Does an individual's fitness level affect baseline concussion symptoms?

Youth Preseason Performance on the Sport Concussion Assessment Tool 5 Across Multiple Sports

OBJECTIVE

To examine preseason Sport Concussion Assessment Tool 5 (SCAT5) performance of adolescent sport participants by environment (in-person/virtual), sex, age, concussion history, collision/noncollision sport participation, and self-reported medical diagnoses.

DESIGN

Cross-sectional.

SETTING

Canadian community and high-school sport settings.

PARTICIPANTS

Three thousand eight hundred five adolescent (2493 male, 1275 female, and 37 did not disclose; 11- to 19-year-old) sport participants.

ASSESSMENT OF RISK FACTORS

Sport Concussion Assessment Tool 5 administration method (in-person/virtual), sex (male/female/unreported), age (years), concussion history (0/1/2/3+), collision/noncollision sport participant, and self-reported medical diagnoses [attention deficit disorder or attention-deficit/hyperactivity disorder, headache/migraine, learning disability, and psychiatric disorder (ie, anxiety/depression/other)].

OUTCOME MEASURES

Preseason SCAT5 outcomes including total number of symptoms (TNS; /22), symptom severity score (SSS; /132), Standardized Assessment of Concussion (SAC; /50), and modified Balance Error Scoring System (mBESS; /30).

RESULTS

Multiple multilevel linear or Poisson regression complete case analyses adjusting for clustering and robust standard errors, with β-coefficients (95% CI) back-transformed to indicate an increase/decrease in SCAT5 subdomains when relevant for clinical interpretation. Virtual (V) performance was associated with fewer symptoms reported [TNS Difference V-IP = -1.53 (95% CI, -2.22 to -0.85)], lower SSS [-2.49 (95% CI, -4.41 to -0.58)], and fewer mBESS errors (IP) [-0.52 (95% CI, -0.77 to -0.27)] compared with in-person. For every one-year increase in age, more symptoms [TNS = 0.22 (95% CI, 0.01-0.44)], higher SSS [0.52 (95% CI, 0.01-1.06)], higher SAC [0.27 (95% CI, 0.15-0.38), and poorer balance [mBESS = -0.19 (-0.28 to -0.09)] were observed. Differences between males and females were also seen across all SCAT5 outcomes. Individuals reporting any medical diagnosis or 3+ concussion history also reported more symptoms (TNS) and higher SSS than those who did not.

CONCLUSIONS

Administration environment, sex, age, concussion history, and medical diagnoses were associated with SCAT5 subdomains and are important considerations when interpreting the SCAT5 results.

Acute evaluation of sport-related concussion and implications for the Sport Concussion Assessment Tool (SCAT6) for adults, adolescents and children: a systematic review

OBJECTIVES

To systematically review the scientific literature regarding the acute assessment of sport-related concussion (SRC) and provide recommendations for improving the Sport Concussion Assessment Tool (SCAT6).

DATA SOURCES

Systematic searches of seven databases from 2001 to 2022 using key words and controlled vocabulary relevant to concussion, sports, SCAT, and acute evaluation.

ELIGIBILITY CRITERIA

(1) Original research articles, cohort studies, case-control studies, and case series with a sample of >10; (2) ≥80% SRC; and (3) studies using a screening tool/technology to assess SRC acutely (<7 days), and/or studies containing psychometric/normative data for common tools used to assess SRC.

DATA EXTRACTION

Separate reviews were conducted involving six subdomains: Cognition, Balance/Postural Stability, Oculomotor/Cervical/Vestibular, Emerging Technologies, and Neurological Examination/Autonomic Dysfunction. Paediatric/Child studies were included in each subdomain. Risk of Bias and study quality were rated by coauthors using a modified SIGN (Scottish Intercollegiate Guidelines Network) tool.

RESULTS

Out of 12 192 articles screened, 612 were included (189 normative data and 423 SRC assessment studies). Of these, 183 focused on cognition, 126 balance/postural stability, 76 oculomotor/cervical/vestibular, 142 emerging technologies, 13 neurological examination/autonomic dysfunction, and 23 paediatric/child SCAT. The SCAT discriminates between concussed and non-concussed athletes within 72 hours of injury with diminishing utility up to 7 days post injury. Ceiling effects were apparent on the 5-word list learning and concentration subtests. More challenging tests, including the 10-word list, were recommended. Test-retest data revealed limitations in temporal stability. Studies primarily originated in North America with scant data on children.

