Making a Difference: Affective Distress Explains Discrepancy Between Objective and Subjective Cognitive Functioning After Mild Traumatic Brain Injury.

OBJECTIVE: To assess the relationship between subjective cognitive symptoms and objective cognitive test scores in patients after concussion. We additionally examined factors associated with subjective and objective cognitive dysfunction, as well as their discrepancy. PARTICIPANTS: Eighty-six individuals (65.1% female; 74.4% adult) from an interdisciplinary concussion clinic. METHODS: Subjective and objective cognitive functioning was measured via the SCAT-Symptom Evaluation and the CNS Vital Signs Neurocognition Index (NCI), respectively. Cognitive discrepancy scores were derived by calculating standardized residuals (via linear regression) using subjective symptoms as the outcome and NCI score as the predictor. Hierarchical regression assessed predictors (age, education, time postinjury, attention-deficit/hyperactivity disorder, affective distress, and sleep disturbance) of cognitive discrepancy scores. Nonparametric analyses evaluated relationships between predictor variables, subjective symptoms, and NCI. RESULTS: More severe affective and sleep symptoms (large and medium effects), less time postinjury (small effect), and older age (small effect) were associated with higher subjective cognitive symptoms. Higher levels of affective distress and less time since injury were associated with higher cognitive discrepancy scores (ß = .723, P < .001; ß = -.204, P < .05, respectively). CONCLUSION: Clinical interpretation of subjective cognitive dysfunction should consider these additional variables. Evaluation of affective distress is warranted in the context of higher subjective cognitive complaints than objective test performance.

King-Devick Test Time Varies by Testing Modality.

OBJECTIVE: To explore differences in baseline King-Devick Test (KD) completion time between 2 testing modalities: (1) spiral-bound paper cards (cards) and (2) iPad application (iPad). DESIGN: Cross-sectional cohort analysis. SETTING: National Collegiate Athlete Association (NCAA) institutions. PARTICIPANTS: Student athletes from 13 women's and 11 men's collegiate sports who completed KD baseline testing as part of their first year in the Concussion Assessment, Research and Education (CARE) Consortium from 2014 to 2016 (n = 2003, 52.2% male). INDEPENDENT VARIABLES: King-Devick Test modalities; cards or iPad. MAIN OUTCOME MEASURE: Baseline KD completion time (seconds). RESULTS: Mean baseline KD completion time of the iPad modality group [42.8 seconds, 95% confidence interval (CI), 42.1-43.3] was 2.8 seconds (95% CI, 2.1-3.4) greater than the cards group (40.0 seconds, 95% CI, 39.7-40.3) (t(1, 1010.7) = -8.0, P < 0.001, Cohen's d = 0.41). CONCLUSIONS: Baseline KD performance is slower when tested on an iPad than when tested on spiral-bound paper cards. The 2 KD modalities should not be used interchangeably in concussion assessments because differences in the modalities can lead to time differences similar in magnitude to those used to indicate concussion. From a research perspective, modality may influence interpretation and/or synthesis of findings across studies.

Factors Influencing Clinical Correlates of Chronic Traumatic Encephalopathy (CTE): a Review.

Chronic traumatic encephalopathy (CTE) is a neuropathologically defined disease reportedly linked to a history of repetitive brain trauma. As such, retired collision sport athletes are likely at heightened risk for developing CTE. Researchers have described distinct pathological features of CTE as well a wide range of clinical symptom presentations, recently termed traumatic encephalopathy syndrome (TES). These clinical symptoms are highly variable, non-specific to individuals described as having CTE pathology in case reports, and are often associated with many other factors. This review describes the cognitive, emotional, and behavioral changes associated with 1) developmental and demographic factors, 2) neurodevelopmental disorders, 3) normal aging, 4) adjusting to retirement, 5) drug and alcohol abuse, 6) surgeries and anesthesia, and 7) sleep difficulties, as well as the relationship between these factors and risk for developing dementia-related neurodegenerative disease. We discuss why some professional athletes may be particularly susceptible to many of these effects and the importance of choosing appropriate controls groups when designing research protocols. We conclude that these factors should be considered as modifiers predominantly of the clinical outcomes associated with repetitive brain trauma within a broader biopsychosocial framework when interpreting and attributing symptom development, though also note potential effects on neuropathological outcomes. Importantly, this could have significant treatment implications for improving quality of life.

