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Athletes sometimes choose not to report suspected concussions, risking delays in treatment and health consequences. How and why do athletes make these reporting decisions? Using original survey data from a cohort of college football players, we evaluate two assumptions of the current literature on injury reporting: first, that the probability of reporting a concussion or injury is constant over time; second, that athletes make reasoned deliberative decisions about whether to report their concussion or other injury. We find that athletes are much less likely to report a concussion to a medical professional than they are to report another injury (47% vs. 80%), but no association between reporting and a measure of athletes' ability to switch from fast, reactive thinking to reasoned, deliberative thinking. The likelihood of reporting decreases as the number of injuries and concussions increases, and no athlete reported more than four concussions. Sports medicine clinicians sometimes use four concussions as a time to discuss possibly curtailing sports participation, which may influence athletes' subsequent reporting behavior. Sports medicine clinicians may want to consider athlete injury history as a risk factor for concussion and injury under-reporting. [ABSTRACT FROM AUTHOR]

Objective: To investigate the association between dual-task gait performance and brain network activation (BNA) using an electroencephalography (EEG)-based Go/No-Go paradigm among children and adolescents with concussion. Methods: Participants with a concussion completed a visual Go/No-Go task with collection of electroencephalogram brain activity. Data were treated with BNA analysis, which involves an algorithmic approach to EEG-ERP activation quantification. Participants also completed a dual-task gait assessment. The relationship between dual-task gait speed and BNA was assessed using multiple linear regression models. Results: Participants (n = 20, 13.9 ± 2.3 years of age, 50% female) were tested at a mean of 7.0 ± 2.5 days post-concussion and were symptomatic at the time of testing (post-concussion symptom scale = 40.4 ± 21.9). Slower dual-task average gait speed (mean = 82.2 ± 21.0 cm/s) was significantly associated with lower relative time BNA scores (mean = 39.6 ± 25.8) during the No-Go task (β = 0.599, 95% CI = 0.214, 0.985, p = 0.005, R2 = 0.405), while controlling for the effect of age and gender. Conclusion: Among children and adolescents with a concussion, slower dual-task gait speed was independently associated with lower BNA relative time scores during a visual Go/No-Go task. The relationship between abnormal gait behaviour and brain activation deficits may be reflective of disruption to multiple functional abilities after concussion. [ABSTRACT FROM AUTHOR]

Context: Concussions affect a large number of US athletes each year. Returning an athlete to activity once selfreported symptoms have resolved can be problematic if unrecognized neurocognitive and balance deficits persist. Pairing cognitive and motor tasks or cognitive and quietstance tasks may allow clinicians to detect and monitor these changes postconcussion. Objective: To prospectively examine adolescent athletes' gait and quiet-stance performance while concurrently completing a cognitive task acutely after concussion and after symptom resolution. Design: Case-control study. Setting: Sport concussion clinic. Patients or Other Participants: Thirty-seven athletes (age = 1±.2 ± 3.1 years; 54% female) were diagnosed with a concussion, and their performance was compared with that of a group of 44 uninjured control participants (age = 15.0 ± 2.0 years; 57% female). Intervention: Participants diagnosed with a concussion completed a symptom inventory and single- and dual-task gait and quiet-stance evaluations within 21 days of injury and then again after symptom resolution. Gait and postural-control measurements were quantified using an inertial sensor system and analyzed using multivariate analyses of covariance. Main Outcome Measure(s): Post-Concussion Symptom Scale, single-task and dual-task gait measures, quiet-stance measures, and cognitive task performance. Results: At the initial postinjury examination, single-task gait stride length (1.1± ± 0.14 versus 1.25 ± 0.13 m, P = .003) and dual-task gait stride length (1.02 ± 0.13 m versus 1.10 ± 0.13 m, P = .011) for the concussion group compared with the control group, respectively, were shorter. After symptom resolution, no single-task gait differences were found, but the concussion group demonstrated slower gait velocity (0.78 ± 0.15 m/s versus 0.92 ± 0.14 m/s, P = .005), lower cadence (92.5 ± 12.2 steps/min versus 99.3 ± 7.8 steps/min, P , .001), and a shorter stride length (0.99 ± 0.15 m versus 1.10 ± 0.13 m, P = .003) during dual-task gait than the control group. No between-groups differences were detected during quiet stance at either time point. Conclusions: Acutely after concussion, single-task and dual-task stride-length alterations were present among youth athletes compared with a control group. Although single-task gait alterations were not detected after symptom resolution, dual-task gait differences persisted, suggesting that dual-task gait alterations may persist longer after concussion than singletask gait or objective quiet-stance alterations. Dual-task gait assessments may, therefore, be a useful component in monitoring concussion recovery after symptom resolution. [ABSTRACT FROM AUTHOR]

We sought to determine whether the exposure to the sub-concussive blows that occur during division III collegiate collision sports affect later life neurobehavioral quality-of-life measures. We conducted a cross-sectional study of alumni from four division III colleges, targeting those between the ages of 40-70 years, using several well-validated quality-of-life measures for executive function, general concerns, anxiety, depression, emotional and behavior dyscontrol, fatigue, positive affect, sleep disturbance, and negative consequences of alcohol use. We used multivariable linear regression to assess for associations between collision sport participation and quality-of-life measures while adjusting for covariates including age, gender, race, annual income, highest educational degree, college grades, exercise frequency, and common medical conditions. We obtained data from 3702 alumni, more than half of whom (2132) had participated in collegiate sports, 23% in collision sports, 23% in non-contact sports. Respondents with a history of concussion had worse self-reported health on several measures. When subjects with a history of concussion were removed from the analyses in order to assess for any potential effect of sub-concussive blows alone, negative consequences of alcohol use remained higher among collision sport athletes (β-coefficient 1.957, 95% CI 0.827-3.086). There were, however, no other significant associations between exposure to collision sports during college and any other quality-of-life measures. Our results suggest that, in the absence of a history of concussions, participation in collision sports at the Division III collegiate level is not a risk factor for worse long-term neurobehavioral outcomes, despite exposure to repeated sub-concussive blows. [ABSTRACT FROM AUTHOR]

Objective: Previous studies suggest athletes underreport concussions. We sought to determine whether athletes in our clinics have sustained previous concussions that went undiagnosed. Design: Multicentered cross sectional study. Setting: Two sport concussion clinics. Patients: Patients diagnosed with sport-related concussions or concussions with injury mechanisms and forces similar to those observed in sports were included. Main Outcome Measures: The proportion of patients who answered "yes" to the following question were defined as having a previously undiagnosed concussion: "Have you ever sustained a blow to the head which was NOT diagnosed as a concussion but was followed by one or more of the signs and symptoms listed in the Post Concussion Symptom Scale?" Results: Of the 486 patients included in the final analysis, 148 (30.5%) patients reported a previously undiagnosed concussion. Athletes reporting previously undiagnosed concussions had a higher mean Post Concussion Symptom Scale (PCSS) score (33 vs 25; P < 0.004) and were more likely to have lost consciousness (31% vs 22%; P = 0.038) with their current injury than athletes without previously undiagnosed concussions. Conclusions: Nearly one-third of athletes have sustained previously undiagnosed concussions, defined as a blow to the head followed by the signs and symptoms included in the PCSS. Furthermore, these previously undiagnosed concussions are associated with higher PCSS scores and higher loss of consciousness rates when future concussions occur. Clinical Relevance: Many athletes have sustained previous blows to the head that result in the signs and symptoms of concussion but have not been diagnosed with a concussion. These injuries are associated with increased rates of loss of consciousness and higher symptom scale scores with future concussions. [ABSTRACT FROM AUTHOR]

Objective Although there is growing awareness of the long-term cognitive effects of repetitive mild traumatic brain injury (rmTBI; eg, sports concussions), whether repeated concussions cause long-term cognitive deficits remains controversial. Moreover, whether cognitive deficits depend on increased amyloid β deposition and tau phosphorylation or are worsened by the apolipoprotein E4 allele remains unknown. Here, we use an experimental model of rmTBI to address these clinical controversies. Methods A weight drop rmTBI model was used that results in cognitive deficits without loss of consciousness, seizures, or gross or microscopic evidence of brain damage. Cognitive function was assessed using a Morris water maze (MWM) paradigm. Immunostaining and enzyme-linked immunosorbent assay (ELISA) were used to assess amyloid β deposition and tau hyperphosphorylation. Brain volume and white matter integrity were assessed by magnetic resonance imaging (MRI). Results Mice subjected to rmTBI daily or weekly but not biweekly or monthly had persistent cognitive deficits as long as 1 year after injuries. Long-term cognitive deficits were associated with increased astrocytosis but not tau phosphorylation or amyloid β (by ELISA); plaques or tangles (by immunohistochemistry); or brain volume loss or changes in white matter integrity (by MRI). APOE4 was not associated with worse MWM performance after rmTBI. Interpretation Within the vulnerable time period between injuries, rmTBI produces long-term cognitive deficits independent of increased amyloid β or tau phosphorylation. In this model, cognitive outcome is not influenced by APOE4 status. The data have implications for the long-term mental health of athletes who suffer multiple concussions. Ann Neurol 2013;74:65-75 [ABSTRACT FROM AUTHOR]