CONCLUSION

Support exists for using the SCAT within the acute phase of injury. Maximal utility occurs within the first 72 hours and then diminishes up to 7 days after injury. The SCAT has limited utility as a return to play tool beyond 7 days. Empirical data are limited in pre-adolescents, women, sport type, geographical and culturally diverse populations and para athletes.

PROSPERO REGISTRATION NUMBER

CRD42020154787.

Concussion in Women's Flat-Track Roller Derby

Concussions are common among flat-track roller derby players, a unique and under-studied sport, but little has been done to assess how common they are or what players can do to manage injury risk. The purpose of this study is to provide an epidemiological investigation of concussion incidence and experience in a large international sampling of roller derby players. Six hundred sixty-five roller derby players from 25 countries responded to a comprehensive online survey about injury and sport participation. Participants also responded to a battery of psychometric assessment tools targeting risk-factors for poor injury recovery (negative bias, social support, mental toughness) and players' thoughts and feelings in response to injury. Per 1,000 athletes, 790.98 concussions were reported. Current players reported an average of 2.2 concussions, while former players reported 3.1 concussions. However, groups were matched when these figures were corrected for differences in years of play (approximately one concussion every 2 years). Other frequent injuries included fractures in extremities and upper limbs, torn knee ligaments, and sprained ankles. We found no evidence that players' position, full-contact scrimmages, or flooring impacted number of concussions. However, neurological history and uncorrected vision were more influential predictors of an individual's number of concussions during roller derby than years of participation or age, though all four contributed significantly. These findings should assist athletes in making informed decisions about participation in roller derby, though more work is needed to understand the nature of risk.

Investigation of Aerobic and Muscular Fitness and Concussion Among Service Academy Cadets at the United States Air Force Academy: Results from the CARE Consortium

INTRODUCTION

Concussion has become the signature injury facing the U.S. military. However, little is understood about the relationship between military fitness and concussion recovery. The current study examined the recoveries of cadets at a U.S. Service Academy to determine whether preinjury physical fitness improved recovery and whether recovery was associated with post-injury physical fitness measures.

METHODS

Participants were enrolled in a longitudinal study of concussion. Aerobic Fitness Test (AFT) and Physical Fitness Test (PFT) data were used to estimate cadet fitness. Survival analysis evaluated significant estimators of concussion recovery time. Linear regression models were used to explore the relationship between recovery duration and change in physical fitness scores.

RESULTS

Between 2014 and 2017, 307 (n = 70; 22.80% Women) cadets who had sustained a concussion were enrolled. Preinjury physical fitness was not significantly associated with recovery duration (P > .05). Men and intercollegiate cadets took fewer days to reach recovery milestones. Compared to women, men had greater decrements in the Aerobic Fitness Test total score (P < .05) and increased 1.5-mile time postconcussion (P < .05). Women had greater decreases in push-ups postconcussion compared to males (P < .05). There was a trend for a negative association between days until asymptomatic and change in the Physical Fitness Test score (P = .07).

CONCLUSION

Preconcussion physical fitness levels do not appear to impact concussion recovery time among a highly physically fit cohort. Possible methods to reduce the effect of symptom duration on strength-related physical fitness should be investigated along with evaluating reductions in strength as a possible mechanism for postconcussion injury risk.

Baseline SCAT Performance in Men and Women: Comparison of Baseline Concussion Screens Between 6288 Elite Men's and 764 Women's Rugby Players

OBJECTIVE

This study compared Sports Concussion Assessment Tool (SCAT) performance in elite male (6288 players) and female (764 players) rugby players, to determine whether reference limits used for the management and diagnosis of concussion should differ between sexes.

DESIGN

Cross-sectional census sample.

SETTING

Data from World Rugby's Head Injury Assessment management system were analyzed. This data set covers global professional rugby.

PARTICIPANTS

All professional players who underwent baseline SCAT testing as part of World Rugby's concussion management requirement formed the study cohort. Ten thousand seven hundred fifty-four SCAT assessments from 6288 elite male rugby players and 1071 assessments from 764 elite female players were analyzed.

INTERVENTION

Elite men and women rugby players are independent variables.

MAIN OUTCOME MEASURES

Sports Concussion Assessment Tool performance, including symptoms endorsed, cognitive submode performance, and balance performance.