Estimated Duration of Continued Sport Participation Following Concussions and Its Association with Recovery Outcomes in Collegiate Athletes: Findings from the NCAA/DoD CARE Consortium.

BACKGROUND: Continued participation after sport-related concussion (SRC) worsens outcomes, but it is unknown if duration of continued participation after SRC impacts recovery outcomes, and which athletes who continue to participate are at greatest risk for poor SRC outcomes. The purpose of this National Collegiate Athletic Association/Department of Defense (NCAA/DoD) Concussion Assessment, Research, and Education (CARE) Consortium study was to evaluate the association of estimated duration of continued participation after SRC with symptom severity and recovery time in collegiate athletes. METHODS: Clinicians estimated if/how long athletes continued participation after SRC. Collegiate athletes who continued participation after suspected SRC (n = 195/373, 52.3%) completed the Graded Symptom Checklist to evaluate the severity of total symptoms and migraine/fatigue, cognitive/ocular, and affective symptom clusters. Linear regression analyzed the associations between estimated duration of continued participation, symptom severity, and recovery time. Binary logistic regression examined the association of estimated duration of continued participation with the odds of recovery ≥ 14 and ≥ 21 days. Statistical significance was p < 0.05. RESULTS: Athletes who continued to participate did so for 27.9 ± 25.3 min (mean ± standard deviation; range 1-90 min). Longer estimated continued participation (1-90 min) was associated with greater symptom severity (ß = 0.122, p = 0.02), affective (ß = 0.171, p = 0.001) and migraine/fatigue symptoms (ß = 0.104, p = 0.049), longer symptom duration (ß = 0.193, p < 0.001), and longer time missed (ß = 0.156, p = 0.003). Longer estimated continued participation positively interacted with female sex (cognitive/ocular: female R2 = 0.03, male R2 = 0.01, p = 0.02; affective: female R2 = 0.06, male R2 = 0.02, p = 0.006), migraine history (affective symptoms: no migraine R2 = 0.02; migraine R2 = 0.18; p = 0.04), and concussion history (affective: 2 + prior concussions [R2 = 0.14] compared with those with 1 [R2 = 0.07] or 0 [R2 < 0.01] prior concussions [p = 0.003]). CONCLUSIONS: Longer estimated duration of continued participation after SRC was associated with higher symptom severity, particularly affective and migraine/fatigue; longer symptom duration; and more time missed from sport. SRC outcomes in those who continue to play may be especially severe for female athletes, athletes with migraine history, and athletes with prior concussion(s). The findings can help clinicians and administrators to educate athletes on the importance of immediate removal following a suspected SRC.

SCAT5 vs. SCAT3 Symptom Reporting Differences and Convergent Validity in Collegiate Athletes.

OBJECTIVE: The Sport Concussion Assessment Tool (SCAT), fifth Edition, Symptom Evaluation (S5SE) differs from previous versions by having examinees report trait (i.e. "typical" feelings) as opposed to state (i.e., "how you feel right now") concussion-like symptoms at baseline. This study assessed differences among, and convergent validity of, scores on the S5SE, SCAT3 Symptom Evaluation (S3SE), and the Brief Symptom Inventory (BSI-18). METHODS: A total of 113 University of Florida varsity athletes completed symptom questionnaires on the same day in a counterbalanced administration. The final sample consisted of 94 participants (mean age ± SD = 18.4 ± 0.8 years, 57% male, 65% white) from 17 sports. We assessed convergent validity using Spearman rank-order correlations. Within-participant differences were analyzed with Wilcoxon Signed-Rank tests. We qualitatively described free-response answers to the S5SE question that asks, "if not feeling 100%, why?". RESULTS: S5SE total severity score demonstrated adequate convergent validity with both the S3SE (rho = .407, p < .001) and BSI-18 (rho = .432, p < .001). Domain-specific analyses indicated variable convergent validity (rho < 0.4 to rho > 0.6). Severity scores did not differ between the S3SE and S5SE (p = .500), but 24.5% of participants reported S3SE > S5SE and 34.0% S5SE > S3SE. Three themes emerged from qualitative examination of reasons for "not feeling 100%": (1) tiredness/sleep, (2) adjustment difficulties, and (3) academic/athletic stress. CONCLUSIONS: Adequate convergent validity exists between SCAT5 and SCAT3 symptom severity in collegiate athletes. However, most examinees report different baseline symptom severity when asked to describe their trait (S5SE) versus state symptoms (S3SE). Clinicians should consider using the new SCAT5 Symptom Evaluation as a screening tool for identifying otherwise healthy or "undiagnosed" individuals who would benefit from targeted interventions.

