Preseason Baseline Research Articles

Differences in Symptom Clusters at Baseline Testing among Student Athletes with ADHD or Migraines

Abstract Purpose This study was designed to determine whether the factor structure of the Post-Concussion Symptom Scale (PCSS) is consistent (i.e., invariant) in subgroups of youth with pre-existing attention-deficit/hyperactivity disorder (ADHD) or migraines. A four-factor model of the PCSS has empirical support (i.e., cognitive-sensory, sleep-arousal, vestibular-somatic, and affective symptoms), and the current investigation examined (i) whether this model is invariant across athletes with and without ADHD or migraines and (ii) group differences across symptom clusters. Methods Participants included a large sample of adolescent athletes (N=39,242; 54.4% boys; 13–18 years-old, M=15.50±1.27 years), among which 2,543 reported ADHD and 2,638 reported having migraines. The 22-item PCSS was administered at pre-season baseline. Statistical analyses included invariance testing across ADHD and migraine groups. Good fit was defined as CFI≥0.95. Effect sizes for group differences in symptom clusters were calculated. Results Configural invariance was established across participants with and without ADHD (CFI=0.967) and with and without migraines (CFI=0.965); however, weak invariance was not established for either diagnostic group. Effect sizes (Cohen’s d) of group differences varied by symptom cluster: cognitive-sensory (ADHD=0.44; migraine=0.38), sleep-arousal (0.33, 0.37), vestibular-somatic (0.17, 0.45), and affective (0.27, 0.28). Conclusion Although the four-factor model has been previously published and replicated among healthy student athletes, this model was only partially invariant for participants with ADHD or migraines. The cognitive-sensory factor showed the largest differences based on ADHD, whereas the vestibular-somatic factor showed the largest differences based on migraine history.

A Four-Factor Symptom Model for Student Athletes with and without Prior Concussions

Abstract Purpose This study was designed to determine whether the factor structure of the Post-Concussion Symptom Scale (PCSS) is consistent (i.e., invariant) in subgroups of youth stratified by their history of prior concussions. A four-factor model of the PCSS has empirical support (i.e., cognitive-sensory, sleep-arousal, vestibular-somatic, and affective symptoms), and the current investigation examined (i) whether this model is invariant across athletes with 0, 1, or ≥2 prior concussions and (ii) group differences across symptom clusters. Methods Participants included a large sample of adolescent athletes (54.4% boys; 13–18 years-old, M=15.50±1.27 years) with 0 (n=32,668), 1 (n=4,110), or ≥2 prior concussions (n=1,681) administered the 22-item PCSS at pre-season baseline. Measurement invariance was tested (good fit=CFI≥0.95; significant change-in-fit=∆CFI≥0.01) and effect sizes for group differences in symptom clusters were calculated. Results The four-factor model showed configural (CFI=0.968) and weak invariance (∆CFI=0.006), but not strong invariance. Comparisons based on concussion history across symptom clusters indicated very small differences between athletes with 0 and 1 prior concussion(s) (d=0.05-0.15), slightly larger differences between athletes with 1 and ≥2 prior concussion(s) (d=0.12-0.24), and modestly larger differences between athletes with 0 and ≥2 prior concussion(s) (d=0.17-0.35). Conclusion These findings support partial invariance of the four-factor PCSS model across athletes with and without a history of concussion. The association with prior concussion was greatest for cognitive-sensory symptoms and smallest for vestibular symptoms. Future research should explore whether alternative factor models are invariant across athletes with different numbers of prior concussions.

The Association Between Past Speech Therapy and Preseason Symptom Reporting in Adolescent Student Athletes

Abstract Purpose Neurodevelopmental conditions, such as ADHD, have been shown to be associated with different baseline symptom reporting, but the relationship between a history of speech therapy and symptom reporting is not well understood. This study examined the association between prior speech therapy and baseline symptom reporting in student athletes. Methods A preseason baseline database contained 40,378 athletes ages 13–18 who had not sustained a concussion in the past 6 months. Of these, 27,550 athletes denied having all developmental/health conditions (controls) and 1,497 reported only having history of speech therapy (total sample: age M=15.5, SD=1.26; 47% girls). Mann-Whitney U-Tests were used to compare baseline symptom reporting on the ImPACT® Post-Concussion Symptom Scale between athletes with prior speech therapy and controls. Individual symptoms were dichotomized (absent vs. present) and compared between groups using chi-square tests. Results There was a higher proportion of boys in the prior speech therapy group than in the control group (62% vs. 53%; X2=41.9, p<.001). Athletes with speech therapy histories reported greater overall baseline symptoms (ps<.001). The effect sizes were minimal-to-small (Cohen’s d: girls= 0.10; boys=0.20). Slightly higher portions of boys and girls with a history of speech therapy reported trouble falling asleep, fatigue, and difficulty concentrating/ remembering compared to their control counterparts (ps<.05). Further, compared to controls, a higher portion of boys (but not girls) with speech therapy histories reported physical and emotional symptoms. Conclusion Adolescents with speech therapy histories report slightly more symptoms than controls during baseline testing, with a stronger effect in boys. However, effect sizes were very small.

