Consensus statement on concussion in sport--the 4th International Conference on Concussion in Sport held in Zurich, November 2012

An Evaluation of the Balance Error Scoring System in Female Soccer Players Following Soccer Heading: A Pilot Study

Background

Soccer is a contact sport during which participants risk injury, including due to concussion. Interestingly, the task most frequently associated with concussions is the act of heading the ball. This study seeks to answer the following research question: Does an acute playing of purposeful soccer heading in female football players lead to changes in BESS normative outcomes and balance? Additionally, we aim to explore the relationship between a gold-standard BESS Test and a Balance Test performed on a force plate.

Methods

This project involved twenty-eight female soccer players (age = 19.6 + 2.96 years, mass = 60.4+ 5.3 kg, and height = 163.6 + 6.4 cm). pre and post the heading condition and the results of the Wilcoxon Signed Ranks Test. The participants were healthy and underwent BESS monitoring on a force plate before and after heading and footing training. Standard 450 g soccer balls were utilized. Participants performed ten headers for the header condition and ten footers for the footer condition. Resultant sway velocity and BESS error outcomes were calculated before and after heading and footing training. I need a brief description of the statistical approach here.

Results

Statistically significant increases after the heading condition were found for Single Leg Stance (COP PATH) score (Z = -3.986, p = 0.000), BESS score on foam surface (Z = -2.511, p = 0.012), BESS score on firm surface (Z = -2.353, p = 0.019). A statistically significant increase after the footer condition was found for the Tandem Stance (mm2) score (Z = -2.900, p = 0.004). A statistically significant difference between the group conditions was found in the post-BESS score foam difference (U = 268.500, p = 0.042). BESS score foam mean increase was 1.93 after the heading condition and 0.21 after the footer condition.

Conclusion

This pilot study not only tests the feasibility of using force plates to measure BESS outcomes after heading in female soccer but also underscores the effectiveness of using BESS parameters to evaluate changes in balance function following heading compared to a control footer condition. The findings of this study provide valuable insights into the potential effects of soccer on balance in female players, contributing to the body of knowledge in sports medicine and physical education.

Level of evidence

3.

A Concussion Management Policy Change Promoted Earlier Initiation of Rehabilitation Services and Improved Clinical Recovery Outcomes in Concussion

CONTEXT

In line with emerging research, an interprofessional specialty concussion clinic instituted a policy change permitting earlier physiotherapy-based treatment entry. Our objective was to determine the effect of this policy change on concussion recovery outcomes.

DESIGN

Secondary analysis of prospectively collected clinical data.

METHODS

600 youth with concussion were included. Active rehabilitation was initiated ≥4 weeks (prepolicy) or ≥2 weeks (postpolicy) postconcussion based on institutional policy. Cox proportional hazard models, linear mixed models, and chi-square analyses were conducted.

RESULTS

The postpolicy group (median = 22 d [interquartile range: 17-27]) started treatment earlier than the prepolicy group (median = 26 d [interquartile range: 24-30], P < .001). Length of episode of care (χ2(1) = 11.55, P < .001, odds ratios = 1.49; 95% confidence interval, 1.19-1.88); rehabilitation (χ2(1) = 9.47, P = .002, odds ratios = 1.73, 95% confidence interval, 1.22-2.45]); and total recovery (χ2(1) = 11.53, P < .001, odds ratios = 1.49; 95% confidence interval, 1.18-1.88) were reduced in patients postpolicy change. A significant interaction effect was found for total postinjury symptom (F2,320 = 3.59, P = .03) and symptom change scores (F2,315 = 5.17, P = .006), with the postpolicy group having faster symptom resolution over time. No group differences were observed for persisting symptoms.

CONCLUSIONS

Earlier rehabilitation initiation occurred as intended following an institutional policy change, which had small, but significant, effects on recovery outcomes in youth with concussion. Health care providers should adopt policies to encourage early active rehabilitation services after concussion.

Epidemiology and Symptom Resolution in Pediatric Patients Seen in a Multidisciplinary Concussion Clinic

OBJECTIVE

Describe epidemiology of pediatric patients with concussion and relationship of injury characteristics and demographic variables to symptom resolution.

SETTING

Outpatient hospital system multidisciplinary concussion clinic.

PARTICIPANTS

N = 1653, 6- to 18-year-old patients with concussion.

DESIGN

Retrospective of patients with concussion seen between 2013 and 2019. Rivermead post-concussion symptom questionnaire was completed at each visit. Demographics and injury characteristics were extracted, and income tertiles were calculated by zip code.

MAIN MEASURES

Descriptive statistics. Multivariate analysis of variance and Cox regression analysis of demographic variables and injury characteristics with time to symptom resolution.

RESULTS

Patients were 44.5% (n = 735) female, 53.5% (n = 885) male, and 2% (n = 33) other/not available. About 376 (22.7%) patients were 6 to 12 years old, 1277 (77.3%) were 13 to 18 years old. Median family income tertiles were <$63 798 (n = 494 [29.9%]), $63 798 to $82 171 (n = 571 [34.5%]), and >$82 171 (n = 545 [33%]). Time to presentation was longer for female patients (P < .0005), patients with non-sports-related concussions (P < .0005), and patients in the lower family income group than the middle- (P = .02) and high-income groups (P = .003). Average symptom resolution was 41 days, with higher initial symptom scores (hazard ratio 0.97; 95% confidence interval (CI), 0.97-0.98; P < .0005), female sex (hazard ratio 1.31; 95% CI, 0.1.18-1.47; P < .0005), older age (hazard ratio 1.17; 95% CI, 1.03-1.33; P = .015), and having a psychiatric diagnosis (hazard ratio 1.33; 95% CI, 1.15-1.54; P < .0005) predicting longer recovery time.

CONCLUSION

Pediatric patients presenting to a specialized multidisciplinary concussion clinic possess several similar predictors of protracted symptom recovery when examined against other cohorts described in the literature, including female sex, longer time to initial presentation and initial concussion symptom burden. In this study, children with non-sports-related concussion have different clinical courses than those with sports-related concussion, and children 6 to 12 years old recover more quickly than adolescents. These findings, in combination with existing literature and future prospective studies, can be used to counsel patients regarding expected resolution of concussion symptoms and help direct resources toward those patients at risk for protracted recovery.

Randomized Controlled Trial: Preliminary Investigation of the Impact of High-Intensity Treadmill Gait Training on Recovery Among Persons with Traumatic Brain Injury

Exercise to treat traumatic brain injury (TBI) is a novel approach that has only become recognized in the past decade. High-intensity gait training (HIGT) has been studied in subjects following stroke; however, little research investigates similar protocols on patients with TBI. The study evaluated HIGT as an intervention for enhancing patient recovery after TBI. Adult subjects (18-65 years) who suffered TBI were randomly allocated to an intervention (HIGT) or control (low-intensity physical therapy) group given three days/week for 1 h over four weeks. Assessments included the 10-m walk test, 6-min walk test, Berg Balance Scale, five-times sit-to-stand (5TSTS), timed up and go (TUG), cognitive TUG, and Montreal Cognitive Assessment (MoCA) at day one, two weeks, four weeks, and a four-week follow-up. In addition to a trend toward improved gait speed (p < 0.1) and significantly improved endurance (p < 0.05) in the HIGT group (n = 5), both the control (n = 4) and HIGT groups demonstrated trends toward improved mobility (5TSTS, p < 0.1; TUG, p < 0.1) and significantly improved cognition (cognitive TUG, p < 0.01; MoCA, p < 0.05) over the four-week time period and at the one-month follow-up. HIGT showed longer-lasting rehabilitative effects on gait distance, endurance, mobility, and cognitive function at the four-week follow-up. This study suggests that HIGT may support functional recovery, and future work will involve increasing sample size.

Prospective evaluation of 24-hour movement behaviors among adolescents recovering from a sport-related concussion

This study aimed to describe the 24-hour composition of movement behaviors, including sleep, sedentary behavior, and physical activity (PA), among pediatric sports-related concussion (SRC) patients over their recovery period, assess the association between movement compositions and recovery time, and understand feasibility of 24-hour accelerometry in the study population. A cohort of 50 pediatric SRC patients were asked to wear a wrist-worn accelerometer continuously for the duration of their recovery. Among all enrolled participants, the sample was primarily 14 or 15 years of age (65%), female (55%), and recovered in under 28 days (88%). Accelerometer compliance was moderate; 35 participants (70%) were compliant with the protocol. Compositional analysis was used to address time-use objectives in 33 participants who provided adequate data for inclusion. Overall, participants spent an average of 50% of their 24-hour day sedentary, 33% sleeping, 11% in light intensity PA, and 6% in moderate or vigorous intensity PA. The 24-hour composition of movement behaviors was not associated with recovery time (p = .09-.99). However, the limited sample size may have contributed to null findings. Given recent evidence supporting the effects of sedentary behavior and PA on concussion recovery, future studies should aim to further validate these findings in a larger sample.

Changes in cerebral vascular reactivity following mild repetitive head injury in awake rats: modeling the human experience

The changes in brain function in response to mild head injury are usually subtle and go undetected. Physiological biomarkers would aid in the early diagnosis of mild head injury. In this study we used hypercapnia to follow changes in cerebral vascular reactivity after repetitive mild head injury. We hypothesized head injury would reduce vascular reactivity. Rats were maintained on a reverse light-dark cycle and head impacted daily at 24 h intervals over three days. All head impacts were delivered while rats were fully awake under red light illumination. There was no neuroradiological evidence of brain damage. After the 3rd impact rats were exposed to 5% CO2 and imaged for changes in BOLD signal. All imaging was done while rats were awake without the confound of anesthesia. The data were registered to a 3D MRI rat atlas with 171 segmented brain areas providing site specific information on vascular reactivity. The changes in vascular reactivity were not uniform across the brain. The prefrontal cortex, somatosensory cortex and basal ganglia showed the hypothesized decrease in vascular reactivity while the cerebellum, thalamus, brainstem, and olfactory system showed an increase in BOLD signal to hypercapnia.

