Predictors of clinical recovery from concussion: a systematic review

Endophenotype presentation of athletes with concussion contingent on sex and time since injury

INTRODUCTION

Athletes with concussions experience heterogeneous symptoms and clinical trajectories. Subclassification provides diagnostic clarity that may improve prognostication and individualized treatments.

METHODS

We hypothesized that endophenotypes of adolescent athletes with concussions differ based on sex and time since injury. Post-concussive testing was performed for athletes (n = 1385) in the North Texas Concussion Registry (ConTex) at four timepoints: acute [0-3 days post-injury (DPI)], subacute-early (4-7DPI), subacute-late (8-28DPI), and persistent (29+DPI). Six endophenotypes (cognitive, headache, ocular-motor, vestibular, affective, sleep) were constructed by allocating post-concussion testing data elements described by the Concussion Subtype Workgroup.

RESULTS

Endophenotypes were defined using correlations between data elements and compared based on sex or time since injury. Correlograms revealed endophenotypes differed based on sex and time since injury. The affective endophenotype was dependent on the interaction between sex and time since injury and was more prevalent at the subacute-late and persistent timepoints. The sleep endophenotype became more prevalent at the persistent timepoint. Affective and sleep endophenotypes were interrelated with cognitive, vestibular, and headache endophenotypes at the persistent timepoint suggesting that dysregulated mood and sleep influence lingering symptoms.

CONCLUSIONS

Adolescent symptom-based concussion endophenotypes differ based on sex and time since injury. Clinical consideration may improve identification of separate trajectories following sport-related concussion and provide targeted care.

Retrospective Study of the Efficacy of Biofeedback Therapy for Pediatric Persistent Posttraumatic Headache

BackgroundPosttraumatic headache is common in pediatrics. Studies have examined treatment of postconcussion symptoms, but few target posttraumatic headache. Biofeedback therapy has been studied in children and teens with primary headaches, but not posttraumatic headache. Our goal was to examine the changes in posttraumatic headache associated with biofeedback therapy in pediatric patients.MethodsThis retrospective study included 74 children aged 10-18 years who received biofeedback therapy for posttraumatic headache. "Positive response" to biofeedback therapy was defined as ≥50% reduction in headache days per week, or 3-point drop in pain rating between the first and last biofeedback therapy visits. Patient characteristics were analyzed using logistic regression to identify factors associated with response.ResultsIn our cohort, 42% of all patients with posttraumatic headache had a positive response to biofeedback therapy. Thirty-six percent experienced ≥50% decrease in headache frequency, 13% had a ≥3-point decrease in headache severity and 8% reported both changes. For those with daily headaches, 36% had a positive response to biofeedback therapy. School absences, selective serotonin reuptake inhibitor or prescription preventive medication use were associated with nonresponse.ConclusionsBiofeedback therapy is a reasonable treatment to consider to manage pediatric posttraumatic headache because more than 40% of our cohort had a beneficial response and biofeedback therapy has few adverse effects.

Association of Premorbid Anxiety and Depression Symptoms in Concussion Recovery in Collegiate Student-Athletes

BACKGROUND

Mental health disorders are linked to prolonged concussion symptoms. However, the association of premorbid anxiety/depression symptoms with postconcussion return-to-play timelines and total symptom burden is unclear.

OBJECTIVE

To examine the association of self-reported premorbid anxiety/depression symptoms in collegiate student-athletes with (1) recovery times until asymptomatic, (2) return-to-play, and (3) postconcussion symptom burden.

STUDY DESIGN

Athletes in the Concussion Assessment, Research and Education Consortium completed baseline concussion assessments (Sport Concussion Assessment Tool [SCAT3] and Brief Symptom Inventory-18 [BSI-18]). Athletes were tested postinjury at <6 hours, 24 to 48 hours, time of asymptomatic and start of return-to-play protocol, unrestricted return-to-play, and 6 months after injury. Injured athletes were categorized into 4 groups based on BSI-18 scores: (1) B-ANX, elevated anxiety symptoms only; (2) B-DEP, elevated depression symptoms only; (3) B-ANX&DEP, elevated anxiety and depression symptoms; and (4) B-NEITHER, no elevated anxiety or depression symptoms. Relationship between age, sex, BSI-18 group, SCAT3 total symptom and severity scores, and time to asymptomatic status and return-to-play was assessed with Pearson's chi-squared test and robust analysis of variance.

LEVEL OF EVIDENCE

Level 3.

RESULTS

Among 1329 athletes with 1352 concussions, no respondents had a self-reported premorbid diagnosis of anxiety/depression. There was no difference in time until asymptomatic or time until return-to-play between BSI-18 groups (P = 0.15 and P = 0.11, respectively). B-ANX, B-DEP, and B-ANX&DEP groups did not have higher total symptom or severity scores postinjury compared with the B-NEITHER group.

CONCLUSION

Baseline anxiety/depression symptoms in collegiate student-athletes without a mental health diagnosis are not associated with longer recovery times until asymptomatic, longer time to return-to-play, or higher postconcussion total symptom and severity scores compared with athletes without baseline symptoms.

CLINICAL RELEVANCE

Anxiety and depression symptoms without a clear mental health diagnosis should be considered differently from other comorbidities when discussing prolonged recovery in collegiate student-athletes.

Research priorities for diagnosis, prognosis, and rehabilitation following concussion: results from a national survey of Australian health professionals

PURPOSE

Recently, the Concussion James Lind Alliance Priority Setting Partnership (JLAPSP) (Canada) identified serious research gaps regarding diagnosis, management, and access to effective rehabilitation for concussion/mild traumatic brain injury (mTBI). Our aim was to determine if the same research priorities are important to Australian health professionals working in the concussion/mTBI field.

MATERIALS AND METHODS

A survey was distributed via professional networks, social media, professional group listservs, a research project noticeboard, and at conferences. It comprised of 25 of the highest ranked concussion research questions from the JLAPSP. We examined how professionals ranked the research questions and analyzed variation in ranking by clinical role and concussion/mTBI work experience.

RESULTS

Our sample of 187 participants included medical and allied health professionals. Most participants were occupational therapists (22%), physiotherapists (18%), neuropsychologists (17%), and worked in Victoria (47%), New South Whales (18%), or Queensland (15%) in metropolitan areas. Health professionals ranked three research questions highest: identifying methods to predict prolonged recovery; effectiveness of early referral and treatment by a specialized concussion/mTBI team; and implementation studies on upskilling healthcare workers.