Background: Little existing data describe which medical professionals and which medical studies are used to assess sport-related concussions in high school athletes.Purpose: To describe the medical providers and medical studies used when assessing sport-related concussions. To determine the effects of medical provider type on timing of return to play, frequency of imaging, and frequency of neuropsychological testing.Study Design: Descriptive epidemiology study.Methods: All concussions recorded by the High School Reporting Information Online (HS RIO) injury surveillance system during the 2009 to 2010 academic year were included. χ2 analyses were conducted for categorical variables. Fisher exact test was used for nonparametric data. Logistic regression analyses were used when adjusting for potential confounders. Statistical significance was considered for P < .05.Results: The HS RIO recorded 1056 sport-related concussions, representing 14.6% of all injuries. Most (94.4%) concussions were assessed by athletic trainers (ATs), 58.8% by a primary care physician. Few concussions were managed by specialists. The assessment of 21.2% included computed tomography. Computerized neuropsychological testing was used for 41.2%. For 50.1%, a physician decided when to return the athlete to play; for 46.2%, the decision was made by an AT. After adjusting for potential confounders, no associations between timing of return to play and the type of provider (physician vs AT) deciding to return the athlete to play were found.Conclusion: Concussions account for nearly 15% of all sport-related injuries in high school athletes. The timing of return to play after a sport-related concussion is similar regardless of whether the decision to return the athlete to play is made by a physician or an AT. When a medical doctor is involved, most concussions are assessed by primary care physicians as opposed to subspecialists. Computed tomography is obtained during the assessment of 1 of every 5 concussions occurring in high school athletes. [ABSTRACT FROM PUBLISHER]

Tumor necrosis factor alpha (TNFα) and Fas receptor contribute to cell death and cognitive dysfunction after focal traumatic brain injury (TBI). We examined the role of TNFα/Fas in postinjury functional outcome independent of cell death in a novel closed head injury (CHI) model produced with weight drop and free rotational head movement in the anterior-posterior plane. The CHI produced no cerebral edema or blood-brain barrier damage at 24 to 48 hours, no detectable cell death, occasional axonal injury (24 hours), and no brain atrophy or hippocampal cell loss (day 60). Microglia and astrocytes were activated (48 to 72 hours). Tumor necrosis factor-α mRNA, Fas mRNA, and TNFα protein were increased in the brain at 3 to 6 hours after injury (P<0.001 versus sham injured). In wild-type (WT) mice, CHI produced hidden platform (P=0.009) and probe deficits (P=0.001) in the Morris water maze versus sham. Surprisingly, injured TNFα/Fas knockout (KO) mice performed worse in hidden platform trials (P=0.036) but better in probe trials than did WT mice (P=0.0001). Administration of recombinant TNFα to injured TNFα/Fas KO mice reduced probe trial performance to that of WT. Thus, TNFα/Fas influence cognitive deficits independent of cell death after CHI. Therapies targeting TNFα/Fas together may be inappropriate for patients with concussive TBI. [ABSTRACT FROM AUTHOR]

Background: An estimated 136 000 concussions occur per academic year in high schools alone. The effects of repetitive concussions and the potential for catastrophic injury have made concussion an injury of significant concern for young athletes.Purpose: The objective of this study was to describe the mechanism of injury, symptoms, and management of sport-related concussions using the High School Reporting Information Online (HS RIO) surveillance system.Study Design: Descriptive epidemiology study.Methods: All concussions recorded by HS RIO during the 2008-2009 academic year were included. Analyses were performed using SPSS software. Chi-square analysis was performed for all categorical variables. Statistical significance was considered for P < .05.Results: A total of 544 concussions were recorded. The most common mechanism (76.2%) was contact with another player, usually a head-to-head collision (52.7%). Headache was experienced in 93.4%; 4.6% lost consciousness. Most (83.4%) had resolution of their symptoms within 1 week. Symptoms lasted longer than 1 month in 1.5%. Computerized neuropsychological testing was used in 25.7% of concussions. When neuropsychological testing was used, athletes were less likely to return to play within 1 week than those for whom it was not used (13.6% vs 32.9%; P < .01). Athletes who had neuropsychological testing appeared less likely to return to play on the same day (0.8% vs 4.2%; P = .056). A greater proportion of injured, nonfootball athletes had computerized neuropsychological testing than injured football players (23% vs 32%; P = .02)Conclusion: When computerized neuropsychological testing is used, high school athletes are less likely to be returned to play within 1 week of their injury. Concussed football players are less likely to have computerized neuropsychological testing than those participating in other sports. Loss of consciousness is relatively uncommon among high school athletes who sustain a sport-related concussion. The most common mechanism is contact with another player. Some athletes (1.5%) report symptoms lasting longer than 1 month. [ABSTRACT FROM AUTHOR]

Background: Aerobic exercise facilitates postconcussion symptom resolution at the group level, but patient-level characteristics may affect the likelihood of treatment efficacy. Purpose: This study aimed to investigate demographic and clinical characteristics, which differentiate postconcussion aerobic exercise treatment efficacy from nonefficacy in the intervention arm of a randomized clinical trial. Methods: Adolescent and young adult participants initiated a standardized aerobic exercise intervention within 14 d of concussion, consisting of self-selected exercise for 100 min⋅wk-1 at an individualized heart rate (80% of heart rate induced symptom exacerbation during graded exercise testing). Treatment efficacy was defined as symptom resolution within 28-d postconcussion. Treatment efficacy and nonefficacy groups were compared on demographics, clinical characteristics, intervention adherence, and persistent symptom risk using the Predicting Persistent Postconcussive Problems in Pediatrics (5P) clinical risk score. Results: A total of 27 participants (16.1 ± 2.3 yr old; range, 11-21 yr; 52% female) began the intervention, with a mean of 9.5 ± 3.7 d after concussion; half (n = 13; 48%) demonstrated treatment efficacy (symptom resolution within 28 d postconcussion). Those whose symptoms resolved within 28 d had significantly lower preintervention postconcussion symptom inventory scores (21.2 ± 13.2 vs 41.4 ± 22.2; P < 0.01), greater adherence to the intervention (77% vs 36%; P = 0.05), and longer average exercise duration (median [interquartile range], 49.7 [36.8-68.6] vs 30.4 [20.7-34.7] min; P < 0.01) than those whose symptoms lasted more than 28 d. Groups were similar in age, sex, timing of intervention, and preintervention 5P risk score. Conclusions: A standardized aerobic exercise intervention initiated within 14 d of concussion demonstrated efficacy for approximately half of participants, according to our definition of treatment efficacy. This multisite aerobic exercise intervention suggests that lower symptom severity, higher intervention adherence, and greater exercise duration are factors that increase the likelihood of symptoms resolving within 28 d of concussion. [ABSTRACT FROM AUTHOR]

Transition from professional sport to nonsport endeavors has implications for postcareer health and well-being of athletes. The purpose of the current study was to examine associations among transition-related psychosocial factors and current mental health outcomes in former National Football League (NFL) players. Participants were former NFL players (n = 1,784; mean age = 52.3 ± 16.3 years) who responded to a questionnaire assessing the nature of their discontinuation from professional football (i.e., any degree of voluntary choice vs. forced discontinuation), prediscontinuation transition planning (yes vs. no), and current symptoms of depression and anxiety. After adjusting for relevant covariates, having an involuntary discontinuation and no transition plan prior to discontinuation were associated with greater depressive and anxiety symptom severity. Autonomy in discontinuation and pretransition planning are important to former NFL football players' mental health. Increasing autonomy in the discontinuation decision and pretransition planning represent psychoeducational intervention targets for this population. [ABSTRACT FROM AUTHOR]

This study compared lower extremity (LE) muscular strength by 3 groups of female athletes using chronological age and consideration of age of peak height velocity (PHV). Isometric quadriceps, hamstrings, and hip abductors strength were assessed from physically active, pediatric females. The body mass normalized isometric strength (N m/kg) was compared by the 3 age groups. There were 388 young female athletes (<10 years [14.2%], 11-14 years [48.7%], and 15-18 years [37.1%]). The body mass normalized LE strength was lower in 11-14 years compared with <10 years (quadriceps [P = .001], hamstrings [P = .001], and hip abductors [P = .037]) as well as in 15-18 years relative to <10 years in quadriceps (P = .001) and hamstrings (P = .001). The analysis results were consistent with both chronological age alone and incorporating effects of age of PHV. In short, body mass normalized LE strength (quadriceps, hamstrings, and hip abductors) of 11-14 years females was lower than <10 years females. [ABSTRACT FROM AUTHOR]

