Predictors of clinical recovery from concussion: a systematic review

A Pilot Study Evaluating the Timing of Vestibular Therapy After Sport-Related Concussion: Is Earlier Better?

BACKGROUND

Vestibular dysfunction, characterized by nausea, dizziness, imbalance, and/or gait disturbance, represents an important sport-related concussion (SRC) subtype associated with prolonged recovery. Vestibular physical therapy promotes recovery; however, the benefit of earlier therapy is unclear.

HYPOTHESIS

Earlier vestibular therapy for young athletes with SRC is associated with earlier return to play (RTP), return to learn (RTL), and symptom resolution.

STUDY DESIGN

Retrospective cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Patients aged 5 to 23 years with SRC who initiated vestibular rehabilitation therapy (VRT) from January 2019 to December 2019 were included and patient records were reviewed. Therapy initiation was defined as either early, ≤30 days postinjury, or late (>30 days). Univariate comparisons between groups, Kaplan-Meier plots, and multivariate Cox proportional hazard modeling were performed.

RESULTS

Overall, 23 patients (10 early, 13 late) aged 16.14 ± 2.98 years and 43.5% were male patients. There was no difference between group demographics or medical history. Median initial total and vestibular symptom scores were comparable between groups. The late therapy group required additional time to RTP (110 days [61.3, 150.8] vs 31 days [22.5, 74.5], P = 0.03) and to achieve symptom resolution (121.5 days [71, 222.8] vs 54 days [27, 91], P = 0.02), but not to RTL (12 days [3.5, 26.5] vs 17.5 days [8, 20.75], P = 0.09). Adjusting for age and initial total symptom score, earlier therapy was protective against delayed symptom resolution (P = 0.01).

CONCLUSION

This pilot study suggests that initiating VRT within the first 30 days after SRC is associated with earlier RTP and symptom resolution. Further prospective trials to evaluate if even earlier VRT should be pursued to further improve recovery time.

CLINICAL RELEVANCE

Clinicians should screen for vestibular dysfunction and consider modifying follow-up schedules after SRC to initiate VRT within a month of injury for improved outcomes.

Assessment and Treatment of Concussion in the Pediatric Population

Traumatic brain injury (TBI) is common in children. The evaluation and management of children with TBI is based on the research performed in adults. There is a relative paucity of research in the literature involving children and many of the practice recommendations for this age are based on expert opinion in the absence of good research studies in both sports and non-sports-related injuries. The pediatric population is heterogeneous and the approach might be specific for infants, preschoolers, school age children, and adolescents. Children may also suffer from neurodevelopmental disabilities, making their evaluation even more challenging. Adult neurologists are often asked to see children due to increasing demands. This review will focus on specific issues related to TBI in children that might be useful to adult neurologists. Science, however, is evolving rapidly and physicians should make sure to remain up to date to offer evidence-based services to their patients.

A cross-sectional study reporting concussion exposure, assessment and management in Western Australian general practice

Background

General Practitioners (GPs) may be called upon to assess patients who have sustained a concussion despite limited information being available at this assessment. Information relating to how concussion is actually being assessed and managed in General Practice is scarce. This study aimed to identify characteristics of current Western Australian (WA) GP exposure to patients with concussion, factors associated with GPs’ knowledge of concussion, confidence of GPs in diagnosing and managing patients with concussion, typical referral practices and familiarity of GPs with guidelines.

Methods

In this cross-sectional study, GPs in WA were recruited via the RACGP WA newsletter and shareGP and the consented GPs completed an electronic survey. Associations were performed using Chi-squared tests or Fisher’s Exact test.

Results

Sixty-six GPs in WA responded to the survey (response rate = 1.7%). Demographics, usual practice, knowledge, confidence, identification of prolonged recovery as well as guideline and resource awareness of GPs who practised in regional and metropolitan areas were comparable (p > 0.05). Characteristics of GPs were similar between those who identified all symptoms of concussion and distractors correctly and those who did not (p > 0.05). However, 84% of the respondents who had never heard of concussion guidelines were less likely to answer all symptoms and distractors correctly (p = 0.039). Whilst 78% of the GPs who were confident in their diagnoses had heard of guidelines (p = 0.029), confidence in managing concussion was not significantly associated with GPs exposure to guidelines. It should be noted that none of the respondents correctly identified signs of concussion and excluded the distractors.

Conclusions

Knowledge surrounding concussion guidelines, diagnosis and management varied across GPs in WA. Promotion of available concussion guidelines may assist GPs who lack confidence in making a diagnosis. The lack of association between GPs exposure to guidelines and confidence managing concussion highlights that concussion management may be an area where GPs could benefit from additional education and support.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-021-01384-1.

Detailed description of Division I ice hockey concussions: Findings from the NCAA and Department of Defense CARE Consortium

OBJECTIVE

Since concussion is the most common injury in ice hockey, the objective of the current study was to elucidate risk factors, specific mechanisms, and clinical presentations of concussion in men's and women's ice hockey.

METHODS

Ice hockey players from 5 institutions participating in the Concussion Assessment, Research, and Education Consortium were eligible for the current study. Participants who sustained a concussion outside of this sport were excluded. There were 332 (250 males, 82 females) athletes who participated in ice hockey, and 47 (36 males, 11 females) who sustained a concussion.

RESULTS

Previous concussion (odds ratio (OR) = 2.00; 95% confidence interval (95% CI): 1.02‒3.91) was associated with increased incident concussion odds, while wearing a mouthguard was protective against incident concussion (OR = 0.43; 95%CI: 0.22‒0.85). Overall, concussion mechanisms did not significantly differ between sexes. There were specific differences in how concussions presented clinically across male and female ice hockey players, however. Females (9.09%) were less likely than males (41.67%) to have a delayed symptom onset (p = 0.045). Additionally, females took significantly longer to reach asymptomatic (p = 0.015) and return-to-play clearance (p = 0.005). Within the first 2 weeks post-concussion, 86.11% of males reached asymptomatic, while only 45.50% of females reached the same phase of recovery. Most males (91.67%) were cleared for return to play within 3 weeks of their concussion, compared to less than half (45.50%) of females.

CONCLUSION

The current study proposes possible risk factors, mechanisms, and clinical profiles to be validated in future concussions studies with larger female sample sizes. Understanding specific risk factors, concussion mechanisms, and clinical profiles of concussion in collegiate ice hockey may generate ideas for future concussion prevention or intervention studies.

Early Life Stress Exacerbates Outcome after Traumatic Brain Injury

The neurocognitive impairments associated with mild traumatic brain injury (TBI) often resolve within 1-2 weeks; however, a subset of people exhibit persistent cognitive dysfunction for weeks to months after injury. The factors that contribute to these persistent deficits are unknown. One potential risk factor for worsened outcome after TBI is a history of stress experienced by a person early in life. Early life stress (ELS) includes maltreatment such as neglect, and interferes with the normal construction of cortical and hippocampal circuits. We hypothesized that a history of ELS contributes to persistent learning and memory dysfunction following a TBI. To explore this interaction, we modeled ELS by separating Sprague Dawley pups from their nursing mothers from post-natal days 2-14 for 3 h daily. At 2 months of age, male rats received sham surgery or mild to moderate parasagittal fluid-percussion brain injury. We found that the combination of ELS with TBI in adulthood impaired hippocampal-dependent learning, as assessed with contextual fear conditioning, the water maze task, and spatial working memory. Cortical atrophy was significantly exacerbated in TBI animals exposed to ELS compared with normal-reared TBI animals. Changes in corticosterone in response to restraint stress were prolonged in TBI animals that received ELS compared with TBI animals that were normally reared or sham animals that received ELS. Our findings indicate that ELS is a risk factor for worsened outcome after TBI, and results in persistent learning and memory deficits, worsened cortical pathology, and an exacerbation of the hormonal stress response.

Sports- and Physical Activity-Related Concussion and Risk for Youth Violence

INTRODUCTION

Sports and physical activities are an important cause of traumatic brain injury among adolescents. Childhood traumatic brain injury has been associated with cognitive impairment, emotional problems, and impaired behavior control, and these neuropsychological changes may place these youth at increased risk for engagement in violence-related behaviors.

METHODS

Data from the 2017 National Youth Risk Behavior Survey (N=14,765), a nationally representative survey of U.S. high school students, were analyzed in 2019 to examine the associations between sports- and physical activity-related concussion and violence-related behaviors occurring in the community and at school. Multivariable logistic regression models were used to calculate sex-stratified, adjusted (for race/ethnicity, grade, athlete status, impaired cognitive functioning, feeling sad/hopeless, and current substance use) prevalence ratios. Prevalence ratios were considered statistically significant if p<0.05.

RESULTS

Male students (17.1%) were more likely than female students (13.0%) to experience a sports- and physical activity-related concussion during the 12 months preceding the survey. Compared with students who did not have a concussion, those who experienced ≥1 sports- and physical activity-related concussion were more likely to be in a physical fight (male students, adjusted prevalence ratio=1.45; female students, adjusted prevalence ratio=1.55), carry a weapon (male students, adjusted prevalence ratio=1.24; female students, adjusted prevalence ratio=1.79), and fight at school (male students, adjusted prevalence ratio=1.40; female students, adjusted prevalence ratio=1.77). In addition, male students were more likely to carry a gun (adjusted prevalence ratio=1.62) and carry a weapon at school (adjusted prevalence ratio=1.73).

CONCLUSIONS

Although the direction of these associations is unknown, return-to-school programs may benefit from inclusion of assessment and counseling around issues of psychological and social functioning, conflict resolution, and coordination with violence prevention programs.

Evaluation of Posttraumatic Headache Phenotype and Recovery Time After Youth Concussion

IMPORTANCE

The Four Corners Youth Consortium was created to fill the gap in our understanding of youth concussion. This study is the first analysis of posttraumatic headache (PTH) phenotype and prognosis in this cohort of concussed youth.