RESULTS

Women endorsed significantly more symptoms, with greater symptom severity, than men (relative ratio 1.34, 95% confidence interval, 1.25-1.45 women vs men). Women outperformed men in cognitive submodes with the exception of immediate memory and delayed recall and made fewer balance errors than men during the modified Balance Error Scoring System. Clinical reference limits, defined as submode score achieved by the worst-performing 50% of the cohort, did not differ between men and women.

CONCLUSIONS

Women and men perform differently during SCAT baseline testing, although differences are small and do not affect either the baseline or clinical reference limits that identify abnormal test results for most submodes. The greater endorsement of symptoms by women suggests increased risk of adverse concussion outcomes and highlights the importance of accurate evaluation of any symptom endorsement at baseline.

The influence of fatiguing exercise on Sport Concussion Assessment Tool (SCAT) scoring in a female pediatric population

There is currently a lack of information available about the effect that exercise fatigue may have on Child Sport Concussion Assessment Tool (SCAT) scoring in a pediatric population. Objective: The goal of this study was to examine the influence of a fatiguing bout of aerobic exercise on Child Sport Concussion Assessment Tool (SCAT) scoring in an adolescent female sporting population. Methods: A prospective, observational-based, test-retest study design was used to collect Child SCAT data from thirty healthy 9-12 year old physically active females during two testing sessions that occurred a minimum of 7 days apart. Within each testing session, each child completed a fatiguing bout of aerobic exercise, and the Child SCAT was administered: (1). Pre-exercise and (2). Post-exercise. Parametric and non-parametric testing was used to compare aerobic exercise test results and pre- vs. post-exercise Child SCAT data. Test-retest reliability was evaluated using intra-class correlation coefficient (ICC 3,1) analysis. Results: No significantly differences were noted between pre- and post-exercise Child SCAT data during either test day. ICC values suggested that a majority of the individual components of the Child SCAT demonstrated poor test-retest reliability. Conclusion: Clinicians using the Child SCAT as a sideline assessment tool during youth sport should have confidence that individual component scores are uninfluenced by aerobic exercise completed immediately prior to assessment. But, clinicians should also be cautioned against using Child SCAT data from consecutive testing days when making decisions about patient recovery and return-to-sport timelines.

The effect of exercise on baseline SCAT5 performance in male professional Rugby players

Background

Rugby Union requires annual baseline testing using the Sports Concussion Assessment Tool (SCAT5) as part of its head injury assessment protocols. Scores achieved during baseline testing are used to guide return-to-play decisions at the time of head impact events during matches, and concussion diagnosis during subsequent diagnostic screens. Baseline values must be valid, accurate representations of a player’s capability in the various SCAT5 sub-modes, including symptom report, cognitive function and balance. The extent to which prior exercise may affect performance is an important consideration, and the present cross-sectional study aimed to explore how SCAT5 performance differs when assessed at rest (RSCAT) compared to after 30 min of exercise (EXSCAT) in 698 male professional rugby players for whom paired exercise and rest SCAT5 data were available.

Results

Symptom endorsement was greater when assessed after exercise than at rest. Fatigue/Low energy was 1.5 times more likely to be reported when assessed during EXSCAT. Orientation score was improved during SCAT5s performed after exercise, but only when rest and exercise SCAT5s were conducted on the same day, suggesting a learning effect. Concentration score was impaired during EXSCAT. No other cognitive sub-modes were affected by exercise. Total errors during Modified Balance Error Scoring System (MBESS) increased during EXSCAT, as a result of increased errors made during single leg balance, irrespective of testing sequence, with 42% of players making more errors in EXSCAT, compared to 28% making more errors in RSCAT.

Conclusions

Symptoms, cognitive sub-modes and balance sub-modes are all affected by exercise. These may be the result of learning effects that improve cognitive performance, and the direct effects of exercise on sub-mode performance. The clinical implications of these changes may be assessed in the future through a study of diagnostic screens in players after head impact events, to confirm whether an exercise baseline screen is required annually, or whether specific sub-modes of the SCAT5 should be obtained at rest and after exercise.