Purpose: The objectives of this study are to 1) describe collegiate student-athlete (SA) race and household income and 2) evaluate time to normal academic performance (i.e., return to learn (RTL)), initiation of the return to play (iRTP) protocol, RTP protocol duration, and time to unrestricted RTP (URTP) after sustaining sport-related concussion (SRC). Methods: Data were collected between 2014 and 2020 by the Concussion Assessment, Research, and Education Consortium. Baseline data were used to characterize participant demographics (N = 22,819) and post-SRC outcomes (n = 5485 SRC) in time to RTL (n = 1724) and RTP outcomes (n = 2646) by race. Descriptive statistics and nonparametric tests examined differences across race by demographic and injury characteristics. Kaplan--Meier curves estimated median days to RTL, iRTP protocol, RTP protocol completion, and URTP by race and covariate measures. Multivariable Cox proportional hazards regression assessed the effect of race on risk of RTL and RTP recovery time points. Results: SA largely identified as White (75%) followed by Black (14%), multiracial (7%), and Asian (3%). More than half (53%) of all SA reported a household income of >$120,000, whereas 41% of Black SA reported a household income <$60,000. Race was not associated with relative risk of RTL or iRTP but was associated with RTP protocol completion and URTP. Non-Black/non-White SA were 17% less likely (adjusted hazard ratio = 0.83; 95% confidence interval = 0.71, 0.97) to complete the RTP protocol, and Black SA were 17% more likely (adjusted hazard ratio = 1.17; 95% confidence interval = 1.05, 1.31) to reach the URTP time point compared with White SA. Conclusions: The present findings suggest collegiate SA enrolled in the Concussion Assessment, Research, and Education Consortium are primarily White and come from household incomes well above the US median. Race was not associated with RTL or iRTP but was associated with RTP protocol duration and total time to URTP. Clinicians should be conscientious of how their implicit or preconceived biases may influence SRC management among National Collegiate Athletic Association SA. [ABSTRACT FROM AUTHOR]

Over a 10-year time frame, this study aimed to evaluate diagnosis, treatment, and referral trends for adolescent runners seeking care for running-related injuries (RRIs) at a clinic that specializes in running medicine.This study was a retrospective chart review of 392 adolescent runners (2,326 encounters) who sought care for RRIs between the years 2011 and 2021. Descriptive statistics were used to summarize clinical assessments, referrals, assistive devices, and medications prescribed or administered overall and by injury type. Chi-square analyses were used to compare proportions of services rendered across the 10-year time frame.Patients most frequently received manual evaluations or special tests during clinic visits. Most visits resulted in at least one referral (91%), primarily for physical therapy or gait-training. Assistive devices and medications/supplements were offered at only 18% of patient visits. The majority of assessments (X2 = 69.7, p = 0.002), treatments (X2: 23.6–43.8, p: <  0.001–0.003), and referrals (X2 = 132, p <  0.001) were for shin injuries. Larger proportions of nutrition assessments (X2 = 40.7, p <  0.001), interventions (X2 = 26.8, p = 0.003), and referrals (X2 = 27.5, p = 0.002) were performed in or after the year 2015.Clinic visits for shin injuries required the most clinical resources per episode of care. There were observed shifts in clinical assessment and treatment approaches to include more expanded nutritional and physiologic considerations. [ABSTRACT FROM AUTHOR]

Objective: To evaluate clinic visits and running-related injury (RRI) characteristics among child and adolescent runners seeking care at an outpatient clinic over a 10-year time frame. Design: Retrospective chart review. Setting: Outpatient hospital-affiliated Injured Runners Clinic. Patients: Children and adolescent runners (6-17 years) with RRIs. Independent Variables: We examined electronic medical records (EMRs) among child and adolescent patients in the hospital database from 2011 to 2021 to obtain RRI characteristics and key demographic factors. Main Outcome Measures: We assessed volume and frequency of patient visits to the clinic by RRI characteristics. Chi square analyses were used to compare the proportion of clinic visits over time and injury trends by body region and diagnosis. Results: There were 392 patients (sex; 277 F; mean age: 16.1 ± 1.3years) and an average of 5 clinic visits per diagnosis (5 ± 4 visits; min: 1 visit, max: 31 visits). Number of visits generally increased over time up to 2016 but declined most drastically during the years of the pandemic (2020-2021; χ² = 644, P < 0 .001). Of the 654 new injury diagnoses, 77.68% were attributed to repetitive stress. Bone stress injuries to the tibia were the most common RRI (χ² = 1940,P < 0.001; N = 132; 20.2% of all injuries) and constituted most of the clinic visits (χ² = 9271, P < 0.001; N = 591; 25.4% of all visits). Conclusion: We identified that adolescents with overuse injuries, particularly bone stress injuries to the tibia, constituted most of the visits to the outpatient healthcare setting. Clinicians should emphasize injury prevention efforts in clinical practice to reduce RRI burden. [ABSTRACT FROM AUTHOR]

Sports medicine clinicians face conflicts of interest in providing medical care to athletes. Using a survey of college football players, this study evaluates whether athletes are aware of these conflicts of interest, whether these conflicts affect athlete trust in their health care providers, or whether conflicts or athletes' trust in stakeholders are associated with athletes' injury reporting behaviors. [ABSTRACT FROM AUTHOR]

Early targeted heart rate (HR) aerobic exercise has been shown to reduce the duration of recovery from sport-related concussion (SRC) as well as the incidence of persistent post-concussive symptoms (PPCS). It is not known, however, if more severe oculomotor and vestibular presentations of SRC benefit from a prescription of aerobic exercise. The current study is an exploratory analysis of two published randomized controlled trials that compared aerobic exercise within 10 days of injury with a placebo-like stretching intervention. Combining the two studies yielded a larger sample size to stratify severity of concussion based on the number of abnormal physical examination signs present at the initial office evaluation, which were confirmed with self-reported symptoms and recovery outcomes. The most discriminant cut-off was between those who had ≤3 oculomotor and vestibular signs and those who had >3 signs. Aerobic exercise (hazard ratio = 0.621 [0.412, 0.936], p = 0.023) reduced recovery times even when controlling for site (hazard ratio = 0.461 [0.303, 0.701], p < 0.001), severity (hazard ratio = 0.528 [0.325, 0.858], p = 0.010) and the interaction term of intervention and severity (hazard ratio = 0.972 [0.495, 1.909], p = 0.935). Adolescents who presented with >3 signs and were assigned to the placebo-like stretching group had a PPCS incidence of 38%, which was the highest of all subgroups (aerobic exercise and ≤3 findings: 8%; stretching and ≤3 findings: 11%; aerobic exercise and >3 findings: 21%). This exploratory study provides pilot evidence that prescribed sub-symptom threshold aerobic exercise treatment early after SRC may be effective for adolescents with more oculomotor and vestibular physical examination signs and should be validated in future adequately powered trials. [ABSTRACT FROM AUTHOR]

Quantification of visual deficits may help to identify dysfunction following concussion. We evaluated eye-tracking measurements among adolescents within 10 days of concussion and healthy control participants. Patients who reported to 2 tertiary care sport concussion clinics within 10 days of concussion completed an objective eye tracking assessment. Seventy-nine participants completed the study, 44 with concussion (mean age = 14.1 ± 2.2 years, 39% female) and 35 controls (mean age = 14.3 ± 2.4 years, 57% female). Right eye skew along the bottom of the screen was significantly higher for the concussion group compared to controls (median = 0.022 [interquartile range = –0.263, 0.482] vs 0.377 [interquartile range = –0.574, –0.031]; P = .002), but not the left eye. Among the variables investigated, right eye skew was altered for adolescents with a concussion. Visual function is an important component in the postconcussion evaluation, and identifying deficits soon after injury may allow for earlier specialist referral and intervention. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the clinical presentation (using PCSS), mechanism of injury, and recovery time of concussions sustained by gymnasts. A retrospective chart review was performed at Boston Children's Hospital: Sports Medicine Clinic. Patients were identified with the words 'gymnastics' and 'concussion.' Male and female gymnasts were included if they sustained a concussion during gymnastics training or competition and were between the ages of 6–22 years old. Sex, age, injury site, diagnosis, mechanism of injury, and time to presentation are described. Patients were compared during different types of gymnastics events for overall symptom burden, and individual symptom severities. A total of 201 charts were assessed over a 6-year period and 62 patients met inclusion criteria. Floor exercise was the most common event at the time of injury. Loss of consciousness occurred in 20% of injuries. There was no significant association between the type of event and PCSS upon initial clinical visit (p = 0.82). A total of 13 gymnasts returned to the clinic for a subsequent injury after their concussion (Table 3). Gymnasts are at risk for sport-related concussions. Most gymnasts reporting to a tertiary care center with the diagnosis of concussion sustain their injuries during floor exercise. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess which combination of intrinsic and extrinsic factors contribute to running-related injury (RRI)among adolescent cross-country, track, and long-distance runners. We conducted a retrospective study at a hospital-affiliated sports injury prevention centre of 130 adolescent runners (F: 62.1%, M: 37.9%; cross-country: 34.1%, track: 56.1%, long-distance running: 9.8%) who underwent an Injury Prevention Evaluation between 2013 and 2021. The evaluation included a questionnaire on personal and training factors, and standardised physical assessments. We used a binomial logistic regression to assess the influence of demographics, lower extremity strength and alignment, training (running volume and intensity, weight training), and dietary factors on RRIs. There were 38 adolescent runners who reported RRIs (ankle sprains: N = 16, shin splints: N = 9, stress fractures: N = 13). Female sex (odds ratio [OR]: 4.58 [1.37, 15.37]; p = 0.01), reduced weekday hours of sleep (OR: 1.75 [1.04, 2.95]; p = 0.04), reduced hip abduction strength (OR: 1.02 [1.00, 1.04]; p = 0.05), and intention to lose weight to improve athletic performance (OR: 4.58 [1.00, 21.28]; p = 0.05) were associated with RRIs. These intrinsic and extrinsic risk factors may represent targets for injury prevention for adolescent runners. [ABSTRACT FROM AUTHOR]