OBJECTIVE

To describe the characteristics of youth with PTH and determine whether the PTH phenotype is associated with outcome.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study examined outcomes from patients in a multi-institutional registry of traumatic brain injury (TBI) clinics from December 2017 to June 2019. Inclusion criteria included being between ages 5 and 18 years at enrollment and presentation within 8 weeks of a mild TBI. Data were analyzed between February 2019 and January 2021.

EXPOSURE

Mild TBI with standard care.

MAIN OUTCOMES AND MEASURES

Time to recovery and headache 3 months after injury; measurement device is the Postconcussion Symptom Inventory (PCSI). PTH with migraine phenotype was defined as moderate-severe headache that is new or significantly worse compared with baseline and associated with nausea and/or photophobia and phonophobia.

RESULTS

A total of 612 patients with 625 concussions were enrolled, of whom 387 patients with 395 concussions consented to participate in this study. One hundred nine concussions were excluded (concussions, rather than patients, were the unit of analysis), leaving 281 participants with 286 concussions (168 [58.7%] girls; 195 [75.6%] White; 238 [83.2%] aged 13-18 years). At the initial visit, 133 concussions (46.5%) were from patients experiencing PTH with a migraine phenotype, 57 (20%) were from patients experiencing PTH with a nonmigraine phenotype, and 96 (34%) were from patients with no PTH. Patients with any PTH after concussion were more likely to have prolonged recovery than those without PTH (median [interquartile range], 89 [48-165] days vs 44 [26-96] days; log-rank P < .001). Patients with PTH and a migraine phenotype took significantly longer to recover than those with nonmigraine phenotype (median [interquartile range], 95 [54-195] days vs 70 [46-119] days; log-rank P = .01). Within each phenotype, there was no significant difference between sexes in recovery or PTH at 3 months.

CONCLUSIONS AND RELEVANCE

PTH with a migraine phenotype is associated with persistent symptoms following concussion compared with nonmigraine PTH or no PTH. Given that female sex is associated with higher rates of migraine and migraine PTH, our finding may be one explanation for findings in prior studies that girls are at higher risk for persistent postconcussion symptoms than boys.

Latent Profile Analysis of Neuropsychiatric Symptoms and Cognitive Function of Adults 2 Weeks After Traumatic Brain Injury: Findings From the TRACK-TBI Study

Importance

Heterogeneity across patients with traumatic brain injury (TBI) presents challenges for clinical care and intervention design. Identifying distinct clinical phenotypes of TBI soon after injury may inform patient selection for precision medicine clinical trials.

Objective

To investigate whether distinct neurobehavioral phenotypes can be identified 2 weeks after TBI and to characterize the degree to which early neurobehavioral phenotypes are associated with 6-month outcomes.

Design, Setting, and Participants

This prospective cohort study included patients presenting to 18 US level 1 trauma centers within 24 hours of TBI from 2014 to 2019 as part of the Transforming Research and Clinical Knowledge in TBI (TRACK-TBI) study. Data were analyzed from January 28, 2020, to January 11, 2021.

Exposures

TBI.

Main Outcomes and Measures

Latent profiles (LPs) were derived from common dimensions of neurobehavioral functioning at 2 weeks after injury, assessed through National Institutes of Health TBI Common Data Elements (ie, Brief Symptom Inventory-18, Patient Health Questionnaire-9 Depression checklist, Posttraumatic Stress Disorder Checklist for DSM-5, PROMIS Pain Intensity scale, Insomnia Severity Index, Rey Auditory Verbal Learning Test, Wechsler Adult Intelligence Scale-Fourth Edition Coding and Symbol Search subtests, Trail Making Test, and NIH Toolbox Cognitive Battery Pattern Comparison Processing Speed, Dimensional Change Card Sort, Flanker Inhibitory Control and Attention, and Picture Sequence Memory subtests). Six-month outcomes were the Satisfaction With Life Scale (SWLS), Quality of Life after Brain Injury-Overall Scale (QOLIBRI-OS), Glasgow Outcome Scale-Extended (GOSE), and Rivermead Post-Concussion Symptoms Questionnaire (RPQ).

Results

Among 1757 patients with TBI included, 1184 (67.4%) were men, and the mean (SD) age was 39.9 (17.0) years. LP analysis revealed 4 distinct neurobehavioral phenotypes at 2 weeks after injury: emotionally resilient (419 individuals [23.8%]), cognitively impaired (368 individuals [20.9%]), cognitively resilient (620 individuals [35.3%]), and neuropsychiatrically distressed (with cognitive weaknesses; 350 individuals [19.9%]). Adding LP group to models including demographic characteristics, medical history, Glasgow Coma Scale score, and other injury characteristics was associated with significantly improved estimation of association with 6-month outcome (GOSE R2 increase = 0.09-0.19; SWLS R2 increase = 0.12-0.22; QOLIBRI-OS R2 increase = 0.14-0.32; RPQ R2 = 0.13-0.34).

Conclusions and Relevance

In this cohort study of patients with TBI presenting to US level-1 trauma centers, qualitatively distinct profiles of symptoms and cognitive functioning were identified at 2 weeks after TBI. These distinct phenotypes may help optimize clinical decision-making regarding prognosis, as well as selection and stratification for randomized clinical trials.

The diagnostic and prognostic utility of the dual-task tandem gait test for pediatric concussion

BACKGROUND

The tandem gait test has gained interest recently for assessment of concussion recovery. The purpose of our study was to determine the prognostic and diagnostic use of the single- and dual-task tandem gait test, alongside other clinical measures, within 10 days of pediatric concussion.

METHODS

We assessed 126 patients post-concussion (6.3 ± 2.3 days post-injury, mean ± SD) at a pediatric sports medicine clinic and compared them to 58 healthy controls (age: 15.6 ± 1.3 years; 43% female). We also compared the 31 patients with concussion who developed persistent post-concussion symptoms (PPCS) (age = 14.9 ± 2.0 years; 48% female) to the 81 patients with concussion who did not develop PPCS following the initial assessment (age: 14.1 ± 3.0 years; 41% female). All subjects completed a test battery, and concussion patients were monitored until they experienced concussion-symptom resolution. The test battery included tandem gait (single-task, dual-task (performing tandem gait while concurrently completing a cognitive test) conditions), modified Balance Error Scoring System (mBESS), and concussion symptom assessment (Health and Behavior Inventory). We defined PPCS as symptom resolution time > 28 days post-concussion for the concussion group. Measurement outcomes included tandem gait time (single- and dual-task), dual-task cognitive accuracy, mBESS errors (single/double/tandem stances), and symptom severity.

RESULTS

The concussion group completed the single-task (mean difference = 9.1 s, 95% confidential interval (95%CI): 6.1-12.1) and dual-task (mean difference = 12.7 s, 95%CI: 8.7-16.8) tandem gait test more slowly than the control group. Compared to those who recovered within 28 days of concussion, the PPCS group had slower dual-task tandem gait test times (mean difference = 7.9 s, 95%CI: 2.0-13.9), made more tandem-stance mBESS errors (mean difference = 1.3 errors, 95%CI: 0.2-2.3), and reported more severe symptoms (mean difference = 26.6 Health and Behavior Inventory rating, 95%CI: 21.1-32.6).

CONCLUSION

Worse dual-task tandem gait test time and mBESS tandem stance performance predicted PPCS in pediatric patients evaluated within 10 days of concussion. Tandem gait assessments may provide valuable information augmenting common clinical practices for concussion management.

MOVEMENT PATTERNS DIFFER BETWEEN ATHLETES AFTER SPORT-RELATED CONCUSSION COMPARED TO HEALTHY CONTROLS DURING JUMP LANDING TASK

CONTEXT

A relationship between a positive history of sport-related concussion (SRC) and lower extremity (LE) injury has been well established in the literature.

OBJECTIVE

The purpose of this study was to determine if biomechanical differences exist during a double limb jump landing (DLJ) between athletes who had been released for return to play after SRC and healthy matched controls (Healthy).

DESIGN

Cross-Sectional Study Setting: Health system-based Outpatient Sports Medicine Center Participants: 21 participants (16.33±12.7 days out from being released to return to sport after SRC) (age: 15.38±1.77; height: 169.23±8.59; mass: 63.43±7.39) were compared to 21 age, sex, activity-matched healthy controls (age: 15.36±1.73; height: 169.92±11.1; mass: 65.62±12.08). No significant differences existed between groups for descriptive data.

MAIN OUTCOME MEASURE(S)

Biomechanical performance during DLJ was assessed using Motion Capture System and force plates. The average of five consecutive trials was used to calculate lower extremity joint kinetic and kinematics. Variables of interest included internal knee extension moment, internal varus moment, and total sagittal plane knee displacement for both the dominant and non-dominant limbs. Independent t-tests were performed to examine the differences between SRC and Healthy groups for variables of interest.

RESULTS

The SRC group demonstrated greater internal knee extension moments on their dominant (KEDomDiff=-.028±.009; p=.003) and non-dominant (KENonDomDiff=-.018±.007, p=.019) limbs. The SRC group also demonstrated greater internal varus moments on their dominant (VDomDiff=.012±.004, p=.005) and non-dominant (VNonDomDiff=.010±.003, p=.005) limbs. For sagittal plane knee displacement, the SRC group demonstrated less knee flexion displacement on their dominant (DispDomDiff=-12.56±4.67, p=.011) but not their non-dominant limb (DispNonDomDiff=-8.30±4.91, p=.099).

CONCLUSIONS

Athletes who have been released for return to sport after SRC land in greater knee valgus compared to healthy matched controls.

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.

Examination of Reaction Time Deficits Following Concussion: A Systematic Review and Meta-analysis

BACKGROUND

Reaction time (RT) deficits are reported following concussion, but it is unknown when these deficits normalize to pre-injury status. It is also unclear how factors such as RT measurement technique and participant characteristics influence post-concussion RT.

OBJECTIVE

The purpose of this systematic review and meta-analysis was to (1) characterize acute post-concussion (0-3 days) RT impairments, (2) examine RT recovery over time, and (3) explore moderating factors related to acute RT impairment following concussion.