Effect of a concussion on subsequent baseline SCAT performance in professional rugby players: a retrospective cohort study in global elite Rugby Union

OBJECTIVES

This study assessed whether concussion affects subsequent baseline performance in professional rugby players. Annual baseline screening tests are used to guide return-to-play decisions and concussion diagnosis during subsequent screens. It is important that baseline performances are appropriate and valid for the duration of a season and unaffected by factors unrelated to the current head impact event. One such factor may be a concussion following baseline assessment.

SETTING

The World Rugby concussion management database for global professional Rugby Union.

PARTICIPANTS

501 professional rugby players with two baseline Sports Concussion Assessment Tools (SCATs) and an intervening concussion (CONC) were compared with 1190 control players with successive annual SCAT5s and no diagnosed concussion (CONT).

PRIMARY AND SECONDARY OUTCOME MEASURES

Symptom endorsement, cognitive and balance performance during annual SCAT baseline assessments.

RESULTS

Players with a diagnosed concussion (CONC) endorsed fewer symptoms (change -0.42, 95% CI -0.75 to -0.09), and reported lower symptom severity scores during their second assessment (T2, p<0.001) than non-concussed players (CONT). Concussed players also improved Digits Backward and Final Concentration scores in T2 (p<0.001). Tandem gait time was improved during T2 in CONT. No other sub-mode differences were observed in either group.

CONCLUSIONS

Reduced symptom endorsement and improved cognitive performance after concussion may be the result of differences in the motivation of previously concussed players to avoid exclusion from play, leading to under-reporting of symptoms and greater effort in cognitive tests. Improved cognitive performance may be the result of familiarity with the tests as a result of greater exposure to concussion screening. The changes are small and unlikely to have clinical significance in most cases, though clinicians should be mindful of possible reasons, possibly repeating sub-modes and investigating players whose baseline scores change significantly after concussion. The findings do not necessitate a change in the sport's concussion management policy.

The possible role of hydration in concussions and long-term symptoms of concussion for athletes. A review of the evidence

The purpose of this review is to address what is known, speculated, and hypothesized regarding the issue of hydration and concussions. Based on the question, “What impact does hydration have on the relative risk for suffering concussive injuries along with long-term ramifications that have been associated with concussive (and repeated subconcussive) traumas to the cerebral cortex?,” a search of available literature was performed through June 2019. Deducing from the available literature, we can stipulate that changes in hydration within the cerebral cortex increase the likelihood for disruption of neurofilament proteins, dysregulation of membrane dynamics of the neurons and exacerbate inflammation responses following head trauma. As such, it can be speculated that differences in incidence rates may be attributed to difference in tissue fluid based on athlete demographics, level of whole-body water balance, and degree of tissue dehydration more than selection of sport. Moreover, tissue hydration in combination with other inflammation factors provides the scaffolding for the development of long-term issues (e.g. chronic traumatic encephalopathy) associated with repetitive head trauma in athletes.

Sport Concussion Assessment Tool: baseline and clinical reference limits for concussion diagnosis and management in elite Rugby Union

OBJECTIVES

Rugby Union has adapted the Sports Concussion Assessment Tool (SCAT) into an abridged off-field concussion screen and the complete SCAT is used during diagnostic screens performed after head impact events. No firm guidelines exist as to what should be considered "abnormal" and warrant further evaluation. This study evaluates SCAT performances in 13,479 baseline SCAT assessments, and proposes clear reference limits for each sub-component of the SCAT5. Baseline reference limits are proposed to guide management of baseline testing by identifying abnormal sub-tests, enhancing the clinical validity of baseline screens, while clinical reference limits are identified to support concussion diagnosis when no baseline is available.

DESIGN

Cross sectional census sample.

METHODS

13,479 baseline SCATs from 7565 elite male rugby players were evaluated. Baseline reference limits were identified for each sub-test as the sub-test result achieved by approximately 5% of the population, while clinical references limits corresponded to the sub-test score achieved by as close as possible to 50% of the cohort.

RESULTS

Players reported symptoms 35% (95% CI 1.29-1.42) more frequently during SCAT5 than SCAT3 baseline assessments (mean 1.4±2.7 vs 1.0±2.4). Ceiling effects were identified for many cognitive sub-tests within the SCAT. Baseline and Clinical reference limits corresponding to the worst performing 5th percentile and 50th percentile were described.

CONCLUSIONS

Targeted baseline re-testing should be repeated when abnormal sub-tests are identified according to proposed baseline reference limits, while a more conservative clinical reference limit supports concussion diagnosis during screens in diagnostic settings.