Purpose: There is growing evidence that subsymptom threshold aerobic exercise speeds recovery from sport-related concussion (SRC). It is not known whether there is a direct relationship between adherence to a personalized exercise prescription and recovery or if initial symptom burden affects adherence to the prescription. Methods: This study was a planned secondary analysis of one arm of a randomized controlled trial. Male and female adolescent athletes (age 13–18 yr) presenting within 10 d of SRC were given aerobic exercise prescriptions based on their heart rate threshold at the point of exercise intolerance on a graded treadmill test. Adherence was determined objectively with HR monitors and compared against time to recovery. Participants who completed at least two-thirds of their aerobic exercise prescription were considered to be adherent. Results: Sixty-one percent of adolescents met the adherence criterion. Those who were adherent were more symptomatic and were more exercise intolerant at their initial visit, yet they recovered faster than those who were not adherent (median recovery time, 12 (interquartile range, 9–22) d vs 21.5 (interquartile range, 13–29.8) d; P = 0.016). On linear regression, adherence during week 1 was inversely related to recovery time (β = −0.002 (−0.003, 0.0), P = 0.046) and to initial exercise tolerance (β = −0.886 (−1.385, −0.387), P < 0.001), but not to initial symptom severity (β = 0.545 (−0.232, 1.323), P = 0.146). No adverse events or near misses were reported. Conclusions: Adherence to individualized subsymptom threshold aerobic exercise within the first week of evaluation is associated with faster recovery from SRC. The data suggest that initial degree of exercise intolerance, but not initial symptom severity, affects adherence to aerobic exercise prescribed to adolescents within 10 d of SRC. [ABSTRACT FROM AUTHOR]

Importance: Adults with apparently minor head trauma (Glasgow Coma Scale [GCS] scores ≥13 who appear well on examination) may have severe intracranial injuries requiring prompt intervention. Findings from clinical examination can aid in determining which adults with minor trauma have severe intracranial injuries visible on computed tomography (CT).Objective: To assess systematically the accuracy of symptoms and signs in adults with minor head trauma in order to identify those with severe intracranial injuries.Data Sources: We performed a systematic search of MEDLINE (1966-2015) and the Cochrane Library to identify studies assessing the diagnosis of intracranial injuries.Study Selection: Studies were included that measured the performance of findings for identifying intracranial injury with a reference standard of neuroimaging or follow-up evaluation. Fourteen studies (range, 431-7955 patients) met inclusion criteria with patients having GCS scores between 13 and 15 and 50% or more older than 18 years.Data Extraction and Synthesis: Three authors independently performed critical appraisal and data extraction.Results: The prevalence of severe intracranial injury (requiring prompt intervention) among the 23,079 patients with minor head trauma was 7.1% (95% CI, 6.8%-7.4%) and the prevalence of injuries leading to death or requiring neurosurgical intervention was 0.9% (95% CI, 0.78%-1.0%). The presence of physical examination findings suggestive of skull fracture (likelihood ratio [LR], 16; 95% CI, 3.1-59; specificity, 99%), GCS score of 13 (LR, 4.9; 95% CI, 2.8-8.5; specificity, 97%), 2 or more vomiting episodes (LR, 3.6; 95% CI, 3.1-4.1; specificity, 92%), any decline in GCS score (LR range, 3.4-16; specificity range, 91%-99%;), and pedestrians struck by motor vehicles (LR range, 3.0-4.3; specificity range, 96%-97%) were associated with severe intracranial injury on CT. Among patients with apparent minor head trauma, the absence of any of the features of the Canadian CT Head Rule (≥65 years; ≥2 vomiting episodes, amnesia >30 minutes, pedestrian struck, ejected from vehicle, fall >1 m, suspected skull fracture, or GCS score <15 at 2 hours) had an LR of 0.04 (95% CI, 0-0.65), lowering the probability of severe injury to 0.31% (95% CI, 0%-4.7%). The absence of all the New Orleans Criteria findings (>60 years, intoxication, headache, vomiting, amnesia, seizure, or trauma above the clavicle) had an LR of 0.08 (95% CI, 0.01-0.84), lowering the probability of severe intracranial injury to 0.61% (95% CI, 0.08%-6.0%).Conclusions and Relevance: Combinations of history and physical examination features in clinical decision rules can identify patients with minor head trauma at low risk of severe intracranial injuries. Certain findings, including signs of skull fracture, GCS score of 13, 2 or more vomiting episodes, decrease in GCS score, and pedestrians struck by motor vehicles, may help identify patients at increased risk of severe intracranial injuries. [ABSTRACT FROM AUTHOR]

Background: Accumulating case reports have described tendon rupture in men who use anabolic-androgenic steroids (AAS). However, no controlled study has assessed the history of tendon rupture in a large cohort of AAS users and comparison nonusers. Hypothesis: Men reporting long-term AAS abuse would report an elevated lifetime incidence of tendon rupture compared with non–AAS-using bodybuilders. Study Design: Cohort study; Level of evidence, 3. Methods: Medical histories were obtained from 142 experienced male bodybuilders aged 35 to 55 years recruited in the course of 2 studies. Of these men, 88 reported at least 2 years of cumulative lifetime AAS use, and 54 reported no history of AAS use. In men reporting a history of tendon rupture, the circumstances of the injury, prodromal symptoms, concomitant drug or alcohol use, and details of current and lifetime AAS use (if applicable) were recorded. Surgical records were obtained for most participants. Results: Nineteen (22%) of the AAS users, but only 3 (6%) of the nonusers, reported at least 1 lifetime tendon rupture. The hazard ratio for a first ruptured tendon in AAS users versus nonusers was 9.0 (95% CI, 2.5-32.3; P < .001). Several men reported 2 or more independent lifetime tendon ruptures. Interestingly, upper-body tendon ruptures occurred exclusively in the AAS group (15 [17%] AAS users vs 0 nonusers; risk difference, 0.17 [95% CI, 0.09-0.25]; P < .001 [hazard ratio not estimable]), whereas there was no significant difference between users and nonusers in risk for lower-body ruptures (6 [7%] AAS users, 3 [6%] nonusers; hazard ratio, 3.1 [95% CI, 0.7-13.8]; P = .13). Of 31 individual tendon ruptures assessed, only 6 (19%) occurred while weightlifting, with the majority occurring during other sports activities. Eight (26%) ruptures followed prodromal symptoms of nonspecific pain in the region. Virtually all ruptures were treated surgically, with complete or near-complete ultimate restoration of function. Conclusion: AAS abusers, compared with otherwise similar bodybuilders, showed a markedly increased risk of tendon ruptures, particularly upper-body tendon rupture. [ABSTRACT FROM AUTHOR]

Objective: Investigate the reliability of concussion symptoms captured through ecological momentary assessment (EMA) and compare time with recovery based on 3 definitions of symptomatic recovery and the date of clinical clearance to begin the return-to-play (RTP) process. Design: We used a mobile app with EMA to monitor concussion symptoms as part of a multicenter randomized controlled trial. Setting: Three sports medicine practices. Participants: Patients between 13 and 18 years old with sport-related concussion were prompted to complete the Post-Concussion Symptom Inventory daily over 4 weeks. Interventions: None. Main Outcome Measures: We compared the elapsed days to reaching the 4 outcomes using scatterplots and Kaplan–Meier curves. Results: Among 118 participants, symptoms reported into the app had excellent agreement with symptoms reported at a clinical visit on the same day (intraclass correlation coefficient = 0.97). Most (>50%) participants reached "specific symptom return to preinjury levels," "overall symptom return to preinjury levels," and "current symptom resolution" based on EMA symptom reports between several days and 1 week before achieving "clinical clearance to RTP" determined at a clinical visit, which had 100% sensitivity, but between 56.3% and 78.1% specificity, relative to the app-measured symptom outcomes. Conclusions: Time until symptom recovery varies based on the chosen definition of symptomatic recovery but is a more precise correlate with clinical clearance to begin the RTP process when defining symptom recovery as a return to a preinjury baseline level of symptomatology. Real-time symptom monitoring may be beneficial clinically, allowing providers to assess patients' recovery status and make more timely and remote treatment recommendations. [ABSTRACT FROM AUTHOR]