The Significance of Off-Season Tailor-Made Baseline Measurements in the Assessment of Post-Concussion in University Athletes

This study aimed to investigate the significance of baseline measurements for amateur team athletes playing contact and collision team sports with a specific focus on the Sports Concussion Assessment Tool (SCAT) to improve concussion management. Symptoms of sports-related concussions (SRCs) can be diverse and long-lasting and include cognitive impairment, sleep disturbances, and vestibular dysfunction. Therefore, comprehensive baseline data are essential to preventing recurrent concussions and secondary injuries. This study was conducted during the 2023 off-season and evaluated the baseline condition of 65 male university rugby players using the SCAT5, which includes self-reported symptoms, and the modified Balance Error Scoring System (mBESS). The athletes were assessed for the presence or absence of SRC, and the mean values were compared using the Mann-Whitney U test. Among the participants, 35.38% (23/65) reported symptoms, with an average of 1.5 ± 2.8 symptoms per player and an average symptom score of 2.66 ± 5.93. In the mBESS, no errors were observed in the tandem stance test; however, 72.31% (47/65) made errors in the single-leg stance test on the non-dominant foot, with an average of 1.7 ± 1.5 errors. Many athletes self-reported symptoms and balance errors, even during asymptomatic periods before experiencing concussion, indicating unresolved issues. In the injury history survey, the baseline evaluations and injury histories of the participants classified into the SRC and non-SRC groups were compared. In the mBESS single-leg stance test (non-dominant foot), 84.21% (32/38) of the SRC group participants made errors, with an average score of 2.13 ± 1.52, whereas 55.55% (15/27) of the non-SRC group participants made errors, with an average score of 1.15 ± 1.35, showing a significant difference (p = 0.007). Additionally, significant differences were observed in the average number of ankle sprains (p = 0.027) and fractures (p = 0.048) between patients with and without a history of SRC. These findings indicate that athletes may have underlying issues even during normal periods before concussion. Moreover, the results highlighted the impact of previous concussions on motor control and injury risk. This underscores the importance of preseason baseline measurements using the SCAT to identify at-risk athletes and implement preventive measures. These findings align with the recommendations of the 6th International Conference on Concussion in Sport and suggest further refinement of concussion assessment tools.

Profiling the neuroimmune cascade in 3xTg-AD mice exposed to successive mild traumatic brain injuries

Repetitive mild traumatic brain injuries (rmTBI) sustained within a window of vulnerability can result in long term cognitive deficits, depression, and eventual neurodegeneration associated with tau pathology, amyloid beta (Aβ) plaques, gliosis, and neuronal and functional loss. However, a comprehensive study relating acute changes in immune signaling and glial reactivity to neuronal changes and pathological markers after single and repetitive mTBIs is currently lacking. In the current study, we addressed the question of how repeated injuries affect the brain neuroimmune response in the acute phase of injury (< 24 h) by exposing the 3xTg-AD mouse model of tau and Aβ pathology to successive (1x-5x) once-daily weight drop closed-head injuries and quantifying immune markers, pathological markers, and transcriptional profiles at 30 min, 4 h, and 24 h after each injury. We used young adult 2-4 month old 3xTg-AD mice to model the effects of rmTBI in the absence of significant tau and Aβ pathology. We identified pronounced sexual dimorphism in this model, with females eliciting more diverse changes after injury compared to males. Specifically, females showed: (1) a single injury caused a decrease in neuron-enriched genes inversely correlated with inflammatory protein expression and an increase in AD-related genes within 24 h, (2) each injury significantly increased a group of cortical cytokines (IL-1α, IL-1β, IL-2, IL-9, IL-13, IL-17, KC) and MAPK phospho-proteins (phospho-Atf2, phospho-Mek1), several of which co-labeled with neurons and correlated with phospho-tau, and (3) repetitive injury caused increased expression of genes associated with astrocyte reactivity and macrophage-associated immune function. Collectively our data suggest that neurons respond to a single injury within 24 h, while other cell types, including astrocytes, transition to inflammatory phenotypes within days of repetitive injury.

Concussion incidence and mechanisms differ between elite females and males in Australian Football

OBJECTIVES

To investigate the incidence and the game circumstances of concussion in the professional female (AFLW) and male (AFL) competitions of Australian Football, to identify potential targets for risk reduction.

DESIGN

Retrospective cohort.

METHODS

Concussion data were obtained from the AFL injury database, which included all concussions sustained by AFL (Male) players from 2015 to 18 and AFLW (Female) players from 2017 to 19. Concussions were diagnosed by experienced clinicians utilising standardised concussion assessment tools and injury definitions, as well as video review. Video footage was analysed to determine the circumstances each concussion occurred, which included the action and the contact-point of impact.

RESULTS

The incidence of concussion was higher in the AFLW (Female) compared to the AFL (Male) (IRR = 2.12, 95 %CI 1.54 to 2.92). Video footage was available for 194/252 (77 %) concussions in the AFL and 35/44 (80 %) concussions in the AFLW. Male players were most frequently concussed during marking contests (28 %) with primary impact from the upper limb (22 %) or the shoulder (19 %). Conversely, being bumped (23 %) or tackled (20 %) were the main actions associated with concussion in female players, with the head (29 %) or the ground (23 %) the most common contact-points of impact.

CONCLUSIONS

In elite Australian Football a higher incidence of concussion was demonstrated in female compared to male players. The mechanisms associated with concussion were also found to differ between male and female competitions, suggesting that different injury prevention interventions may be beneficial. In particular, a review of tackling and bumping skills training and education in the AFLW may reduce the risk of concussion.

Perceptions of personal control and treatment efficacy of sport-related concussions in collegiate athletes

OBJECTIVE

The purpose of this study was to examine healthy collegiate athletes' perceptions of personal control and beliefs regarding the treatment efficacy related to sport-related concussion (SRC) along with identifying factors that may be associated with these perceptions.

METHODS

This cross-sectional study included collegiate athletes (n = 956) between the age of 18-26 years. Participants completed a 10- to 15-min survey regarding their demographics, diagnosed SRC history, SRC knowledge, and Perceptions of Concussion Inventory for Athletes (PCI-A). Chi-squared analysis and multivariable logistic regressions were conducted to identify factors associated with the PCI-A outcomes of personal control and treatment efficacy perceptions.

RESULTS

24.2% of respondents reported higher perceptions of personal control, while 77.3% reported higher perceptions of treatment efficacy. The multivariable logistic regression revealed males had higher odds of greater perceptions of personal control (OR = 1.50; 95% CI: 1.10-2.03), while those with a history of diagnosed SRC had lower odds of having favorable treatment efficacy beliefs (OR: 0.69; 95% CI: 0.50-0.96).

CONCLUSIONS

This study established that collegiate athletes generally have lower perceptions of personal control and higher perceptions of treatment efficacy related to SRC recovery. Comprehensive SRC education should be expanded for individuals to understand that they have power over their own health outcomes and that SRC is a treatable injury.

Making the case for prophylactic use of betaine to promote brain health in young (15-24 year old) athletes at risk for concussion

Betaine supplementation in the context of human nutrition, athletic performance, and clinical therapy demonstrate that the osmolyte and methyl donor, betaine, is cytoprotective and beneficial to human health. These studies also demonstrate that betaine supplementation in healthy humans is straight-forward with no reported adverse effects. Here, we explore betaine uptake in the central nervous system (CNS) and contribute to evidence that betaine may be uniquely protective to the brain. We specifically describe the therapeutic potential of betaine and explore the potential implications of betaine on inhibition mediated by GABA and glycine neurotransmission. The influence of betaine on neurophysiology complement betaine's role as an osmolyte and metabolite and is consistent with clinical evidence of betaine-mediated improvements to cognitive function (reported in elderly populations) and its anti-convulsant properties. Betaine's therapeutic potential in neurological disorders including epilepsy and neurodegenerative diseases combined with benefits of betaine supplementation on athletic performance support the unique application of betaine as a prophylaxis to concussion. As an example, we identify young athletes (15-24 years old), especially females, for prophylactic betaine supplementation to promote brain health and resilience in a cohort at high risk for concussion and for developing Alzheimer's disease.

Profiling the neuroimmune cascade in 3xTg mice exposed to successive mild traumatic brain injuries

Repetitive mild traumatic brain injuries (rmTBI) sustained within a window of vulnerability can result in long term cognitive deficits, depression, and eventual neurodegeneration associated with tau pathology, amyloid beta (Aβ) plaques, gliosis, and neuronal and functional loss. However, we have limited understanding of how successive injuries acutely affect the brain to result in these devastating long-term consequences. In the current study, we addressed the question of how repeated injuries affect the brain in the acute phase of injury (<24hr) by exposing the 3xTg-AD mouse model of tau and Aβ pathology to successive (1x, 3x, 5x) once-daily weight drop closed-head injuries and quantifying immune markers, pathological markers, and transcriptional profiles at 30min, 4hr, and 24hr after each injury. We used young adult mice (2-4 months old) to model the effects of rmTBI relevant to young adult athletes, and in the absence of significant tau and Aβ pathology. Importantly, we identified pronounced sexual dimorphism, with females eliciting more differentially expressed proteins after injury compared to males. Specifically, females showed: 1) a single injury caused a decrease in neuron-enriched genes inversely correlated with inflammatory protein expression as well as an increase in AD-related genes within 24hr, 2) each injury significantly increased expression of a group of cortical cytokines (IL-1α, IL-1β, IL-2, IL-9, IL-13, IL-17, KC) and MAPK phospho-proteins (phospho-Atf2, phospho-Mek1), several of which were co-labeled with neurons and correlated with phospho-tau, and 3) repetitive injury caused increased expression of genes associated with astrocyte reactivity and immune function. Collectively our data suggest that neurons respond to a single injury within 24h, while other cell types including astrocytes transition to inflammatory phenotypes within days of repetitive injury.

Research Trends and Prospects of Sport-Related Concussion: A Bibliometric Study Between 2000 and 2021

BACKGROUND

Research around sport-related concussion (SRC) has made great advances during the twenty-first century. However, few studies have systematically analyzed the published SRC research.

METHODS

A bibliometric analysis was conducted of data from articles from the Web of Science Core Collection database. Descriptive statistics were used to analyze publication trends, most productive countries, institutions, authors, journals, research fields, and references with the highest citation number. VOSviewer software was used to perform network visualization and keywords co-occurrence analysis. CiteSpace software was used to perform reference co-citation analysis.