CONCLUSIONS

The research priorities identified can guide research efforts to improve the assessment, management, and rehabilitation of individuals with concussion/mTBI in Australia.

Association between magnetic resonance imaging use and recovery time following concussion: a CARE consortium study

Researchers may implement magnetic resonance imaging (MRI) to evaluate neurophysiological metrics (e.g. connectivity) in athletes with sports-related concussion (SRC). MRI usage has been purported to exacerbate symptoms that mimic SRC symptomatology, possibly influencing recovery. The present study examined MRI use on SRC recovery outcomes in collegiate athletes. Ninety student-athletes (45 with MRI acutely post-SRC, 45 non-MRI) from four collegiate sites were analysed. Multivariable Cox proportional hazard regressions were used to measure the SRC recovery risk [return-to-play (RTP) initiation (RTP-I) and unrestricted RTP] with hazard ratios (HR) and 95% confidence intervals (95% CI). No hazard differences for median days to RTP-I [MRI: 10, interquartile range (IQR) = 7-15; non-MRI: 7 (IQR = 4-9)] were observed (HR = 0.75; 95% CI: 0.28-1.21). No hazard differences for median days to RTP [(MRI: 17 (IQR = 11-60); non-MRI: 12 (IQR = 8-24)] were observed (HR = 0.77; 95% CI: 0.29-1.26). MRI use post-SRC does not affect recovery; researchers/clinicians can employ such a procedure without affecting athlete recovery.

Social Demographic and Clinical Predictors of Time to Clinic Presentation After a Sport-Related Concussion

OBJECTIVE

To investigate the associations between clinical risk factors, social demographic and time to concussion clinic presentation after sports-related concussion in young athletes.

DESIGN

Retrospective cohort study.

SETTING

Multidisciplinary regional concussion center.

PATIENTS

Athletes ages 12 to 18 years who sustained a SRC from November 2017 to April 2022.

INDEPENDENT VARIABLES

Independent variables included social demographic factors (ie, race, ethnicity, public vs private school, public vs private insurance), patient medical history, family medical history, acute concussion characteristics, and initial presentation elsewhere.

MAIN OUTCOME MEASURES

Descriptive statistics were employed to assess for group differences. Mann-Whitney U tests, Spearman rank order correlations, and linear regressions were performed to explore associations between each independent variable and the main outcome, days to concussion clinic presentation.

RESULTS

A total of 945 athletes we included (age 15.8 ± 1.61, 33.7% female). Hispanic/Latino background, ( P = 0.009), public insurance status ( U = 47 377.0, P = 0.002), amnesia ( U = 57 738.0, P = 0.002) at time of injury, family psychiatric ( U = 35 091.0, P < 0.001) or migraine ( U = 59 594.5, P < 0.001) histories, and personal psychiatric ( U = 30 798.0 , P = 0.004) or migraine ( U = 34 133.5, P = 0.011) histories were associated with longer time to concussion clinic presentation. A multivariable linear regression found that initial presentation elsewhere (β = 0.37, P < 0.001), family migraine history (β = 0.18, P < 0.001), public insurance status (β = 0.09, P = 0.024), and history of learning disability (β = 0.09, P = 0.032) were the only predictors of longer time to concussion clinic presentation.

CONCLUSIONS

Variables that predicted longer time to concussion clinic presentation included initial presentation elsewhere, public insurance status, positive family migraine history, and history of learning disability. Further research is needed to elucidate these findings and determine how they impact concussion seeking behavior.

Complexity of post-concussion syndrome assessment and management: a case for customizing rehabilitation

BACKGROUND

Post-concussion syndrome is a challenging condition to manage for even the most experienced chronic pain experts. Patients' presentations are heterogeneous with symptoms spanning physical, cognitive and emotional domains. The symptoms reported are often non-specific, making it difficult for health professionals to prescribe effective rehabilitation. The aim of the present study was to examine the effectiveness of a customized rehabilitation program based on subgroup determination following a standardized clinical exam in adults with post-concussion syndrome.

METHODS

A total of 16 adults (mean age ± SD, 38.3 ± 12.5 years) with post-concussion syndrome participated in a 6-week rehabilitation program. Participants were recruited from external community concussion clinics around the greater Toronto area, Canada. Participants underwent a comprehensive standardized clinical exam to subgroup the ostensible symptom generators into either autonomic, cervical or vestibulo-ocular. Customized rehabilitation was then prescribed based on their subgroupings. The primary outcome measure was the Rivermead Post-Concussion Questionnaire (RPQ). Secondary outcome measures included the Patient Health Questionnaire-9 (PHQ-9), the Neck Disability Index (NDI), and exercise tolerance as assessed via the Buffalo Concussion Treadmill Test (BCTT).

RESULTS

Following 6 weeks of customized rehabilitation, participants on average experienced a significant and clinically meaningful change with respect to the RPQ-3 and RPQ-13 (p < 0.001). We also observed a significant change in all secondary outcome measures including a reduction in PHQ-9 (p < 0.01), NDI (p < 0.001) and exercise tolerance, expressed as heart rate threshold (p < 0.001).

CONCLUSION

The standardized exam was feasible and useful in assisting the clinician in prescribing effective rehabilitation. The 6-week customized rehabilitation program demonstrated significant changes in patient-reported persistent post-concussion symptoms and exercise tolerance. The implementation of a customized program based on a standardized exam performed to subgroup the ostensible symptom generators may be key to successful management in this population.

Utility of the Vestibular/Ocular Motor Screening in Military Medicine: A Systematic Review

INTRODUCTION

The Vestibular/Ocular Motor Screening (VOMS) was created as a brief clinical screening tool for identifying vestibular and ocular motor symptoms and impairments post-concussion. It was found to have predictive validity in correctly identifying concussed athletes from healthy controls. In 2018, the Military Acute Concussion Evaluation 2 (MACE2) replaced the original Military Acute Concussion Evaluation (MACE); the most prominent change between the MACE and MACE2 was the addition of the VOMS. Despite its adoption into military medicine, it is not known if the addition of the VOMS to the MACE2 is acutely helpful, and if it provides additional information for diagnosis, prognosis, and/or management. The purposes of this systematic review were: (1) to determine the utility of the VOMS in correctly identifying concussed individuals, particularly as it pertains to military medicine; (2) to explore the extent to which the VOMS can inform concussion prognosis; and (3) to establish the value of the VOMS as a measure for monitoring the evolution of symptoms throughout a service member's course of care.