Academic aptitude mediates the relationship between socioeconomic status and race in predicting ImPACT scores in college athletes.

Objective: To evaluate the influences of sociodemographic factors, estimated head impact exposure, and academic aptitude on ImPACT scores in college athletes.Methods: Data were reported on 18,886 participants (58% male) from the NCAA/DoD CARE Consortium. Race, SES, concussion history, estimated repetitive head impact exposure (eRHIE), and academic aptitude (SAT or ACT score) were our predictors of interest. Cognition was measured using ImPACT composite scores. We evaluated the mediating effects of academic aptitude on sociodemographic predictors and eRHIE on ImPACT scores. We then evaluated a football-only subsample and added age of first exposure to football (AFE) to the model. Males, females, and football players were analyzed separately using structural equation modeling.Results: Academic aptitude was associated with Black/African American race, SES, and each of the ImPACT composite scores. There were significant indirect effects of Black/African American race and SES on all ImPACT composite scores. Academic aptitude fully mediated SES effects and either fully or partially mediated race effects. Contrary to expectation, greater concussion history and eRHIE predicted better ImPACT scores.Conclusions: Academic aptitude, a stable indicator of premorbid cognitive function, consistently and most strongly predicted baseline ImPACT scores in collegiate student-athletes. Concussion and eRHIE history demonstrated a small positive, but non-significant, relationship with cognitive scores at the time of college athletic participation. This study suggests that attempts to characterize cognitive ability across the lifespan must consider premorbid functioning and sociodemographic variables.

Word-reading ability as a "hold test" in cognitively normal young adults with history of concussion and repetitive head impact exposure: A CARE Consortium Study.

Objective: Neuropsychological evaluations include hold tests like word-reading ability as estimates of premorbid intellect thought to be resilient to the effects of neurologic insult. We tested the alternative hypothesis that exposure to concussion or repetitive subclinical head impacts throughout early life may stunt acquisition of word-reading skills.Method: Data were obtained from student-athletes within the CARE Consortium that completed the Wechsler Test of Adult Reading (WTAR). Measures of head trauma burden included self-reported concussion history and cumulative years of exposure to collision sports. We evaluated the effects of head trauma, sociodemographic (race, SES), and academic (SAT/ACT scores, learning disorder) variables on WTAR standard score using linear regression. Analyses were repeated in a football-only subsample estimating age of first exposure to football as a predictor.Results: We analyzed data from 6,598 participants (72.2% white, 39.6% female, mean ± SD age = 18.8 ± 1.2 years). Head trauma variables collectively explained 0.1% of the variance in WTAR standard scores, with years of collision sport exposure weakly predicting lower WTAR standard scores (ß = .026-.035, very small effect). In contrast, sociodemographic and academic variables collectively explained 20.9-22.5% of WTAR standard score variance, with strongest effects noted for SAT/ACT scores (ß = .313-.337, medium effect), LD diagnosis (ß = -.115 to -.131, small effect), and SES (ß = .101-.108, small effect). Age of first exposure to football did not affect WTAR scores in a football-only sample.Conclusion: Wechsler Test of Adult Reading performance appears unrelated to history of self-reported concussion(s) and/or repetitive subclinical head trauma exposure in current collegiate athletes. Sociodemographic and academic variables should be incorporated in test score interpretations for diverse populations like athletes.

Correction to: A Normative Reference vs. Baseline Testing Compromise for ImPACT: The CARE Consortium Multiple Variable Prediction (CARE-MVP) Norms.

Unfortunately, in the published article the symbol "% ile" has incorrectly been published as "‰". We have now corrected this in all the occurrences.

A Normative Reference vs. Baseline Testing Compromise for ImPACT: The CARE Consortium Multiple Variable Prediction (CARE-MVP) Norms.