Test-Retest Reliability of ImPACT Across a Two-Year Interval in Collegiate Athletes

Abstract Purpose To examine the two-year test-retest reliability of Immediate Post-concussion Assessment and Cognitive Testing (ImPACT) in a sample of collegiate athletes. Methods A total of 163 college athletes (63.8% female) completed two pre-season baseline assessments two years apart as mandated by their athletic programs. Participants completed the first baseline prior to their first year of competition (M age=18.38, M edu=12.13). Individuals with baselines flagged as invalid by ImPACT were excluded. No diagnosed concussions occurred between baseline assessments. Results Pearson r correlations for ImPACT composite scores between assessments ranged from .32 to .70. Paired samples t-tests indicated significant differences between verbal memory (t(162)=-4.61, p<.001, MD=-3.6) and visual-motor speed (t(162)=-4.10, p<.001, MD=-1.5) at time 1 and time 2. Intraclass correlation coefficients (ICCs) with a “two-way mixed” model and “consistency” type indicated higher reliability for all composite scores. Visual-motor speed (mean ICC=.83; .76–.87 95% confidence interval [CI]) was the most reliable composite score, followed by visual memory (.66; 95% CI .53-.75), impulse control (.62; 95% CI .48–.72), verbal memory (.58; 95% CI .43–.69), and reaction time (.49; 95% CI .30-.62). The total symptom score showed moderate reliability (.63; 95% CI .50–.73). Conclusion Overall, ImPACT composite and total symptom scores appear to maintain relative long-term stability in a collegiate sample across a two-year period. ImPACT composite scores showed moderate to good reliability, and total symptom scores showed moderate reliability. Results of this study corroborate previous research indicating moderately stable ImPACT scores across a 2-year test-retest period in collegiate athletes (Schatz, 2010).

Addressing the ``Replication Crisis'' in Sports Neuropsychology: Validation of the Two-Factor Theory of ImPACT

Abstract Purpose The "replication crisis" in psychology and across the broader field of social sciences raises criticism due to a lack of data to show that esoteric research findings can be replicated. The present study replicated and validated the two-factor “memory” and “speed” structure of ImPACT (Schatz & Maerlender, 2013). Methods High school aged athletes (N=18,918, Mean age=15.4, SD=1.2) who completed pre-season baseline ImPACT testing were randomly assigned to one of 5 independent samples of approximately 3,780 athletes. Exploratory factor analyses (FA) for a two-factor solution were conducted with ImPACT composite scores within each of the five groups. Post-Concussion Symptom Scale (PCSS) scores were included, with the expectation they would load on a third, unique factor. Results All five samples met assumptions for FA (KMO Measure of Sampling Adequacy above .600), and all five analyses yielded the same “memory” and “speed” two-factor structure. Visual Motor Speed and Reaction Time loaded on the first "Speed" factor and Verbal and Visual Memory loaded on a second "Memory" factor. The PCSS scores loaded on a third, unique “symptom” factor. Conclusion Replication of the two-factor structure for ImPACT in a five large high school sample further validates the model. Given that both visual and verbal memory involve encoding of information presented visually, use of a “memory” factor may improve interpretation of ImPACT scores. Similarly, similarities between constructs measuring speed of responding (Reaction Time) and speed of processing (Visual Motor Processing Speed) may be best explained using a “speed” factor.

Acute Sport Concussion Assessment Optimization: A Prospective Assessment from the CARE Consortium.

