as group recovery occurred within normal timelines. Our study supports current clinical practice: recommending that athletes be withheld from activity until they are asymptomatic, followed by a graduated return-to-play progression.

Head Impact Biomechanics in Women's College Soccer.

INTRODUCTION: There are limited nonlaboratory soccer head impact biomechanics data. This is surprising given soccer's global popularity. Epidemiological data suggest that female college soccer players are at a greater concussion injury risk than their male counterparts. Therefore, the purposes of our study were to quantify head impact frequency and magnitude during women's soccer practices and games in the National Collegiate Athletic Association and to characterize these data across event type, playing position, year on the team, and segment of game (first and second halves). METHODS: Head impact biomechanics were collected from female college soccer players (n = 22; mean ± SD age = 19.1 ± 0.1 yr, height = 168.0 ± 3.5 cm, mass = 63.7 ± 6.0 kg). We employed a helmetless head impact measurement device (X2 Biosystems xPatch) before each competition and practice across a single season. Peak linear and rotational accelerations were categorized based on impact magnitude and subsequently analyzed using appropriate nonparametric analyses. RESULTS: Overall, women's college soccer players experience approximately seven impacts per 90 min of game play. The overwhelming majority (~90%) of all head impacts were categorized into our mildest linear acceleration impact classification (10g-20g). Interestingly, a higher percentage of practice impacts in the 20g-40g range compared with games (11% vs 7%) was observed. CONCLUSION: Head impact biomechanics studies have provided valuable insights into understanding collision sports and for informing evidence-based rule and policy changes. These have included changing the football kickoff, ice hockey body checking ages, and head-to-head hits in both sports. Given soccer's global popularity, and the growing public concern for the potential long-term neurological implications of collision and contact sports, studying soccer has the potential to impact many athletes and the sports medicine professionals caring for them.

Differential Sensitivity Between a Virtual Reality Balance Module and Clinically Used Concussion Balance Modalities.

OBJECTIVE: Balance assessments are part of the recommended clinical concussion evaluation, along with computerized neuropsychological testing and self-reported symptoms checklists. New technology has allowed for the creation of virtual reality (VR) balance assessments to be used in concussion care, but there is little information on the sensitivity and specificity of these evaluations. The purpose of this study is to establish the sensitivity and specificity of a VR balance module for detecting lingering balance deficits clinical concussion care. DESIGN: Retrospective case-control study. SETTING: Institutional research laboratory. PARTICIPANTS: Normal controls (n = 94) and concussed participants (n = 27). INTERVENTIONS: All participants completed a VR balance assessment paradigm. Concussed participants were diagnosed by a Certified Athletic Trainer or physician (with 48 hours postinjury) and tested in the laboratory between 7 and 10 days postinjury. Receiver operating characteristic curves were performed to establish the VR module's sensitivity and specificity for detecting lingering balance deficits. MAIN OUTCOME MEASURES: Final balance score. RESULTS: For the VR balance module, a cutoff score of 8.25 was established to maximize sensitivity at 85.7% and specificity at 87.8%. CONCLUSIONS: The VR balance module has high sensitivity and specificity for detecting subacute balance deficits after concussive injury. CLINICAL RELEVANCE: The VR balance has a high subacute sensitivity and specificity as a stand-alone balance assessment tool and may detect ongoing balance deficits not readily detectable by the Balance Error Scoring System or Sensory Organization Test. Virtual reality balance modules may be a beneficial addition to the current clinical concussion diagnostic battery.

Validation of a virtual reality balance module for use in clinical concussion assessment and management.

OBJECTIVE: To determine the criterion and content validity of a virtual reality (VR) balance module for use in clinical practice. DESIGN: Retrospective, VR balance module completed by participants during concussion baseline or assessment testing session. SETTING: A Pennsylvania State University research laboratory. PARTICIPANTS: A total of 60 control and 28 concussed students and athletes from the Pennsylvania State University. INTERVENTIONS: None. MAIN OUTCOME MEASURES: This study examined: (1) the relationship between VR composite balance scores (final, stationary, yaw, pitch, and roll) and area of the center-of-pressure (eyes open and closed) scores and (2) group differences (normal volunteers and concussed student-athletes) on VR composite balance scores. RESULTS: With the exception of the stationary composite score, all other VR balance composite scores were significantly correlated with the center of pressure data obtained from a force platform. Significant correlations ranged from r = -0.273 to -0.704 for the eyes open conditions and from r = -0.353 to -0.876 for the eyes closed condition. When examining group differences on the VR balance composite modules, the concussed group did significantly (P < 0.01) worse on all measures compared with the control group. CONCLUSIONS: The VR balance module met or exceeded the criterion and content validity standard set by the current balance tools and may be appropriate for use in a clinical concussion setting. CLINICAL RELEVANCE: Virtual reality balance module is a valid tool for concussion assessment in clinical settings. This novel type of balance assessment may be more sensitive to concussion diagnoses, especially later (7-10 days) in the recovery phase than current clinical balance tools.

Balance and cognitive performance during a dual-task: preliminary implications for use in concussion assessment.

OBJECTIVES: To determine the reliability and effects of a dual-task paradigm on balance and cognitive function compared to a single-task paradigm. DESIGN: Repeated measures. METHODS: Healthy participants (n=23) completed a variation of the Sensory Organization Test and the incongruent Stroop test individually (single-task) and concurrently (dual-task) during two testing sessions. RESULTS: The Sensory Organization Test and incongruent Stroop test had moderate to high reliability (1.00>ICC2,k>0.60) under the dual-task conditions. Reaction time was significantly longer (t21=-2.54, p=0.019) under the dual-task conditions, while balance scores under one of the four conditions of the Sensory Organization Test (sway floor/fixed wall) were statistically better (t22=-3.03, p=0.006) under the dual-task conditions. However, this difference in balance scores may not be clinically meaningful. CONCLUSIONS: These findings illustrate that the Sensory Organization Test and incongruent Stroop task can be reliably incorporated into a dual-task assessment paradigm. The slowed reaction time under the dual-task paradigm indicates that the dual-task provided an additional cost to cognitive function. Dual-task concussion assessment paradigms involving these two tasks are psychometrically appropriate as well as more representative of actual sporting situations. However, more research should be conducted in a concussed population to further validate this claim.