MATERIALS AND METHODS

A comprehensive search of PubMed was performed from January 1, 2014 through August 16, 2023. Articles were included if they researched concussion or a related health condition or healthy controls and administered the VOMS. Articles were excluded if they discussed health conditions other than concussion; did not administer the VOMS; or were written in languages other than English. The tools used to assess methodological quality and risk of bias varied according to study design. Articles were classified into three primary domains: diagnosis, prognosis, and/or rehabilitation/recovery over time.

RESULTS

A total of 231 articles were retrieved and 3 were duplicates, leaving 228 articles for review. Of the 228 articles screened, 100 relevant full-text articles were assessed for eligibility. Fifty-nine articles met our inclusion and exclusion criteria while the other 41 articles were rejected. Thirty-two articles helped to inform diagnosis, 15 prognosis, and 16 rehabilitation/recovery over time.

CONCLUSIONS

The VOMS had excellent internal consistency and moderate to good test-retest reliability; however, a false-positive rate of 21.9% was found. Most studies indicated that a positive VOMS was associated with a delayed recovery. Several studies indicated that VOMS scores improved with targeted, active interventions and/or a symptom-guided progressive return to activity. The greatest limitation was the paucity of published evidence in the military population. More research is needed on the use of the VOMS in service members.

Self-reported concussion history is not related to cortical volume in college athletes

The long-term consequences of concussion are still being uncovered but have been linked to disruptions in cognition and psychological well-being. Previous studies focusing on the association between concussion history and structural changes in the brain have reported inconsistent results. We sought to examine the effect of concussion history on cortical volume with a focus on functional networks. These networks are associated with many of the functions that can be disrupted in those with an extensive concussion history. We collected baseline behavioral data including the Immediate Post-Concussion Assessment and Cognitive Testing, a self-report measure of the number of diagnosed concussions, and structural MRI in college athletes (n=296; 263 men and 33 women, age range 17-24). Behavioral measures were collected by members of the Department of Athletics concussion management team using a standardized protocol as part of their on-boarding process. Collegiate athletes in the present study who self-reported concussion history did not report different baseline symptoms and did not exhibit consistent differences in cognitive performance relative to those who reported no concussion history. We found that concussion history was not related to cortical volume at the network or region level, even when we compared participants with two or more concussions to those with no concussion history. We did identify relationships between cortical volume in the visual network and dorsal attention network with cognitive performance. In addition to comparing cortical volume between individuals with and without reported concussion history, we also examined whether cortical volume changes could be observed within individuals from baseline to acutely following concussion. We found that network level cortical volume did not change within subjects from baseline measurement to acutely post-concussion. Together, these results suggest that both self-reported concussion history and acute concussion effects are not associated with changes in cortical volume in young adult athletes.

The relationship between personality traits and health-related quality of life after mild-to-moderate traumatic brain injury

BACKGROUND

Traumatic brain injury (TBI) causes major societal burden and may negatively influence an individual's health-related quality of life (HRQoL). Personality factors have been linked to persistent post-concussion symptoms (PPCS), and PPCS have been found to affect HRQoL. However, there is a knowledge gap concerning the association between personality traits and HRQoL after mild-to-moderate TBI. Thus, this study aims to investigate the association between personality traits and HRQoL in patients with mild-to-moderate TBI at 15 months post-injury, while controlling for socio-demographic characteristics, injury-related factors and symptom burden.

METHODS

Data from 86 participants with mild- to-moderate TBI from a previous randomised controlled trial were analysed. Sociodemographic, injury-related and psychological factors were recorded 2-3 months post-injury. Personality traits were measured at 15 months post-injury with The NEO Five-factor Inventory-3. The Quality of Life after Brain Injury- Overall Scale (QOLIBRI-OS) and the EuroQol-visual analogue scale (EQ-VAS) were used to measure HRQoL at 15 months post-injury. Two separate multiple linear regression models were performed for the outcome variables; QOLIBRI-OS (model 1) and EQ-VAS (model 2).

RESULTS

The factors associated with lower HRQoL were more severe PPCS, higher levels of the personality traits neuroticism and conscientiousness (model 1), female sex and being single/living alone (model 2). Higher levels of the personality trait extraversion were associated with higher HRQoL in both models.

CONCLUSION

The results highlight how non-injury factors may be associated with recovery and HRQoL after TBI. Considering personality factors may be helpful when identifying individual risk and protective factors for outcomes after mild-to-moderate TBI.

Clinical Cut Point for the Pittsburgh Sleep Quality Index After Adolescent Concussion

Background

Concussions can have negative implications for sleep quality. Self-report measures, such as the Pittsburgh Sleep Quality Index (PSQI), have been used in clinical and research settings to identify individuals with sleep impairments. However, the accuracy/applicability of historically established PSQI scoring criteria for differentiating good versus poor sleep quality has not been critically examined in adolescents with concussion.

Purpose

To establish a relevant PSQI clinical cut point for adolescents with a recent concussion.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Adolescents within 16 days of concussion and uninjured controls completed the PSQI, and a global score of 0 to 21 was calculated. Independent-samples t tests were used to compare PSQI global scores, and logistic regression was used to calculate odds ratios (outcome = group; predictors = PSQI, covariates). A receiver operating characteristic curve was used to evaluate the area under the curve (AUC) and determine the optimal cut point to distinguish between adolescents with and without a concussion.

Results

A total of 110 adolescents with a concussion (mean age, 14.9 ± 1.6 years; 53% female; 9.8 ± 3.6 days since injury) and 129 uninjured controls (mean age, 15.6 ± 1.1 years; 86% female) were included for analysis. The concussion group had significantly worse (higher) PSQI scores than controls (mean, 7.41 ± 3.62 vs 2.26 ± 1.97; P < .001; Cohen d = 1.8). Both the univariable model and multivariable model (controlling for age, sex, concussion history, history of anxiety and/or depression, and self-reported use of sleep medication) had excellent diagnostic accuracy (univariable AUC, 0.90; multivariable AUC, 0.99). Within the multivariable model, a cut point of 4 correctly classified 81% of participants as concussed or control (sensitivity, 87%; specificity, 74%).