Numerous medical organizations recommend a multifaceted approach to the assessment of concussion occurring during sporting events. A number of tools are available to clinicians, with a wide breadth of sensitivity and specificity; however, little work has been done to evaluate the combined efficiency of these tools in concussed male and female athletes from a broad array of collegiate sports and with variable time from the pre-season baseline evaluation. The aim of this study was to optimize the concussion assessment battery for application within the first 72h of injury, and to identify the necessary baseline retesting frequency. Between 2014 and 2017, a total of 1458 National Collegiate Athletic Association (NCAA) athletes sustaining 1640 diagnosed concussions completed a baseline assessment each year of the investigation and were evaluated up to three times within the first 72h of injury using a standardized assessment protocol. Classification and regression tree analyses were implemented to identify the most efficient multifaceted assessment pathway to quantify concussion-related outcomes. Results were optimized for assessments occurring within 1h post-injury, 1-24h post-injury, and 24-72h post-injury when using the raw post-injury assessment performance, difference scores from baseline evaluations occurring in the same year, and difference scores from baseline evaluations occurring the year prior. At each of the assessment time points, the analyses indicated that alone or in combination, a symptom evaluation, Balance Error Scoring System (BESS) scores collected on the firm surface, and Standardized Assessment of Concussion (SAC) total score offered the best overall performance when compared with pre-morbid performance captured in the same season. Optimized sensitivity of the multifaceted approach was 61% within 1h of injury, 67% at the 1-24h interval, and 55% at the 24-72h interval when difference scores from the same-season baseline were available. This investigation identified key concussion assessments in quantifying post-concussion performance among student athletes, that were maximized when same-season pre-morbid evaluations were available. Consistent with clinical recommendations, medical professionals should continue to focus on symptom reporting, postural control, and neurocognitive screening to support the clinical examination when making a concussion diagnosis.

Direct Comparison of Multidimensional Clinical Assessment Tools: Sensitivity to Concussion in Student Athletes

Abstract Purpose Consensus guidelines recommend multidimensional assessment for concussion diagnosis and management. Among cognitive, oculomotor, and postural stability, it remains unclear which modalities perform best in the acute/subacute periods. We conducted a direct comparison to identify those with the strongest sensitivity to sport-related concussion. Methods High school and collegiate football players (aged 14–24) completed preseason baseline assessments. Concussed (n=91) and matched non-concussed teammates (n=85) underwent repeat testing at 48 hours, 8 days, and 15 days post-injury. Postconcussive symptoms (SCAT-3 symptom severity), cognition (Standardized Assessment of Concussion, Immediate Post-Concussion and Cognitive Testing, Trail Making Test, Wechsler Adult Intelligence Scale-IV Processing Speed Index), oculomotor functioning (King-Devick Test), and postural stability (Balance Error Scoring System) were compared using Cohen’s d and Receiver Operating Characteristic analyses. Results Symptom severity had the greatest sensitivity at 48 hours and 8 days post-injury (Cohen’s d=1.43 and 0.53, AUC=.93 and .63, p<.01). Of the performance-based assessments, BESS was most sensitive to SRC at 48 hours post-injury (Cohen’s d=.74, AUC=.70, p<.01). Oculomotor and cognitive testing via ImPACT, WAIS-IV PSI, and TMT-A were sensitive to a lesser degree (Cohen’s d=.35–.58, p<.05). Verbal memory was the only significant performance-based assessment at days 8 and 15, with small-to-medium effect sizes (Cohen’s d=.37 and .44, p<.05). Other cognitive measures (SAC, TMT-B) were not sensitive to SRC across timepoints (p>.05). Conclusion We observed heterogeneity in clinical assessment performance such that the clinical domains strongest in the initial days post-injury (symptom severity, balance) were less sensitive at later follow-up, supporting the potential need for multidimensional assessment.

The Influence of Hormonal Contraceptives on Baseline ImPACT Performance

Abstract Purpose Our study examined the influence of hormonal contraceptives (HC) on pre-injury (baseline) ImPACT performance in female collegiate athletes. Methods Participants in our cross-sectional study consisted of 304 NCAA Division I female athletes who self-reported taking (HC+ [n=154]) or not taking (HC- [n=154]) HC. HC+ participants were matched to HC- participants for height, weight, sport, and position. HC+ participants had an average age of 19.0±1.33 years, height of 170.5–8.70 cm, and mass of 64.2–10.58 kg. HC- participants had an average age of 19.0±1.24 years, height of 170.3–9.19 cm, and mass of 64.2–9.75 kg. Participants completed ImPACT as part of their preseason baseline assessment. Only participants with valid ImPACT assessments were included in our analyses. Chi-squared (χ2) tests were performed to compare groups in terms of medical history variables. Independent t-tests were used to compare groups in terms of demographic variables, self-reported hours of sleep, and ImPACT (Verbal and Visual Memory, Visual Motor Speed [VMS], Reaction Time [RT], and Total Symptom Severity [TSS]) outcome scores. Analyses were performed with α=0.05. Results No differences were observed between groups for demographic variables, hours of sleep, or medical history variables (p<0.05). For VMS, the HC- group (42.9+5.63) scored significantly worse (t[304]=2.17, p=0.03; d=0.25; 95% CI [0.1, 2.7]) than the HC+ group (44.3+5.67). For RT, the HC- group (0.55+0.06) performed significantly slower (t[304]=-2.02, p=0.05; d=0.23; 95% CI [-0.03, -0.0003]) than the HC+ group (0.54+0.05). Conclusion Our results suggest HCs may influence ImPACT performance in female collegiate athletes. Clinicians must consider the role of HCs when interpreting ImPACT outcome scores.