METHODS

Database searches (PubMed, CINAHL, EBSCOhost) were conducted according to PRISMA guidelines for articles published in English from January 2002 to March 2019. Studies compared baseline-to-post-injury RT within individuals (within-subject) and/or RT in concussed individuals to non-concussed controls (between-subject). Sixty studies met inclusion criteria, reporting on a total of 9688 participants with 214 discrete RT effects (Hedges' d; between-subject: N = 29, k = 129; within-subject: N = 42, k = 85). Of the 214 effects, 93 occurred in the acute (0-3 days) post-injury timeframe (k = 47 between-subject). Numerous demographic [sex, age, concussion history, population type (athlete, military, and general population), athlete level (high school, college), and sport], and method-based (RT test and measure type, computerized neurocognitive testing platform, concussion definition, and time post-injury) moderators were examined for mean effect influence. Mixed-effects multi-level modeling with restricted-maximum-likelihood estimation was used to account for nested effects and high heterogeneity for the pooled effect size (D+).

RESULTS

Significant medium-magnitude RT deficits were observed acutely for between- (D+ = - 0.7279, 95% CI - 0.9919, - 0.4639, I² = 88.66, p < 0.0001) and within-subject (D+ = - 0.7472, 95% CI - 0.9089, - 0.5855, I² = 89.21, p < 0.0001) effect models. RT deficits were present at the sub-acute and intermediate-term timeframes for between-subject effects (sub-acute: D+ = - 0.5655, 95% CI - 0.6958, - 0.4352, p < 0.0001; intermediate-term: D+ = - 0.3219, 95% CI - 0.5988, - 0.0450, p = 0.0245). No significant RT mean effect was observed for the between-subject model at the long-term timeframe, indicating RT recovery among concussed participants relative to controls (D+ = 0.3505, 95% CI - 0.4787, 1.1797, p = 0.3639). Sex was a significant moderator for between-subject effects, with every 1% male sample size increase demonstrating - 0.0171 (95% CI - 0.0312, - 0.0029, p = 0.0193) larger RT deficits. Within-subject effect models resulted in RT measure type (simple: [D+ = - 0.9826] vs. mixed: [D+ = - 0.6557], p = 0.0438) and computerized neurocognitive testing platforms (ANAM: [D+ = - 0.3735] vs. HeadMinder CRI: [D+ = - 1.4799] vs. ImPACT: [D+ = - 0.6749], p = 0.0004) having significantly different RT-deficit magnitudes. No other moderators produced significantly different RT-deficit magnitudes (between-subject: [p ≥ 0.0763], within-subject: [p ≥ 0.1723]).

CONCLUSIONS

Robust RT deficits were observed acutely following concussion. Minimal magnitude differences were noted when comparing between- and within-subject effects, suggesting that pre-injury baselines may not add clinical value in determining post-injury RT impairment. RT deficits persisted up till the intermediate-term (21-59 days post-injury) timeframe and indicate lingering deficits exist. Mean effect size differences were observed between RT measure types and computerized neurocognitive testing platforms; however, all categories displayed negative effects consistent with impaired RT following concussion. Clinical interpretation suggests that measuring RT post-concussion is more important than considering the RT method employed so long as reliable and valid tools are used. PROSPERO Registration #CRD42019119323.

Concussion in cricket: Clinical findings using Sport Concussion Assessment Tool and recovery timeframes

Objectives

To retrospectively review data of concussed and non-concussed elite cricket athletes following head impact to describe which clinical features on the day of injury are associated with concussion diagnosis. A secondary aim was to describe the recovery time of concussed athletes.

Design

Retrospective cohort study.

Methods

This study reviewed five seasons of Sport Concussion Assessment Tool (SCAT) data and clinical records for elite male and female cricket athletes who sustained a head impact during a cricket match or training.

Results

Data from 30 concussed and 37 non-concussed athletes were compared. Symptoms of ‘don’t feel right’ and ‘feeling slowed down’ had the strongest clinical utility for a concussion diagnosis post head impact. Concussed athletes reported a significantly lower ‘percent of normal’ (median 60%, IQR 60–90%) compared to athletes who sustained a non-concussive head impact (median 99%, IQR 95–100%, p = 0.003). No other component of the SCAT distinguished concussed from non-concussed athletes on day of injury. Concussed athletes typically experienced symptom resolution within 2–8 days and completed a graded return to play protocol within 4–14 days. No differences in SCAT findings or recovery times were observed between genders.

Conclusion

The SCAT may be used as a clinical tool to assist in diagnosis of concussionin elite cricket athletes. The components of the SCAT with the greatest clinical utility on day of injury were athlete-reported symptoms and ‘percent of normal’. Concussed cricket athletes typically complete their graded return to play protocol within 14 days however individualised management is paramount.

Time-to-Event Analyses: Return to Unrestricted Participation After Sport-Related Concussion in a Cohort of High School Athletes

CONTEXT

Understanding time loss resulting from sport-related concussion (SRC) within individual sports allows high school athletic trainers to provide accurate and evidence-based clinical information. Currently, research regarding patterns of clinical recovery outcomes in high school student-athletes across sports is lacking.

OBJECTIVE

To describe the time to authorized unrestricted return to participation (RTP) after SRC in a large cohort of high school student-athletes in a variety of sports using a time-to-event analysis.

DESIGN

Descriptive epidemiology study.

SETTING

Aggregate injury and player exposure data from the Michigan High School Athletic Association Head Injury Reporting System.

PATIENTS OR OTHER PARTICIPANTS

High school student-athletes.

MAIN OUTCOME MEASURE(S)

Dates for SRC injury events and authorized unrestricted RTP were entered into the Head Injury Reporting System for each case and were used to calculate time to unrestricted RTP. Survival analysis indicated the time to authorized RTP for males and females in weekly increments across sports and academic years. Separate Kaplan-Meier analyses adjusted for SRC cases with a history of concussion also identified the proportions of student-athletes who obtained authorized medical clearance in weekly increments.

RESULTS

A total of 15 821 SRCs, 10 375 (65.6%) in males and 5446 (34.4%) in females, were reported during the 2015-2016 through 2018-2019 academic years. The median time to authorized unrestricted RTP was 11 days for all patients. Approximately 30% of concussed student-athletes were not cleared for unrestricted RTP by 14 days after their SRC diagnosis, with 13% taking longer than 21 days to return to unrestricted RTP after SRC.

CONCLUSIONS

The results from this multisite, state-based injury surveillance system indicated that it is not abnormal for high school student-athletes to take longer than 14 days to fully recover from an SRC. This information may be useful for educating high school student-athletes and sport stakeholders, normalizing SRC recovery trajectory perceptions, and establishing realistic RTP timeline expectations.

Functional recovery after brain injury: Independent predictors of psychosocial outcome one year after TBI

INTRODUCTION

Traumatic Brain Injury (TBI) is the leading cause of death and disability in people aged under 40 in the UK. Many patients suffer residual deficits, which limits their functional recovery. The aim of this study was to determine independent predictors of functional outcome at 1-year post-TBI.

METHODS

Utilising a prospective observational cohort design, 1131 consecutive adult admissions with non-recurrent TBI were recruited from the ED (Emergency Department). Using routine consultant-led follow up clinics, data was collected between August 2011 and July 2015. The Rivermead Head Injury Follow Up Questionnaire (RHFUQ) was used to measure psychosocial function at 1 year.

RESULTS

A multiple linear regression model showed that previous psychiatric history (p < 0.001), lower Glasgow Coma Scale (p < 0.001), a severe CT scan (p = 0.002), aetiology of assault compared to sport (p = 0.011) and falls (p = 0.005), initial unemployment (p < 0.001) and no job at 8-10 weeks (p < 0.001) after TBI had a significant association with a worse RHFUQ score at 1 year. Follow up rate was >90 %.

CONCLUSIONS

This study adds valuable information on the prognostic indicators of TBI recovery and possible targets for intervention. Future development of a validated prognostic model to predict long term functional outcomes after TBI will help improve long-term treatment of the condition.

Participation Restrictions among Children and Young Adults with Acquired Brain Injury in a Pediatric Outpatient Rehabilitation Cohort: The Patients' and Parents' Perspective

Improving participation is an important aim in outpatient rehabilitation treatment. Knowledge regarding participation restrictions in children and young adults with acquired brain injury (ABI) is scarce and little is known regarding the differences in perspectives between patients and parents in the outpatient rehabilitation setting. The aims are to describe participation restrictions among children/young adults (5–24 years) with ABI and investigating differences between patients’ and parents’ perspectives. At admission in 10 rehabilitation centers, patients and parents were asked to complete the Child and Adolescent Scale of Participation (CASP; score 0–100; lower score = more restrictions) and injury/patient/family-related questions. CASP scores were categorized (full/somewhat-limited/limited/very-limited participation). Patient/parent-reported outcomes were compared using the Wilcoxon signed-rank test. 223 patients and 245 parents participated (209 paired-samples). Median patients’ age was 14 years (IQR; 11–16), 135 were female (52%), 195 had traumatic brain injury (75%). The median CASP score reported by patients was 82.5 (IQR: 67.5–90) and by parents 91.3 (IQR: 80.0–97.5) (difference = p < 0.05). The score of 58 patients (26%) and 25 parents (10%) was classified as ‘very-limited’. Twenty-six percent of children and young adults referred for rehabilitation after ABI had “very-limited” participation. Overall, parents rated their child’s participation better than patients themselves. Quantifying participation restrictions after ABI and considering both perspectives is important for outpatient rehabilitation treatment.