Objective: It has been posited that alcohol use may confound the association between greater concussion history and poorer neurobehavioral functioning. However, while greater alcohol use is positively correlated with neurobehavioral difficulties, the association between alcohol use and concussion history is not well understood. Therefore, this study investigated the cross-sectional and longitudinal associations between cumulative concussion history, years of contact sport participation, and health-related/psychological factors with alcohol use in former professional football players across multiple decades. Participants and Methods: Former professional American football players completed general health questionnaires in 2001 and 2019, including demographic information, football history, concussion/medical history, and health-related/psychological functioning. Alcohol use frequency and amount was reported for three timepoints: during professional career (collected retrospectively in 2001), 2001, and 2019. During professional career and 2001 alcohol use frequency included none, 1-2, 3-4, 5-7 days/week, while amount included none, 12, 3-5, 6-7, 8+ drinks/occasion. For 2019, frequency included never, monthly or less, 2-4 times/month, 2-3 times/week, >4 times/week, while amount included none, 1-2, 3-4, 5-6, 7-9, 10+ drinks/occasion. Scores on a screening measure for Alcohol Use Disorder (CAGE) were also available at during professional career and 2001 timepoints. Concussion history was recorded in 2001 and binned into five groups: 0, 1-2, 3-5, 6-9, 10+. Depression and pain interference were assessed via PROMIS measures at all timepoints. Sleep disturbance was assessed in 2001 via separate instrument and with PROMIS Sleep Disturbance in 2019. Spearman's rho correlations tested associations between concussion history and years of sport participation with alcohol use across timepoints, and whether poor health functioning (depression, pain interference, sleep disturbance) in 2001 and 2019 were associated with alcohol use both within and between timepoints. Results: Among the 351 participants (Mage=47.86[SD=10.18] in 2001), there were no significant associations between concussion history or years of contact sport participation with CAGE scores or alcohol use frequency/amount during professional career, 2001, or 2019 (rhos=-.072-.067, ps>.05). In 2001, greater depressive symptomology and sleep disturbance were related to higher CAGE scores (rho=.209, p<.001; rho=.176, p<.001, respectively), while greater depressive symptomology, pain interference, and sleep disturbance were related to higher alcohol use frequency (rho=.176, p=.002; rho=.109, p=.045; rho=.132, p=.013, respectively) and amount/occasion (rho=.215, p<.001; rho=.127, p=.020; rho=.153, p=.004, respectively). In 2019, depressive symptomology, pain interference, and sleep disturbance were not related to alcohol use (rho s=-.047-.087, p s>.05). Between timepoints, more sleep disturbance in 2001 was associated with higher alcohol amount/occasion in 2019 (rho=.115, p=.036). Conclusions: Increased alcohol intake has been theorized to be a consequence of greater concussion history, and as such, thought to confound associations between concussion history and neurobehavioral function later in life. Our findings indicate concussion history and years of contact sport participation were not significantly associated with alcohol use cross-sectionally or longitudinally, regardless of alcohol use characterization. While higher levels of depression, pain interference, and sleep disturbance in 2001 were related to greater alcohol use in 2001, they were not associated cross-sectionally in 2019. Results support the need to concurrently address health-related and psychological factors in the implementation of alcohol use interventions for former NFL players, particularly earlier in the sport discontinuation timeline. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to estimate prevalence of mild cognitive impairment (MCI) and dementia diagnoses in former National Football League (NFL) players >=50 yr old and examine the relationships among these diagnoses and an array of predictors of long-term brain health. Methods : A cross section of former NFL players (n = 922; mean +/- SD age, 64.8 +/- 8.9 yr) completed a questionnaire. Prevalence of self-reported medical diagnoses of MCI and dementia was reported alongside U.S. population estimates across 5-yr age intervals (e.g. 60-64 yr). Prevalence ratios (PR) were calculated for multiple predictors of long-term brain health. Results : Overall, MCI prevalence and dementia prevalence were n = 219(23.8%) and n = 82(8.9%), respectively. Each diagnosis was more prevalent in former NFL players across age-groups than U.S. norms, with greater disparities at relatively younger ages (e.g. 65-69 yr) compared with older ages. Greater prevalence of MCI and dementia was associated with self-reported concussion history (10+ vs 0; PRadjusted [95% CI] = 1.66 [1.02-2.71] and 2.61 [1.01-6.71], respectively); recent pain intensity (PRadjusted [95% CI] = 1.13 [1.07-1.20] and 1.15 [1.03-1.28]); and diagnoses of depression (PRadjusted [95% CI] = 2.70 [1.92-3.81] and 3.22 [1.69-6.14]), anxiety (PRadjusted [95% CI] = 1.96 [1.26-3.07] and 3.14 [1.47-6.74]), or both (PRadjusted [95% CI] = 3.11 [2.38-4.08] and 4.43 [2.71-7.25]). Higher MCI prevalence was related to sleep apnea (PRadjusted [95% CI] = 1.30 [1.06-1.60]); higher dementia prevalence was associated with age (5-yr interval, PRadjusted [95% CI] = 1.42 [1.26-1.60]) and race (non-White vs White, PRadjusted [95% CI] = 1.64 [1.07-2.53]). Conclusions : Self-reported MCI prevalence and dementia prevalence were higher in former NFL players than national estimates and were associated with numerous personal factors, including mood-related disorders and a high number of self-reported concussions. Predictors of higher MCI and dementia prevalence may be modifiable and warrant consideration by clinicians and researchers as potential targets to mitigate the onset of these conditions. [ABSTRACT FROM AUTHOR]

Concussion research generally centers on physical challenges, though aspects such as social functioning and returning to school also warrant attention in pediatric populations. Restoring academic performance postconcussion remains a challenge. Here we provide recommendations addressing a uniform policy for pediatric concussion patients in academic institutions. Tools that may minimize difficulty with academic re-entry include independent educational evaluations, individualized educational programs (IEPs), student support teams (SSTs), letters of academic accommodation, time off, and 504 Plans. Recognition and treatment is crucial for symptom relief and prevention of functional disruption, as is specialist referral during the acute window. We recommend early intervention with a letter of academic accommodation and SST and suggest that 504 Plans and IEPs be reserved for protracted or medically complicated cases. Students with concussion should be observed for anxiety and depression because these symptoms can lead to prolonged recovery, decreased quality of life, and other social challenges. [ABSTRACT FROM PUBLISHER]

Cerebrovascular reactivity (CVR) deficits in adolescents with concussion may persist after resolution of neurological symptoms. Whether or not CVR deficits predict long term neurological function is unknown. We used adolescent mice closed head injury (CHI) models (54 g, 107 cm or 117 cm drop height), followed by blood oxygenation level dependent (BOLD)-functional MRI with CO2 challenge to assess CVR and brain connectivity. At one week, 3HD 107 cm mice showed delayed BOLD responses (p = 0.0074), normal striatal connectivity, and an impaired respiratory rate response to CO2 challenge (p = 0.0061 in ΔRmax). The 107 cm group developed rotarod deficits at 6 months (p = 0.02) and altered post-CO2 brain connectivity (3-fold increase in striatum to motor cortex correlation coefficient) by one year, but resolved their CVR and respiratory rate impairments, and did not develop cognitive or circadian activity deficits. In contrast, the 117 cm group had persistent CVR (delay time: p = 0.016; washout time: p = 0.039) and circadian activity deficits (free-running period: 23.7 hr in sham vs 23.9 hr in 3HD; amplitude: 0.15 in sham vs 0.2 in 3HD; peak activity: 18 in sham vs 21 in 3HD) at one year. Persistent CVR deficits after concussion may portend long-term neurological dysfunction. Further studies are warranted to determine the utility of CVR to predict chronic neurological outcome after mild traumatic brain injury. [ABSTRACT FROM AUTHOR]

Objective: To assess acute cerebrovascular function in concussed adolescents (14–21 years of age), whether it is related to resting cerebral hemodynamics, and whether it recovers chronically. Methods: Cerebral vasoreactivity and autoregulation, based on middle cerebral artery blood flow velocity, was assessed in 28 concussed participants (≤14 days of injury) and 29 matched controls. The participants in the concussion group returned for an 8‐week follow‐up assessment. Over the course of those 8‐weeks, participants recorded aerobic exercise frequency and duration. Results: Between groups, demographic, clinical, and hemodynamic variables were not significantly different. Vasoreactivity was significantly higher in the concussed group (p = 0.02). Within the concussed group, 60% of the variability in resting cerebral blood flow velocity was explained by vasoreactivity and two components of autoregulation – falling slope and effectiveness of autoregulation (adjusted R2 = 0.60, p < 0.001). Moreover, lower mean arterial pressure, lower responses to increases in arterial pressure, and lower vasoreactivity were significantly associated with larger symptom burden (adjusted R2 = 0.72, p < 0.01). By the 8‐week timepoint, symptom burden, but not vasoreactivity, improved in all but four concussed participants (p < 0.01). 8‐week change in vasoreactivity was positively associated with aerobic exercise volume (adjusted R2 = 0.19, p = 0.02). Interpretation: Concussion resulted in changes in cerebrovascular regulatory mechanisms, which in turn explained the variability in resting cerebral blood flow velocity and acute symptom burden. Furthermore, these alterations persisted chronically despite symptom resolution, but was positively modified by aerobic exercise volume. These findings provide a mechanistic framework for further investigation into underlying cerebrovascular related symptomatology. ANN NEUROL 2021;90:43–51 [ABSTRACT FROM AUTHOR]