RESULTS

1) The number of publications and number of citations of research in SRC progressively increased between 2000 and 2021; 2) the United States was the leading country in research in SRC; 3) extensive cooperation among countries, institutions, and investigators was prevalent in SRC research; 4) P. McCrory, M. McCrea, and K.M. Guskiewicz were the 3 most prolific and influential authors; 5) research in SRC involved multidisciplinary perspectives and approaches; 6) research in SRC mainly covered aspects of primary prevention, diagnosis, and management, and the latter two have gained more attention in recent years; and 7) specific questions about "education," "predictors," "youth," "exercise," "reliability," "validity," and "baseline" were the research frontiers of SRC.

CONCLUSIONS

Attention to research in SRC has rapidly increased in recent years. Our work is a holistic overview that summarizes the hotspots, frontiers, and prospects of SRC, thus providing valuable information and guidance concerning research directions for those who are interested in or are dedicated to SRC research.

Cortical Spreading Depolarization, Blood Flow, and Cognitive Outcomes in a Closed Head Injury Mouse Model of Traumatic Brain Injury

BACKGROUND

Cortical spreading depolarizations (CSDs) are associated with worse outcomes in many forms of acute brain injury, including traumatic brain injury (TBI). Animal models could be helpful in developing new therapies or biomarkers to improve outcomes in survivors of TBI. Recently, investigators have observed CSDs in murine models of mild closed head injury (CHI). We designed the currently study to determine additional experimental conditions under which CSDs can be observed, from mild to relatively more severe TBI.

METHODS

Adult male C57Bl/6J mice (8-14 weeks old) were anesthetized with isoflurane and subjected to CHI with an 81-g weight drop from 152 or 183 cm. CSDs were detected with minimally invasive visible light optical intrinsic signal imaging. Cerebral blood flow index (CBFi) was measured in the 152-cm drop height cohort using diffuse correlation spectroscopy at baseline before and 4 min after CHI. Cognitive outcomes were assessed at 152- and 183-cm drop heights for the Morris water maze hidden platform, probe, and visible platform tests.

RESULTS

CSDs occurred in 43% (n = 12 of 28) of 152-cm and 58% (n = 15 of 26) of 183-cm drop height CHI mice (p = 0.28). A lower baseline preinjury CBFi was associated with development of CSDs in CHI mice (1.50 ± 0.07 × 10-7 CHI without CSD [CSD-] vs. 1.17 ± 0.04 × 10-7 CHI with CSD [CSD+], p = 0.0001). Furthermore, in CHI mice that developed CSDs, the ratio of post-CHI to pre-CHI CBFi was lower in the hemisphere ipsilateral to a CSD compared with non-CSD hemispheres (0.19 ± 0.07 less in the CSD hemisphere, p = 0.028). At a 152-cm drop height, there were no detectable differences between sham injured (n = 10), CHI CSD+ (n = 12), and CHI CSD- (n = 16) mice on Morris water maze testing at 4 weeks. At a 183-cm drop height, CHI CSD+ mice had worse performance on the hidden platform test at 1-2 weeks versus sham mice (n = 15 CHI CSD+, n = 9 sham, p = 0.045), but there was no appreciable differences compared with CHI CSD- mice (n = 11 CHI CSD-).

CONCLUSIONS

The data suggest that a lower baseline cerebral blood flow prior to injury may contribute to the occurrence of a CSD. Furthermore, a CSD at the time of injury can be associated with worse cognitive outcome under the appropriate experimental conditions in a mouse CHI model of TBI.

Identifying Trends of Dysautonomia Signs and Symptoms Associated with Protracted Concussion Recovery during the Buffalo Concussion Treadmill Test: A Retrospective Study

Objective:

To identify trends of provoked dysautonomia signs and symptoms during the Buffalo Concussion Treadmill Test (BCTT).

Subjects:

This is a retrospective cohort study of 101 patient charts post-concussion who were screened for suspected dysautonomia.

Methods:

Patients with suspected dysautonomia were assessed for exercise intolerance using a BCTT. Symptoms and rate of perceived exertion were recorded on a standardized form. Digital pulse oximetry was used to collect heart rate (HR) and oxygen saturation. Descriptive analyses were conducted on BCTT results.

Results:

Of 101 patient charts, 57 were excluded from analysis, including four patients who completed the BCTT by asymptomatically reaching the target HR zone for their estimated HR max. The remaining 44 patients demonstrated: 35 (79.5%) poor HR stabilization defined as a drop or plateau in HR during exercise, 28 (63.8%) exacerbated concussion symptoms, 13 (29.5%) autonomic nervous system response such as hot flushed sensation, 12 (27.3%) rebound symptoms during recovery phases, and 8 (18.2%) desaturation of 90% or below. The mean delta (80% expected HR max – 80% achieved HR max) on the initial test was 80.66 (± 23.08) beats per minute.

Conclusions:

This study is the first to identify trends of signs and symptoms during the BCTT in an expanded population with suspected dysautonomia after concussion. Future studies are indicated to validate these findings and contribute to development of modified termination criteria for the BCTT in individuals with suspected dysautonomia associated with protracted concussion recovery.

Identifying Trends of Dysautonomia Signs and Symptoms Associated with Protracted Concussion Recovery during the Buffalo Concussion Treadmill Test: A Retrospective Study

OBJECTIVE

To identify trends of provoked dysautonomia signs and symptoms during the Buffalo Concussion Treadmill Test (BCTT).

SUBJECTS

This is a retrospective cohort study of 101 patient charts post-concussion who were screened for suspected dysautonomia.

METHODS

Patients with suspected dysautonomia were assessed for exercise intolerance using a BCTT. Symptoms and rate of perceived exertion were recorded on a standardized form. Digital pulse oximetry was used to collect heart rate (HR) and oxygen saturation. Descriptive analyses were conducted on BCTT results.

RESULTS

Of 101 patient charts, 57 were excluded from analysis, including four patients who completed the BCTT by asymptomatically reaching the target HR zone for their estimated HR max. The remaining 44 patients demonstrated: 35 (79.5%) poor HR stabilization defined as a drop or plateau in HR during exercise, 28 (63.8%) exacerbated concussion symptoms, 13 (29.5%) autonomic nervous system response such as hot flushed sensation, 12 (27.3%) rebound symptoms during recovery phases, and 8 (18.2%) desaturation of 90% or below. The mean delta (80% expected HR max â€" 80% achieved HR max) on the initial test was 80.66 (± 23.08) beats per minute.

CONCLUSIONS

This study is the first to identify trends of signs and symptoms during the BCTT in an expanded population with suspected dysautonomia after concussion. Future studies are indicated to validate these findings and contribute to development of modified termination criteria for the BCTT in individuals with suspected dysautonomia associated with protracted concussion recovery.

Developing Biomarkers of Mild Traumatic Brain Injury: Promise and Progress of CNS-Derived Exosomes

Mild traumatic brain injuries (mTBI) are common injuries across civilian and military populations. Although most individuals recover after mTBI, some individuals continue to show long-term symptoms as well as increased risk for neurodegenerative and neuropsychiatric disorders. Currently, diagnosing TBI severity relies primarily on self-report and subjective symptoms, with limited tools for diagnosis or prognosis. Brain-derived exosomes, a form of extracellular vesicle, may offer a solution for interpreting injury states by aiding in diagnosis as well as outcome prediction with relatively low patient burden. Exosomes, which are released into circulation, contain both protein and RNA cargo that can be isolated and quantified, providing a molecular window into molecular status of the exosome source. Here we examined the current literature studying the utility of exosomes, in particular neuronal- and astrocyte-derived exosomes, to identify protein and miRNA biomarkers of injury severity, trajectory, and functional outcome. Current evidence supports the potential for these emerging new tools to capture an accessible molecular window into the brain as it responds to a traumatic injury, however a number of limitations must be addressed in future studies. Most current studies are relatively small and cross sectional; prospective, longitudinal studies across injury severity, and populations are needed to track exosome cargo changes after injury. Standardized exosome isolation as well as advancement in identifying/isolating exosomes from CNS-specific tissue sources will improve mechanistic understanding of cargo changes as well as reliability of findings. Exosomes are also just beginning to be used in model systems to understand functional effects of TBI-associated cargo such as toxicity. Finally linking exosome cargo changes to objective markers of neuronal pathology and cognitive changes will be critical in validating these tools to provide insights into injury and recovery states after TBI.

Biomarkers to aid the return to play decision following sports-related concussion: a systematic review

Premature return to play (RTP) following sports-related concussion (SRC) is associated with significant morbidity including risk of neurological and non-neurological injury, persistent post-concussion symptoms and chronic neurological deficits. Assessing athletes for RTP is critical but these decisions are currently based on clinical assessments that are subject to bias and symptomatic reporting that rely on compliance. An objective and easily obtained biomarker that can indicate recovery following SRC would aid clinicians to make safer RTP decisions. We performed a systematic review to identify potential biomarkers from saliva, urine and blood sources that could inform the clinical RTP decision. The MEDLINE database was searched. Inclusion criteria were studies focusing on adults diagnosed with SRC, fluid biomarkers from blood, saliva or urine and clinical recovery from SRC or at RTP. We assessed each biomarker for their time course post SRC and relationship to clinical recovery. Secondary outcomes included correlation with symptom scores and predictive value for prolonged RTP. We identified 8 studies all investigating blood-based markers of diffuse axonal injury (tau, NFL, SNTF), neuroglial injury (NSE, VLP-1, UCH-L1, S100B, GFAP), inflammation and hormonal disturbances. Tau, SNTF, UCH-1, GFAP, S100B and the inflammatory cytokine MCP-4 are raised post SRC and return to baseline by RTP. Changes in tau, NFL, SNTF, GFAP and MCP-4 post SRC correlate with severity of concussion as measured by symptom severity or RTP duration. There is only preliminary case-reporting for hormonal biomarkers. The evidence is limited by a lack of highly powered studies, variation in use of athletic and Contact sport controls (CSC) and a lack of consistent sampling and assessment protocols. There is promise for biomarkers to aid RTP decisions following SRC, most notably in use alongside clinical assessment in RTP criteria to allow greater precision in identifying mild and severe concussion.