The Influence of Family History of Neurodegenerative Disease on Adolescent Concussion Outcomes

Evidence suggests that factors associated with a family history of neurodegenerative disease (fhNDD) may influence outcomes following a concussion. However, the relevance of these findings in adolescent populations has not been fully explored. Therefore, the present study sought to evaluate the relationship between fhNDD and neurological outcomes following an adolescent concussion. Data from a local pediatric concussion clinic were used to compare adolescents with (n = 22) and without (n = 44) an fhNDD. Clinical symptom burden, emotional health, cardio-autonomic function, and cognitive performance were assessed at initial (~2 weeks) and follow-up (~5 weeks) post-injury evaluations. Cardio-autonomic function was assessed at rest and during isometric handgrip contraction (IHGC). Results indicated no significant group differences in emotional health or cognitive performance. Across evaluations, those with an fhNDD exhibited greater somatic symptom severity, alterations in HRV at rest, and early blunted cardio-autonomic reactivity during IHGC compared to those without an fhNDD. These findings suggest that positive fhNDD is negatively associated with clinical symptomology and cardio-autonomic functioning following an adolescent concussion. Further, these findings encourage clinicians to utilize a comprehensive neurological evaluation to monitor concussion recovery. Future studies should look into exploring the role of specific neurodegenerative processes and conditions on concussion outcomes in adolescents.

Symptom Provocation During Aerobic and Dynamic Supervised Exercise Challenges in Adolescents With Sport-Related Concussion

CONTEXT

Supervised exercise challenges (SECs) have been shown to be safe and beneficial in the early symptomatic period after concussion. Thus far, most in-clinic SECs studied have included a form of basic aerobic exercise only. An SEC that also includes dynamic forms of exercise mimics all steps of a standard return-to-play progression and may enhance the detection of concussion symptoms to guide in-clinic management decisions.

OBJECTIVE

To determine whether an SEC that includes a dynamic SEC (DSEC) uncovered symptoms that would not have been identified by an SEC involving an aerobic SEC (ASEC) alone in adolescent patients with sport-related concussion.

DESIGN

Retrospective case series.

SETTING

Multidisciplinary sport concussion clinic at a tertiary care center.

PATIENTS OR OTHER PARTICIPANTS

A total of 65 adolescent athletes (mean age = 14.9 ± 2.0 years, 72.3% males) who underwent an in-clinic SEC within 30 days of concussion.

MAIN OUTCOME MEASURE(S)

Presence of pre-exercise symptoms and symptom provocation during the SEC were recorded, with exercise-provoked symptoms categorized as occurring during ASEC or DSEC.

RESULTS

Of the total patient sample, 69.2% (n = 45/65) experienced symptom provocation at some point during the SEC. Symptoms were provoked in 20 patients during the ASEC, whereas 25 completed the ASEC without symptom provocation before becoming symptomatic during the subsequent DSEC and 20 completed the SEC without any symptom provocation. Of the 65 patients in the total sample, 46 were asymptomatic immediately before the SEC. Of these previously asymptomatic patients, 23.9% (n = 11/46) experienced symptom provocation during the ASEC, and an additional 37.0% (n = 17/46) remained asymptomatic during the ASEC but then developed symptoms during the DSEC.

CONCLUSIONS

The ASEC alone may not detect symptom provocation in a significant proportion of concussion patients who otherwise would develop symptoms during a DSEC.

Postconcussion Syndrome: A Diagnosis of Past Diagnostic and Statistical Manual of Mental Disorders

ABSTRACT

After concussion, a subset of patients have persistent symptoms that are functionally limiting and may be difficult to treat. These symptoms were previously captured in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) under the diagnosis of "Post-Concussion Syndrome." However, in the recently published fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, postconcussion syndrome has been eliminated. The elimination of "Post-Concussion Syndrome" moves the Diagnostic and Statistical Manual of Mental Disorders further away from congruence with the International Classification of Diseases (ICD-10) with respect to the classification of postconcussion symptomology. Although this change likely had the positive effect of reducing misdiagnoses of symptoms due to other causes, the authors highlight the potential issues surrounding the elimination of postconcussion syndrome in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. This opinion piece also emphasizes the multiple diagnostic and therapeutic challenges that may result for those involved in the treatment of, or research regarding, concussion patients with persistent symptoms. Future revisions that provide clear clinical diagnostic criteria may be beneficial.

Loss of Consciousness is Associated with Elevated Cognitive Intra-Individual Variability Following Sports-Related Concussion

OBJECTIVE

The purpose of this study was to evaluate whether loss of consciousness (LOC), retrograde amnesia (RA), and anterograde amnesia (AA) independently influence a particular aspect of post-concussion cognitive functioning-across-test intra-individual variability (IIV), or cognitive dispersion.

METHOD

Concussed athletes (N = 111) were evaluated, on average, 6.04 days post-injury (SD = 5.90; Mdn = 4 days; Range = 1-26 days) via clinical interview and neuropsychological assessment. Primary outcomes of interest included two measures of IIV-an intra-individual standard deviation (ISD) score and a maximum discrepancy (MD) score-computed from 18 norm-referenced variables.

RESULTS

Analyses of covariance (ANCOVAs) adjusting for time since injury and sex revealed a significant effect of LOC on the ISD (p = .018, ηp2 = .051) and MD (p = .034, ηp2 = .041) scores, such that athletes with LOC displayed significantly greater IIV than athletes without LOC. In contrast, measures of IIV did not significantly differ between athletes who did and did not experience RA or AA (all p > .05).

CONCLUSIONS

LOC, but not RA or AA, was associated with greater variability, or inconsistencies, in cognitive performance acutely following concussion. Though future studies are needed to verify the clinical significance of these findings, our results suggest that LOC may contribute to post-concussion cognitive dysfunction and may be a risk factor for less efficient cognitive functioning.

Post-concussion symptoms in sports-related mild traumatic brain injury compared to non-sports-related mild traumatic brain injury

OBJECTIVES

To compare post-concussion symptoms in patients who sustained a sports-related mild traumatic brain injury (TBI) to those with non-sports-related mild TBI at 7 and 90 days post-injury.

METHODS

This prospective multicentre cohort study took place in seven Canadian Emergency Departments (ED). Non-hospitalized patients aged ≥ 14 years with a documented mild TBI that occurred ≤ 24 h of ED visit and a Glasgow Coma Scale score ≥ 13 were included. Main outcome measure was the presence of ≥ 3 symptoms on the Rivermead Post-concussion Questionnaire at 90 days post-injury. Secondary outcomes were the prevalence of (1) individual Rivermead Post-concussion Questionnaire symptom, (2) total Rivermead Post-concussion Questionnaire score ≥ 21 and (3) return to normal daily activities. Adjusted risk ratios (RR) were calculated.

RESULTS

1727 patients were included, 363 (21.0%) sustained a sports-related mild TBI. Similar proportions of patients with ≥ 3 symptoms, a Rivermead Post-concussion Questionnaire score ≥ 21 and those who returned to their normal daily activities were observed at 7 and 90 days post-injury. Sports-related mild TBI patients were at higher risk of poor concentration [RR: 1.3 (95% CI 1.05-1.54)] and non-return to sports activities [RR: 2.2 (95% CI 1.69-2.94)] at 7 days post-injury. At 90 days, sports-relate -mild TBI patients reported less fatigue [RR: 0.7 (95% CI 0.51-0.98)] and feeling of dizziness [RR: 0.6 (95% CI 0.35-0.99)].

CONCLUSION

Patients who sustained sports-related mild TBI could be at lower risk of experiencing symptoms such as fatigue and dizziness 90 days post-injury. Clinicians should be mindful that non-sports-related mild TBI patients may experience more post-concussion symptoms and that the level of physical activity may influence the patient's rehabilitation.

Prolonged elevation of serum neurofilament light after concussion in male Australian football players

Background

Biomarkers that can objectively guide the diagnosis of sports-related concussion, and consequent return-to-play decisions, are urgently needed. In this study, we aimed to determine the temporal profile and diagnostic ability of serum levels of neurofilament light (NfL), ubiquitin carboxy-terminal hydrolase L1 (UCHL1), glial fibrillary acidic protein (GFAP), and tau in concussed male and female Australian footballers.

Methods

Blood was collected from 28 Australian rules footballers (20 males, 8 females) at 2-, 6-, and 13-days after a diagnosed concussion for comparison to their levels at baseline (i.e. pre-season), and with 27 control players (19 males, 8 females) without a diagnosis of concussion. Serum concentrations of protein markers associated with damage to neurons (UCHL1), axons (NfL, tau), and astrocytes (GFAP) were quantified using a Simoa HD-X Analyzer. Biomarker levels for concussed players were compared over time and between sex using generalised linear mixed effect models, and diagnostic performance was assessed using area under the receiver operating characteristic curve (AUROC) analysis.

Results

Serum NfL was increased from baseline in male footballers at 6- and 13-days post-concussion. GFAP and tau were increased in male footballers with concussion at 2- and 13-days respectively. NfL concentrations discriminated between concussed and non-concussed male footballers at all time-points (AUROC: 2d = 0.73, 6d = 0.85, 13d = 0.79), with tau also demonstrating utility at 13d (AUROC = 0.72). No biomarker differences were observed in female footballers after concussion.

Conclusions

Serum NfL may be a useful biomarker for the acute and sub-acute diagnosis of concussion in males, and could inform neurobiological recovery and return-to-play decisions. Future adequately powered studies are still needed to investigate biomarker changes in concussed females.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40364-020-00256-7.

Associations between frequent pain or headaches and neurobehavioral symptoms by gender and TBI severity

Objective: To investigate differences in frequent pain or headaches and associated neurobehavioral symptoms among men, women, and transgender individuals with and without a history of traumatic brain injury (TBI).Setting: CommunityParticipants: English and Spanish-speaking adults (n = 2,862) with and without self-reported TBIDesign: Cross-sectional studyMain Measures: Behavioral Assessment Screening Tool (BAST) subscales for Negative Affect, Substance Abuse, Executive Function, Fatigue, Impulsivity, and one item for experiencing "frequent pain or headache."Results: Women reported more pain than men. Women with a mild TBI (mTBI) more often reported frequent headaches/pain than woman in general or those with mTBI alone. Women reporting frequent headache/pain reported more negative affect and fatigue than men with comparable TBI history. Individuals identifying as transgender/other without TBI had higher negative affect and fatigue than both men and women without TBI. Individuals with mTBI and frequent headache/pain reported more executive function problems than those with mTBI without headache/pain. Pain and moderate/severe TBI were associated with more executive function problems in men and women, but more so for women.Conclusion: Results suggest frequent headache/pain may differ between genders, particularly after mTBI. Pain, fatigue, executive function, and negative affect may be especially important in women's recovery from TBI.