Conclusion

Adolescents with a concussion demonstrated worse sleep quality than uninjured controls. The results suggest that sleep quality, as measured by the PSQI, can distinguish between adolescents with and without a concussion, using a cut point of 4.

Evidence for Altered White Matter Organization After Mild Traumatic Brain Injury: A Scoping Review on the Use of Diffusion Magnetic Resonance Imaging and Blood-Based Biomarkers to Investigate Acute Pathology and Relationship to Persistent Post-Concussion Symptoms

Mild traumatic brain injury (mTBI) is the most common form of traumatic brain injury. Post-concussive symptoms typically resolve after a few weeks although up to 20% of people experience these symptoms for >3 months, termed persistent post-concussive symptoms (PPCS). Subtle white matter (WM) microstructural damage is thought to underlie neurological and cognitive deficits experienced post-mTBI. Evidence suggests that diffusion magnetic resonance imaging (dMRI) and blood-based biomarkers could be used as surrogate markers of WM organization. We conducted a scoping review according to PRISMA-ScR guidelines, aiming to collate evidence for the use of dMRI and/or blood-based biomarkers of WM organization, in mTBI and PPCS, and document relationships between WM biomarkers and symptoms. We focused specifically on biomarkers of axonal or myelin integrity post-mTBI. Biomarkers excluded from this review therefore included the following: astroglial, perivascular, endothelial, and inflammatory markers. A literature search performed across four databases, EMBASE, Scopus, Google Scholar, and ProQuest, identified 100 records: 68 analyzed dMRI, 28 assessed blood-based biomarkers, and 4 used both. Blood biomarker studies commonly assessed axonal cytoskeleton proteins (i.e., tau); dMRI studies assessed measures of WM organization (i.e., fractional anisotropy). Significant biomarker alterations were frequently associated with heightened symptom burden and prolonged recovery time post-injury. These data suggest that dMRI and blood-based biomarkers may be useful proxies of WM organization, although few studies assessed these complementary measures in parallel, and the relationship between modalities remains unclear. Further studies are warranted to assess the benefit of a combined biomarker approach in evaluating alterations to WM organization after mTBI.

Anxiety, pain, and fear of pain: predictors of postural stability after a concussion

A concussion can lead to anxiety, pain, kinesiophobia, and/or postural control deficits. We conducted a cross-sectional study evaluating adolescents with a recent concussion. We hypothesized that those reporting higher levels of anxiety, pain-interference, and kinesiophobia would perform worse on postural control tests. Participants completed anxiety, pain-interference, and kinesiophobia ratings and postural control tests (single/dual-task tandem gait and a modified balance error scoring system). Using a multivariable linear regression model, we evaluated the relationship among anxiety, pain-interference, and kinesiophobia (predictors) with postural control measures (tandem gait and a modified balance error scoring system, outcomes), adjusting for sex and anxiety history. We enrolled 128 participants (53% female, age=15.4±1.7 y, and 9.3±4.0 d post-concussion). Higher anxiety was weakly correlated with slower dual-task tandem gait times (r=0.31; p=0.001) and more modified balance error scoring system errors (r=0.22; p=0.01). Multivariable modeling indicated that a higher post-concussion anxiety rating was associated with a slower dual-task tandem gait time (β=0.21, 95% confidence interval=0.01-0.41; p=0.04). The female sex was associated with slower single-task tandem gait (β=-3.01, 95% confidence interval=-6.01, -0.01; p=0.049). Adolescents with a higher anxiety post-concussion performed worse on dual-task tandem gait assessments, while pain-interference and kinesiophobia were not associated with postural control. Anxiety and impaired postural control are independently associated with poor concussion outcomes; thus, this association may inform individualized concussion care strategies.

Concurrent symptom domains and associations with recovery timelines among collegiate athletes with sport-related concussion

OBJECTIVE

Concussion symptoms can be clustered into domains and understanding how multiple symptom domains present clinically may guide more accurate interventions. We investigate the associations between concurrent symptom domains and clinical recovery outcomes, as well as the role of sex in these relationships.

METHODS

We analysed data from the Ivy League-Big Ten Epidemiology of Concussion Study and included sport-related concussions (SRC) across five academic years 2015-2016/2019-2020 with complete data (n=1160). We used symptoms from the Sport Concussion Assessment Tool 22-symptom evaluation, previously categorised into symptom domains. Symptom profiles characterise how athletes endorse concurrent symptom domains. Outcomes are time (in days) from SRC to symptom resolution, return to academics, and full play.

RESULTS

Females more commonly endorsed headache, sensory, and affective symptom domains. Four classes/symptom profiles emerged: (1) 'low' on all domains, (2) 'high' on headache and sensory domains, (3) 'high' on vestibulo-ocular, cognitive, and sleep domains, and (4) 'high' on all domains. Time to symptom resolution, return to academics, and return to play were consistently shorter among class/symptom profile 1 compared with other classes/profiles. Compared with class/profile 1, the chance of having symptoms resolve was lower among classes/profiles 2, 3, and 4 (HR 0.74, 95% CI 0.63 to 0.88; HR 0.74, 95% CI 0.60 to 0.92; HR 0.50, 95% CI 0.43 to 0.57, respectively). Results were similar for return to academics and full play outcomes. Interactions with sex were not statistically significant.

CONCLUSIONS

Four symptom profiles characterised how concussion symptom domains co-occur. We found differences in recovery timelines among these groups, but not by sex. Findings inform and support targeted, symptom domain-specific interventions in concussion management.

Developing a multivariate model for the prediction of concussion recovery in sportspeople: a machine learning approach

Background

Sportspeople suffering from mild traumatic brain injury (mTBI) who return prematurely to sport are at an increased risk of delayed recovery, repeat concussion events and, in the longer-term, the development of chronic traumatic encephalopathy. Therefore, determining the appropriate recovery time, without unnecessarily delaying return to sport, is paramount at a professional/semi-professional level, yet notoriously difficult to predict.

Objectives

To use machine learning to develop a multivariate model for the prediction of concussion recovery in sportspeople.