Attention-Deficit/Hyperactivity Disorder and Outcome from Concussion: Examining Duration of Active Rehabilitation and Clinical Recovery

AIMS

The objective of this study was to compare recovery time and duration of active rehabilitation following concussion between adolescents with and without attention-deficit/hyperactivity disorder (ADHD).

METHODS

A retrospective cohort study was conducted among adolescents presenting to a specialty concussion clinic. One-quarter of the eligible episodes of care were selected. The final sample included 540 adolescents (ages 13-17 years, median age 15 years; 49.8% girls), of which 65 (12.0%) had a pre-injury diagnosis of ADHD. Days to recovery and days of active rehabilitation were examined.

RESULTS

ADHD was not associated with recovery time (ADHD: median = 49 days, IQR = 25-77; No ADHD: median = 47 days, IQR = 29-85) in univariate (Z = -0.45; p = 0.65) or multivariable analyses (Hazard Ratio: 1.17 (0.85-1.61); χ²(1) = 0.95; p = 0.33). The duration of active rehabilitation services received did not differ between youth with ADHD (median = 38.5 days, IQR = 27.5-54.5) and without ADHD (median = 37.5 days, IQR = 18.5-66) in univariate (Z = -0.19; p = 0.85) or multivariable analyses (Hazard Ratio: 1.04 (0.67-1.63); χ²(1) = 0.03; p = 0.85).

CONCLUSIONS

Our findings support accumulating evidence that ADHD, in and of itself, is not a risk factor for longer recovery or worse outcomes following pediatric concussion.

Observable player behaviours and playing performance following helmet strikes in elite cricket

OBJECTIVES

Investigate the observable player behaviours and features of both concussive (HS-C) and non-concussive (HS-NC) helmet strikes and describe their impact on playing performance.

METHODS

Elite male cricketers sustaining helmet strikes between the 2016 and 2018 seasons were identified by the England and Wales Cricket Board. Medical records identified players sustaining a concussion and those in whom concussion was excluded. Retrospective cohort analysis was performed on batting and bowling performance data available for these players in the 2 years prior to and 3 months post helmet strike. Video analysis of available incidents was conducted to describe the characteristics of the helmet strike and subsequent observable player behaviours. The HS-C and HS-NC cohorts were compared.

RESULTS

Data were available for 194 helmet strikes. 56 (29%) resulted in concussion. No significant differences were seen in playing performance in the 3 months post concussive helmet strike. However, a significant decline in batting performance was seen in this period in the HS-NC group (p<0.001).Video features signifying motor incoordination were most useful in identifying concussion post helmet strike, however, typical features suggesting transient loss of consciousness were not seen. Features such as a longer duration pause prior to the batsman resuming play and the level of concern shown by other players were also useful features.

CONCLUSION

HS-NC may be more significant for player performance than previously thought. Guidance for using video replay to identify concussion in cricket may need to be modified when compared with other field sports.

Top-100 Most-Cited Sports-Related Concussion Articles Focus on Symptomatology, Epidemiology, and Demographics

Purpose

To analyze the top-100 cited articles on sports-related concussions together with a bibliometric analysis to determine citations by year, level of evidence, study design, and several other factors related to the top referenced articles in sports concussions.

Methods

The Clarivate Analytics Web of Knowledge database was used to gather data using Boolean queries to capture all possible iterations of sports-related concussion research. Articles were organized in descending order based on the number of citations and included or excluded based on relevance to concussion. Collected information included author name, publication year, country of origin, journal name, article type, study focus, and the level of evidence.

Results

The top-100 articles were cited 31,197 times with an average of 312.0 citations per publication. More than one half were published in 2006 or later (52). Cohort studies and descriptive articles were the most prevalent study types (22 each). Studies with Level V evidence were the most common (33). The most common areas of study were symptomatology (short term, long term) with 17 articles, followed by epidemiology/demographics with 16 articles. The least common area of study was concussion prevention (2 articles), followed by management/treatment, diagnostics (labs, imaging) with 4 articles each.

Conclusions

We identified the most influential studies in sports-related concussion based on number of citations and citation density. A majority of these articles were published in the United States after 2006 and are most commonly cohort studies (Level IV evidence) and descriptive articles (Level V evidence). Current research focuses most heavily on the symptomatology and epidemiology/demographics of sports concussion.

Clinical Relevance

This study serves to identify the most influential articles in sports-related concussion and identify research topics with general deficiencies within the field of sports-related concussion research.

A New In-Skates Balance Error Scoring System for Ice Hockey Players

OBJECTIVE

Evaluate a new in-skates balance error scoring system (SBESS) for ice hockey players wearing their equipment.

DESIGN

Prospective, randomized, single blinded study.

SETTING

Sport Medicine Clinic.

PARTICIPANTS

Eighty university hockey players.

INTERVENTION

A control group performed the SBESS assessment at rest on 2 separate occasions and an experimental group performed the assessment at rest and after exertion. The SBESS consists of maintaining different stances on ice skates for 20 seconds each, while wearing full equipment (no stick, gloves and helmet) and standing on a hard rubber surface. Three independent reviewers scored the video recorded assessments.

MAIN OUTCOMES MEASURES

Primary outcome was the number of balance errors and the secondary outcome was the number of falls.

RESULTS

The control group's median SBESS scores were 2 and 3 on the first and second attempts at rest, respectively. The experimental group's median SBESS scores were 2 at rest and 2 after exertion. There was no fatigue effect and no athletes fell while performing the test. Of the 4 stances tested, the tandem stance had the highest variability in error scores between athletes and when repeated by the same athlete. The intraclass correlation coefficient (ICC) for interrater reliability was above 0.82, and the intrarater reliability ICC was above 0.86 for all SBESS scores. There was no concordance between the SBESS and the modified BESS.

CONCLUSIONS

The SBESS, omitting the tandem stance, is a safe and reproducible sideline balance assessment of ice hockey players wearing full equipment.

Paediatric Trauma Score as a non-imaging tool for predicting intracranial haemorrhage in patients with traumatic brain injury

To identify a useful non-imaging tool to screen paediatric patients with traumatic brain injury for intracranial haemorrhage (ICH). We retrospectively analysed patients aged < 15 years who visited the emergency department with head trauma between January 2015 and September 2020. We divided patients into two groups (ICH and non-ICH) and compared their demographic and clinical factors. Among 85 patients, 21 and 64 were in the ICH and non-ICH groups, respectively. Age (p = 0.002), Pediatric trauma score (PTS; p < 0.001), seizure (p = 0.042), and fracture (p < 0.001) differed significantly between the two groups. Factors differing significantly between the groups were as follows: age (odds ratio, 0.84, p = 0.004), seizure (4.83, p = 0.013), PTS (0.15, p < 0.001), and fracture (69.3, p < 0.001). Factors with meaningful cut-off values were age (cut-off [sensitivity, specificity], 6.5 [0.688, 0.714], p = 0.003) and PTS [10.5 (0.906, 0.81), p < 0.001]. Based on the previously known value for critical injury (≤ 8 points) and the cut-off value of the PTS identified in this study (≤ 10 points), we divided patients into low-risk, medium-risk, and high-risk groups; their probabilities of ICH (95% confidence intervals) were 0.16-12.74%, 35.86-89.14%, and 100%, respectively. PTS was the only factor that differed significantly between mild and severe ICH cases (p = 0.012). PTS is a useful screening tool with a high predictability for ICH and can help reduce radiation exposure when used to screen patient groups before performing imaging studies.

Early targeted heart rate aerobic exercise versus placebo stretching for sport-related concussion in adolescents: a randomised controlled trial

BACKGROUND

Sport-related concussion is a public health problem, particularly in adolescents. Quality of life is reduced in adolescents with persistent post-concussive symptoms (symptoms >28 days). We replicated a previous randomised controlled trial to validate the safety, efficacy, and generalisability of, and objective adherence to, prescribed early targeted heart rate subsymptom threshold aerobic exercise compared with placebo-like stretching exercise for adolescent recovery from sport-related concussion and for reducing the risk of persistent post-concussive symptoms.

METHODS

This randomised controlled trial was done at three community and hospital-affiliated sports medicine concussion centres in the USA. Male and female adolescent athletes (aged 13-18 years) presenting within 10 days of sport-related concussion were randomly assigned to individualised subsymptom threshold aerobic or stretching exercise at least 20 min daily, for up to 4 weeks after injury. Exercise adherence and intensity were measured by heart rate monitors. The primary outcome was clinical recovery (ie, return to baseline symptoms, normal exercise tolerance, and a normal physical examination) within the 4-week intervention period, and development of persistent post-concussive symptoms beyond 28 days after injury. This study is registered with ClinicalTrials.gov, NCT02959216.

FINDINGS

Between Aug 1, 2018, and March 31, 2020, 118 adolescents were recruited (61 were randomly assigned to the aerobic exercise group and 57 to the stretching exercise group) and included in the intention-to-treat analysis. On survival analysis, controlling for sex, site, and mean daily exercise time, patients assigned to aerobic exercise were more likely to recover within 4 weeks after injury compared with those assigned to stretching exercise, with a 48% reduced risk of persistent post-concussive symptoms (hazard ratio for stretching vs aerobic exercise of 0·52 [95% CI 0·28-0·97], p=0·039). No adverse events were reported.

INTERPRETATION

This multicentre study found that early treatment with subsymptom threshold aerobic exercise safely speeds recovery from sport-related concussion and reduces the risk for persistent post-concussive symptoms, an important result given the impact of delayed recovery on adolescent quality of life. Adherence was good and there were no adverse events from this non-pharmacological treatment. These results suggest that physicians should not only permit, but consider prescribing, early subsymptom threshold physical activity to adolescents as treatment for sport-related concussion and to reduce the risk of persistent post-concussive symptoms.

FUNDING

American Medical Society for Sports Medicine.

State-Level Implementation of Health and Safety Policies to Prevent Sudden Death and Catastrophic Injuries Within High Schools: An Update

BACKGROUND

Mandated sports safety policies that incorporate evidence-based best practices have been shown to mitigate the risk of mortality and morbidity in sports. In 2017, a review of the state-level implementation of health and safety policies within high schools was released.

PURPOSE

To provide an update on the assessment of the implementation of health and safety policies pertaining to the leading causes of death and catastrophic injuries in sports within high school athletics in the United States.