Positive association between serum quinolinic acid and functional connectivity following concussion

The molecular mechanisms underlying the diverse psychiatric and neuropathological sequalae documented in subsets of athletes with concussion have not been identified. We have previously reported elevated quinolinic acid (QuinA), a neurotoxic kynurenine pathway metabolite, acutely following concussion in football players with prior concussion. Similarly, work from our group and others has shown that increased functional connectivity strength, assessed using resting state fMRI, occurs following concussion and is associated with worse concussion-related symptoms and outcome. Moreover, other work has shown that repetitive concussion may have cumulative effects on functional connectivity and is a risk factor for adverse outcomes. Understanding the molecular mechanisms underlying these cumulative effects may ultimately be important for therapeutic interventions or the development of prognostic biomarkers. Thus, in this work, we tested the hypothesis that the relationship between QuinA in serum and functional connectivity following concussion would depend on the presence of a prior concussion. Concussed football players with prior concussion (N = 21) and without prior concussion (N = 16) completed a MRI session and provided a blood sample at approximately 1 days, 8 days, 15 days, and 45 days post-injury. Matched, uninjured football players with (N = 18) and without prior concussion (N = 24) completed similar visits. The association between QuinA and global connectivity strength differed based on group (F(3, 127) = 3.46, p = 0.019); post-hoc analyses showed a positive association between QuinA and connectivity strength in concussed athletes with prior concussion (B = 16.05, SE = 5.06, p = 0.002, 95%CI[6.06, 26.03]), but no relationship in concussed athletes without prior concussion or controls. Region-specific analyses showed that this association was strongest in bilateral orbitofrontal cortices, insulae, and basal ganglia. Finally, exploratory analyses found elevated global connectivity strength in concussed athletes with prior concussion who reported depressive symptoms at the 1-day visit compared to those who did not report depressive symptoms (t(15) = 2.37, mean difference = 13.50, SE = 5.69, p = 0.032, 95%CI[1.36, 25.63], Cohen's d = 1.15.). The results highlight a potential role of kynurenine pathway (KP) metabolites in altered functional connectivity following concussion and raise the possibility that repeated concussion has a "priming" effect on KP metabolism.

Preinjury and Postinjury Factors That Predict Sports-Related Concussion and Clinical Recovery Time

OBJECTIVES

To evaluate the relationship between preinjury risk factors (RFs) and subsequent occurrence of concussion and examine whether preinjury RFs or postinjury assessments predict clinical recovery in collegiate athletes.

METHODS

Risk factors (sex, sport, and self-report history of concussion, migraine, attention-deficit disorder, learning disability, depression, and anxiety) and Sport Concussion Assessment Tool (SCAT), depression/anxiety screenings, and neuropsychological testing were obtained before the season. For athletes who sustained concussion, RFs, postinjury SCAT, neuropsychological assessment, and clinical recovery were assessed.

RESULTS

We assessed 1152 athletes (69% male) at baseline and 145 (75% male) after subsequent concussion diagnosis. Only sport type (Wald = 40.29, P = 0.007) and concussion history (Wald = 9.91, P = 0.007) accounted for unique variance in subsequent concussion. Of athletes followed until full recovery, mean days until symptom-free (DUSF) was 9.84 ± 11.11 days (n = 138, median = 5 days, range = 1-86) and mean days until full return to play (DUFRTP) was 20.21 ± 19.17 (n = 98, median = 20.21, range = 4-150). None of the RFs or baseline testing measures were associated with DUSF or DUFRTP (P's > 0.05). After injury, athletes who reported more total symptoms (rs = 0.31, P < 0.001) and higher symptom severity (rs = 0.33, P < 0.001) exhibited longer DUSF. Days until symptom-free correlated with DUFRTP (rs = 0.75, P < 0.001). Among athletes assessed within 2 days after injury, DUSF was associated with Immediate Postconcussion Assessment and Cognitive Test visual motor (rs = -0.31, P = 0.004), reaction time (rs = 0.40, P < 0.001), and symptom score (rs = 0.54, P < 0.001).

CONCLUSIONS

Only sport type and concussion history predicted subsequent occurrence of concussion, and none of the RFs or baseline measures predicted clinical recovery. Immediate postinjury assessments, including symptom number and severity, and select clinical measures predicted longer clinical recovery.

Graded Exercise Testing Predicts Recovery Trajectory of Concussion in Children and Adolescents

OBJECTIVE

To determine whether graded exercise testing can predict recovery trajectory of concussion in children and adolescents.

DESIGN

Prospective study.

SETTING

Children's Hospital, Westmead, Australia.

PARTICIPANTS

One hundred thirty-nine children aged 12 to 16 years at 5 to 7 days after an acute concussive injury.

INTERVENTION

Graded exercise testing on a treadmill at the subacute phase to assess symptom provocation and determine clinical recovery indicating readiness to commence a return to activity (RTA) protocol. Exercise time to symptom exacerbation and clinical recovery were measured.

MAIN OUTCOME MEASURES

Standard concussion assessment and clinical testing (neurocognitive, vestibular/ocular, and balance) were conducted to determine major clinical drivers/indicators.

RESULTS

Participants (mean age 12.4 ± 2.8 years, 73% male) had a confirmed sport-related concussion. The main clinical drivers identified on exercise testing were headache, balance, and vestibular dysfunction. Participants fell into 1 of 2 groups, exercise-tolerant (54%) and exercise-intolerant (46%). Exercise-tolerant patients showed mild clinical indicators, no symptom exacerbation during 10.3 ± 3.3 minutes of exercise, were safely transitioned to a RTA protocol, and recovered within 10 days. Exercise-intolerant patients had high clinical indicators, significant symptom exacerbation at 4.2 ± 1.6 minutes of exercise, and prolonged recovery of 45.6 days. No adverse effects from exercise were reported in either group. Combined use of provocative exercise and clinical testing was 93% predictive of outcome.

CONCLUSIONS

Exercise testing during the subacute phase after a concussion can predict longer recovery. Exercise testing can identify a unique window where patients can be safely transitioned to activity, enabling clinicians to better inform patients and families, allocate resources and streamline care.

Understanding Traumatic Brain Injury in Females: A State-of-the-Art Summary and Future Directions

In this report, we identify existing issues and challenges related to research on traumatic brain injury (TBI) in females and provide future directions for research. In 2017, the National Institutes of Health, in partnership with the Center for Neuroscience and Regenerative Medicine and the Defense and Veterans Brain Injury Center, hosted a workshop that focused on the unique challenges facing researchers, clinicians, patients, and other stakeholders regarding TBI in women. The goal of this "Understanding TBI in Women" workshop was to bring together researchers and clinicians to identify knowledge gaps, best practices, and target populations in research on females and/or sex differences within the field of TBI. The workshop, and the current literature, clearly highlighted that females have been underrepresented in TBI studies and clinical trials and have often been excluded (or ovariectomized) in preclinical studies. Such an absence in research on females has led to an incomplete, and perhaps inaccurate, understanding of TBI in females. The presentations and discussions centered on the existing knowledge regarding sex differences in TBI research and how these differences could be incorporated in preclinical and clinical efforts going forward. Now, a little over 2 years later, we summarize the issues and state of the science that emerged from the "Understanding TBI in Women" workshop while incorporating updates where they exist. Overall, despite some progress, there remains an abundance of research focused on males and relatively little explicitly on females.

Sleep Deprived or Concussed? The Acute Impact of Self-Reported Insufficient Sleep in College Athletes

OBJECTIVE

Sleep deprivation is common among both college students and athletes and has been correlated with negative health outcomes, including worse cognition. As such, the current study sought to examine the relationship between sleep difficulties and self-reported symptoms and objective neuropsychological performance at baseline and post-concussion in collegiate athletes.

METHOD

Seven hundred seventy-two collegiate athletes completed a comprehensive neuropsychological test battery at baseline and/or post-concussion. Athletes were separated into two groups based on the amount of sleep the night prior to testing. The sleep duration cutoffs for these group were empirically determined by sample mean and standard deviation (M = 7.07, SD = 1.29).

RESULTS

Compared with athletes getting sufficient sleep, those getting insufficient sleep the night prior to baseline reported significantly more overall symptoms and more symptoms from each of the five symptom clusters of the Post-Concussion Symptom Scale. However, there were no significant differences on objective performance indices. Secondly, there were no significant differences on any of the outcome measures, except for sleep symptoms and headache, between athletes getting insufficient sleep at baseline and those getting sufficient sleep post-concussion.

CONCLUSION

Overall, the effect of insufficient sleep at baseline can make an athlete appear similar to a concussed athlete with sufficient sleep. As such, athletes completing a baseline assessment following insufficient sleep could be underperforming cognitively and reporting elevated symptoms that would skew post-concussion comparisons. Therefore, there may need to be consideration of prior night's sleep when determining whether a baseline can be used as a valid comparison.

First-time sports-related concussion recovery revisited: management changes and impact on recovery

Context

Concussion is among the most common injuries in athletes. Over the past 10 years, concussion knowledge has expanded, and guidelines for management have changed. Recent changes include recommendations against strict mental and physical rest after sustaining a concussion, a better recognition of preexisting conditions predisposing protracted concussion recovery, and the addition of preliminary patient counseling and education about the expected course of concussion recovery.

Objective

To assess the impact of changes in concussion management on the duration of symptoms in middle school and high school athletes after sustaining a first-time, sports-related concussion.