Objective: To evaluate recovery trajectories among youth athletes with a concussion and healthy controls across different domains using a quantitative and multifaceted protocol. Study design: Prospective repeated measures. Participants: Youth athletes diagnosed with a concussion between the ages of 8 and 18 years were evaluated (1) within 10 days after injury, (2) approximately 3 weeks after injury, and (3) after return-to-play clearance. Control participants completed the same protocol. Setting: Sport concussion clinic. Interventions: N/A. Main outcome measures: Participants underwent a multifaceted protocol that assessed symptoms (postconcussion symptom scale [PCSS]), dual-task gait, event-related potentials (ERPs), and eye tracking. Results: Sixty-seven athletes participated: 36 after concussion (age = 14.0 ± 2.6 years; 44% female) and 31 controls (age = 14.6 ± 2.2 years; 39% female). Concussion symptoms were higher for the concussion group compared with controls at the first (PCSS = 31.7 ± 18.8 vs 1.9 ± 2.9; P < 0.001) and second time points (PCSS = 10.8 ± 11.2 vs 1.8 ± 3.6; P = 0.001) but resolved by the final assessment (PCSS = 1.7 ± 3.6 vs 2.0 ± 3.8; P = 0.46). The concussion group walked slower during dual-task gait than controls at all 3 tests including after return-to-play clearance (0.83 ± 0.19 vs 0.95 ± 0.15 m/s; P = 0.049). There were no between-group differences for ERP connectivity or eye tracking. Those with concussions had a decrease in ERP connectivity recovery over the 3 time points, whereas control participants' scores increased (concussion Δ = -8.7 ± 28.0; control Δ = 13.9 ± 32.2; χ² = 14.1, P = 0.001). Conclusions: Concussion is associated with altered dual-task gait speeds after resolution of concussion symptoms, but ERP and eye tracking measures did not demonstrate between-group differences across time. Some objective approaches to concussion monitoring may support with identifying deficits after concussion, but further work is required to delineate the role of gait, electrophysiological, and eye tracking methods for clinical decision-making. [ABSTRACT FROM AUTHOR]

Public concern is growing about the short- and long-term effects of pediatric mild traumatic brain injury (mTBI). This concern is amplified because pediatric mTBI has the potential to go undiagnosed in acute care settings, placing children at increased risk for reinjury prior to complete recovery. The management of mTBI can be particularly challenging due to the lack of validated biomarkers that clinicians can use to objectively diagnose pediatric mTBI, predict risk for prolonged recovery, or demonstrate mTBI recovery. Fluid-based biomarkers have drawn increased attention as an objective measure to diagnose and manage pediatric mTBI, but investigations of promising biomarkers may pose unique challenges in pediatric populations. Our systematic review confirms the relative paucity of high-quality, clinically impactful diagnostic or prognostic fluid biomarker studies, on samples representing only a small fraction of pediatric mTBI. Ultimately, well-designed longitudinal studies across diverse points of care are needed to truly characterize the utility of fluid biomarkers of injury and recovery for the pediatric mTBI patient. [ABSTRACT FROM AUTHOR]

Background: Concussion prognosis is a challenging clinical task. Identification of measures useful for persistent symptom risk can help optimize treatment pathways and allow clinicians to offer appropriate anticipatory guidance.Research Question: Can a multifaceted single/dual-task postural control assessment within one week of a diagnosed concussion identify the odds of developing persistent post-concussion symptoms (PPCS; symptoms that persist for more than 28 days post-concussion)?Methods: We conducted a prospective cohort study of youth and young adult athletes who were evaluated within 7 days of injury, and followed until they no longer reported concussion symptoms. Participants were grouped into those who developed PPCS and those who did not. During the initial evaluation, participants completed a postural control evaluation in single/dual-task conditions. We calculated six gait performance variables (in single/dual-task conditions), nine quiet stance performance variables, and three cognitive task performance (standing and walking) variables. We conducted between-group comparisons to identify candidate PPCS prognostic variables, and multivariable models to adjust for covariates (age, post-injury evaluation time, history of concussion, and BMI).Results: Sixty-six participants completed the study: 24% reported PPCS (mean age = 16.9 ± 3.5 years; 50% female; evaluated 4.2 ± 1.9 days post-injury) and 74% (mean age = 18.3 ± 3.0 years; 52% female; evaluated 3.5 ± 1.6 days post-injury) did not. Between-group comparisons indicated greater dual-task transverse plane center-of-mass (COM) range of motion (ROM) (13.1 ± 4.3 vs. 9.9 ± 2.5 degrees; p = 0.013) and lateral step variability (5.1 ± 1.4 vs. 4.0 ± 1.2 cm; p = 0.003) for the PPCS group relative to the no PPCS group. After multivariable modeling, dual-task transverse plane COM ROM (adjusted odds ratio = 1.34, 95% CI = 1.07, 1.68) and lateral step variability (adjusted odds ratio = 1.85, 95% CI = 1.13, 3.05) were significantly associated with PPCS.Significance: Dual-task transverse plane movement and lateral step variability demonstrate viable prognostic ability for PPCS among youth and young adult athletes and, along with other established factors, may add incremental value to PPCS prognosis models. [ABSTRACT FROM AUTHOR]

Clinical practice strongly relies on patients' self-report. Former professional American-style football players are hesitant to seek help for mental health problems, but may be more willing to report cognitive symptoms. We sought to assess the association between cognitive symptoms and diagnosed mental health problems and quality of life among a cohort of former professional players. In a cross-sectional design, we assessed self-reported cognitive function using items from the Quality of Life in Neurological Disorders (Neuro-QOL) Item Bank. We then compared mental health diagnoses and quality of life, assessed by items from the Patient-Reported Outcome Measurement Information System (PROMIS®), between former professional players reporting daily problems in cognitive function and former players not reporting daily cognitive problems. Of the 3758 former professional players included in the analysis, 40.0% reported daily problems due to cognitive dysfunction. Former players who reported daily cognitive problems were more likely to also report depression (18.0% vs. 3.3%, odds ratio [OR] = 6.42, 95% confidence interval [CI] [4.90–8.40]) and anxiety (19.1% vs. 4.3%, OR = 5.29, 95% CI [4.14–6.75]) than those without daily cognitive problems. Further, former players reporting daily cognitive problems were more likely to report memory loss and attention deficit(/hyperactivity) disorder and poorer general mental health, lower quality of life, less satisfaction with social activities and relationships, and more emotional problems. These findings highlight the potential of an assessment of cognitive symptoms for identifying former players with mental health, social, and emotional problems. [ABSTRACT FROM AUTHOR]

• Repetitive mild TBI results in subacute loss of oligodendrocytes and decreased expression of myelin basic protein. • NMDAR-mediated excitotoxicity is proposed to mediate these post-injury sequelae. • Treatment with an NMDAR antagonist partially prevented these sequelae of injury. Repetitive mild traumatic brain injury (rmTBI; e.g., sports concussions) is common and results in significant cognitive impairment, white matter injury and increased risk of neurodegeneration. Targeted therapies for rmTBI are lacking, though evidence from other injury models indicates that targeting N-methyl- d -aspartate (NMDA) receptor (NMDAR)-mediated glutamatergic toxicity might mitigate rmTBI-induced injury. We have previously shown that the NMDAR antagonist memantine lessens axonal injury and restores long term potentiation after rmTBI. Here, we evaluated whether the protective effects of memantine include oligodendrocyte specific mechanisms, as prior studies suggest that oligodendrocytes are particularly vulnerable to glutamatergic toxicity. Mice were subjected to rmTBI injury (5 injuries in 5 days) and randomized to treatment with memantine or with vehicle (n = 32/group). At the molecular level, oligodendrocyte counts and function (myelin basic protein, MBP) were assessed by immunohistochemistry and western blot at days 3, 7 and 28 days after the last injury. Axon integrity was assessed by neurofilament light chain (NF-l) expression and axonal ultrastructure was evaluated by electron microscopy. Compared to vehicle-treated mice, memantine-treated mice were protected against oligodendrocyte loss and decreased MBP expression at subacute time points after injury. Memantine treatment also protected against axon damage assessed by NF-l expression. These data suggest that the therapeutic effects of post-concussive NMDAR antagonism may in part work through oligodendrocyte specific mechanisms, which may have implications for long term neurodegenerative sequelae after multiple concussions. [ABSTRACT FROM AUTHOR]

Objectives: (1) To examine how age influences initial symptom presentation following concussion; and (2) to determine whether specific symptom profiles are associated with duration of postconcussion symptoms, and whether they vary by age group. Design: A total of 689 patients (20% children 7-12 years of age, 69% adolescents 13-18 years of age, and 11% young adults 19-30 years of age) were seen and diagnosed with a concussion within 21 days after injury. Patients completed the Post-Concussion Symptom Scale (PCSS) and were followed until they no longer required care. Setting: Two specialty care sport concussion clinical practices. Main outcome measures: Overall PCSS score was obtained, as well as severity ratings from somatic, vestibular-ocular, cognitive, sleep, and emotional symptom domains. We also calculated total symptom duration time. Results: No significant main effect of age, or age by sex associations were identified among the symptom domains. Females endorsed a higher somatic symptom severity rating than males (9.8 +/- 6.7 vs 8.1 +/- 6.7; P = 0.03). For patients between 7 and 12 years of age, higher somatic [[beta]-coefficient = 1.57, 95% confidence interval (CI), 1.47-1.67] and cognitive ([beta]-coefficient = 2.50, 95% CI, 2.32-2.68) symptom severities were associated with longer duration of concussion symptoms. Among adolescents, longer total symptom duration was associated with more severe somatic ([beta]-coefficient = 1.25, 95% CI, 0.34-2.15) and vestibular-ocular ([beta]-coefficient = 2.36, 95% CI, 1.49-3.23) symptoms. Conclusions: Within 21 days after concussion, symptom-reporting behavior seems to be similar across the age spectrum, but the relationship between symptom profiles and time to symptom resolution varies by age. Although overall symptom ratings are beneficial in determining clinical pathways, symptom domain use may provide a beneficial method to determine individualized patient care that differs between children and adolescents after concussion. [ABSTRACT FROM AUTHOR]