STUDY DESIGN

Cross-sectional study.

METHODS

A rubric composed of 5 equally weighted sections for sudden cardiac arrest, traumatic head injuries, exertional heatstroke, appropriate health care coverage, and emergency preparedness was utilized to assess an individual state's policies. State high school athletic/activities association (SHSAA) policies, enacted legislation, and Department of Education policies were extensively reviewed for all 50 states and the District of Columbia between academic year (AY) 2016-2017 (AY16/17) and 2019-2020 (AY19/20). To meet the specific rubric criteria and be awarded credit, policies needed to be mandated by all SHSAA member schools. Weighted scores were tabulated to calculate an aggregate score with a minimum of 0 and a maximum of 100.

RESULTS

A total of 38 states had increased their rubric scores since AY16/17, with a mean increase of 5.57 ± 6.41 points. In AY19/20, scores ranged from 30.80 to 85.00 points compared with 23.00 to 78.75 points in AY16/17. Policies related to exertional heatstroke had the greatest change in scores (AY16/17 mean, 6.62 points; AY19/20 mean, 8.90 points; Δ = 2.28 points [11.40%]), followed by emergency preparedness (AY16/17 mean, 8.41 points; AY19/20 mean, 10.29 points; Δ = 1.88 points [9.40%]).

CONCLUSION

A longitudinal review of state high school sports safety policies showed progress since AY16/17. A wide range in scores indicates that continued advocacy for the development and implementation of policies at the high school level is warranted.

Systematic Review of the Long-Term Neuroimaging Correlates of Mild Traumatic Brain Injury and Repetitive Head Injuries

Objective: To systematically review the literature on the long-term neuroimaging findings (≥10 years from exposure) for exposure in adulthood to mild traumatic brain injury (mTBI) and repetitive head impacts (RHIs) using neuroimaging across all available populations. Data sources: Four electronic databases: MEDLINE, SPORTDiscus, PsycINFO, and EMBASE. Study selection: All articles were original research and published in English. Studies examined adults with remote exposure to mTBI and/or RHIs from ten or more years ago in addition to any associated neuroimaging findings. Data extraction: Parameters mainly included participants' population, age, years since head injury, race, sex, education level, and any neuroimaging findings. Scores for the level of evidence and risk of bias were calculated independently by two authors. Results: 5,521 studies were reviewed, of which 34 met inclusion criteria and were included in this study. The majority of adults in these studies showed positive neuroimaging findings one or more decades following mTBI/RHI exposure. This was consistent across study populations (i.e., veterans, athletes, and the general population). There was evidence for altered protein deposition patterns, micro- and macro-structural, functional, neurochemical, and blood flow-related differences in the brain for those with remote mTBI/RHI exposure. Conclusion: Findings from these studies suggest that past mTBI/RHI exposure may be associated with neuroimaging findings. However, given the methodological constraints related to relatively small sample sizes and the heterogeneity in injury types/exposure and imaging techniques used, conclusions drawn from this review are limited. Well-designed longitudinal studies with multimodal imaging and in-depth health and demographic information will be required to better understand the potential for having positive neuroimaging findings following remote mTBI/RHI.

Acute and Chronic Effects of Multiple Concussions on Midline Brain Structures

BACKGROUND AND OBJECTIVES

To test the hypothesis that a history of concussion (HOC) causes greater disturbances in cerebral blood flow (CBF) and white matter microstructure of midline brain structures after subsequent concussions, during the acute and chronic phases of recovery.

METHODS

In this longitudinal MRI study, 61 athletes with uncomplicated concussion (36 with HOC) were imaged at the acute phase of injury (1-7 days after injury), the subacute phase (8-14 days), medical clearance to return to play (RTP), 1 month after RTP, and 1 year after RTP. A normative group of 167 controls (73 with HOC) were also imaged. Each session assessed CBF of the cingulate cortex, along with fractional anisotropy (FA) and mean diffusivity (MD) of the corpus callosum. Linear mixed models tested for interactions of HOC with time since injury. The Sport Concussion Assessment Tool (SCAT) was also used to evaluate effects of HOC on symptoms, cognition, and balance.

RESULTS

Athletes with HOC had significantly greater declines in midcingulate CBF subacutely (z = -3.29, p = 0.002) and greater declines in posterior cingulate CBF at 1 year after RTP (z = -2.42, p = 0.007). No significant effects of HOC were seen for FA, whereas athletes with HOC had higher MD of the splenium at RTP (z = 2.54, p = 0.008). These effects were seen in the absence of significant differences in SCAT domains (|z| ≤ 1.14, p ≥ 0.256) or time to RTP (z = 0.23, p = 0.818).

DISCUSSION

Results indicate subacute and chronic effects of HOC on cingulate CBF and callosal microstructure in the absence of differences in clinical indices. These findings provide new insights into physiologic brain recovery after concussion, with cumulative effects of repeated injury detected among young, healthy athletes.

Establishing Test-Retest Reliability and Reliable Change for the King-Devick Test in High School Athletes

OBJECTIVE

To establish test-retest reliability in nonconcussed high school athletes and compare absolute change, reliable change indices (RCIs), and minimal detectable change (MDC) methods for classifying impairment after sport-related concussion.

DESIGN

Prospective, repeated measures.

SETTING

High schools from the Midwest and Central regions of the United States.

PARTICIPANTS

A convenience sample of 772 nonconcussed high school athletes (n = 546 men) completed preseason K-D testing. In addition, 69 athletes completed a second postseason K-D test, and 54 athletes sustained a concussion and completed postconcussion K-D tests.

INTERVENTION

K-D test.

MAIN OUTCOME MEASURES

Data for age, sex, and concussion history were determined using preseason K-D test outcomes. Test-retest reliability, RCIs, and MDCs were calculated using postseason K-D tests (M = 98.9, SD = 9.1 days). Postinjury K-D assessments within 5 days of injury (M = 1.5, SD = 1.5 days) were used to classify impairment on K-D using absolute change, RCI, and MDC methods.

RESULTS

Significant effects for age (P < 0.001) and history of concussion (P = 0.001) were supported on baseline K-D time, with no sex differences (P = 0.21). Preseason to postseason reliability for K-D times was 0.60 (intraclass correlation coefficient, 95% CI, 0.43-0.73), although 38% of athletes exhibited slower postseason K-D times compared with baseline. Impairment on K-D exhibited for 72% of the concussed sample using absolute change, 48% using MDC, and 44% using RCI methods.

CONCLUSIONS

K-D exhibited moderate test-retest reliability across 1 season. Absolute change yielded the highest sensitivity for preinjury to postinjury impairment on the K-D compared with RCI and MDC methods.

Factors Associated With Energy Expenditure and Energy Balance in Acute Sport-Related Concussion

CONTEXT

Sport-related concussion (SRC) is characterized by a pathologic neurometabolic cascade that results in an increased intracranial energy demand and a decreased energy supply. Little is known about the whole-body energy-related effects of SRC.

OBJECTIVE

To examine factors associated with whole-body resting metabolic rate (RMR), total energy expenditure (TEE), energy consumption (EC), and energy balance (EBal) in student-athletes acutely after SRC and healthy matched control individuals.

DESIGN

Case-control study.

SETTING

University research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Student-athletes diagnosed with SRC (n = 28, 50% female, age = 18.4 ± 1.8 years, body mass index [BMI] = 24.1 ± 4.1 kg/m2) assessed ≤72 hours postinjury and a matched control group (n = 28, 50% female, age = 19.4 ± 2.9 years, BMI = 24.7 ± 4.78 kg/m2).

MAIN OUTCOME MEASURE(S)

Resting metabolic rate was measured via indirect calorimetry. Participants reported their physical activity and dietary intake for 3 days, which we used to estimate TEE and EC, respectively, and to calculate EBal (EC:TEE ratio). Resting metabolic rate, TEE, and EC were normalized to body mass. Group and group-by-sex comparisons were conducted for RMR·kg-1, TEE·kg-1, EC·kg-1, and EBal using independent t tests with the a priori α = .05. Associations of age, sex, concussion history, BMI, and symptom burden with RMR·kg-1 and EBal were explored with linear regression models.

RESULTS

Total energy expenditure·kg-1 was lower (P < .01; mean difference ± SD = -5.31 ± 1.41 kcal·kg-1) and EBal was higher (P < .01; 0.28 ± 0.10) in SRC participants than in control participants. Both sexes with SRC had lower TEE·kg-1 than did the control participants (P values ≤ .04); females with SRC had higher EBal than controls (P = .01), but male groups did not differ. Higher RMR·kg-1 was associated with history of concussion (adjusted R2 = .10, β = 0.65). Younger age (β = -0.35), fewer concussions (β = -0.35), lower BMI (β = -0.32), greater symptom duration (β = 1.50), and lower symptom severity (β = -1.59) were associated with higher EBal (adjusted R2 = .54).

CONCLUSIONS

Total energy expenditure·kg-1 and EBal appeared to be affected by acute SRC, despite no differences in RMR·kg-1. Sex, concussion history, BMI, and symptom burden were associated with acute energy-related outcomes.

RELATIONSHIP BETWEEN PHYSICAL ACTIVITY PARTICIPATION AND RECOVERY OUTCOMES IN COLLEGE-AGED ADULTS WITH A CONCUSSION

CONTEXT

Previously, the most common treatment for a concussion was prolonged physical and cognitive rest. Recent research suggests that earlier physical activity (PA) may be better at promoting recovery. Research has not evaluated the relationship between free-living PA (e.g., walking) and symptom reporting or recovery duration.

OBJECTIVE

To assess the relationship between free-living physical activity (PA) participation and two recovery outcomes in college-aged adults with a concussion.

DESIGN

Prospective Cohort Setting: Division 1 & 3 Universities Participants: Thirty-two college-aged adults (68.8% female, age: 19.8±1.4) with a concussion.

MAIN OUTCOME MEASURES

Participants completed a post-concussion symptom evaluation at visits 1 (<72 hours from concussion) and 2 (8 days later). Between visits, participants' PA was monitored using an Actigraph GT9X Link PA monitor and expressed as total PA (counts per minute) and percent time of PA spent in moderate-to-vigorous intensity (%MVPA). Recovery time was the number of days from injury occurrence to medical clearance. Separate hierarchical multiple regressions evaluated the relationship between total PA and each recovery variable (visit 2 symptom severity, recovery time). Additionally, separate exploratory hierarchical multiple regressions evaluated the relationship between %MVPA and each recovery variable. Statistical significance was set a priori at p ≤ .05.