Methods

A retrospective review was performed of medical records of athletes who sustained a concussion between 2016 and 2018 and were treated by the same primary care physician (J.M.N) using the revised approach to concussion management described. Patients were included if they were 11 to 18 years old and had a diagnosis of first-time concussion sustained while playing organized sports. Athletes who sustained a concomitant injury or sustained a concussion outside of organized sports were excluded from the study; athletes lost to follow-up or with incomplete forms were also excluded. Each athlete's length of symptomatic time from his or her concussion was calculated. This data was then compared with a previously-published data set of athletes who sustained a concussion between 2011 and 2013, with the same inclusion criteria but a different approach to concussion management.

Results

A total of 110 male and 72 female athletes (N=182) met the study's eligibility criteria. Collectively, athletes of both sexes from the 2016-2018 data set reported a higher incidence of preexisting conditions associated with prolonged concussion recovery compared with the data set of 2011-2013 athletes. However, both sexes from the 2016-2018 data set also reported a shorter median duration of concussion symptoms compared with the 2011-2013 athletes (median duration 5 vs. 11 days for male athletes and 7 vs. 28 days for female athletes, respectively; p<0.001).

Conclusion

Recent changes in concussion management have led to decreased duration of symptoms among 11- to 18-year-old athletes with first-time, sports-related concussions. These management changes include advocating for early activity, recognizing preexisting conditions, and educating athletes about the realities of concussion recovery.

Dual-Task Gait Recovery after Concussion among Female and Male Collegiate Athletes

PURPOSE

Few studies have investigated recovery between sexes using objective outcome measures. Our purpose was to examine the independent association between biological sex and recovery of postconcussion gait among collegiate athletes.

METHODS

We evaluated participants with a diagnosed concussion <7 d postinjury, and approximately 1.5 months and 3.5 months postinjury. Participants completed a single/dual-task gait evaluation and symptom inventory. During dual-task trials, they completed a mental task (backward subtraction, spelling, or month recitation). The primary outcome measure was height-adjusted gait velocity recovery, defined as achieving normal gait velocity using established values: >0.56 and >0.50 gait velocity (m·s)/height (m) under single and dual-task conditions, respectively. We used a multivariable Cox proportional hazard model to identify associations between sex and dual-task recovery, controlling for age, concussion history, symptom severity, and loss of consciousness at the time of injury.

RESULTS

Ninety-four individuals participated in the study: 47 (50%) were female athletes (mean age = 20.1, SD = 1.3 yr) and 47 (50%) were male athletes (mean age = 20.3, SD = 1.3 yr). Sex was not independently associated with height-adjusted single-task gait velocity recovery after controlling for potential confounders (hazard ratio = 1.62, 95% confidence interval = 0.87-3.01). However, male sex was independently associated with longer dual-task gait recovery time after controlling for potential confounders (hazard ratio = 2.43, 95% confidence interval = 1.11-5.35).

CONCLUSION

Male athletes required a longer duration of time after concussion to achieve dual-task gait recovery than female athletes. Thus, functional dual-task abilities after concussion may be affected differentially by sex and should be accounted for within individualized concussion management strategies.

The Effects of On-Field Heat Index and Altitude on Concussion Assessments and Recovery Among NCAA Athletes

BACKGROUND

Recent literature has indicated altitude may be a protective factor for concussion but it is unknown whether altitude or heat index affects recovery.

OBJECTIVE

To examine whether on-field heat index and altitude at the time of injury alter acute (< 48 h) concussion assessments, days-to-asymptomatic, and days-to-return-to-play in collegiate athletes following concussion.

METHODS

Collegiate athletes (n = 187; age = 19.7 ± 1.4 years; male = 70.6%) underwent baseline assessments across 30 universities and experienced a concussion in this retrospective cohort study. Altitude (m) and heat index (°C) at the time and location of injury were determined using valid online database tools. Acute concussion assessments included the Sport Concussion Assessment Tool (SCAT) symptom inventory, Balance Error Scoring System (BESS), and the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT). We used multiple linear regression models to determine whether heat index and altitude predicted each acute assessment outcome, days-to-asymptomatic, and days-to-return-to-play.

RESULTS

Collegiate athletes were concussed at a 181.1 m (range - 0.6 to 2201.9 m) median altitude and 17.8 °C (range - 6.1 to 35.6 °C) median heat index. Altitude did not predict (p ≥ 0.265) any outcomes. Every one-degree increase in heat index reduced days-to-asymptomatic (p = 0.047; R² = 0.06) and days-to-return-to-play (p = 0.006; R² = 0.09) by 0.05 and 0.14 days, respectively. Heat index and altitude did not explain significant variance in SCAT, BESS, and ImPACT composite scores (p's = 0.20-0.922).

CONCLUSION

Our findings suggest that on-field altitude and heat index at the time of injury do not contribute to clinically meaningful changes on acute assessments or concussion recovery. On-field altitude and heat index do not appear to significantly alter assessment outcomes or clinical recovery, suggesting that environmental factors at altitudes below < 2500 m are negligible outcomes for researchers and clinicians to consider post-concussion.

Influence of Anxiety on Baseline Cognitive Testing and Symptom Reporting in Adolescent Student Athletes

Anxiety symptoms are commonly endorsed by student athletes. This study examined the possible influence of anxiety on baseline cognitive testing and symptom reporting in a large sample of adolescent student athletes. Participants were 37,945 adolescent student athletes from the state of Maine who completed baseline testing using ImPACT^®. ImPACT includes an evaluation of cognitive functioning and a questionnaire assessing the presence and severity of common post-concussion symptoms. Participants were divided into high and low anxiety groups based on endorsement of anxiety-like symptoms. Student athletes in the high anxiety group were more likely to be girls and to have a greater lifetime history of treatment for mental health problems and headaches (ps < 0.001). The high anxiety group scored slightly lower on cognitive tests (Cohen ds = 0.15-0.26) and reported a much greater amount of baseline pre-season symptoms (Cohen d = 3.38). More than eight of 10 youth in the high anxiety group (82.7%) met International Statistical Classification of Diseases and Related Health Problems-10th Revision (ICD-10) symptom criteria for at least a mild form of the postconcussional syndrome compared with less than two of 10 (18.4%) in the low anxiety group. Students in the high anxiety group had slightly lower scores on neurocognitive testing, but the differences were not practically meaningful; however, they endorsed dramatically more physical, cognitive, and emotional symptoms. Anxiety can mimic the ICD-10 postconcussional syndrome in adolescent student athletes at baseline, when they have not been injured.

Neuromodulation for Mild Traumatic Brain Injury Rehabilitation: A Systematic Review

Background: Mild traumatic brain injury (mTBI) results from an external force to the head or body causing neurophysiological changes within the brain. The number and severity of symptoms can vary, with some individuals experiencing rapid recovery, and others having persistent symptoms for months to years, impacting their quality of life. Current rehabilitation is limited in its ability to treat persistent symptoms and novel approaches are being sought to improve outcomes following mTBI. Neuromodulation is one technique used to encourage adaptive neuroplasticity within the brain. Objective: To systematically review the literature on the efficacy of neuromodulation in the mTBI population. Method: A systematic review was conducted using Medline, Embase, PsycINFO, PsycARTICLES and EBM Review. Preferred Reporting Items for Systematic Reviews and the Synthesis Without Meta-analysis reporting guidelines were used and a narrative review of the selected studies was completed. Fourteen articles fulfilled the inclusion criteria which were published in English, investigating an adult sample and using a pre- and post-intervention design. Studies were excluded if they included non-mild TBI severities, pediatric or older adult populations. Results: Thirteen of fourteen studies reported positive reductions in mTBI symptomatology following neuromodulation. Specifically, improvements were reported in post-concussion symptom ratings, headaches, dizziness, depression, anxiety, sleep disturbance, general disability, cognition, return to work and quality of life. Normalization of working memory activation patterns, vestibular field potentials, hemodynamics of the dorsolateral prefrontal cortex and excessive delta wave activity were also seen. The studies reviewed had several methodological limitations including small, heterogenous samples and varied intervention protocols, limiting generalisability. Further research is required to understand the context in which neuromodulation may be beneficial. Conclusions: While these positive effects are observed, limitations included unequal representation of neuromodulation modalities in the literature, and lack of literature describing the efficacy of neuromodulation on the development or duration of persistent mTBI symptoms. Better clarity regarding neuromodulation efficacy could have a significant impact on mTBI patients, researchers, clinicians, and policy makers, facilitating a more productive post-mTBI population. Despite the limitations, the literature indicates that neuromodulation warrants further investigation. PROSPERO registration number: CRD42020161279.

Headache- and Dizziness-Specific Health-Related Quality-of-Life Impairments Persist for 1 in 4 Amateur Athletes Who Are Cleared to Return to Sporting Activity Following Sport-Related Concussion: A Prospective Matched-Cohort Study

OBJECTIVES

To prospectively investigate the recovery of athlete-reported symptoms and the condition-specific health-related quality of life (HRQoL) following sport-related concussion.

DESIGN

Prospective matched-cohort study.

METHODS

We recruited amateur athletes who were diagnosed with sport-related concussion by emergency department physicians. Study participants were assessed at 3 time points following sport-related concussion. At each assessment, participants completed 5 condition-specific HRQoL patient-reported outcome measures to evaluate participants' perceptions of the effects of specific concussion-related symptoms on their HRQoL. We performed log-linear analyses to assess the proportion of concussed participants with clinically impaired condition-specific HRQoL compared with the proportion of participants in the control group with clinically impaired condition-specific HRQoL.

RESULTS

Fifty participants with sport-related concussion and 50 control participants matched by sex, age, and activity completed the study. Upon return to sporting activity, there was a significantly greater proportion of participants in the concussion group who perceived that headache, neck pain, and dizziness had an adverse effect on their HRQoL compared with the control group. Two weeks after return to sporting activity, there was still a significantly greater proportion of participants in the concussion group who perceived that headache (χ²₁ = 9.0; odds ratio [OR] = 4.4; 95% confidence interval [CI]: 1.5, 15.2; P = .003) and dizziness (χ²₁ = 9.5; OR = 13.5; 95% CI: 1.8, 604.9; P = .006) had an adverse effect on their HRQoL compared with the proportion of clinically impaired participants in the control group.