The identification of clinical phenotypes may help parse the substantial heterogeneity that characterizes children with concussion. This study used latent class analysis (LCA) to identify discernible phenotypes among children with acute concussion and examine the association between phenotypes and persistent post-concussive symptoms (PPCS) at 4 and 12 weeks post-injury. We conducted LCA of variables representing pre-injury history, clinical presentation, and parent symptom ratings, derived from a prospective cohort, observational study that recruited participants from August 2013 until June 2015 at nine pediatric emergency departments within the Pediatric Emergency Research Canada network. This substudy included 2323 children from the original cohort ages 8.00–17.99 years who had data for at least 80% of all variables included in each LCA. Concussion was defined according to Zurich consensus statement diagnostic criteria. The primary outcome was PPCS at 4 and 12 weeks after enrollment. Participants were 39.5% female and had a mean age of 12.8 years (standard deviation = 2.6). Follow-up was completed by 1980 (85%) at 4 weeks and 1744 (75%) at 12 weeks. LCA identified four groups with discrete pre-injury histories, four groups with discrete clinical presentations, and seven groups with discrete profiles of acute symptoms. Clinical phenotypes based on the profile of group membership across the three LCAs varied significantly in their predicted probability of PPCS at 4 and 12 weeks. The results indicate that children with concussion can be grouped into distinct clinical phenotypes, based on pre-injury history, clinical presentation, and acute symptoms, with markedly different risks of PPCS. With further validation, clinical phenotypes may provide a useful heuristic for clinical assessment and management. [ABSTRACT FROM AUTHOR]

Our objective was to identify factors associated with trouble falling asleep postconcussion. Patients seen for care after sport-related concussion were assessed ≤10 days postinjury and were between 6 and 19 years of age. Outcomes included symptoms (Post-Concussion Symptom Scale), postural steadiness, missed school, and medical history. There were 261 patients (49% female; mean age=14.8±2.5 years): 45% reported trouble falling asleep. A greater proportion of patients who reported trouble falling asleep missed ≥2 days of school (64% vs 49%; P = .02). Patients who reported trouble falling asleep endorsed more severe symptom severity than those who did not (median=38 vs 18; P < .001). After covariate adjustment, confusion (aOR = 1.95, 95% CI = 1.131-3.375), missing ≥2 days of school (aOR = 4.52, 95% CI = 1.553-13.16), and noise sensitivity (aOR = 1.48, 95% CI = 1.1.042-2.010) were independently associated with trouble falling asleep. Sleep disturbances are associated with poorer clinical outcomes after concussion. Inclusion of sleep assessments may help to provide early therapeutic pathways for pediatric concussion patients. [ABSTRACT FROM AUTHOR]

Prior studies suggest that concussion may lead to an increased risk of a subsequent time-loss sport-related injury, but the mechanisms responsible are unknown. We measured the symptom and dual-task gait outcomes for athletes initially post-concussion and after clinical recovery. Participants then self-reported any additional injuries incurred in the year after their concussion. Forty-two athletes (52% female, mean age = 16.8 ± 3.2 years) completed the study. They underwent a dual-task gait evaluation and symptom inventory within 21 days post-concussion, and again after they were deemed clinically recovered. Approximately one year later, participants documented if they had sustained any subsequent sport-related injuries. The repeated measures analysis of variance (ANOVA) was used to evaluate changes in dual-task gait and symptoms across time and between groups. A significant group*time interaction (p = 0.02) indicated that the group that went on to sustain a subsequent time-loss injury after returning to sports (n = 15) demonstrated significant average walking speed dual-task cost worsening across time (−17.9 ± 9.1% vs. −25.1 ± 12.5%; p = 0.007). In contrast, the group that did not sustain an additional injury walked with consistent dual-task cost values across time (−25.2 ± 9.2% vs. −24.6 ± 8.4%; p = 0.76). Symptoms improved for all participants (main effect of time, p < 0.001; Post-Concussion Symptom Scale [PCSS] = 25.0 ± 16.9 vs. 2.8 ± 7.5; p < 0.001), but did not differ between groups (p = 0.77). Significant dual-task gait cost worsening throughout concussion recovery was associated with time-loss injuries during sports in the year after a concussion. These findings indicate that worsening ability to execute a concurrent gait and cognitive task may relate to the risk of incurring an injury during sports after clinical concussion recovery. [ABSTRACT FROM AUTHOR]

Background: Sleep deficits are associated with motor and cognitive function deficits, even in the absence of a recent concussion.Research Question: Does the amount of self-reported sleep prior to pre-season concussion testing affect single-task and dual-task instrumented steady-state gait and timed tandem gait test performance?Methods: One hundred and fourteen healthy collegiate athletes (mean age 18.8 ± 0.7 years; 60% female) reported the amount of sleep they received during the prior night and completed a timed tandem gait test and an instrumented assessment of steady-state gait in both single-task and dual-task conditions. Outcome variables included spatio-temporal gait parameters during steady-state gait, best and mean tandem gait times, and cognitive test accuracy.Results: Participants who reported sleeping <7 h of sleep during the night prior to testing (n = 62) had significantly longer tandem gait times in single-task and dual-task conditions (11.1 ± 2.2 vs. 10.1 ± 2.0 s and 14.5 ± 4.3 vs. 12.3 ± 2.6 s, respectively; p = .009) compared to those who reported sleeping ≥7 h (n = 52). No significant differences between groups were observed for spatio-temporal steady-state gait variables or for cognitive test accuracy.Significance: Self-reported sleep duration may be associated with baseline testing tandem gait performance. Thus, as sleep can play a role in motor abilities, clinicians may consider interpreting tandem gait performance in light of sleep duration during the night prior to testing. [ABSTRACT FROM AUTHOR]

The association between preexisting anxiety, depression, and/or neurodevelopmental disorders and symptom duration among younger children who sustain concussions is not well known. The authors conducted a prospective cohort study of 569 patients presenting to a pediatric neurology clinic with the diagnosis of concussion. The authors measured associations between symptom duration and premorbid conditions, as well as gender, age, mechanism of injury, and other factors. Premorbid conditions were common in both age groups. On univariate modeling female gender, age >12 years, and premorbid conditions were associated with longer symptom duration. On multivariable modeling, females and patients ≤12 years old with a history of headaches, migraines, or a history of psychiatric conditions took significantly longer to recover than those without such conditions. Premorbid conditions are associated with a prolonged recovery from concussion among those patients ≤12 years old. [ABSTRACT FROM AUTHOR]

Quantitative gait measurements can identify persistent postconcussion impairments. However, their prognostic utility after injury to identify the likelihood of prolonged concussion symptoms remains unknown. Our objective was to examine if dual-task gait performance measures are independently associated with persistent (> 28 days) concussion symptoms among a sample of athletes. Sixty individuals diagnosed with a sport-related concussion were assessed within 10 days of their injury. Each participant completed a postconcussion symptom scale, an injury history questionnaire, and a single/dual-task gait examination. They were followed until they no longer reported symptoms, and the duration of time required for symptom resolution was calculated. A binary multivariable logistic regression model determined the independent association between dual-task gait and symptom duration (≤ 28 days vs. >28 days) while controlling for the effect of gender, age, symptom severity, injury-to-examination time, and history of concussion. Seventeen (28%) participants reported a symptom duration >28 days. The dual-task cost for average gait speed (−25.9 ± 9.5% vs. −19.8 ± 8.9%; p = 0.027) and cadence (−18.0 ± 2.9% vs. −12.0 ± 7.7%; p = 0.029) was significantly greater among participants who experienced symptoms for >28 days. After adjusting for potential confounding variables, greater dual-task average gait speed costs were independently associated with prolonged symptom duration (aOR = 0.908; 95% CI = 0.835-0.987). Examinations of dual-task gait may provide useful information during multifaceted concussion examinations. Quantitative assessments that simultaneously test multiple domains, such as dual tasks, may be clinically valuable after a concussion to identify those more likely to experience symptoms for >28 days after injury. [ABSTRACT FROM AUTHOR]

While pathophysiology underlying post-concussion symptom burden is unknown, data suggest that cerebrovascular dysfunction may be among the culprits. We sought to determine whether the degree of impairment in the ability of cerebrovasculature to buffer against changes in arterial gases (vasoreactivity) is associated with concussion symptoms. In 15 participants (19 ± 5 years, 1 week to 1 year post-injury) diagnosed with concussion, we assessed vasoreactivity from the slope of the linear relationship of beat-by-beat middle cerebral artery blood flow velocity (transcranial Doppler ultrasound) to end-tidal CO2 during progressive increases in end-tidal CO2 (air rebreathing). Symptom burden was assessed using the Post-Concussion Symptom Scale. Subsequently, we explored the relationship between vasoreactivity and the severity of post-concussion headache and cognitive difficulties by linear models. During rebreathing, CO2 increased from 32.6 ± 1.6 to 46.8 ± 1.8 mmHg and cerebrovascular conductance (i.e., flow velocity over pressure) increased from 0.48 ± 0.04 to 0.74 ± 0.06 cms−1 mmHg−1. There was a strong linear relationship between the increase in CO2 and in conductance ( R2 = 0.81 ± 0.05; p < 0.05). On average, cerebral vasoreactivity was 0.018 ± 0.003 cm−1 s−1 mmHg CO2−1. Although vasoreactivity tended to be somewhat higher in the asymptotic participants (0.019 ± 0.003 vs. 0.015 ± 0.005 cm−1 s−1 mmHg CO2−1), this difference was not statistically significant ( p = 0.48). Higher vasoreactivity was strongly associated with more severe headaches ( R2 = 0.57; p < 0.01) and worse cognitive symptoms ( R2 = 0.71; p < 0.01). Thus, cerebral vasoreactivity relates strongly to post-concussive headache and cognitive symptom burden. This has significant implications for understanding the pathophysiology underlying post-concussive symptom burden and for devising effective treatment options. [ABSTRACT FROM AUTHOR]