RESULTS

Participants averaged 2446±441 counts per minute and spent 12.1±4.2% of their PA performing MVPA. Participants yielded median symptom severities of 28[24] and 2[8] for visit 1 and 2, respectively. Average recovery time was 14.7±7.5 days. Total PA did not significantly contribute to the model for visit 2 symptom severity (p=.122) or recovery time (p=.301). Similarly, %MVPA had little contribution to the model for visit 2 symptom severity (p=.358) or recovery time (p=.276).

CONCLUSION

Results suggest that free-living PA may not be enough to reduce symptoms or shorten recovery. Thus, clinicians may need to provide patients with more structured PA protocols mimicking previous research.

Psycho-affective health, cognition, and neurophysiological functioning following sports-related concussion in symptomatic and asymptomatic athletes, and control athletes

Little is known about the neuropsychiatric and neurophysiological differences that characterize abnormal recovery following a concussion. The present study aimed to investigate the psycho-affective, cognitive, and neurophysiological profiles of symptomatic, slow-to-recover, concussed athletes, asymptomatic concussed athletes, and control athletes. Seventy-eight athletes (26 symptomatic, 26 asymptomatic, 26 control) completed the Beck Depression Inventory-II, Profile of Mood States, and 2-Back task. Additionally, event-related brain potentials were recorded during an experimental three-stimulus visual Oddball paradigm. Compared to asymptomatic and control groups, the symptomatic group reported greater depression symptoms and negatively altered mood states. Symptomatic athletes also exhibited poorer cognitive performance on the 2-Back task, indicated by more errors and slower reaction time. ERP analyses indicated prolonged P3b latency for both symptomatic and asymptomatic groups, but symptomatic athletes also exhibited reduced P3b amplitude compared to both asymptomatic and control groups. For the asymptomatic group, correlations were observed between time since last concussion and functioning, but no relations were observed within the symptomatic group for any measure. The current findings provide valuable information regarding the psycho-affective, cognitive, and neurophysiological profiles of athletes with and without persistent symptoms following a concussion and highlight the need to assess and treat symptomatic, slow-to-recover athletes from a multidimensional and integrative perspective.

A Biomarker for Concussion: The Good, the Bad, and the Unknown

BACKGROUND

Traumatic brain injury (TBI) is a significant cause of morbidity, mortality, and disability in the US, with >2.8 million patients presenting to the emergency department (ED) annually. However, the diagnosis of TBI is challenging and presents a number of difficulties, particularly at the mildest end of the spectrum: concussion. A number of groups have researched biomarkers to aid in the evaluation of TBI, and most recently in 2018 the Food and Drug Administration approved a new blood-based immunoassay biomarker using ubiquitin carboxyl hydrolase L1 and glial fibrillary acidic protein to aid in head computed tomography (CT) triage.

CONTENT

This review clarifies the practical challenges in assessing and implementing a new blood biomarker. It then examines the clinical context and need, as well as the evidence used to validate this new immunoassay.

SUMMARY

Concussion is a multifaceted diagnosis with a need for biomarkers to assist in diagnostic and prognostic assessment. Recent articles in the lay press have revealed misunderstanding about the function of this new test, expressing hopes that this biomarker serves patients at the mildest end of the spectrum and is useful for athletes and children. None of these assumptions are correct, as this biomarker has been evaluated in patients only at the moderate end of the spectrum and has been validated only in adults presenting to the ED who have already been triaged to receive head CT, not in athletes or children. The next steps for this assay should consider clinical work flow and clarifying its intended use, including integration with existing triage methods, and validating the assay for a broader population.

Sex-Based Differences in Symptoms with Mouthguard Use Following Pediatric Sport-Related Concussion

CONTEXT

Current evidence regarding the protective effect of mouthguard use on symptom severity in children and adolescents who sustain sport-related concussions is insufficient to make clinical recommendations.

OBJECTIVE

To compare the association between mouthguard-use and symptoms stratified by sex in the first 4-weeks after pediatric sport-related concussion. We hypothesized that mouthguard-use would be associated with lower symptoms.

DESIGN

Prospective cohort study.

SETTING

Nine Canadian pediatric emergency departments (EDs).

PATIENTS

Children aged 5-18 years presenting ≤48 hours of concussion sustained during a collision or contact sport.

MAIN OUTCOME MEASURES

Injury characteristics were collected using the Acute Concussion Evaluation. Primary outcome measure was symptom score (0-6), measured using age-appropriate versions (5-7 years; 8-12 years; 13-18 years) of the Post-Concussion Symptom Inventory. Independent variable was time postconcussion (at initial assessment, 1-, 2-, 4, weeks).

RESULTS

Of 1019 children (73% male; median [IQR] age=13.43[11.01,15.27] years), 42% wore a mouthguard at time of injury. There was no significant group by sex by time interaction for symptoms (χ23=0.27; p=.965). Male mouthguard users reported similar symptom scores in the ED (diff=-0.07; 95%CI:-0.23,0.09), at week-1 (diff=-0.02; 95%CI:-0.18,0.14), week-2 (diff=-0.03; 95%CI:-0.19,0.13), and week-4 (diff=-0.13; 95%CI:-0.29,0.04) compared with males who didn't wear a mouthguard. Female mouthguard users reported minimally higher symptom scores at week-1 compared with non-mouthguard users (diff=0.29; 95%CI:0.01,0.56). Symptom scores were not significantly different for females who wore a mouthguard and those who didn't in the ED (diff=0.22; 95%CI:-0.04,0.48), at week-2 (diff=0.22; 95%CI:-0.06,0.51), or week-4 (diff=0.08; 95%CI:-0.20,0.36).

CONCLUSION

Wearing a mouthguard at time of injury is not associated with reduced acute and subacute symptoms after sport-related concussion in either males or females who were treated in the ED compared with those who did not wear a mouthguard. Athletes are still encouraged to wear a mouthguard during sports since overwhelming evidence supports their use in preventing dental injuries.

The ENIGMA sports injury working group:- an international collaboration to further our understanding of sport-related brain injury

Sport-related brain injury is very common, and the potential long-term effects include a wide range of neurological and psychiatric symptoms, and potentially neurodegeneration. Around the globe, researchers are conducting neuroimaging studies on primarily homogenous samples of athletes. However, neuroimaging studies are expensive and time consuming, and thus current findings from studies of sport-related brain injury are often limited by small sample sizes. Further, current studies apply a variety of neuroimaging techniques and analysis tools which limit comparability among studies. The ENIGMA Sports Injury working group aims to provide a platform for data sharing and collaborative data analysis thereby leveraging existing data and expertise. By harmonizing data from a large number of studies from around the globe, we will work towards reproducibility of previously published findings and towards addressing important research questions with regard to diagnosis, prognosis, and efficacy of treatment for sport-related brain injury. Moreover, the ENIGMA Sports Injury working group is committed to providing recommendations for future prospective data acquisition to enhance data quality and scientific rigor.

Quantitative EEG Analysis in Clinical Practice: Concussion Injury

Concussion is a common brain injury. The American Academy of Neurology provides a definition of concussion: "Concussion is a traumatically, or biomechanically, induced alteration of brain function. Emphasis is placed on a pathophysiological process, or functional disruption, as opposed to anatomic, structural, or tissue injury.". The incidence of mild traumatic brain injury (mTBI) is estimated at 200 per 100 000. The Centers for Disease Control and Prevention (CDC) estimates 3.8 million sport and recreational mTBIs occurring in the United States each year. A more recent CDC assessment estimates 2.5 million concussion injuries in high school sports alone. The controlled environment and opportunity for direct surveillance and observation has made the sports arena the scientific "wet lab" for the study of mTBI natural history, short- and long-term consequences and opportunities to intervene. Quantitative EEG methods have been utilized in the assessment and management of mTBI and lends to provide a cost-effective procedure that has the sensitivities needed to identify pathology where routine visual inspection of the EEG has failed.

Clinical Recovery Timelines following Sport-Related Concussion in Men's and Women's Collegiate Sports

CONTEXT

Past work has identified sex differences in sport-related concussion (SRC) incidence and recovery time; however, few have examined sex differences in specific recovery trajectories: time to symptom resolution, return-to-academics, and return-to-athletic activity across collegiate sports.

OBJECTIVE

To examine sex differences in SRC recovery trajectories across a number of varsity sports with differing levels of contact.

DESIGN

Descriptive Epidemiology Study.

SETTING

College varsity and club sports.

PATIENTS OR OTHER PARTICIPANTS

SRCs sustained by student-athletes (N=1,974; 38.7% female) participating in Ivy League sports were tracked from 2013/14-2018/19.

INTERVENTION(S)

Athletic trainers collected concussive injury and recovery characteristics as part of the Ivy League-Big Ten Epidemiology of Concussion Study's surveillance system.

MAIN OUTCOME MEASURE(S)

Time to symptom resolution, return-to-academics, and return-to-limited and full athletic activity were collected. Survival analyses determined time from injury to each recovery outcome for males and females by sport. Peto tests compared recovery outcomes between males and female athletes and by sport.

RESULTS

The median time to symptom resolution overall was 9 days [IQR:4,18], return-to-academics was 8 days [IQR:3,15], return-to-limited activity was 12 days [IQR:8,23], and return-to-full activity was 16 days [IQR:10,29]. There were significant differences overall between sexes for median time to symptom resolution (males: 8 days [IQR:4,17], females: 9 days [IQR:5,20], p=0.029) and return-to-academics (males: 7 days [IQR:3,14], females: 9 days [IQR:4,17], p<.001), but not return to athletics (limited activity, p=0.107; full activity, p=0.578). Within-sport comparisons found that female lacrosse athletes had longer symptom resolution (p=0.030) and return to academics (p=0.035) compared to males, while male volleyball athletes took longer to return to limited (p=0.020) and full (p=0.049) athletic activity compared to females.