CONCLUSION

Of concussed participants, 1 in 4 perceived that headache and dizziness had adverse effects on their HRQoL after returning to sporting activity following sport-related concussion compared with nonconcussed, control participants. J Orthop Sports Phys Ther 2020;50(12):692-701. doi:10.2519/jospt.2020.9485.

Sex differences in reporting of concussion symptoms in adults

OBJECTIVE

To examine differences in concussion symptom reporting between female and male adults considering current psychological symptoms such as anxiety and depression and pre-injury factors in order to identify sex differences which may guide treatment efforts. Method: This prospective study is part of the North Texas Concussion Registry (ConTex). Subjects (N = 132) age 19 to 78 years had sustained a concussion within 30 days of clinic visit. The independent variable was sex and covariates included age, ethnicity, current anxiety and depression ratings, history of attention deficit disorder, history of headache/migraine, and time to clinic. The dependent variables were 22 post-concussion symptoms as measured by the Sport Concussion Assessment Tool-5 Post-Concussion Symptom Scale. Results: Analysis of covariance and ordinal logistic regression results both revealed that females had a greater likelihood of reporting increased symptom severity for 15/22 concussion symptoms. The largest risk ratios (effect size) in symptom reporting between sexes (higher symptoms in females) included: feeling more emotional 4.05 (0.72), fatigue or low energy 4.05 (0.72), sensitivity to light 3.74 (0.69), headache 3.65 (0.57), balance problems 3.31 (0.53), pressure in head 3.06 (0.51), and neck pain 2.97 (0.60). Conclusions: Adult females in our sample reported higher levels of many concussion symptoms than males and showed an increased risk of developing these same symptoms following concussion. Examination of the magnitude of sex difference in concussion symptom reporting will better inform medical staff to anticipate and address symptoms that may present greater challenges for adult females.

A randomized cohort study of the efficacy of PO magnesium in the treatment of acute concussions in adolescents

INTRODUCTION/STUDY OBJECTIVE

Concussions are becoming a growing concern in society today with one out of every five adolescents being affected. This accounts for 1.6 to 3.8 million emergency department visits annually. The current standard of care involves an initial period of mental rest with symptomatic care and symptom-based return to daily activities/sports. High dose IV magnesium has been proven to be neuroprotective in severe TBI. We hypothesized that oral magnesium replacement following a concussion will decrease the overall symptomatic period allowing a quicker return to functional baseline.

METHODS

We used a randomized cohort study involving patients aged 12-18 who presented within 48 h after a concussion. Our study design had a treatment arm including acetaminophen, ondansetron, and magnesium PO and a placebo arm of acetaminophen and ondansetron. We then utilized the Post- Concussion Severity Score (PCSS) to evaluate the extent of the patient's symptoms. This score was collected immediately prior to obtaining medications, 1 h, 48 h, and 120 h after starting the study. The study relied on outpatient follow up through phone conversations, and a Sports Medicine clinic locally.

RESULTS

Our data shows that there was a statistically significant decrease in the PCSS at 48 h (p = 0.016) in the magnesium group relative to the placebo treatment arm. This study does imply that magnesium supplementation has potential benefit in treatment of concussions acutely.

CONCLUSION

Oral magnesium replacement decreases symptoms acutely following a concussion and should be provided with symptomatic management following a concussion in the emergency setting.

Using functional movement tests to investigate the presence of sensorimotor impairment in amateur athletes following sport-related concussion: A prospective, longitudinal study

OBJECTIVE

To longitudinally investigate the presence of sensorimotor impairments in amateur athletes following sport-related concussion using two functional movement tests.

DESIGN

Prospective, longitudinal study.

SETTING

Human movement analysis laboratory.

PARTICIPANTS

Athletes who presented to a hospital emergency department and were diagnosed with sport-related concussion, and sex-, age-, and activity-matched non-concussed, control athletes. Concussed participants were assessed within one-week following sport-related concussion, upon clearance to return-to-sporting activity (RTA), and two weeks after RTA. Control participants were assessed at an initial time-point and approximately two and four weeks following their initial study assessment.

MAIN OUTCOMES MEASURES

At each laboratory assessment, participants completed two functional movement tests: the Star Excursion Balance Test to evaluate anterior reach distance (normalised for leg length) and fractal dimension (centre of pressure path complexity), and the Multiple Hop Test to evaluate corrective postural strategies and time-to-stabilisation.

RESULTS

Fifty concussed athletes and 50 control athletes completed the study. There were no significant differences at any study assessment between the concussion and control group on the Star Excursion Balance Test anterior reach distance or fractal dimension (centre of pressure path complexity). During the Multiple Hop Test, the concussion group used a significantly greater number of corrective postural strategies than the control group one-week following sport-related concussion and upon clearance to RTA, but not two weeks following RTA.

CONCLUSION

Recently concussed athletes made a greater number of corrective postural strategies than control participants during the Multiple Hop Test upon clearance to RTA but not two weeks after RTA. The Multiple Hop Test may offer a clinically useful tool for practitioners to examine the recovery of subtle sensorimotor impairments and related RTA readiness.

Estimated age of first exposure to American football and outcome from concussion

OBJECTIVE

To examine the association between estimated age at first exposure (eAFE) to American football and clinical measures throughout recovery following concussion.

METHODS

Participants were recruited across 30 colleges and universities as part of the National Collegiate Athletic Association (NCAA)-Department of Defense Concussion Assessment, Research and Education Consortium. There were 294 NCAA American football players (age 19 ± 1 years) evaluated 24-48 hours following concussion with valid baseline data and 327 (age 19 ± 1 years) evaluated at the time they were asymptomatic with valid baseline data. Participants sustained a medically diagnosed concussion between baseline testing and postconcussion assessments. Outcome measures included the number of days until asymptomatic, Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) composite scores, Balance Error Scoring System (BESS) total score, and Brief Symptom Inventory 18 (BSI-18) subscores. The eAFE was defined as participant's age at the time of assessment minus self-reported number of years playing football.

RESULTS

In unadjusted regression models, younger eAFE was associated with lower (worse) ImPACT Visual Motor Speed (R 2 = 0.031, p = 0.012) at 24-48 hours following injury and lower (better) BSI-18 Somatization subscores (R 2 = 0.014, p = 0.038) when the athletes were asymptomatic. The effect sizes were very small. The eAFE was not associated with the number of days until asymptomatic, other ImPACT composite scores, BESS total score, or other BSI-18 subscores.

CONCLUSION

Earlier eAFE to American football was not associated with longer symptom recovery, worse balance, worse cognitive performance, or greater psychological distress following concussion. In these NCAA football players, longer duration of exposure to football during childhood and adolescence appears to be unrelated to clinical recovery following concussion.

Predictors of Concussion Outcomes in Individuals With ADHD

OBJECTIVES

To describe and delineate the epidemiological profile of concussion injuries in individuals with attention-deficit/hyperactivity disorder (ADHD) by identifying characteristics associated with poorer outcomes.

SETTING

One hundred forty-four multidisciplinary concussion-specialized clinics across Canada.

PARTICIPANTS

Two hundred twenty-two individuals with a diagnosis of ADHD aged 7 to 53 years who sustained a concussion within the last year.

DESIGN

Multicenter cohort study.

MAIN MEASURES

Candidate predictor variables (ie, age, sex, concussion history, loss of consciousness, and internalized and learning disorder comorbidities) were collected through oral interviews. Concussion outcomes (ie, symptom severity and total number of symptoms experienced) were assessed with the Sport Concussion Assessment Tool.

RESULTS

Older age, female sex, and the presence of an internalized disorder predicted poorer concussion outcomes in individuals with ADHD. Males with ADHD reported significantly worse concussion outcomes with increasing age, while outcomes remained fairly stable across age in females.

CONCLUSION

The current findings represent a promising step toward the optimization of concussion management in individuals with ADHD. With a more thorough understanding of the demographic and comorbidity variables, clinical care decisions and intervention strategies can be developed to help individuals with ADHD who might be at a higher risk of poorer outcomes following a concussion.

A Within-Subjects Comparison of Clinical Outcomes for Patients' First and Second Concussions

OBJECTIVES

To examine the difference between an individual's first and second concussion using a comprehensive, multidomain assessment including symptoms, neurocognitive, vestibular, ocular, and individual demographic and medical history risk factors associated with protracted recovery.

SETTING

Concussion Specialty Clinic.

PARTICIPANTS

Seventy-three patients (aged 13-21 years; 57% female) diagnosed with 2 separate concussions (380.5 ± 278.7 days between injuries) from August 2016 to August 2018.

DESIGN

Retrospective within-subjects cohort study.

MAIN MEASURES

ImPACT, PCSS, and Vestibular-Ocular Motor Screen (VOMS) at each visit. Patients were divided into "normal" (≤30 days) and "protracted" recovery (>30 days) for χ2 analyses.

RESULTS

There were no differences between the first and second injuries in recovery time, VOMS, visual and verbal memory, or reaction time. Visual motor speed scores were higher at the second injury time point and reported sleep symptoms were higher at the first injury time point. In addition, participants reported to the clinic on average 3 days earlier for an evaluation for their second injury. Results from χ2 analyses indicated that female sex predicted protracted recovery (>30 days) from concussion at the first injury time point (OR = 4.1; 95% CI, 1.5-11.6; P = .006).

CONCLUSIONS

The findings provide preliminary evidence that there is no clinical difference between patients' first and second concussions when both injuries were treated through a concussion specialty clinic.

The Molecular Pathophysiology of Concussion

After a concussion, a series of complex, overlapping, and disruptive events occur within the brain, leading to symptoms and behavioral dysfunction. These events include ionic shifts, damaged neuronal architecture, higher concentrations of inflammatory chemicals, increased excitatory neurotransmitter release, and cerebral blood flow disruptions, leading to a neuronal crisis. This review summarizes the translational aspects of the pathophysiologic cascade of postconcussion events, focusing on the role of excitatory neurotransmitters and ionic fluxes, and their role in neuronal disruption. We review the relationship between physiologic disruption and behavioral alterations, and proposed treatments aimed to restore the balance of disrupted processes.