Motor Deficits in Youth with Concussion History: Issues with Task Novelty or Task Demand?

The present study expands previous work on eye-hand decoupling deficits in youth with concussion history. It examines whether deficits can be linked to difficulties adapting to new task constraints or meeting ongoing task demands. Data from 59 youth with concussion history (M=11 months post-concussion) and 55 no history controls were analyzed. All 114 participants (M=12.5 yrs.) performed two touchscreen-based eye-hand coordination tasks: A standard task with vision and motor action in alignment, and an eye-hand decoupling task with both spatially decoupled, with twenty trials per task condition. First (trial 1-4), middle (trial 9-12), and last (trial 17-20) trial blocks were analyzed in each condition across groups, as well as first and last blocks only. The latter analysis showed in the first block longer response times in the concussion history group in the eye-hand decoupling condition due to a general slowdown of the reaction times across blocks and a trend for higher movement times. Our findings suggest that youth with concussion history have difficulty to adapt to new task constraints associated with complex skill performance during a short series of trials. These results are relevant for athletic trainers, therapists and coaches who work with youth with concussion history.

The Influence of Self-Reported Tobacco Use on Baseline Concussion Assessments

INTRODUCTION

Baseline symptom, balance, and neurocognitive scores have become an integral piece of the concussion management process. Factors such as sleep, learning disorders, fitness level, and sex have been linked to differences in performance on baseline assessments; however, it is unclear how tobacco use may affect these scores. The objective of this study was to compare baseline concussion assessment scores between service academy cadets who use and do not use tobacco.

METHODS

Cadets completed a standard battery of concussion baseline assessments per standard of care and were classified into two groups: tobacco users (n = 1,232) and nonusers (n = 5,922). Dependent variables included scores on the Balance Error Scoring System, Standardized Assessment of Concussion, Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT), Brief Symptom Inventory-18, and Brief Sensation Seeking Scale (BSSS). Separate Mann-Whitney U-tests were used to compare all baseline assessment scores between groups with an adjusted P-value < 0.004.

RESULTS

Cadets that used tobacco performed significantly worse on the impulse control (P < 0.001) section of the ImPACT, reported greater ImPACT symptom severity scores (P < 0.001), and were more likely to take risks as measured by the BSSS (P < 0.001). No differences were detected for Balance Error Scoring System, Standardized Assessment of Concussion, Brief Symptom Inventory-18, and Sport Concussion Assessment Tool-3 symptom scores, verbal memory, visual memory, visual-motor speed, or reaction time on the ImPACT (P > 0.004).

CONCLUSIONS

Tobacco users performed significantly worse than tobacco nonusers on the impulse control section of the ImPACT, reported greater symptom severity scores on the ImPACT, and were more likely to take risks as measured by the BSSS. Despite statistical significance, these results should be interpreted with caution, as the overall effect sizes were very small. Future research should examine the influence of tobacco use on recovery post-concussion.

The effects of socioeconomic status on baseline neurocognitive testing scores

Baseline neurocognitive testing has been recommended to provide a more accurate representation of the pre-concussion cognitive status of individual athletes. Socioeconomic status is not typically controlled for when obtaining baseline scores, which may lead to inaccurate findings if post-injury scores are compared to normative data. Understanding the role of socioeconomic status in baseline testing is important for the accurate analysis of test scores and proper evaluation of patients if individualized baseline data are not available. Our purpose was to investigate the effects of socioeconomic status, as determined by eligibility for free or reduced cost lunch on baseline neurocognitive test scores in secondary school athletes. 1,788 secondary school athletes (females = 778, males = 1,010, age = 14.96 ± 1.11 years, height = 171.25 ± 17.83 cm, mass = 66.82 ± 21.63 kg) completed the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) upon starting scholastic athletics. ImPACT components (symptom severity scores and composite scores of verbal memory, visual memory, visual motor speed, and reaction time) served as the dependent variables. School administration coded free or reduced cost lunch eligibility (N = 1255 not eligible, N = 563 eligible) for each participant (group), which served as the independent variable. Free or reduced cost lunch eligibility significantly altered the combined dependent variables (multivariate F_5,1780=14.41, p < .001, ɳ² = .04) when sex and age were controlled. Follow up ANOVAs showed that participants eligible for free or reduced cost lunch scored significantly worse on verbal memory (F_1,1784 = 24.81, p < .001, ɳ² = .01), visual memory (F_1,1784 = 24.90, p < .001, ɳ² = .01), and visual motor speed (F_1,1784 = 50.54, p < .001, ɳ² = .03). In addition, slower reaction times (F_1,1784 = 35.10, p < .001, ɳ² = .02) and higher symptom severity scores (F_1,1784 = 10.37, p < .01, ɳ² = .01) were observed in those eligible for free or reduced cost lunch. If normative data are used instead of individual baselines, potential modifiers such as socioeconomic status should be taken into account when analyzing concussion scores to provide accurate diagnoses.