Methods

Demographics, injury history, Sport Concussion Assessment Tool fifth edition questionnaire and MRI head reports were collected for sportspeople who suffered mTBI and were referred to a tertiary university hospital in the West Midlands over 3 years. Random forest (RF) machine learning algorithms were trained and tuned on a 90% outcome-balanced corpus subset, with subsequent validation testing on the previously unseen 10% subset for binary prediction of greater than five missed sporting games. Confusion matrices and receiver operator curves were used to determine model discrimination.

Results

375 sportspeople were included. A final composite model accuracy of 94.6% based on the unseen testing subset was obtained, yielding a sensitivity of 100% and specificity of 93.8% with a positive predictive value of 71.4% and a negative predictive value of 100%. The area under the curve was 96.3%.

Discussion

In this large single-centre cohort study, a composite RF machine learning algorithm demonstrated high performance in predicting sporting games missed post-mTBI injury. Validation of this novel model on larger external datasets is therefore warranted.

Trial registration number

ISRCTN16974791.

Postconcussion Clinical Insomnia is Associated With Heightened Symptom Severity and Delayed Recovery in Children and Adolescents

BACKGROUND

There is limited evidence on the prevalence and implications of specific types of sleep disturbance in pediatric concussion. This study aimed to (1) identify the prevalence of postconcussion clinical insomnia (PCCI) in children, (2) determine the impact of PCCI on concussion recovery outcomes, and (3) ascertain clinical characteristics associated with PCCI.

METHODS

A cross-sectional study was conducted in patients (n = 164, aged 9-17 years) presenting to a pediatric tertiary referral concussion clinic from January 2021 to December 2022. PCCI was identified using the Insomnia Severity Index. Characteristics, including symptom severity, cognitive function, sleep hygiene behavior, and exercise tolerance, were compared between patients presenting with and without insomnia postinjury. A subgroup analysis of recovered patients was undertaken to determine the impact of PCCI on concussion recovery duration.

RESULTS

Over one third of patients (n = 59, 36%) presented with PCCI. Symptom severity was three times greater in patients with PCCI compared with patients without insomnia postconcussion (P < 0.001). Patients with PCCI had inferior cognitive function in verbal memory (P = 0.01) and visual memory (P = 0.02) cognitive test domains and poorer sleep hygiene behavior (P < 0.001). The subgroup analysis of recovered patients (n = 113) revealed that patients with PCCI had a significantly prolonged recovery duration, taking over one month longer to recover compared with patients without insomnia postinjury (mean recovery duration: 89 vs 57 days, P = 0.004).

CONCLUSIONS

PCCI is an important contributing factor of symptom burden and severity in pediatric concussion.

Motor vehicle crash concussion mechanism displays a greater total number of symptoms and greater affective symptom severity but no neurocognitive differences compared with sport-related concussion mechanism

Previous research among adolescents has shown differences in symptoms and neurocognitive performance between sport-related (SRC) and motor vehicle crash (MVC) concussion mechanisms. Limited research has focused on young adults. The purpose of our study was to compare symptoms, balance, and neurocognitive performance between SRC and MVC mechanisms in young adults. Forty-three (58.1% female, age = 25.5 ± 3.2 years, days since concussion = 12.8 ± 12.7) and 26 (76.9% female, age = 24.1 ± 5.6 years, days since concussion = 12.6 ± 8.3) individuals with an SRC and MVC mechanism, respectively, participated. Primary outcome measures included the total number, severity, cluster (disorientation, migraine, lethargy, and affective) of post-concussion symptoms endorsed, Balance Error Scoring System (BESS), and CNS Vital Signs scores. Clusters are subgroups of symptoms used for targeted rehabilitation. We used independent t-tests and Mann-Whitney U tests to compare symptoms, BESS, and neurocognitive performance. Cliff's Delta effect size was interpreted as negligible (<0.15), small (0.15-0.33), medium (0.34-0.47), and large (≥0.48). There were no group differences for any demographic factors or preexisting conditions (p-range = 0.112-0.991). Participants with an MVC mechanism reported a greater number of total post-concussion symptoms (p = 0.025, Cliff's Delta = 0.32) and a more severe affective symptom cluster (p = 0.010, Cliff's Delta = 0.37). There were no group differences for BESS or neurocognitive performance after correcting for multiple comparisons. The MVC mechanism resulted in a greater total symptom burden relative to the SRC mechanism. Medical practitioners and individuals experiencing a concussion should know that concussions are heterogeneous within and across various mechanisms.

Differing clinical characteristics among individuals with concussions sustained at work, in motor vehicle collisions, and sport

PURPOSE

To compare clinical characteristics in patients with concussions sustained by prevalent, but understudied, mechanisms (work-related concussion [WRC] and motor vehicle collision [MVC]-related concussion) to sport-related concussion (SRC).

METHODS

Retrospective review of 281 electronic medical records from an outpatient concussion clinic. Time since injury (days), duration of care (days), amount of care (number of visits), and perceived health (Short-Form 12) were collected.

RESULTS

The time between injury and clinic presentation was significantly greater in WRC and MVC-related concussion compared to SRC. These groups were also older, had a longer duration of care, required more referrals for outside clinical services, and reported worse perceived mental and physical health versus SRC.

CONCLUSION

These results suggest that clinical courses may be significantly different for individuals with SRC, WRC and MVC-related concussion, and that different management approaches and expectations may be necessary for these groups. Further research is indicated.

Attention-Deficit/Hyperactivity Disorder as a Predictor of Prolonged Functional Recovery From Sports-Related Concussion in High School Athletes

CONTEXT

Attention-deficit/hyperactivity disorder (ADHD) has been speculated to prolong concussion recovery; however, the evidence regarding concussion recovery for individuals with ADHD is limited.

OBJECTIVE

To examine the concussion recovery time based on ADHD status, sex, and age.

DESIGN

Cross-sectional study.

SETTING

High school.

PATIENTS OR OTHER PARTICIPANTS

Nine hundred and thirty-five (female: n = 382, 40.1%) concussions, including 78 (female: n = 13, 20.0%) self-identified ADHD data, were analyzed.

MAIN OUTCOME MEASURE(S)

A Poisson regression was used to estimate the return-to-learn and return-to-sport recovery outcomes with 3 predicting variables: ADHD status, sex, and age.