Performance Validity in Collegiate Football Athletes at Baseline Neurocognitive Testing.

To assess the prevalence of invalid performance on baseline neurocognitive testing using embedded measures within computerized tests and individually administered neuropsychological measures, and to examine the influence of incentive status and performance validity on neuropsychological test scores. Sport-related concussion management program at a regionally accredited university. A total of 83 collegiate football athletes completing their preseason baseline assessment within the University's concussion management program and a control group of 140 nonathlete students. Cross-sectional design based on differential incentive status: motivated to do poorly to return to play more quickly after sustaining a concussion (athletes) versus motivated to do well due to incentivizing performance (students). Immediate Post-Concussion and Cognitive Testing (ImPACT), performance validity tests, and measures of cognitive ability. Half of the athletes failed at least 1 embedded validity indicator within ImPACT (51.8%), and the traditional neuropsychological tests (49.4%), with large effects for performance validity on cognitive test scores (d: 0.62-1.35), incentive status (athletes vs students; d: 0.36-1.15), and the combination of both factors (d: 1.07-2.20) on measures of attention and processing speed. Invalid performance on baseline assessment is common (50%), consistent across instruments (ImPACT or neuropsychological tests) and settings (one-on-one or group administration), increases as a function of incentive status (risk ratios: 1.3-4.0) and results in gross underestimates of the athletes' true ability level, complicating the clinical interpretation of the postinjury evaluation and potentially leading to premature return to play.

Investigation into repetitive concussion in sport (RECOS): study protocol of a prospective, exploratory, observational cohort study

IntroductionSport-related concussion management remains a diagnostic dilemma to clinicians in all strata of care, coaching staff and players alike. The lack of objective diagnostic and prognostic biomarkers and over-reliance on...

Preseason Vestibular Ocular Motor Screening in Children and Adolescents.

The primary purpose of this study was to examine vestibular/ocular motor screening (VOMS) test performance in a sample of healthy youth ice hockey players. A particular focus was to investigate the potential effects of age and pre-existing health conditions, including concussion history, attention-deficit/hyperactivity disorder (ADHD), learning disability (LD), headaches/migraines, and depression/anxiety on preseason baseline VOMS performance, including the near point of convergence (NPC) distance. Cross-sectional cohort. Outpatient physiotherapy clinic. Three hundred eighty-seven male youth hockey players, with an average age of 11.9 years (SD = 2.2, range = 8-17), completed the VOMS and responded to self- or parent-reported demographic and medical history questionnaires during preseason baseline assessments. Age, sex, and mental and physical health history including ADHD, headaches, depression, anxiety, migraine, and LD. Vestibular/ocular motor screening. The large majority of boys scored within normal limits on the VOMS, ie, they reported no symptom provocation of more than 2 points on any VOMS subset (89%) and had a normal NPC distance, ie, <5 cm (78%). The individual VOMS subtests had low abnormality rates, and demographic and pre-existing health conditions, such as age, headache or migraine history, previous neurodevelopmental conditions, or mental health problems, were not associated with clinically meaningful symptom provocation during the VOMS. There was a low rate of abnormal findings for the individual VOMS subtests, with the exception of NPC distance, among male youth hockey players during preseason assessment.

Previous Concussion History Influences Health-related Quality Of Life Among Collegiate Student-athletes: Baseline Findings From The Active Rehab Study

