Psychological Constructs From the Fear Avoidance Model and Beyond as Predictors for Persisting Symptoms After Concussion: An Integrative Review.

OBJECTIVES: To identify the range of evidence for relationships between psychological factors using the Fear Avoidance Model (FAM) as a guiding framework and relevant clinical outcomes in adult patients with persisting symptoms after concussion (PSaC), develop a comprehensive understanding of psychological factors that have been identified as predictors of clinical outcomes for PSaC, and contribute to the theoretical framework of the FAM for PSaC. DATA SOURCES: Six databases (CINAHL, Embase, PsycINFO, PubMed, SportDiscus, and Web of Science) were searched by a librarian for empirical and theoretical publications and experimental and quasi-experimental study designs. The literature search was not limited by publication date restrictions. Gray literature, with the exception of doctoral dissertations, was excluded. STUDY SELECTION: We included studies in the English language consisting of human participants aged ≥18 years. Articles must have included both outcomes pertaining to PSaC (≥3mo after injury) and psychological constructs. DATA EXTRACTION: One reviewer extracted data from the resulting studies using a standardized data extraction form designed for this review. Two reviewers independently assessed risk of bias using the Quality in Prognosis Studies tool. DATA SYNTHESIS: This review found numerous psychological constructs, some directly linked to the FAM, that have potential prognostic relationships with PSaC. However, research remains limited and some psychological factors central to FAM were only identified in a small number of studies (catastrophizing, cogniphobia, and avoidance), whereas other psychological factors were studied more extensively (anxiety and depression). CONCLUSIONS: There is the need for additional evidence, and this integrative review provides an adaptation of the FAM for PSaC to be used as a guiding preliminary framework for future research. Future research should aim to include psychological factors proposed in this modified FAM to fully understand PSaC.

The Effect of Aerobic Exercise on Concussion Recovery: A Pilot Clinical Trial.

OBJECTIVE: The purpose of this study was to pilot safety and tolerability of a 1-week aerobic exercise program during the post-acute phase of concussion (14-25 days post-injury) by examining adherence, symptom response, and key functional outcomes (e.g., cognition, mood, sleep, postural stability, and neurocognitive performance) in young adults. METHOD: A randomized, non-blinded pilot clinical trial was performed to compare the effects of aerobic versus non-aerobic exercise (placebo) in concussion patients. The study enrolled three groups: 1) patients with concussion/mild traumatic brain injury (mTBI) randomized to an aerobic exercise intervention performed daily for 1-week, 2) patients with concussion/mTBI randomized to a non-aerobic (stretching and calisthenics) exercise program performed daily for 1-week, and 3) non-injured, no intervention reference group. RESULTS: Mixed-model analysis of variance results indicated a significant decrease in symptom severity scores from pre- to post-intervention (mean difference = -7.44, 95% CI [-12.37, -2.20]) for both concussion groups. However, the pre- to post-change was not different between groups. Secondary outcomes all showed improvements by post-intervention, but no differences in trajectory between the groups. By three months post-injury, all outcomes in the concussion groups were within ranges of the non-injured reference group. CONCLUSIONS: Results from this study indicate that the feasibility and tolerability of administering aerobic exercise via stationary cycling in the post-acute time frame following post-concussion (14-25 days) period are tentatively favorable. Aerobic exercise does not appear to negatively impact recovery trajectories of neurobehavioral outcomes; however, tolerability may be poorer for patients with high symptom burden.

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.

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.

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.

Baseline Neurocognitive Performance and Clearance for Athletes to Return to Contact.

CONTEXT: Computerized neurocognitive assessments are commonly used to manage sport-related concussion. Variations in baseline performance may influence neurocognitive performance after injury as well as the amount of time needed for an athlete to be cleared for return to sport participation. OBJECTIVE: To investigate the relationship between mean baseline Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) scores and postconcussion reliable decline as well as the association between postconcussion cognitive decline and days missed after injury. DESIGN: Cross-sectional study. SETTING: University concussion databank. PATIENTS OR OTHER PARTICIPANTS: A total of 84 collegiate athletes who sustained a concussion between 2008 and 2015 were studied. For each ImPACT composite score (verbal memory, visual memory, visual motor speed, reaction time), athletes were grouped based on the presence or absence of reliable decline and on the presence of reliable decline in 0, 1, 2, 3, or 4 cognitive domains. MAIN OUTCOME MEASURE(S): Outcome measures were baseline ImPACT composite scores and days missed due to concussion. RESULTS: Athletes with a reliable decline in visual memory scored higher on baseline visual memory than did athletes with no decline or an improvement (t82 = -2.348, P = .021, d = 0.65). When comparing athletes who displayed a reliable decline with those who showed no change or an improvement in any composite score, days missed did not differ. The number of composite scores with a reliable decline demonstrated no main effect on days missed (P = .530). CONCLUSIONS: Athletes who exhibited cognitive decline in most or all of the composite scores did not miss more days after injury than athletes with a decline in fewer or none of the composite scores. Athletes should be educated regarding the lack of association between baseline neurocognitive scores and the presence or absence of a reliable decline after concussion, as well as the fact that, on average, individuals with a reliable decline across multiple domains did not miss more time after concussion.