The Future of Concussion

Over the past 2 decades, concussion care is increasingly in demand as research and media attention shed light on the importance of proper diagnosis and medical management to prevent complex, potentially disabling sequelae. The purpose of this review is to discuss the future of clinical concussion care across selected topics under the broad themes of diagnosis/assessment, intervention/treatment, and patient characteristics/presentations with the intent to direct clinicians' attention to important anticipated developments in the field. The current status of biomarkers, clinical settings, models of clinical concussion, return-to-activity, clinical subpopulations, treatment approaches, patient perceptions of injury, and social media are reviewed along with predictions for future developments.

Descriptive Analysis of a Baseline Concussion Battery Among U.S. Service Academy Members: Results from the Concussion Assessment, Research, and Education (CARE) Consortium

Introduction

The prevalence and possible long-term consequences of concussion remain an increasing concern to the U.S. military, particularly as it pertains to maintaining a medically ready force. Baseline testing is being used both in the civilian and military domains to assess concussion injury and recovery. Accurate interpretation of these baseline assessments requires one to consider other influencing factors not related to concussion. To date, there is limited understanding, especially within the military, of what factors influence normative test performance. Given the significant physical and mental demands placed on service academy members (SAM), and their relatively high risk for concussion, it is important to describe demographics and normative profile of SAMs. Furthermore, the absence of available baseline normative data on female and non-varsity SAMs makes interpretation of post-injury assessments challenging. Understanding how individuals perform at baseline, given their unique individual characteristics (e.g., concussion history, sex, competition level), will inform post-concussion assessment and management. Thus, the primary aim of this manuscript is to characterize the SAM population and determine normative values on a concussion baseline testing battery.

Materials and Methods

All data were collected as part of the Concussion Assessment, Research and Education (CARE) Consortium. The baseline test battery included a post-concussion symptom checklist (Sport Concussion Assessment Tool (SCAT), psychological health screening inventory (Brief Symptom Inventory (BSI-18) and neurocognitive evaluation (ImPACT), Balance Error Scoring System (BESS), and Standardized Assessment of Concussion (SAC). Linear regression models were used to examine differences across sexes, competition levels, and varsity contact levels while controlling for academy, freshman status, race, and previous concussion. Zero inflated negative binomial models estimated symptom scores due to the high frequency of zero scores.

Results

Significant, but small, sex effects were observed on the ImPACT visual memory task. While, females performed worse than males (p < 0.0001, pη2 = 0.01), these differences were small and not larger than the effects of the covariates. A similar pattern was observed for competition level on the SAC. There was a small, but significant difference across competition level. SAMs participating in varsity athletics did significantly worse on the SAC compared to SAMs participating in club or intramural athletics (all p's < 0.001, η2 = 0.01). When examining symptom reporting, males were more than two times as likely to report zero symptoms on the SCAT or BSI-18. Intramural SAMs had the highest number of symptoms and severity compared to varsity SAMs (p < 0.0001, Cohen's d < 0.2). Contact level was not associated with SCAT or BSI-18 symptoms among varsity SAMs. Notably, the significant differences across competition level on SCAT and BSI-18 were sub-clinical and had small effect sizes.

Conclusion

The current analyses provide the first baseline concussion battery normative data among SAMs. While statistically significant differences may be observed on baseline tests, the effect sizes for competition and contact levels are very small, indicating that differences are likely not clinically meaningful at baseline. Identifying baseline differences and significant covariates is important for future concussion-related analyses to inform concussion evaluations for all athlete levels.

Reconsidering Return-to-Play Times: A Broader Perspective on Concussion Recovery

Background:

Return-to-play protocols describe stepwise, graduated recoveries for safe return from concussion; however, studies that comprehensively track return-to-play time are expensive to administer and heavily sampled from elite male contact-sport athletes.