Prior concussion history is posited to influence many outcomes. Understanding how concussion history affects quality of life may identify student-athletes needing intervention and those predisposed to other conditions. PURPOSE: To examine how prior concussion history influences college athletes’ pre-season baseline health-related quality life (HRQOL). METHODS: Student-athletes (n = 1599) from six Canadian and US college institutions and 24 college sports, completed a comprehensive concussion baseline assessment including an HRQOL evaluation (PROMIS-29, Neuro-QOL Fatigue, and Neuro-QOL Cognition Scales). The primary predictor was concussion history and covariates included age, sex, BMI, and contact sport participation. Primary outcomes were Anxiety, Physical Function, Depression, Sleep Disturbance, Social Role/Activities, Pain Interference, Pain Intensity, Cognition, and Neuro-related Fatigue raw scores. Linear regression models clustered on study site using generalized estimating equations examined the association between concussion history and HRQOL outcomes. RESULTS: Analysis was limited to 1509 (94%) participants with complete outcome and covariate data [538 females (35.6%); median age = 19 years (range: 18-27); 553 (36.7%) with 1+ prior concussions); 1154 (76.5%) played a contact sport]. Concussion history, adjusted for age, sex, BMI, and contact sport participation, were associated with greater anxiety, sleep disturbance, depressive feelings, fatigue, and worse cognition function. However, these differences were mostly minor. Clinically meaningful mean differences (MD) suggest those with multiple concussions report worse cognitive function (MD=-1.2; 95%CI: -2.4, -0.1 for 3+ vs 0 concussions; MD=-1.1, 95% CI:-2.3, 0.1 for 2 vs. 0 concussions) and greater neuro-related fatigue (MD=1.3, 95% CI: -0.1, 2.7 for 3+ vs 0 concussions; MD=0.9, 95% CI: 0.1, 1.7 for 2 vs 0 concussions). CONCLUSIONS: After controlling for covariates, these data suggest that following primary recovery, those with prior concussions may exhibit increased cognitive and fatigue related complaints. These residual effects may confound incident concussion assessments, particularly when pre-season baseline measures are not available. Supported in part by a grant from the National Football League

One-year Test-retest Properties Of Binocular Vision Tests

PURPOSE: Binocular vision tests (BVTs) are increasingly recommended for use in concussion management, but their reliability remains unknown. Our objective was to determine the one-year test-retest reliability of 10 BVTs proposed for use in concussion management, where concussions may occur months after a baseline measure. METHODS: We used routinely collected data on young athletes who had two sessions of pre-season baseline testing of 10 BVTs at least 11 months apart with no intervening concussion or training that might influence BVT scores. The tests assessed: 3D vision (gross stereoscopic acuity, GSA), saccades, anatomic deviation (AD) at 30cm and 3m, ability of eyes to move/fixate in-sync (positive fusional vergence [PFV] and negative fusional vergence [NFV] at 30cm and 3m, near point of convergence [NPC], and near point of convergence - break [i.e. double vision, (NPCb)]). RESULTS: There were 8 males and 9 females with a mean age of 22.4 (SD = 4.6) years. The intraclass correlations (ICC) suggest good reliability for PFV (0.94) and NPV (0.72) at 30cm. There was moderate reliability for NPCb (0.58), saccade (0.57), and PFV at 3m (0.58). There was poor reliability for AD 30cm (0.34) and NPC (0.45). Reliability was essentially 0 for NPV at 3m, and GSA (0.0). Limits of agreement (LoA) were best for saccade (±25%) and worst for AD 30 cm (±172%), and ranged from ±40% to ±114% for 7 of the 8 other tests. For AD 3m, the distribution was highly skewed leading LoA to be uninformative. CONCLUSIONS: The results indicate one-year test-retest reliability of the BVTs ranged from poor to good, with the majority being moderate. The effect of concussion must have a moderate to large effect on the scores of most BVTs to be clinically useful.

MULES on the sidelines: A vision-based assessment tool for sports-related concussion

ObjectiveThe Mobile Universal Lexicon Evaluation System (MULES) is a test of rapid picture naming under investigation. Measures of rapid automatic naming (RAN) have been used for over 50 years to capture aspects of vision and cognition. MULES was designed as a series of 54 grouped color photographs (fruits, random objects, animals) that integrates saccades, color perception and contextual object identification. We examined MULES performance in youth, collegiate and professional athletes at pre-season baseline and at the sidelines following concussion. MethodsOur study teams administered the MULES to youth, collegiate and professional athletes during pre-season baseline testing. Sideline post-concussion time scores were compared to pre-season baseline scores among athletes with concussion to determine degrees and directions of change. ResultsAmong 681 athletes (age 17 ± 4 years, range 6–37, 38% female), average test times at baseline were 41.2 ± 11.2 s. The group included 280 youth, 357 collegiate and 44 professional athletes; the most common sports were ice hockey (23%), soccer (17%) and football (11%). Age was a predictor of MULES test times, with longer times noted for younger participants (P < .001, linear regression). Consistent with other timed performance measures, significant learning effects were noted for the MULES during baseline testing with trial 1 test times (mean 49.2 ± 13.1 s) exceeding those for trial 2 (mean 41.3 ± 11.2 s, P < .0001, paired t-test). Among 17 athletes with concussion during the sports seasons captured to date (age 18 ± 3 years), all showed increases (worsening) of MULES time scores from pre-season baseline (median increase 11.2 s, range 0.6–164.2, P = .0003, Wilcoxon signed-rank test). The Symptom Severity Score from the SCAT5 Symptom Evaluation likewise worsened from pre-season baseline following injury among participants with concussion (P = .002). ConclusionsConcussed athletes demonstrate worsening performance on the MULES test compared to their baseline time scores. This test samples a wide network of brain pathways and complements other vision-based measures for sideline concussion assessment. The MULES test demonstrates capacity to identify athletes with sports-related concussion.