Concussion-like symptom reporting in non-concussed adolescent athletes.

OBJECTIVE: The primary goals of this study were (1) to report rates of concussion-like symptoms in healthy adolescent student athletes assessed using the Sport Concussion Assessment Tool, 3rd edition (SCAT3) at baseline, (2) to examine rates of psychiatric diagnoses in this population, and (3) to evaluate effects of baseline symptoms on SCAT3 cognitive and balance performance. METHODS: 349 adolescent student athletes (245 male) were administered the SCAT3 during pre-participation physical examinations. We described the prevalence rate of student athletes meeting criteria for International Classification of Diseases, 10th revision, post-concussional syndrome (ICD-10 PCS) diagnosis at baseline, and evaluated associations between symptom reporting and demographic/medical history factors using chi-square tests. Rates of self-reported psychiatric diagnosis were compared to general population estimates with one-sample binomial tests. We also compared SCAT3 cognitive and balance performance between adolescents with and without baseline ICD-10 PCS symptoms. RESULTS: Overall, 20.3% of participants met ICD-10 PCS criteria at baseline. Rates were similar across sexes and age groups. We found no statistical association with medical history factors. The proportion of student athletes reporting a history of psychiatric diagnosis (5.2%) was significantly lower than general population estimates (14.0%; p < .001), and this effect was consistent across sexes and age groups. SCAT3 cognitive and balance performance did not differ based on baseline symptom reporting. CONCLUSIONS: Healthy adolescent student athletes frequently report concussion-like symptoms at baseline. Clinicians should factor pre-injury symptomatology and medical history into concussion management when determining symptom etiology throughout the course of recovery.

Concussion-Like Symptom Reporting in Non-Concussed Collegiate Athletes.

OBJECTIVE: Non-concussed individuals may report a variety of concussion-like symptoms even in the absence of a diagnosed brain injury. Previous studies described concussion-like symptom reporting in adolescent athletes. This study provides complementary data on concussion-like symptoms in collegiate athletes. METHODS: We analyzed baseline symptom scales from 738 collegiate athletes (452 men and 286 women) who completed either the Sport Concussion Assessment Tool, 3 Symptom Evaluation (S3SE; n = 377) or the Post-Concussion Scale (PCS; n = 361) and determined if subjects met criteria for diagnosis of International Classification of Diseases 10th Revision (ICD-10) postconcussional syndrome. Symptoms were grouped as somatic, cognitive, emotional, or sleep-related. We analyzed associations with medical history factors using chi-square analyses, and examined recovery time of a subset of concussed athletes based on baseline symptomatology (n = 117) with independent samples t-test. RESULTS: Across all athletes, 120 (16.3%) reported baseline symptoms meeting criteria for ICD-10 postconcussional syndrome. Women were 1.7 times more likely to meet these criteria (21.7% vs. 12.8%, p = .002). Athletes completing the S3SE were 1.5 times more likely to meet criteria than those completing the PCS (p = .011). Previously diagnosed psychiatric disorder was significantly associated with emotional domain symptom reporting, and attention deficit-hyperactivity disorder diagnosis was associated with cognitive domain symptom reporting. On average, athletes meeting ICD-10 postconcussional syndrome criteria at baseline experienced longer recovery from concussion (t[115] = 2.35, p = .020). CONCLUSIONS: Non-concussed collegiate athletes report concussion-like symptoms at a clinically significant rate. Pre-injury medical history and reporting rates of concussion-like symptoms may explain variance in post-concussion symptom expression. Measured incidence of baseline postconcussional syndrome may, in part, depend on the symptom report measure that is used.

"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.

A normative study of the sport concussion assessment tool (SCAT2) in children and adolescents.

Recent clinical practice parameters encourage systematic use of concussion surveillance/management tools that evaluate participating athletes at baseline and after concussion. Office-based tools (Sports Concussion Assessment Tool; SCAT2) require accurate baseline assessment to maximize utility but no normative data exist for children on the SCAT2, limiting identification of "normal" or "impaired" score ranges. The purpose of this study was to develop child and adolescent baseline norms for the SCAT2 to provide reference values for different age groups. A community-based approach was implemented to compile baseline performance data on the SCAT2 in 761 children aged 9 to 18 to create age- and sex-graded norms. Findings indicate a significant age effect on SCAT2 performance such that older adolescents and teenagers produced higher (better) total scores than younger children (ages 9 to 11) driven by age differences on individual components measuring cognition (SAC), postural stability (BESS), and symptom report. Females endorsed greater numbers of symptoms at baseline than males. Normative data tables are presented. Findings support the SCAT2 as a useful clinical tool for assessing baseline functioning in teenagers, but suggest clinical utility may be limited in children under age 11. Follow-up studies after incident concussion are needed to confirm this assumption.