BACKGROUND: Sports medicine clinicians routinely use computerized neurocognitive testing in sport-related concussion management programs. Debates continue regarding the appropriateness of normative reference comparisons versus obtaining individual baseline assessments, particularly for populations with greater likelihood of having below- or above-average cognitive abilities. Improving normative reference methods could offer alternatives to perceived logistical and financial burdens imposed by universal baseline testing. OBJECTIVES: To develop and validate the Concussion Assessment, Research, and Education (CARE) Consortium Multiple Variable Prediction (MVP) norms for the Immediate Postconcussion Assessment and Cognitive Testing (ImPACT). METHODS: We developed the CARE-MVP norms for ImPACT composite scores using regression-based equations. Predictor variables included sex, race (white/Caucasian, black/African American, Asian, or Multiple Races), medical history [attention-deficit/hyperactivity disorder (ADHD), learning disorder (LD), prior concussion(s), prior psychiatric diagnosis], and an estimate of premorbid intellect (Wechsler Test of Adult Reading). CARE-MVP norms were first validated in an independent sample of healthy collegiate athletes by comparing predicted and actual baseline test scores using independent-samples t-tests and Cohen's d effect sizes. We then evaluated base rates of low scores in athletes self-reporting ADHD/LD (vs. non-ADHD/LD) and black/African American race (vs. white/Caucasian) across multiple normative reference methods (Chi square, Cramer's V effect size). Lastly, we validated the CARE-MVP norms in a concussed sample (dependent samples t test, Cohen's d effect size). RESULTS: A total of 5233 collegiate athletes (18.8 ± 1.2 years, 70.5% white/Caucasian, 39.1% female) contributed to the CARE-MVP norms (development N = 2616; internal validation N = 2617). Race and WTAR score were the strongest and most consistent ImPACT score predictors. There were negligible mean differences between observed and predicted (CARE-MVP) baseline scores (Cohen's d < 0.1) for all ImPACT composite scores except Reaction Time (predicted ~ 20 ms faster than observed, d = - 0.28). Low score base rates were similar for athletes across subpopulations when using CARE-MVP norms (ADHD/LD, V = 0.017-0.028; black/African American, V = 0.043-0.053); while, other normative reference methods resulted in disproportionately higher rates of low scores (ADHD/LD, V = 0.062-0.101; black/African American race, V = 0.163-0.221). Acute (24-48 h) postconcussion ImPACT scores were significantly worse than CARE-MVP norms but notably varied as a function of concussion symptom severity. CONCLUSIONS: Results support CARE-MVP norm use in populations typically underrepresented or not adjusted for in traditional normative reference samples, such as those self-reporting ADHD/LD or black/African American race. CARE-MVP norms improve upon prior normative methods and may offer a practical, simple alternative for collegiate institutions concerned about logistical and financial burden associated with baseline testing. An automated scoring program is provided.

Relationship Between the King-Devick Test and Commonly Used Concussion Tests at Baseline.

CONTEXT: Comprehensive assessments are recommended to evaluate sport-related concussion (SRC). The degree to which the King-Devick (KD) test adds novel information to an SRC evaluation is unknown. OBJECTIVE: To describe relationships at baseline among the KD and other SRC assessments and explore whether the KD provides unique information to a multimodal baseline concussion assessment. DESIGN: Cross-sectional study. SETTING: Five National Collegiate Athletic Association institutions participating in the Concussion Assessment, Research and Education (CARE) Consortium. PATIENTS OR OTHER PARTICIPANTS: National Collegiate Athletic Association student-athletes (N = 2258, age = 20 ± 1.5 years, 53.0% male, 68.9% white) in 11 men's and 13 women's sports. MAIN OUTCOME MEASURE(S): Participants completed baseline assessments on the KD and (1) the Symptom Inventory of the Sport Concussion Assessment Tool-3rd edition, (2) the Brief Symptom Inventory-18, (3) the Balance Error Scoring System, (4) the Standardized Assessment of Concussion (SAC), (5) the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) test battery, and (6) the Vestibular/Ocular Motor Screening tool during their first year in CARE. Correlation coefficients between the KD and the 6 other concussion assessments in isolation were determined. Assessments with ρ magnitude >0.1 were included in a multivariate linear regression analysis to evaluate their relative association with the KD. RESULTS: Scores for SAC concentration, ImPACT visual motor speed, and ImPACT reaction time were correlated with the KD (ρ = -0.216, -0.276, and 0.164, respectively) and were thus included in the regression model, which explained 16.8% of the variance in baseline KD time (P < .001, Cohen f2 = 0.20). Better SAC concentration score (ß = -.174, P < .001), ImPACT visual motor speed (ß = -.205, P < .001), and ImPACT reaction time (ß = .056, P = .020) were associated with faster baseline KD performance, but the effect sizes were small. CONCLUSIONS: Better performance on cognitive measures involving concentration, visual motor speed, and reaction time was weakly associated with better baseline KD performance. Symptoms, psychological distress, balance, and vestibular-oculomotor provocation were unrelated to KD performance at baseline. The findings indicate limited overlap at baseline among the CARE SRC assessments and the KD.