Association of Increased Serum S100B Levels With High School Football Subconcussive Head Impacts.

Astrocyte-enriched marker, S100B, shows promise for gauging the severity of acute brain trauma, and understanding subconcussive effects will advance its utility in tracking real-time acute brain damage. The aim of the study was to investigate whether serum S100B elevations were associated with frequency and magnitude of subconcussive head impacts in adolescents. This prospective cohort study of 17 high-school football players consisted of the following 12 time points: pre-season baseline, 5 in-season pre-post games, and post-season. A sensor-installed mouthguard recorded the number of head impacts, peak linear (PLA) and peak rotational (PRA) head accelerations from every practice and game. During the 5 games, players wore chest-strap heart-rate monitors to estimate players' excess post-exercise oxygen consumption (EPOC), accounting for physical exertion effects. At each time point, blood samples were obtained and assessed for S100B and creatine kinase levels to account for astrocyte damage/activation and muscle damage, respectively. Using k-means clustering on the impact data, players were categorized into high- or low-impact group. Two players withdrew during the first month of the study. A total of 156 blood samples from 15 players were assessed for S100B and creatine kinase levels and included in the analysis. A median value of 596 head impacts from 15 players were recorded during all practices and games in a season. S100B levels were significantly elevated in all post-game measures compared with the respective pre-game values (median-increase, 0.022 μg/L; interquartile-range, 0.011–0.043 μg/L, p < 0.05 for all games). Greater acute S100B increases were significantly associated with greater impact frequency, sum of PLA and PRA, with negligible contributions from physical exertion and muscle damage effects. The high-impact group exhibited greater increases in serum S100B levels at post-games than the low-impact group (high vs. low, 0.043 ± 0.035 μg/L vs. 0.019 ± 0.017 μg/L, p = 0.002). The degree of acute S100B increases was correlated with subconcussive head impact exposure, suggesting that acute astrocyte damage may be induced in an impact-dependent manner. Acute changes in serum S100B levels may become a useful tool in monitoring real-time brain damage in sports.