RESULTS

The mean return-to-learn days of the ADHD and non-ADHD groups were 12.86 ± 10.89 (median = 11.0; interquartile range [IQR] = 8.0; 7.0-15.25) and 1.43 ± 8.39 (median = 9.0; IQR = 9.0; 6.0-14.0), respectively. The mean return-to-sport days of the ADHD and non-ADHD groups were 20.82 ± 15.25 days (median = 17.0; IQR = 9.0; 12.0-21.0) and 18.03 ± 11.42 days (median = 15.0; IQR = 10.0; 11.0-21.0), respectively. For return-to-learn, ADHD status (risk ratio [RR] = 1.16; 95% confidence interval [95% CI]: 1.08, 1.24; P < .001) and female sex (RR = 1.13; 95% CI: 1.08, 1.17; P < .001) were significant variables for longer recovery, whereas age was not (RR = 0.995; 95% CI: 0.98, 1.01; P = .056). For return to sport, ADHD status (RR = 1.17; 95% CI: 1.12, 1.23; P < .001), female sex (RR = 1.07; 95% CI: 1.04, 1.11; P < .001), and younger age (RR = 0.98; 95% CI: 0.96, 0.99; P < .001) were all significant variables for longer recovery.

CONCLUSIONS

Health care providers must be aware of the elevated risk of prolonged concussion recovery among high school athletes with ADHD.

Differences in Network Functional Connectivity in Response to Sub-Symptomatic Exercise Between Elite Adult Athletes after Sport-Related Concussion and Healthy Matched Controls: A Pilot Study

Resting-state electroencephalography (rsEEG) has developed as a method to explore functional network alterations related to sport-related concussion (SRC). Although exercise is an integral part of an athlete's return to sport (RTS) protocol, our understanding of the effects of exercise on (impaired) brain network activity in elite adult athletes is limited. However, this information may be beneficial to inform recovery and RTS progressions. Recording (128-channel) rsEEG datasets before and after a standardized moderate aerobic bike exercise test, this study aimed to explore functional connectivity patterns in whole brain and relevant functional networks in a group of elite adult athletes post-injury compared with healthy matched controls. The following networks were selected a priori: whole brain (68 regions of interest [ROIs]), default mode network (14 ROIs), central autonomic network (CAN, 24 ROIs), and visual network (8 ROIs). Twenty-one SRC athletes and 21 age-, sex-, sport type-, and skill level-matched healthy controls participated in this study. The SRC athletes were recruited during their RTS protocol (days since injury: 2-140 days). All athletes were able to achieve the exercise goal of reaching a moderate intensity (70% of their age-calculated maximum heart rate) while staying sub-symptomatic. Before and after exercise, functional connectivity was calculated by the phase locking value, in the alpha band (7-13 Hz). Mann-Whitney U and Wilcoxon signed rank tests were used to explore neurophysiological differences between and within groups, respectively. Whole-brain connectivity increased significantly from pre- to post-exercise within both groups (SRC: 0.264-0.284; p = 0.011 vs. controls: 0.253-0.257; p = 0.011). While CAN connectivity significantly increased only within the SRC group from pre-(0.298) to post-exercise (0.317; p = 0.003). Although all athletes reached their exercise goal without exacerbation of symptoms, the impact of exercise on the CAN appears to be greater for the SRC athletes, than matched healthy controls. The potential clinical significance of this finding is that it may have revealed an underlying mechanism for the cardiac autonomic alterations post-injury. This study merits further investigation into the CAN, as a network of interest more closely aligned with the clinical features (e.g., autonomic dysfunction) during athletes' RTS.

Use of Knowledge Translation Action Framework to Improve Physical Therapy Rehabilitation Outcomes in Concussion Management

CONTEXT

Translating new evidence into clinical practice is a dynamic and iterative process. Research is ever evolving specific to concussion rehabilitation and requires a systematic approach rooted in science for translation into clinical practice. The knowledge-to-action (KTA) cycle framework is an effective strategy to ensure optimal outcomes and sustainability. The objective of this study was to investigate changes in clinical outcomes and clinician self-efficacy specific to concussion management in a suburban health care system utilizing the KTA framework.

DESIGN

Pretraining and posttraining intervention study.

METHODS

Rehabilitation professionals were electronically surveyed pre-post targeted concussion educational intervention. Questions were adapted from the General Self-Efficacy scale and tailored specifically to confidence in current concussion management. Retrospective chart reviews were also completed pre-post knowledge translation educational intervention to examine practice patterns. Data from the presurvey and retrospective chart review were utilized to identify the know-do gap and design intentional educational interventions. Statistical analysis was performed utilizing SPSS (version 28).

RESULTS

Within-group differences revealed an increase in confidence with evaluation (P = .01), intervention (P = .01), and consultation (P = .01) in concussion management. When comparing physical therapists who participated in the intervention with those who did not, there was significantly higher self-confidence in all areas (P ≤ .001) for those who engaged in the educational intervention. Pre-post chart reviews revealed improvement in clinical practice patterns in the following constructs: use of patient-reported outcome measures (P ≤ .001), objective outcome measures (P = .002), exertional testing (P ≤ .001), completion of comprehensive evaluation (P ≤ .001), and use of evidence-based practice (P ≤ .001).

CONCLUSIONS

Utilizing the KTA framework resulted in improved self-efficacy of clinicians as well as improved clinical practice patterns in concussion management in an outpatient hospital-based practice. The KTA framework is a potential tool for translating current evidence related to concussion management for improved clinical outcomes.

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

CONTEXT

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

DESIGN

Secondary analysis of prospectively collected clinical data.

METHODS

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

RESULTS

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

CONCLUSIONS

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

What Is in a Name? Depression and Anxiety Symptoms in Collegiate Athletes With and Without a History of Concussion

CONTEXT

Athletes with a history of concussion (CON) have been demonstrated to have heightened levels of anxiety and depression that may continue well beyond the resolution of concussion symptoms. The global events of 2020 resulted in elevated levels of anxiety and depression in the general population, which may have unequally presented in collegiate athletes with (CON) than those without a history of concussion (NoCON). Using a deception design, our survey-based study compared levels of anxiety and depression in CON and NoCON collegiate athletes in response to the pandemic and social injustices. We hypothesized that the CON group would have significantly elevated anxiety and depression as compared to the NoCON group in response to events of 2020.