Concussion BASICS II: Baseline serum biomarkers, head impact exposure, and clinical measures.

OBJECTIVE: To examine the effect of concussion history and cumulative exposure to collision sports on baseline serum biomarker concentrations, as well as associations between biomarker concentrations and clinical assessments. METHODS: In this observational cohort study, ß-amyloid peptide 42 (Aß42), total tau, S100 calcium binding protein B (S100B), ubiquitin carboxy-terminal hydrolyzing enzyme L1 (UCH-L1), glial fibrillary acidic protein, microtubule associated protein 2, and 2',3'-cyclic-nucleotide 3'-phosphodiesterase serum concentrations were measured in 415 (61% male, 40% white, aged 19.0 ± 1.2 years) nonconcussed collegiate athletes without recent exposure to head impacts. Regression analyses were used to evaluate the relationship between self-reported history of concussion(s), cumulative years playing collision sports, clinical assessments, and baseline biomarker concentrations. Football-specific analyses were performed using a modified Cumulative Head Impact Index. Clinical assessments included symptom, cognitive, balance, and oculomotor tests. RESULTS: Athletes with a greater number of concussions had a higher baseline Aß42 concentration only (ρ = 0.140, p = 0.005, small effect size). No biomarker concentrations correlated with cumulative exposure to collision sports. Race status fully mediated the correlations of S100B, UCH-L1, and Aß42 with cognitive scores. Football exposure, specifically, was not associated with serum biomarker concentrations or clinical assessment scores based on the modified Cumulative Head Impact Index. CONCLUSION: Concussion-related serum biomarkers showed no consistent association with concussion history, cumulative exposure to collision sports, or clinical assessments in a sample of healthy collegiate athletes. Serum Aß42 concentrations could increase following multiple previous concussions. Considering race status is essential when investigating links between biomarkers and cognition. The biomarkers studied may not detect residual effects of concussion or repetitive head impact exposure in otherwise asymptomatic collegiate athletes without recent exposure to head impacts. Much more research is needed for identifying reliable and valid blood biomarkers of brain trauma history.

Concussion Biomarkers Assessed in Collegiate Student-Athletes (BASICS) I: Normative study.

OBJECTIVE: To describe variability in concussion biomarker concentrations collected from serum in a sample of healthy collegiate athletes, as well as report reliability metrics in a subsample of female athletes. METHODS: In this observational cohort study, ß-amyloid peptide 42 (Aß42), total tau, S100 calcium binding protein B (S100B), ubiquitin carboxy-terminal hydrolyzing enzyme L1 (UCH-L1), glial fibrillary acidic protein, microtubule associated protein 2, and 2',3'-cyclic-nucleotide 3'-phosphodiesterase (CNPase) serum concentrations were measured in 415 (61% male, 40% white, aged 19.0 ± 1.2 years) nonconcussed collegiate athletes without recent exposure to head impacts. Standardized normative distributions are reported for each biomarker. We evaluated main effects (analyses of variance) of sex and race, reporting demographic-specific normative metrics when appropriate. In a subset of 31 female participants, test-retest reliability (Pearson r) and reliable change indices (80%, 90%, and 95% confidence intervals) across a 6- to 12-month interval are reported for Aß42, total tau, S100B, and UCH-L1. RESULTS: Males exhibited higher UCH-L1 (p < 0.001, Cohen d = 0.75) and S100B (p < 0.001, d = 0.56) than females, while females had higher CNPase (p < 0.001, d = 0.43). Regarding race, black participants had higher baseline levels of UCH-L1 (p < 0.001, d = 0.61) and S100B (p < 0.001, d = 1.1) than white participants. Conversely, white participants had higher baseline levels of Aß42 (p = 0.005, d = 0.28) and CNPase (p < 0.001, d = 0.46). Test-retest reliability was generally poor, ranging from -0.02 to 0.40, and Aß42 significantly increased from time 1 to time 2. CONCLUSION: Healthy collegiate athletes express concussion-related serum biomarkers in variable concentrations. Accounting for demographic factors such as sex and race is essential. Evidence suggested poor reliability for serum biomarkers; however, understanding how other factors influence biomarker expression, as well as knowledge of reliable change metrics, may improve clinical interpretation and future study designs.