INFLUENCE OF A PRE-SEASON COACHES’ EDUCATION WORKSHOP STRATEGY ON ATHLETE INJURY RISK ASSESSMENT

Background: Evidence-based preventive training programs (PTPs) used as a pre-participation warm-up for sport have been shown to reduce injury risk in youth athletes; however, injury risk improvements depend on PTP dosage and fidelity, where increased levels of PTP compliance facilitate and sustain greater reductions in injury risk. While coaches represent the best option to facilitate PTPs long term, it is unknown how to best train coaches to ensure effective PTP implementation behavior. In other areas of health behavior research, education strategies tailored specifically to an individual’s needs and interests increase the likelihood of adopting a given behavior. To encourage youth sport coaches to implement PTPs, it may be beneficial to tailor workshops. One way to gauge the impact of an education strategy is to look at end-user outcomes. Therefore, the purpose of this study was to evaluate changes in athlete injury risk, as measured by the Landing Error Scoring System (LESS), between adolescent basketball and soccer athletes whose coach attended a General pre-season education workshop on PTP implementation compared to a Tailored pre-season education workshop. Methods: A cluster randomized control trial was utilized. Youth soccer and basketball organizations were contacted to participate in a pre-season coaches’ education workshop on PTP implementation. Organizations were randomized into either a General or Tailored workshop. All participating coaches within a given organization attended the same workshop. General workshops contained standardized content including: youth sport injury epidemiology, injury rate and risk reduction benefits of PTPs, and hands-on instruction on how to implement a PTP. Coaches in Tailored workshops completed pre-workshop surveys. The pre-workshop survey contained Likert-style questions on knowledge of and experience with implementing PTPs. Researchers used the results to prioritize and inform content emphasis within the Tailored workshop. For example, if an organization had a high frequency of coaches who reported that they were particularly interested in the sport performance benefits of PTPs, the research team would devote increased time to discussing that particular component. Both the General and Tailored workshop were approximately 1-hour in length but varied in the amount of time spent on different topic areas. Athletes completed a PRE and POST season baseline assessment of injury risk. The injury risk assessment included three trials of a jump-landing task that was evaluated using the Landing Error Scoring System (LESS). The LESS is a valid and reliable clinical movement assessment used to identify high-risk movement patterns during a jump-landing task. LESS scores are based on observable errors, where a higher score indicates a greater number of movement errors and an increased risk of sustaining a lower extremity injury. To complete the task, participants jumped off a 30-cm high box to a distance half of their height and immediately rebounded straight in the air for maximum vertical height. A single, reliable rater graded all trials for PRE and POST. All three trials were averaged together for one composite LESS score at each time point. A mixed model analysis of variance (ANOVA) was used to evaluate differences in composite LESS score over time (PRE, POST) between educational workshops (General, Tailored). All data were analyzed using SPSS Version 21.0 with an a priori alpha level of p&lt;0.05. Results: Seventy-seven athletes on 9 teams across 6 different organizations (Coaches’ Workshops: General=5 teams from 4 organizations; Tailored=4 teams from 2 organizations) completed both PRE and POST testing sessions. There were no significant differences between workshop (General, Tailored) and LESS scores at POST (P&gt;0.05). Regardless of workshop LESS scores improved over time ((Mean±SD [95%CI]) Generalized PRE: 5.46±0.10 [4.84, 6.08], Generalized POST: 4.62±0.10 [4.00, 5.25], Tailored PRE: 5.99±0.09[5.40, 6.59], Tailored POST: 5.66±0.09[5.06, 6.25])(P=0.03). Conclusions: Regardless of coaches’ educational workshop strategy, athletes improved movement technique from PRE to POST across a single sport season. These findings suggest that any level of exposure to PTP-related content could have beneficial downstream effects for the end user, or in this case reduced injury risk for youth athletes. Future studies should look to evaluate the content of pre-season coach education workshops in conjunction with tracking fidelity of program delivery in order to optimize efforts to disseminate and implement PTPs for youth sport coaches. [Figure: see text]

Novel strain analysis informs about injury susceptibility of the corpus callosum to repeated impacts.

Increasing evidence for the cumulative effects of head trauma on structural integrity of the brain has emphasized the need to understand the relationship between tissue mechanic properties and injury susceptibility. Here, diffusion tensor imaging, helmet accelerometers and amplified magnetic resonance imaging were combined to gather insight about the region-specific vulnerability of the corpus callosum to microstructural changes in white-matter integrity upon exposure to sub-concussive impacts. A total of 33 male Canadian football players (meanage = 20.3 ± 1.4 years) were assessed at three time points during a football season (baseline pre-season, mid-season and post-season). The athletes were split into a LOW (N = 16) and HIGH (N = 17) exposure group based on the frequency of sub-concussive impacts sustained on a per-session basis, measured using the helmet-mounted accelerometers. Longitudinal decreases in fractional anisotropy were observed in anterior and posterior regions of the corpus callosum (average cluster size = 40.0 ± 4.4 voxels; P < 0.05, corrected) for athletes from the HIGH exposure group. These results suggest that the white-matter tract may be vulnerable to repetitive sub-concussive collisions sustained over the course of a football season. Using these findings as a basis for further investigation, a novel exploratory analysis of strain derived from sub-voxel motion of brain tissues in response to cardiac impulses was developed using amplified magnetic resonance imaging. This approach revealed specific differences in strain (and thus possibly stiffness) along the white-matter tract (P < 0.0001) suggesting a possible signature relationship between changes in white-matter integrity and tissue mechanical properties. In light of these findings, additional information about the viscoelastic behaviour of white-matter tissues may be imperative in elucidating the mechanisms responsible for region-specific differences in injury susceptibility observed, for instance, through changes in microstructural integrity following exposure to sub-concussive head impacts.

Influence of Self-reported Fatigue and Sex on Baseline Concussion Assessment Scores.