DESIGN AND METHODS

Collegiate athletes (N = 106) during the academic 2020-2021 academic year were divided into CON and NoCON groups based on their preinjury (baseline) concussion assessment. Participants completed the Social Readjustment Rating Scale (SSRS), Center for Epidemiologic Studies Depression Scale (CES-D), and Generalized Anxiety Disorder Scale-7 (GAD-7) via an electronic survey pertaining to the events of 2020. The term "concussion" was not used in any study materials which was the basis for our deception-based design. An analysis of covariance was used to compare group CES-D and GAD-7 outcome scores while controlling for the SSRS outcome score.

RESULTS

Our survey response rate was 14.2% (48/337 [77.1% female]) and 10.1% (58/580 [67.2% female]), for the NoCON and CON groups, respectively. The NoCON group had significantly (F1 = 5.82, P = .018, ηp2=.06) higher anxiety (8.3 [5.89]) as compared to the CON group (5.5 [2.85]). The NoCON group also had significantly (F1 = 13.7, P < .001, ηp2=.12) higher levels of depression (21.0 [12.52]) as compared to the CON group (16.07 [9.10]).

DISCUSSION

Our deception-based study revealed NoCON participants had elevated and clinically relevant mood states as compared to CON participants in response to the events of 2020.

Four-Year Trajectories of Symptoms and Quality of Life in Individuals Hospitalized After Mild Traumatic Brain Injury

OBJECTIVES

To (1) detect distinct trajectories of symptoms and quality of life (QoL) over the first 4 years after mild traumatic brain injury (mTBI); (2) assess the relationship between symptom trajectory membership and QoL trajectory membership; and (3) identify participant characteristics associated with QoL trajectory membership.

DESIGN

Prospective longitudinal cohort study. Assessments occurred at 4, 8, 12, 24, 36, and 48 months after mTBI.

SETTING

Recruitment occurred in Level 1 Trauma Centers; follow-up was completed in the community.

PARTICIPANTS

Participants were 143 adults (aged 18-65y) who sustained an mTBI and were hospitalized (≥24h) at a Level 1 Trauma Center.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Fatigue Severity Scale, Hospital Anxiety and Depression Scale, Insomnia Severity Index, Medical Outcomes Study Cognitive Functioning Scale, Quality of Life after Brain Injury questionnaire, presence/absence of headaches or dizziness.

RESULTS

Group-based trajectory modeling revealed relatively stable symptom and QoL trajectories over time. Considerable percentages of participants were classified in trajectories of clinically significant symptoms throughout the full follow-up period: 62% for subjective cognitive issues, 54% for fatigue, 44% for anxiety, 43% for insomnia, 27% for depression, 23% for headaches, and 17% for dizziness. Sixty-six percent of participants belonged to trajectories of persistently poor QoL. For all symptoms, trajectories of greater severity were associated with trajectories of poorer QoL. None of the sociodemographic or injury-related variables examined were associated with QoL trajectory membership.

CONCLUSIONS

A substantial proportion of individuals hospitalized after mTBI experiences clinically significant persistent symptoms ≤4 years after injury, and those with more severe symptoms have poorer QoL. Further research is required to better understand the factors leading to symptom persistence and poor QoL.

Association of Cognitive Symptoms and Abnormal Oculomotor Signs With Recovery in Adolescents After Sport-Related Concussion

OBJECTIVE

Sport-related concussion (SRC) affects cognitive and oculomotor function. We evaluated recovery from SRC in athletes with cognitive symptoms and/or oculomotor impairments who were prescribed early aerobic exercise treatment.

DESIGN

Secondary exploratory analysis of a randomized controlled trial.

SETTING

Outpatient sports medicine clinics.

PARTICIPANTS

Male and female adolescents (13-18 years) within 10 days of SRC who were prescribed aerobic exercise and who reported either a low (<12 points) or high (≥12 points) burden of cognitive symptom scores on the Post-Concussion Symptom Inventory at initial assessment.

INTERVENTIONS

Early aerobic exercise treatment.

MAIN OUTCOME MEASURES

Recovery time and incidence of persisting postconcussive symptoms beyond 1 month.

RESULTS

Adolescents with a high burden of cognitive symptoms (n = 24, 16.0 ± 1.3 years old, 50% male, 5.3 ± 2.4 days since injury) took longer to recover (34.4 ± 37.1 vs 15.3 ± 7.6 days) than adolescents with a low burden (n = 32, 14.9 ± 1.4 years old, 69% male, 6.1 ± 2.3 days since injury) and had 6-fold higher odds of developing persisting postconcussive symptoms (odds ratio = 6.17 [1.15-33.15]). Abnormal repetitive saccades and vestibular ocular reflex were independently associated with longer recovery after controlling for multiple comparisons ( P < 0.0125), but only abnormal smooth pursuits were a significant effect modifier for the association between cognitive symptoms and recovery (interaction term hazard ratio = 0.133 [0.035-0.504], P = 0.003).

CONCLUSIONS

Individuals with impaired ability to smoothly track a moving target and whose cognitive symptoms are a significant burden are at substantial risk for delayed recovery from SRC. Early initiation of oculomotor rehabilitation may facilitate recovery in these patients.

TRIALS REGISTRATION

Clinicaltrials.gov ID NCT02959216.

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

OBJECTIVE

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

SETTING

Outpatient hospital system multidisciplinary concussion clinic.

PARTICIPANTS

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

DESIGN

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

MAIN MEASURES

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

RESULTS

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

CONCLUSION

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

Exercise Tolerance in Pediatric Concussion: An 8-Year Longitudinal Study

OBJECTIVES

To determine the relationship between exercise tolerance and post-concussion symptom deficits, cognitive function, and recovery duration; (2) examine the longitudinal effect of exercise tolerance on symptom burden over the clinical timecourse of a child's recovery from concussion; and (3) explicate whether exercise intolerance is a significant determinant of recovery in pediatric concussion.

SETTING

Pediatric tertiary referral concussion clinic.

PARTICIPANTS

Children and adolescents (aged 6-18 years) presenting to the concussion clinic between January 2015 and December 2022.

DESIGN

Retrospective longitudinal study.