Although environmental enrichment has been shown to improve functional and histologic outcomes in pre-clinical moderate-to-severe traumatic brain injury (TBI), there are a paucity of pre-clinical data regarding enrichment strategies in the setting of repetitive mild traumatic brain injury (rmTBI). Given the vast numbers of athletes and those in the military who sustain rmTBI, the mounting evidence of the long-term and progressive sequelae of rmTBI, and the lack of targeted therapies to mitigate these sequelae, successful enrichment interventions in rmTBI could have large public health significance. Here, we evaluated enrichment strategies in an established pre-clinical rmTBI model. Seventy-one male C57BL/6 mice were randomized to two different housing conditions, environmental enrichment (EE) or normal condition (NC), then subjected to rmTBI injury (seven injuries in 9 days) or sham injury (anesthesia only). Functional outcomes in all four groups (NC-TBI, EE-TBI, NC-sham, and EE-sham) were assessed by motor, exploratory/anxiety, and mnemonic behavioral tests. At the synaptic level, N-methyl d-aspartate receptor (NMDAR) subunit expression of phosphorylated glutamate receptor 1 (GluR1), phosphorylated Ca2+/calmodulin-dependent protein kinase II (CaMKII), and calpain were evaluated by western blot. Compared to injured NC-TBI mice, EE-TBI mice had improved memory and decreased anxiety and exploratory activity post-injury. Treatment with enrichment also corresponded to normal NMDAR subunit expression, decreased GluR1 phosphorylation, decreased phosphorylated CaMKII, and normal calpain expression post-rmTBI. These data suggest that enrichment strategies may improve functional outcomes and mitigate synaptic changes post-rmTBI. Given that enrichment strategies are feasible in the clinical setting, particularly for athletes and soldiers for whom the risk of repetitive injury is greatest, these data suggest that clinical trials may be warranted. [ABSTRACT FROM AUTHOR]

Aim: To correlate television or unrestricted, unmonitored Internet access in room of sleep with body mass index (BMI).Methods: Cross-sectional study of athletes ≤19 years who underwent an injury prevention evaluation. Independent variables included proportion of athletes categorised as overweight or obese who answered positively to American Academy of Pediatrics recommended questions: (i) Do you have a TV in the room where you sleep? (ii) Do you have unrestricted, unmonitored access to the Internet in the room where you sleep?Results: 555 athletes; 324 female; mean age 13.83 ± 2.60. Athletes with a TV in their room of sleep had higher BMI (22.73 vs. 20.54; p < 0.001), slept less hours/week (7.65 vs. 8.12; p = 0.003) and were more likely to be overweight/obese (40.32% vs. 25.52%; p = 0.022). Athletes with unrestricted, unmonitored Internet access in the room of sleep had a higher BMI (21.68 vs. 19.83; p < 0.001), slept fewer hours/week (7.58 vs. 8.60; p < 0.001) and per/weekend (9.00 vs. 9.37; p < 0.001). After adjusting for age and gender, having a TV in the room of sleep remained significantly associated with BMI and WHO criteria for overweight/obesity.Conclusion: Athletes with television in their room of sleep were more likely to have higher BMI and be overweight or obese. [ABSTRACT FROM AUTHOR]

Aim: The purpose of this study was to determine whether high levels of strenuous physical activity outside of organised sports are associated with better functional test performance.Methods: Youth athletes (n = 445, mean = 14.2 ± 2.5 years) reported their frequency of strenuous physical activity outside of organised sports. The functional performance tests: vertical jump height, pro agility test time, estimated maximal oxygen uptake (VO2 max), front plank time and postural stability were measured and compared between groups.Results: Athletes in the five or more times a week group demonstrated faster pro agility times (5.37 ± 0.43 seconds) than the never group (5.59 ± 0.56 seconds; p = 0.002) and the 1-4 times a week group (5.52 ± 0.47 seconds; p = 0.005). The five or more times a week group demonstrated higher mean vertical jump height (42.9 ± 13.3 vs. 40.3 ± 10.8 cm; p = 0.009) and higher estimated VO2 max (48.1 vs. 45.6 mL/kg/minute; p = 0.001) than the 1-4 times a week group.Conclusion: Youth athletes who engaged in strenuous physical activity outside of organised sports five or more times a week performed best on functional performance tests. [ABSTRACT FROM AUTHOR]

Concussion may affect females and males differentially. Identification of gender-related differences after concussion, therefore, may help clinicians with individualized evaluations. We examined potential differences in dual-task gait between females and males after concussion. Thirty-five participants diagnosed with a concussion (49% female, mean age=15.0±2.1 years, 7.5±3.0 days post-injury) and 51 controls (51% female, mean age=14.4±2.1 years) completed a symptom inventory and single/dual-task gait assessment. The primary outcome variable, the dual-task cost, was calculated as the percent change between single-task and dual-task conditions to account for individual differences in spatio-temporal gait variables. No significant differences in symptom severity measured by the post-concussion symptom scale were observed between females (32.0±18.0) and males (27.8±18.2). Compared with males, adolescent females walked with significantly decreased cadence dual-task costs after concussion (-19.7%±10.0% vs. -11.3%±9.2%, p=0.007) when adjusted for age, height, and prior concussion history. No significant differences were found between female and male control groups on other dual-task cost gait measures. Females and males with concussion also walked with significantly shorter stride lengths than controls during single-task (females: 1.13±0.11m vs. 1.26±0.11m, p=0.001; males: 1.14±0.14m vs. 1.22±0.15m, p=0.04) and dual-task gait (females: 0.99±0.10m vs. 1.10±0.11m, p=0.001; males: 1.00±0.13m vs. 1.08±0.14m, p=0.04). Females demonstrated a significantly greater amount of cadence change between single-task and dual-task gait than males after a sport-related concussion. Thus, differential alterations may exist during gait among those with a concussion; gender may be one prominent factor affecting dual-task gait. [ABSTRACT FROM AUTHOR]

Sustaining repeated concussions has been associated with worse outcomes after additional injuries. This effect has been identified using symptom inventories and neurocognitive tests; however, few investigations have examined how a prior concussion history affects gait soon after a subsequent concussion. We examined the gait characteristics of athletes with no documented concussion history ( n = 31), athletes recovering from their first lifetime concussion ( n = 15), and athletes recovering from their second or greater lifetime concussion ( n = 22). All participants completed a single-task and dual-task gait examination, a medical history questionnaire, and a postconcussion symptom scale. Multivariate analyses of covariance (MANCOVA) models were used to evaluate mean gait differences among groups, and Spearman's ρ analyses were used to assess correlations between the number of lifetime concussions and gait characteristics. Patients reporting to the clinic with their second or greater lifetime concussion demonstrated smaller stride lengths than healthy control participants during dual-task walking ( p = 0.01; d = 0.70). A moderate but insignificant correlation was detected between dual-task gait speed and the number of prior concussions (ρ = 0.41, p = 0.07). These results indicate that a cumulative effect of concussions across the lifetime may contribute to worsening dual-task dynamic motor function after concussion. [ABSTRACT FROM AUTHOR]

Concussion is increasingly recognized as a risk of participation in contact and collision sports. There have been few examinations of athletes' perceptions of their susceptibility to concussion or concussion-related health consequences. We examine college football players' perceptions of their risk of sustaining a concussion and concussion-related health consequences in their future, whether these perceptions change over time, and how concussion history is related to perceived future risk of concussion and concussion-related health consequences. A survey was administered to National Collegiate Athletic Association Division I Football Championship Series athletes on 10 teams in 2013 and to nine of those teams in 2014. Athletes answered questions assessing their perceptions of concussion and potential concussion-related health consequences. Approximately 40% of athletes believed there was a strong possibility that they would sustain a concussion in the future, while approximately one-in-four thought a concussion would make them miss a few games. About one-in-10 athletes predicted dementia, Alzheimer's disease, or chronic traumatic encephalopathy would develop from concussions. These beliefs were stronger among athletes who had sustained previous concussions. Across the two years studied, athletes' perceptions of the risk of concussion and missing a few games because of concussion decreased significantly. Overall, a substantial proportion of college football players believe they will have long-term health consequences as a result of sustaining sport-related concussions. The true incidence and prevalence of many of these outcomes are unknown. Further research is needed to determine whether athletes have an accurate perception of the risks of these outcomes developing. [ABSTRACT FROM AUTHOR]