Background:Baseline concussion assessments are advocated to provide an objective preinjury point of comparison for determining the extent of postconcussion neurological deficits and to assist with return-to-activity decision making. Many factors, including testing environment, proctor availability, and testing group size, can influence test accuracy and validity; however, it is unknown how self-reported fatigue affects test scores.Purpose:To investigate the influence of self-reported fatigue and patient sex on baseline concussion assessment scores.Study Design:Cross-sectional study; Level of evidence, 3.Methods:Participants included 494 healthy Division I college student-athletes (221 women, 273 men; mean ± SD age, 20.0 ± 1.3 years). During preseason baseline testing, participants were asked to rate their fatigue on a scale from 0 to 100 based on how they normally feel and function each day (0, completely exhausted; 100, completely awake and alert). Each participant then completed a multimodal baseline concussion assessment, including a graded symptom checklist (number of symptoms endorsed and total symptom severity score), Standardized Assessment of Concussion (SAC), Balance Error Scoring System (BESS), and CNS Vital Signs computerized neurocognitive testing. Multiple linear regressions tested whether self-reported fatigue and sex predicted baseline concussion examination scores.Results:Athletes with higher self-reported fatigue levels (ß = –0.014, P < .01) and female athletes (ß = –0.216, P < .01) reported more total symptoms. Being male (ß = 0.856, P < .01) increased the likelihood of endorsing zero symptoms versus any symptoms by a factor of 2.40. Women also had significantly higher SAC scores (ß = 0.569, P < .001), BESS scores (ß = –2.747, P < .001), and CNS Vital Signs summary scores (ß = 4.506, P < .001). SAC, BESS, and CNS Vital Signs scores were not predicted by fatigue level (P > .05).Conclusion:Female athletes and fatigued athletes endorsed more symptoms and higher symptom severity at baseline. Using total symptom endorsement and total symptom severity scores as part of the postinjury management is a common practice. The current data suggest that levels of reported exhaustion can influence concussion assessment scores meant to represent a healthy baseline and likely would interfere with postinjury assessment scores.

Resting CMRO2 fluctuations show persistent network hyper-connectivity following exposure to sub-concussive collisions.

Exposure to head impacts may alter brain connectivity within cortical hubs such as the default-mode network (DMN). However, studies have yet to consider the confounding effects of altered resting cerebral blood flow (CBF0) and cerebrovascular reactivity (CVR) on changes in connectivity following sub-concussive impacts. Here, 23 Canadian collegiate football players were followed during a season using calibrated resting-state MRI and helmet accelerometers to examine the interplay between the neural and vascular factors that determine functional connectivity (FC). Connectivity-based analyses using blood oxygen level dependent (BOLD) and cerebral metabolic rate of oxygen consumption (CMRO2) mapping were used to study the DMN longitudinally. Network-specific decreases in CBF0 were observed one month following the season, while impaired CVR was documented at both mid-season and one month following the season, compared to pre-season baseline. Alterations in CBF0 and BOLD-based CVR throughout the season suggest that neurophysiological markers may show different susceptibility timelines following head impacts. DMN connectivity was increased throughout the season, independent of changes in cerebrovascular physiology, suggesting that alterations in FC following sub-concussive impacts are robust and independent of changes in brain hemodynamics. No significant correlations between impact kinematics and DMN connectivity changes were documented in this study. Altogether, these findings create a strong paradigm for future studies to examine the underlying neural and vascular mechanisms associated with increases in network connectivity following repeated exposure to sub-concussive collisions, in an effort to improve management of head impacts in contact sports.

Executive functions in adolescent hockey players competing with different rules for body checking

A history of multiple concussions may lead to later-life neurodegeneration and persistent cognitive impairment. Repeated sub-concussive impacts over a career could play a role in this process, however evidence remains limited. Although imaging studies reveal cortical thinning and white matter changes, no impairments are detected in neuropsychological studies. Thus, we sought to explore the effect of body checking experience, which can be considered as repeated sub-concussive impacts, on executive functions in young hockey players. Sixty-six young hockey players, aged between 12 and 17 years, went through a preseason baseline cognitive testing. In this age range, players are separated into 3 groups according to the body checking rule each division is playing (i.e., full body checking, progressive body checking, and no body checking). Executive functions were assessed using a task-switching paradigm. Primary outcome measures were accuracy and reaction time. An ANCOVA with age as covariate was conducted to compare groups according to the body checking rule they have experienced. Analysis revealed no significant group difference in task performance ( p = 0.91), suggesting that executive functions are not influenced by body checking experience. Age strongly correlated with accuracy ( p = 0.01; r2 = 0.37), suggesting that younger athletes performed poorly on the task relative to their older teammates. These preliminary results support that body checking experience did not appear to affect executive functions in adolescent hockey players. However, age seemed to be a predictor of accuracy agreeing with literature that executive functions continue to develop during adolescence. A post-season testing will be conducted to investigate the effect of body checking on executive functions over an entire season.