CONCLUSION

There were significant differences in recovery timelines between sexes. Females experienced longer symptom duration and time to return-to-academics compared to male athletes, but females and males presented similar timelines for return-to-athletics.

Exo70 intracellular redistribution after repeated mild traumatic brain injury

BACKGROUND

Exo70 is a subunit of the greater exocyst complex, a collection of proteins that oversees cellular membrane addition and polarized exocytosis by acting as a tethering intermediate between the plasma membrane and newly synthesized secretory vesicles. Although Exo70 function has been implicated in several developmental events including cytokinesis and the establishment of cell polarity, its role in neuropathologies is poorly understood. On the other hand, traumatic brain injury is the result of mechanical external force including contusion, fast acceleration, and expansive waves that produce temporal or permanent cognitive damage and triggers physical and psychosocial alterations including headache, memory problems, attention deficits, difficulty thinking, mood swings, and frustration. Traumatic brain injury is a critical health problem on a global scale, constituting a major cause of deaths and disability among young adults. Trauma-related cellular damage includes redistribution of N-methyl-D-aspartate receptors outside of the synaptic compartment triggering detrimental effects to neurons. The exocyst has been related to glutamate receptor constitutive trafficking/delivery towards synapse as well. This work examines whether the exocyst complex subunit Exo70 participates in traumatic brain injury and if it is redistributed among subcellular compartments RESULTS: Our analysis shows that Exo70 expression is not altered upon injury induction. By using subcellular fractionation, we determined that Exo70 is redistributed from microsomes fraction into the synaptic compartment after brain trauma. In the synaptic compartment, we also show that the exocyst complex assembly and its interaction with GluN2B are increased. Finally, we show that the Exo70 pool that is redistributed comes from the plasma membrane.

CONCLUSIONS

The present findings position Exo70 in the group of proteins that could modulate GluN2B synaptic availability in acute neuropathology like a traumatic brain injury. By acting as a nucleator factor, Exo70 is capable of redirecting the ensembled complex into the synapse. We suggest that this redistribution is part of a compensatory mechanism by which Exo70 is able to maintain GluN2B partially on synapses. Hence, reducing the detrimental effects associated with TBI pathophysiology.

Epidemiology and risk stratification of minor head injuries in school-going children

INTRODUCTION

Head injuries occur commonly in children and can lead to concussion injuries. We aim to describe the epidemiology of head injuries among school-going children and identify predictors of brain concussions in Singapore.

METHODS

This is a retrospective study of children 7-16 years old who presented to the Emergency Department (ED) of KK Women's and Children's Hospital in Singapore with minor head injury between June 2017 and August 2018. Data including demographics, clinical presentation, ED and hospital management were collected using a standardised electronic template. Multivariable logistic regression analysis was performed to identify early predictors for brain concussion. Concussion symptoms were defined as persistent symptoms after admission, need for inpatient intervention, or physician concerns necessitating neuroimaging.

RESULTS

Among 1,233 children (mean age, 6.6 years; 72.6% boys) analysed, the commonest mechanism was falls (64.6%). Headache and vomiting were the most common presenting symptoms. A total of 395 (32.0%) patients required admission, and 277 (22.5%) had symptoms of concussion. Older age (13-16 years old) (adjusted odds ratio [aOR] 1.53, 95% confidence interval [CI] 1.12-2.08), children involved in road traffic accidents (aOR 2.12, CI 1.17-3.85) and a presenting complaint of headache (aOR 2.64, CI 1.99-3.50) were significantly associated with symptoms of concussion.

CONCLUSION

This study provides a detailed description of the pattern of head injuries among school-going children in Singapore. High risk patients may require closer monitoring to detect post-concussion syndrome early.

The role of family burden on informant discrepancies between parents and youths with protracted recovery from mild traumatic brain injury

Previous literature shows that family burden can lead to symptom-report discrepancies between parents and children. The present study sought to extend this research by investigating the influence of family burden factors, including socioeconomic status (SES) and family stress on informant discrepancies between parents and youths with mild traumatic brain injury (mTBI). Participants were clinically referred youths with mTBI ages 8-17, consecutively seen in a hospital-based neuropsychology concussion clinic (N = 81; females = 54.3%). Parents and children completed the Behavioral Assessment for Children System (BASC) and the Postconcussive Symptom Scale (PCSS). Parents rated changes in family stress related to the mTBI (categorized as "no change," "minor change," or "major change") and provided information to calculate SES. Results revealed that family stress but not SES influenced parent-child report discrepancies for the BASC Internalizing Symptoms Index (F = 8.72(2, 79), p <.000), and that the discrepancies were independent of postconcussive symptom severity. Clinical implications of these findings are discussed.

Concussion Acutely Decreases Plasma Glycerophospholipids in Adolescent Male Athletes

Concussions are frequent in sports and can contribute to significant and long-lasting neurological disability. Adolescents are particularly susceptible to concussions, with accurate determination of the injury challenging. Our previous study demonstrated that concussion diagnoses could be aided by metabolomics profiling and machine learning, with particular weighting on changes in plasma glycerophospholipids (PCs). Here, our aim was to report directional change of PCs after concussion and develop a diagnostic concussion panel utilizing a minimum number of plasma PCs. To this end, we enrolled 12 concussed male athletes at our academic Sport Medicine Concussion Clinic, as well as 17 sex-, age-, and activity-matched healthy controls. Blood was drawn and 71 plasma PCs were measured for statistically significant changes within 72 h of injury, and individual PCs were further analyzed with receiver operating characteristic (ROC) curves. Our data demonstrated that 26 of 71 PCs measured were significantly decreased after sports-related concussion (p < 0.01). None of the PCs increased in plasma after concussion. ROC curve analyses identified the top four PCs with areas under the curve (AUCs) ≥0.86 for concussion diagnosis: PCaeC36:0 (0.92; p < 0.001); PCaaC42:6 (0.90; p < 0.001); PCaeC36:2 (0.86; p = 0.001), and PCaaC32:0 (0.86; p = 0.001). Cut-off values in μM were ≤0.31, 0.22, 5.07, and 4.63, respectively. Importantly, combining these four PCs produced an AUC of 0.96 for concussion diagnoses (p < 0.001; 95% confidence interval, 0.89, 1.00). Our data suggest that as few as four circulating PCs may provide excellent diagnostic potential for adolescent concussion. External validation is required in larger cohorts.

Derivation of a Focused, Brief Concussion Physical Examination for Adolescents With Sport-Related Concussion

OBJECTIVE

To describe the derivation of a brief but pertinent physical examination (PE) for adolescents who have sustained sport-related concussion (SRC).

DESIGN

Prospective cohort.

SETTING

University concussion management clinic.

PARTICIPANTS

Acutely concussed (AC, n = 52, 15.5 ± 1.4 years, 4.4 ± 2 days since injury, 26.2 ± 38 days to recovery, 71% males) and healthy control (HC) adolescents (n = 30, 15.8 ± 1.4 years, 73% males).

INTERVENTION

Acutely concussed had a PE on visit 1 and were retested at visit 2 (13.6 ± 1 day after visit 1). Acutely concussed were further characterized as normal recovery (NR, n = 41, 15.5 ± 1.5 years, recovery time 13.0 ± 7 days) and delayed recovery (DR, n = 11, 15.5 ± 1.2 years, recovery time 75.4 ± 63 days).

MAIN OUTCOME MEASURE

Physical examination findings, including cervical, vestibular, and oculomotor systems.

RESULTS

Visit 1 abnormal PE signs were significantly greater in AC versus HC (2.79 ± 2.13 vs 0.07 ± 0.37, P < 0.0001) but not in NR versus DR (2.61 ± 2.2 vs 3.45 ± 1.8, P = 0.246). Visit 2 abnormal PE signs differentiated NR versus DR (0.17 ± 0.7 vs 2.45 ± 2.1, P < 0.0001).

CONCLUSIONS

A brief focused PE can help to diagnose SRC, establish recovery, and may have prognostic value.

Toward Complete, Candid, and Unbiased International Consensus Statements on Concussion in Sport

Five international consensus statements on concussion in sports have been published. This commentary argues that there is a strong need for a new approach to them that foregrounds public health expertise and patient-centered guidance. Doing so will help players, parents and practitioners keep perspective about these potentially life-altering injuries especially when they recur.

Preventing Concussions From Foul Tips and Backswings in Professional Baseball: Catchers' Perceptions of and Experiences With Conventional and Hockey-Style Masks

OBJECTIVE

To understand catchers' preferences for mask type and perceptions regarding safety, comfort, and fit, and determine whether mask type is correlated with self-reported concussion and related symptoms after impacts from foul tips or backswings.

DESIGN

Cross-sectional study.

SETTING

Survey of active baseball catchers.

PARTICIPANTS

Professional baseball catchers.

INTERVENTION

From May 1, 2015, to June 30, 2015, an online survey was administered in English and Spanish to all Major and Minor League catchers (n = 836).

MAIN OUTCOME MEASURES

Survey items addressed the type of mask routinely and previously used (conventional or hockey style); brand and material (steel or titanium); perceptions regarding safety, comfort, and fit; and experiences with concussions.

RESULTS

The sample consisted of 596 catchers of which 26% reported being diagnosed with a concussion. Some concussions occurred from non-baseball activities, such as car accidents or off the field incidents. For those that occurred playing baseball, 35% resulted from a foul tip. Once catchers entered professional baseball, the use of a conventional mask rose significantly: 71% of catchers reported wearing conventional-style masks, and 30% hockey-style masks at the time the survey was conducted (P < 0.05). Both conventional and hockey-style mask wearers significantly selected hockey-style masks as providing better overall safety and protection than conventional masks (P < 0.05).

CONCLUSIONS

This research supports foul tips as an important cause of concussion in catchers and provides important information about preferences among catchers for masks that are not perceived as the safest and strongest. Future research should supplement these data by conducting laboratory testing to determine which masks are stronger and by collecting qualitative data to explore why some players are more likely to wear a mask type that they perceive as offering less safety or protection.