Purpose:

To retrospectively assess probable recovery time for collegiate patients to return to play after concussion, especially for understudied populations, such as women and nonelite athletes.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Medical staff at a military academy logged a total of 512 concussion medical records over 38 months. Of these, 414 records included complete return-to-play protocols with return-to-play time, sex, athletic status, cause, and other data.

Results:

Overall mean return to play was 29.4 days. Sex and athletic status both affected return-to-play time. Men showed significantly shorter return to play than women, taking 24.7 days (SEM, 1.5 days) versus 35.5 days (SEM, 2.7 days) (P < .001). Intercollegiate athletes also reported quicker return-to-play times than nonintercollegiate athletes: 25.4 days (SEM, 2.6 days) versus 34.7 days (SEM, 1.6 days) (P = .002). These variables did not significantly interact.

Conclusion:

Mean recovery time across all groups (29.4 days) showed considerably longer return to play than the most commonly cited concussion recovery time window (7-10 days) for collegiate athletes. Understudied groups, such as women and nonelite athletes, demonstrated notably longer recovery times. The diversity of this sample population was associated with longer return-to-play times; it is unclear how other population-specific factors may have contributed. These inclusive return-to-play windows may indicate longer recovery times outside the population of elite athletes.

Effects of Exercise on Sport Concussion Assessment Tool-Third Edition Performance in Professional Athletes

BACKGROUND

The Sport Concussion Assessment Tool-Third Edition (SCAT3) is currently considered the standard sideline assessment for concussions. In-game exercise, however, may affect SCAT3 performance and the diagnosis of concussions.

PURPOSE

To examine the influence of exercise on SCAT3 performance in professional male athletes.

STUDY DESIGN

Controlled laboratory study.

METHODS

We examined the SCAT3 performance of 82 professional male athletes under 2 conditions: at rest and after exercise.

RESULTS

Athletes reported significantly fewer total symptoms (mean, 1.0 ± 1.5 vs 1.6 ± 2.3 total symptoms, respectively; P = .008; Cohen d = 0.34), committed significantly fewer errors on the modified Balance Error Scoring System (mean, 3.5 ± 3.5 vs 4.6 ± 4.1 errors, respectively; P = .017; d = 0.31), and required significantly less time to complete the tandem gait test (mean, 9.5 ± 1.4 vs 9.9 ± 1.7 seconds, respectively; P = .02; d = 0.30) during the at-rest condition compared with the postexercise condition.

CONCLUSION

The interpretation of in-game (sideline) SCAT3 results should consider the effects of postexercise fatigue levels on an athlete's performance, particularly if preseason baseline data have been collected when the athlete was well rested.

CLINICAL RELEVANCE

Exercise appears to affect symptom burden and physical abilities, such as balance and tandem gait, more so than the cognitive components of the SCAT3.

Psychological and Lifestyle Factors That Influence the Serial Reporting of Postconcussion-like Symptoms in a Non-concussed Population

BACKGROUND

Symptoms related to concussion are generally nonspecific in nature, as they are also reported by non-concussed individuals. What is currently not known is whether the symptoms vary over time, and whether they are also influenced by a multitude of factors.

OBJECTIVE

The aim of this study was to investigate the potential influence of psychological, lifestyle, and situational factors on the change in postconcussion-like symptoms reported over 7 consecutive days in a cohort of normal individuals.

DESIGN

This was a longitudinal observational study.

SETTING

The setting was a real-world context.

PARTICIPANTS

A convenience sample of 180 non-concussed university students were enrolled. Of these, 110 participants provided data for the entire period of the study.

METHODS

An experience-sampling methodology was used to document the symptoms reported over time. Stepwise multivariate linear mixed-effects modeling was performed to identify the predictors contributing to the serially reported symptoms.

INDEPENDENT VARIABLES

Independent variables considered were gender, time of the day, location, primary activity, and type of interactant (person) of the participant, physical activity status, trouble sleeping, alcohol consumption, caffeine consumption, stress, anxiety, depression, mental and physical fatigue, and life stressors.

MAIN OUTCOME MEASURES

The key outcome measures were the change in total symptom score (TSS_change) and symptom severity score (SSS_change) reported over 7 consecutive days.