Immediate Removal From Activity After Sport-Related Concussion Is Associated With Shorter Clinical Recovery and Less Severe Symptoms in Collegiate Student-Athletes.

BACKGROUND: Timely removal from activity after concussion symptoms remains problematic despite heightened awareness. Previous studies indicated potential adverse effects of continuing to participate in physical activity immediately after sustaining a concussion. Hypothesis/Purpose: The purpose was to determine the effect of timing of removal from play after concussion on clinical outcomes. It was hypothesized that immediate removal from activity after sport-related concussion (SRC) would be associated with less time missed from sport, a shorter symptomatic period, and better outcomes on acute clinical measures. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Data were reported from the National Collegiate Athletic Association and Department of Defense Grand Alliance: Concussion Awareness, Research, and Education (CARE) Consortium. Participants with 506 diagnosed SRCs from 18 sports and 25 institutions and military service academies were analyzed and classified as either immediate removal from activity (I-RFA) or delayed removal from activity (D-RFA). Outcomes of interest included time missed from sport attributed to their SRC, symptom duration, and clinical assessment scores. RESULTS: There were 322 participants (63.6%) characterized as D-RFA. I-RFA status was associated with significantly less time missed from sport ( R2 change = .022-.024, P < .001 to P = .001) and shorter symptom duration ( R2 change = .044-.046, P < .001 [all imputations]) while controlling for other SRC recovery modifiers. These athletes missed approximately 3 fewer days from sport participation. I-RFA athletes had significantly less severe acute SRC symptoms and were at lower risk of recovery taking ≥14 days (relative risk = .614, P < .001, small-medium effect size) and ≥21 days (relative risk = .534, P = .010, small effect size). CONCLUSION: I-RFA is a protective factor associated with less severe acute symptoms and shorter recovery after SRC. Conveying this message to athletes, coaches, and others involved in the care of athletes may promote timely injury reporting.

"Playing Through It": Delayed Reporting and Removal From Athletic Activity After Concussion Predicts Prolonged Recovery.

CONTEXT: Preclinical research has demonstrated a window of vulnerability in the immediate aftermath of concussion wherein continued activity and stimulation can impair or prolong neurobehavioral recovery. However, this concept has not been quantified in a human population. OBJECTIVE: To examine the effect of delayed reporting and removal from athletic activity after concussion on recovery time. DESIGN: Cross-sectional study. SETTING: A National Collegiate Athletic Association Division I university. PATIENTS OR OTHER PARTICIPANTS: Ninety-seven athletes who sustained a sport-related concussion between 2008 and 2015 were analyzed (age = 20.4 ± 1.3 years). Athletes were grouped as immediate removal from activity (I-RFA) or delayed removal from activity (D-RFA). MAIN OUTCOME MEASURE(S): Days missed was defined as the number of days between the concussion-causing event and clearance for return to contact. Associations between RFA group and prolonged (8 or more days') versus normal (7 or fewer days') recovery were also analyzed. RESULTS: Fifty (51.5%) of the 97 athletes did not immediately report concussion symptoms. The D-RFA athletes averaged 4.9 more days missed than the I-RFA athletes. Membership in the specific RFA group predicted days missed even after controlling for sex, concussion history, learning disability or attention-deficit/hyperactivity disorder diagnosis, diagnosed psychological disorder, and acute symptom severity (R( 2) change = 0.097, ß = .319, P = .002). The D-RFA athletes were approximately 2.2 times more likely to have a prolonged recovery (8 or more days) compared with the I-RFA athletes (χ(2) = 10.268, P = .001, ϕ = 0.325). CONCLUSIONS: Athletes who do not immediately report symptoms of a concussion and continue to participate in athletic activity are at risk for longer recoveries than athletes who immediately report symptoms and are immediately removed from activity. Continuing to participate in athletic activity during the immediate aftermath of a concussion potentially exposes the already injured brain to compounded neuropathophysiologic processes.