Sports-Related Concussions and the Pediatric Patient

Pediatric patients with concussions have different needs than adults throughout the recovery process. Adolescents, in particular, may take longer to recover from concussion than adults. Initially, relative rest from academic and physical activities is recommended for 24 to 48 hours to allow symptoms to abate. After this time period, physicians should guide the return to activity and return to school process in a staged fashion using published guidelines. Further concussion research in pediatric patients, particularly those younger than high-school age, is needed to advance the management of this special population.

Premorbid anxiety and depression and baseline neurocognitive, ocular-motor and vestibular performance: A retrospective cohort study

Concussion has become a growing concern among sport and healthcare practitioners. Experts continue to investigate ways to advance the quality of concussion evaluation, diagnosis and management. Psychological conditions have been reported to influence concussion assessment outcomes at baseline and post-concussion; however, little evidence has examined psychological conditions and their effect on multifaceted measures of concussion. A retrospective cohort design was employed to examine differences between those with and without a premorbid psychological condition for high school and collegiate athletes who completed a preseason baseline battery, consisting of symptom reporting, computerized neurocognitive assessment, Vestibular-Ocular Motor Screening (VOMS), and the King-Devick (KD) test. Forty athletes within the sample self-reported a diagnosed psychological risk factor, consisting of depression and/or anxiety, and each were matched with a discordant control. Controls were matched on sex, age, sport, concussion history and ocular history. Athletes with psychological conditions reported higher symptom severity and had worse visual motor speed than controls. There were no differences between groups on other neurocognitive domains, VOMS, or KD. These results suggest that vestibular-ocular tools may be more consistent or less likely to vary between those with and without a premorbid psychological diagnosis, adding value to tools such as the KD and VOMS.

Concussion Management for the Orthopaedic Surgeon

Orthopaedic surgeons functioning as team physicians are in a unique position to recognize subtle changes in an athlete's behavior and may be the first responders to concussions at sporting events. The rate of sports-related concussions has increased over the past few decades, necessitating that orthopaedic team physicians gain a greater understanding of the diagnosis and management of this condition. During the sideline evaluation, life-threatening injuries must be ruled out before concussion evaluation may take place. In most cases, patients experience a resolution of symptoms within a week; however, a smaller subset of patients experience persistent symptoms. Physicians covering sporting events must remain current regarding recommendations for treating sports-related concussions and must document their management plan to minimize potential harm to an athlete.

Transcranial Magnetic Stimulation for the Treatment of Concussion: A Systematic Review

BACKGROUND

Post-concussive symptoms (PCSs) are common, disabling, and challenging to manage. Evolving models of concussion pathophysiology suggest evidence of brain network dysfunction that may be amenable to neuromodulation. Repetitive transcranial magnetic stimulation (rTMS) has emerged as a potential novel treatment option for PCSs.

OBJECTIVES

To systematically review rTMS trials for the treatment of symptoms following concussion/mild traumatic brain injury (mTBI).

MATERIALS AND METHODS

We conducted a systematic review of Pubmed/Medline, Embase, and PsychINFO databases were searched up to May 19, 2020. Studies were included if they were prospective rTMS treatment studies of patients with mTBI/concussion. Variables including patient demographics, study design, rTMS protocol parameters, primary outcome measures, and efficacy data were extracted and qualitatively synthesized. rTMS methodology and study quality were also evaluated.

RESULTS

Of the 342 studies identified, 11 met eligibility criteria and were included for synthesis. Forty-one percent of patients were female and age ranged from 18 to 65 (average age = 38.5 years). Post-concussive depression (seven studies) and headache (four studies) were the most commonly investigated symptoms. The majority of trials were sham-controlled with randomized control trial (RCT) designs, but all were small pilot samples (n < 30). Methodological heterogeneity and a low number of identified trials precluded quantitative meta-analysis. Regarding rTMS for post-concussive depression, positive results were found in two out of four studies with depression as a primary outcome, and all three studies that assessed depression as a secondary outcome. All four rTMS studies for post-concussive headache reported positive results.

CONCLUSIONS

rTMS for the treatment of concussion/mTBI shows promising preliminary results for post-concussive depression and headache, symptoms that otherwise have limited effective treatment options. More studies with larger sample sizes are needed to further establish potential efficacy.

No Clinical Predictors of Postconcussion Musculoskeletal Injury in College Athletes

PURPOSE

This study aimed to identify clinical predictors of postconcussion subsequent musculoskeletal (MSK) injuries.

METHODS

We recruited 66 National Collegiate Athletic Association intercollegiate student-athletes with a diagnosed concussion as well as 36 National Collegiate Athletic Association student-athletes without a concussion. All participants completed a multifaceted concussion baseline consisting of 1) 22-item 0-6 self-reported symptom checklist with outcomes including both the number of symptoms endorsed (0-22) and 2) total symptom score (0-132), 3) Standard Assessment of Concussion, 4) Balance Error Scoring System, 5) Immediate Post-Concussion Assessment and Cognitive Testing, 6) clinical reaction time, and 7) the King-Devick as well as demographic and injury characteristics. The concussion participants completed the same examination acutely postconcussion, and binary logistic regression was used to identify predictors of subsequent MSK from the change scores (acute minus baseline). From the 66 concussed student-athletes, a subset 36, matched with the healthy athletes, compared the risk of subsequent MSK in the year before and year after their concussion.

RESULTS

The concussion participants were 1.78 times (95% confidence interval, 1.12-2.84; P = 0.015) more likely to suffer a lower extremity MSK in the year after their concussion than the control participants. The participant demographics and injury characteristics (P = 0.318) and concussion clinical outcomes (P = 0.461) did not predict subsequent MSK.

CONCLUSION

The concussion participants were 1.78 times more likely to sustain a subsequent MSK; however, no demographic, injury characteristic, or concussion assessments predicted the MSK. Thus, clinicians are not able to utilize common neurological measures or participant demographics to identify those at risk for subsequent lower extremity MSK. Injury prevention strategies should be considered for collegiate student-athletes upon premature return to participation after a concussion to reduce the subsequent MSK.

Anxiety, Depression, and Quality of Life: A Long-Term Follow-Up Study of Patients with Persisting Concussion Symptoms

Persisting concussion symptoms (PCS) can last for months, years, or indefinitely and affect a considerable number of concussion patients. The objectives of this study were to evaluate the prevalence of clinical symptoms of anxiety and depression and the relationship between PCS and quality of life in patients examined at the Canadian Concussion Centre. The Depression and Anxiety Stress Scale-42 (DASS-42) and the World Health Organization Quality of Life Assessment-BREF (WHOQOL-BREF) were sent to 526 adult patients diagnosed with PCS. Median with interquartile range follow-up time was 5 (4-7) years. Of the 105 respondents, 35.2% displayed mild or greater symptoms of anxiety, depression, or both. Importantly, the number of previous concussions was correlated with elevations on the DASS-42 Anxiety (p = 0.030) and Depression (p = 0.018) subscale scores, suggesting an acquired cause of symptoms. Patients with clinical elevations of depression, anxiety, or both exhibited poorer mean WHOQOL-BREF scores in each domain (p < 0.001) compared to those who scored in the normal range on the DASS-42. These findings indicate that depression and anxiety in PCS can endure for years and are associated with diminished quality of life. Consequently, depression and anxiety should be identified and treated early in PCS populations in order to optimize recovery. Although the underlying etiology of depression and anxiety cannot be ascertained with certainty in the present study, the association between depression and anxiety and the number of concussions may indicate an organic explanation. In the future, quality-of-life measures should be incorporated into treatment and research in PCS to improve intervention strategies and enhance understanding of the trajectory of recovery in this population.

Flying After Concussion and Symptom Recovery in College Athletes and Military Cadets

IMPORTANCE

Concussions are a common occurrence in young athletes. Hypobaric hypoxemia, such as that experienced during airplane travel, can potentially cause alterations to cerebral blood flow and increased neuroinflammatory response. It remains unknown whether flying early after a concussion may influence the clinical course of injury.

OBJECTIVE

To determine whether there is an association between concussion recovery and airplane travel in collegiate athletes and military cadets.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was conducted by the National Collegiate Athletic Association and US Department of Defense Concussion Assessment, Research, and Education Consortium from August 3, 2014, to September 13, 2018. Participant groups were categorized by those who flew within 72 hours of injury and those who did not fly. All participants included in the final analyses had complete data of interest and only 1 injury during the study. Data analysis was performed from September 2018 to March 2020.

MAIN OUTCOMES AND MEASURES

Recovery outcome measures were defined as time (in days) from injury to return to activity, school, and baseline symptoms. Symptom and headache severity scores were derived from the Sports Concussion Assessment Tool-Third Edition. Scores for both groups were taken at baseline and a median of 2 days after injury.

RESULTS

A total of 92 participants who flew (mean [SD] age, 19.1 [1.2] years; 55 male [59.8%]) and 1383 participants who did not fly (mean [SD] age, 18.9 [1.3] years; 809 male [58.5%]) were included in the analysis of symptom recovery outcomes (analysis 1). Similarly, 100 participants who flew (mean [SD] age, 19.2 [1.2] years; 63 male [63.0%]) and 1577 participants who did not fly (mean [SD] age, 18.9 [1.3] years; 916 male [58.1%]) were included in the analysis of symptom severity outcomes (analysis 2). No significant group differences were found regarding recovery outcome measures. Likewise, there were no group differences in symptom (estimated mean difference, 0.029; 95% CI, -0.083 to 0.144; P = .67) or headache (estimated mean difference, -0.007; 95% CI, -0.094 to 0.081; P = .91) severity scores.

CONCLUSIONS AND RELEVANCE

Airplane travel early after concussion was not associated with recovery or severity of concussion symptoms. These findings may help guide future recommendations on flight travel after concussion in athletes.