RESULTS

The predictors of location at the time of reporting, physical fatigue (estimate: -0.98, P < .001) and mental fatigue (estimate: -0.53, P < .001) contributed to the TSS_change. Post hoc analysis of the variable of location at the time of reporting revealed that participants reported increased TSS_change when they were at a café/restaurant compared to a flat/college or university.

CONCLUSIONS

A number of factors within the context of daily life influenced the postconcussion-like symptoms reported over time. These findings indicate that clinicians need to be cautious when interpreting the serially assessed symptom scores to track the recovery profile of a concussed athlete to make decisions on return-to-play. Additional investigation is warranted to examine the change in symptom scores reported over time by concussed individuals, considering that this study was conducted in a nonconcussed cohort.

LEVEL OF EVIDENCE

Not applicable.

Concussion Baseline Testing: Preexisting Factors, Symptoms, and Neurocognitive Performance

CONTEXT

Neurocognitive test scores are often considered an important aspect of concussion management. To best use these data, clinicians must understand potential factors that may influence baseline performance on these tests.

OBJECTIVE

To determine preexisting factors that may influence performance on the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT).

DESIGN

Cross-sectional study.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

A total of 486 National Collegiate Athletic Association Division I collegiate student-athletes.

MAIN OUTCOME MEASURE(S)

To determine neurocognitive functioning and total symptom score at baseline, ImPACT was administered. Outcomes were verbal memory, visual memory, visual motor speed, reaction time, and total symptom score. A self-report demographic section at the beginning of ImPACT was used to gather information concerning previous treatment for headaches, migraines, and psychiatric conditions; diagnosis of attention-deficit/hyperactivity disorder; and exposure to previous strenuous exercise. We conducted multivariate analyses of variance to determine if the ImPACT composite and total symptom scores differed according to preexisting factors (P < .0083).

RESULTS

Sex showed an effect on verbal memory (P = .001), visual motor speed (P < .001), and reaction time (P = .006), with women performing better than men. A previous diagnosis of attention-deficit/hyperactivity disorder affected visual motor speed (P = .008). Previous treatment for headaches (P < .001), migraines (P = .001), a psychiatric condition (P < .001), or a diagnosis of attention-deficit/hyperactivity disorder (P < .001) all showed effects on the total symptom score. Strenuous exercise did not affect neurocogntive performance or total symptom score.

CONCLUSIONS

Based on our findings and the previous literature, we suggest that many preexisting factors influence baseline neurocognitive data. Baseline testing is an important aspect of concussion management. Sports medicine professionals should be cognizant of these factors when developing concussion-management protocols.

SCAT2 and SCAT3 scores at baseline and after sports-related mild brain injury/concussion: qualitative synthesis with weighted means

Objective

Identify all Sport Concussion Assessment Tool (SCAT2/3) studies, compare baseline and postconcussion results.

Design

Systematic review (qualitative synthesis, weighted means).

Data sources

18 databases, 9 grey literature resources searched for SCAT2/3 data; 9150 articles identified, titles/abstracts assessed/data-entry independently by two reviewers.

Eligibility criteria for selecting studies

Any studies reporting partial/complete SCAT2/3 data.

Results

21 studies with data (partial/complete data 16 SCAT2 (4087 athletes); 5 SCAT3 (891). Newcastle-Ottawa risk-of-bias scale: studies with maximum possible score of 4, 85% scored 3 or 4; studies with maximum possible score of 6, 75% scored 5 or 6. SCAT2 high schoolers: weighted mean score for symptoms 18.46 (22=no symptoms), Balance Error Scoring System (BESS) 26.14, Standardised Assessment of Concussion (SAC) 26.00 and SCAT2 total 88.63. Collegiate/adults weighted means: symptoms 20.09, BESS 25.54, SAC 27.51 and total SCAT2 91.20. Between-study and within-study variability similar to those of the high schoolers. Limited variability between genders. Only 2 studies report baseline and postconcussion scores and 9 partial scores, but data are too limited to provide weighted average scores.

Conclusions

Group mean baseline SCAT scores for high school and collegiate athletes are similar, with minimal gender differences; baseline symptoms show more variability than other components. There are minimal data for elementary students and professionals, no data for adult non-collegiate athletes. Two studies provide preconcussion and postconcussion scores. No data on minimal significant clinical differences to guide players/coaches in withdrawing from a game in progress and deciding when recovery is complete and play can be resumed. The SCAT needs supplementing with clinical and neuropsychological return-to-play assessments.