Seizure Disorders and Exercise/Sports Participation

ABSTRACT

Persons with epilepsy have traditionally been restricted from physical exercise and sports participation because of misinformation and fear. The physical and psychosocial benefits of exercise on general health are well known and have been denied to persons with epilepsy because of these restrictions. Exercise has been shown to decrease seizure frequency and has even been assessed as a means to prevent epilepsy. The risk of injury is a commonly cited reason for restricting physical activity although the majority of these injuries are soft tissue injuries. Literature has shown that the benefits of sports participation for persons with epilepsy far outweigh the risk to the participant. While there are recommended contraindications to a small number of sports, persons with epilepsy can safely participate in the majority of sports with correct counseling and observation.

Recovery of Theta Frequency Oscillations in Rats Following Lateral Fluid Percussion Corresponds With a Mild Cognitive Phenotype

Whether from a fall, sports concussion, or even combat injury, there is a critical need to identify when an individual is able to return to play or work following traumatic brain injury (TBI). Electroencephalogram (EEG) and local field potentials (LFP) represent potential tools to monitor circuit-level abnormalities related to learning and memory: specifically, theta oscillations can be readily observed and play a critical role in cognition. Following moderate traumatic brain injury in the rat, lasting changes in theta oscillations coincide with deficits in spatial learning. We hypothesized, therefore, that theta oscillations can be used as an objective biomarker of recovery, with a return of oscillatory activity corresponding with improved spatial learning. In the current study, LFP were recorded from dorsal hippocampus and anterior cingulate in awake, behaving adult Sprague Dawley rats in both a novel environment on post-injury days 3 and 7, and Barnes maze spatial navigation on post-injury days 8–11. Theta oscillations, as measured by power, theta-delta ratio, peak theta frequency, and phase coherence, were significantly altered on day 3, but had largely recovered by day 7 post-injury. Injured rats had a mild behavioral phenotype and were not different from shams on the Barnes maze, as measured by escape latency. Injured rats did use suboptimal search strategies. Combined with our previous findings that demonstrated a correlation between persistent alterations in theta oscillations and spatial learning deficits, these new data suggest that neural oscillations, and particularly theta oscillations, have potential as a biomarker to monitor recovery of brain function following TBI. Specifically, we now demonstrate that oscillations are depressed following injury, but as oscillations recover, so does behavior.

Perceptual Cognitive Training Does Not Improve Clinical Outcomes at 4 and 12 Weeks Following Concussion in Children and Adolescents: A Randomized Controlled Trial

OBJECTIVE

To determine whether a perceptual-cognitive training program using 3D-multiple object tracking (3D-MOT) can improve symptoms following acute pediatric concussion.

SETTING

Research laboratory within a pediatric trauma center.

PARTICIPANTS

Children and adolescents (n = 62, age= 13.27 ± 2.50) with diagnosed concussion.

DESIGN

Randomized controlled trial. Children were randomized into either 3D-MOT, 2048 game, or standard care-only groups. Participants and parents completed the Post-Concussion Symptom Inventory (PCSI) at baseline, 4, 8, and 12 weeks postinjury. Intervention participants completed either the 3D-MOT protocol or the 2048 game at 6 sessions between the baseline and 4-week assessment.

MAIN MEASURES

A 3 (group) × 10 (time) mixed-model analysis of variance evaluated PCSI total scores. The rate of persistent postconcussive symptom (PPCS) was evaluated at 4 weeks using χ2 analysis.

RESULTS

Symptoms decreased throughout the study using both child-reported (F(9,374) = 22.03, P < .001) and parent-reported scores (F(9,370) = 28.06, P < .001). Twenty-four (44.4%) children met the study definition for PPCS using the child-reported PCSI, while 20 (37.7%) children had PPCS using parent reports. The intervention did not significantly affect symptom resolution or PPCS rates.

CONCLUSION

There is no benefit to prescribing 3D-MOT training for acute rehabilitation in pediatric patients with concussion and clinicians should instead focus on more effective programs.

Progress and Future Directions of the NCAA-DoD Concussion Assessment, Research, and Education (CARE) Consortium and Mind Matters Challenge at the US Service Academies

Despite the significant impact that concussion has on military service members, significant gaps remain in our understanding of the optimal diagnostic, management, and return to activity/duty criteria to mitigate the consequences of concussion. In response to these significant knowledge gaps, the US Department of Defense (DoD) and the National Collegiate Athletic Association (NCAA) partnered to form the NCAA-DoD Grand Alliance in 2014. The NCAA-DoD CARE Consortium was established with the aim of creating a national multisite research network to study the clinical and neurobiological natural history of concussion in NCAA athletes and military Service Academy cadets and midshipmen. In addition to the data collected for the larger CARE Consortium effort, the service academies have pursued military-specific lines of research relevant to operational and medical readiness associated with concussion. The purpose of this article is to describe the structure of the NCAA-DoD Grand Alliance efforts at the service academies, as well as discuss military-specific research objectives and provide an overview of progress to date. A secondary objective is to discuss the challenges associated with conducting large-scale studies in the Service Academy environment and highlight future directions for concussion research endeavors across the CARE Service Academy sites.

Management of unfavorable outcome after mild traumatic brain injury: Review of physical and cognitive rehabilitation and of psychological care in post-concussive syndrome

INTRODUCTION

Mild Traumatic Brain Injury (mTBI) is a public health issue with approximately 42 million people worldwide affected yearly. Most patients have a favorable short-term recovery but 10-20% are likely to develop post-concussive syndrome (association of physical, cognitive, and psychological difficulties after injury). Post-concussive syndrome can be associated with Post-Traumatic Stress Disorder (PTSD). There is to date no recommendation on the interventions that could be done to reduce post-concussive syndrome. The present review aims at summarizing the effect of therapeutic education, physical and cognitive rehabilitation and of psychological care in mTBI patients with post-concussive syndrome.

METHODS

In the current international literature, we investigated the effects of therapeutic education, physical and cognitive rehabilitation and of psychological care in this population using the Medline database and we discussed the results of these studies.

RESULTS

The application of a therapeutic education intervention within 3 months after mTBI has been found appropriate and effective to prevent post-concussion syndrome in several studies but the timeline of this intervention differs among the existing studies. Concerning physical disabilities, several pharmacological, rehabilitative and non-pharmacological techniques have shown some efficacy in reducing headache and vertigo; rTMS seems also promising in this context. The management of fatigue is also crucial and requires a multidisciplinary approach. We did not find any intervention in mTBI patients with post-concussive syndrome suffering from dysosmia and/or dysgueusia. No pharmacological treatment is currently recommended to reduce the cognitive symptoms of post-concussive syndrome after mTBI. Rehabilitation and brain-stimulation techniques have already proven their efficacy to reduce the cognitive impairment in this population. Even if the use of Virtual Reality software seems well tolerated in this population, its efficacy and additional value needs to be demonstrated in larger studies. Concerning the psychological care after mTBI, Cognitive and Behavioral Therapy interventions are the most frequently reported in this population, followed by psychoeducational interventions. PTSD management seems crucial in overall recovery of patients with post-concussive syndrome.

CONCLUSION

Many studies have sought to demonstrate the effectiveness of various rehabilitation techniques, including different cognitive rehabilitation programs, technology-assisted rehabilitation, different types of brain stimulation and some pharmacological treatments. However, most of these studies are of a low level of scientific evidence and it would be necessary to carry out well-conducted prospective randomized trials in order to offer an appropriate and effective multidisciplinary management for patients with post-concussive syndrome after mTBI.

A Cohort Study of the Temporal Stability of ImPACT Scores Among NCAA Division I Collegiate Athletes: Clinical Implications of Test-Retest Reliability for Enhancing Student Athlete Safety

OBJECTIVE

In this study we examined the temporal stability of the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) within NCAA Division I athletes across various timepoints using an exhaustive series of statistical models.

METHODS

Within a cohort design, 48 athletes completed repeated baseline ImPACT assessments at various timepoints. Intraclass correlation coefficients (ICC) were calculated using a two-way mixed effects model with absolute agreement.

RESULTS

Four ImPACT composite scores (Verbal Memory, Visual Memory, Visual Motor Speed, and Reaction Time) demonstrated moderate reliability (ICC = 0.51-0.66) across the span of a typical Division I athlete's career, which is below previous reliability recommendations (0.90) for measures used in individual decision-making. No evidence of fixed bias was detected within Verbal Memory, Visual Motor Speed, or Reaction Time composite scores, and minimal detectable change values exceeded the limits of agreement.

CONCLUSIONS

The demonstrated temporal stability of the ImPACT falls below the published recommendations, and as such, fails to provide robust support for the NCAA's recommendation to obtain a single preparticipation cognitive baseline for use in sports-related concussion management throughout an athlete's career. Clinical interpretation guidelines are provided for clinicians who utilize baseline ImPACT scores for later performance comparisons.

Soccer-Related Concussions Among Swedish Elite Soccer Players: A Descriptive Study of 1,030 Players

Objective: There are growing concerns about the short- and long-term consequences of sports-related concussion, which account for about 5–9% of all sports injuries. We hypothesized there may be sex differences in concussion history and concussion-related symptoms, evaluated among elite soccer players in Sweden.

Design: Retrospective survey study.

Participants and Setting: Soccer players (n = 1,030) from 55 Swedish elite soccer teams. Questionnaires were completed prior to the start of the 2017 season.

Assessment of Risk Factors: Player history of soccer-related concussion (SoRC), symptoms and management following a SoRC were evaluated.

Main Outcome Measures: Before the start of the season the players completed a baseline questionnaire assessing previous concussions. The Sports Concussion Assessment Tool 3 was included with regard to symptom evaluation.

Results: Out of 993 responding players 334 (34.6%) reported a previous SoRC and 103 players (10.4%) reported a SoRC during the past year. After sustaining a SoRC, 114 players (34.2%) reported that they continued their ongoing activity without a period of rest, more commonly female (44.9%) than male players (27.7%; P = 0.002). Symptom resolution time was 1 week or less for 61.3% of the players that reported having persisting symptoms. A positive correlation was observed between number of previous concussions and prevalence of three persisting symptoms: fatigue (P < 0.001), concentration/memory issues (P = 0.002) and headache (P = 0.047).

Conclusion: About 35% of male and female elite soccer players in Sweden have experienced a previous SoRC, and about 10% experienced a SoRC during the last year. Female players continued to play after a SoRC, without a period of rest, more often than males. A higher risk of persisting symptoms was observed in players with a history of multiple concussions.