MAIN MEASURES

Graded exercise test (GXT) data, derived from a standardized treadmill test (Bruce Protocol), was used to measure exercise tolerance following concussion. Based on initial GXT times, participants were dichotomized into 2 groups: (1) exercise tolerant (GXT time ≥9 minutes), or (2) exercise intolerant (GXT time <9 minutes). Symptom burden, cognitive function, and recovery duration were compared between groups. A subgroup analysis of participants requiring multiple clinic visitations was conducted to explore the longitudinal effect of post-concussion exercise tolerance over time.

RESULTS

Of the 603 children presenting to the concussion clinic, 313 participants (mean age ± SD: 13 ± 2 years, 79% male) were eligible. Exercise-intolerant participants (mean GXT [95% confidence interval, CI], 6.9 [6.5-7.3] minutes) reported 2 times greater initial symptom severity (P < .001) and performed poorly in visual memory (P = .002) and reaction time (P = .02) cognitive domains compared to exercise-tolerant participants (mean GXT [95% CI], 12.3 [12.0-12.5] minutes). Recovery time was longer in exercise-intolerant participants than exercise-tolerant participants (mean recovery time [95% CI], 94 [71-116] vs 69 [57-81] days, P = .002). Participants requiring multiple clinic visitations showed improvements in exercise tolerance and symptom burden over time (P < .001). Significant predictors of prolonged concussion recovery were delayed presentation time (P < .001), high initial symptom burden (P < .001), and exercise intolerance (P < .001).

CONCLUSION

GXT is a clinically relevant measure to identify children and adolescents at risk of a prolonged concussion recovery.

Symptom presentation and neurocognitive performance following sport-related concussion in adolescents with and without ADHD

The possible impact of premorbid Attention-Deficit/Hyperactivity Disorder (ADHD) in the recovery process following sport-related concussion (SRC) in adolescents is not clear. The purpose of this study was to investigate the impact of ADHD together with other selected variables on symptom presentation and neurocognitive performance in a well-matched sample of adolescents with SRC. We hypothesized that more symptoms and poorer neurocognitive performance would be observed in those with ADHD. Symptoms from the Sideline Concussion Assessment Tool-5 and cognitive test results from the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) were examined at initial visit, and symptoms were re-assessed at 3-months in a sample of 112 participants with (n = 56) and without (n = 56) ADHD (ages 12-18 years; M = 14.68, SD = 1.77) who were matched by age, sex, ethnicity/race, and days post-injury. Exclusion criteria included severe medical illness or moderate/severe brain injury and lack of English fluency. No significant group differences were found in total symptoms (p = .145), symptom severity (p = .179), or neurocognitive functioning at initial visit (all p > .79) or at 3 months. However, athletes with ADHD reported more nausea (p = 0.22) and feeling slowed down at initial testing (p = .021). Additionally, premorbid anxiety influenced symptom report (p = .010). ADHD did not appear to pose a specific risk for greater symptom burden or neurocognitive deficits in the first 3 months post-concussion.

Is Self-Report of Attachment Patterns in Young People Stable From Three to Nine Months After a Concussion?

Insecure adult attachment patterns have recently been associated with an increased risk of developing persistent post-concussion symptoms (PCS) and poorer treatment outcomes, highlighting the potential of attachment-informed treatment protocols for persistent PCS. A key requirement for such approaches is that attachment patterns remain relatively stable during the post-injury illness course, allowing them to serve as reliable indicators for guiding initial care and treatment planning. This study aimed to assess the stability of self-reported attachment anxiety and attachment avoidance in individuals aged 15-30 years, from three (T1) to nine (T2) months after a concussion, corresponding to the period when treatment for PCS typically becomes relevant. This study is a methodological follow-up of a larger clinical cohort study comprising 3080 individuals aged 15-30 years who were diagnosed with a concussion. Attachment dimensions were measured using the Experiences in Close Relationships-Relationship Structures Questionnaire at three (T1) and nine (T2) months post-injury. Both mean-level and individual changes were examined, taking relevant covariates such as sex, age, level of PCS, post-traumatic stress disorder symptoms, and social support into account. At T1, 958 respondents were included (39%), with 416 also responding at T2 (43%). Mean-level changes were minimal (attachment anxiety: β = -0.07 (95% confidence interval [CI]: -0.22; 0.08)), attachment avoidance: β = 0.00 (95% CI: -0.11; 0.11). Larger individual changes that could not be explained by measurement error were observed in 12% of participants. No association was found with any of the covariates. Self-reported attachment patterns appear to remain stable in most young people with a concussion from 3 to 9 months post-injury. The findings strengthen confidence in conducting research to investigate whether attachment-informed treatment approaches can improve healthcare for these patients.

Influence of social determinants of health and adversity on computerized neurocognitive assessment

Introduction: Social determinants of health and adversity, including poverty, maltreatment, and neighborhood deprivation, are individual-level factors that may significantly affect baseline neurocognitive testing and management that have yet to be thoroughly explored within the computerized neurocognitive assessment.Objectives: Examine individual-level experiences of poverty, abuse, neighborhood deprivation, and social mobility on computerized cognitive testing.Methods: The sample included 3,845 student-athletes who completed a baseline Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) and were enrolled in the Child-Household Integrated Longitudinal Data database. Multivariable linear regressions were used to assess independent variables of Supplemental Nutrition Assistance Program enrollment, abuse or neglect cases, Area Deprivation Index scores, and other demographic factors on four baseline ImPACT composite scores: verbal and visual memory, visuomotor, and reaction time.Results: Individual-level factors of persistent poverty and neighborhood deprivation were associated with lower composite scores; however, upward social mobility was not significantly associated with cognitive performance. The effects of mother's race on computerized cognitive testing performance were attenuated when accounting for measures of adversity.Conclusion: Findings highlight the importance of social determinants of health in computerized neurocognitive testing to ensure more culturally sensitive and precise understanding of athletic baselines.

Identifying the 'Miserable Minority' Among Pediatric Patients Following Concussion

OBJECTIVES

To investigate whether there are empirically-detectable subgroups of concussion severity and recovery across three consecutive concussions, as well as to define risk factor and clinical assessment differences across subgroups.

METHODS

The present study was a retrospective chart review of 202 adolescents 13.17 ± 1.99 years old who presented to a concussion specialty clinic within 30 days of injury for multiple injuries between 2019 and 2020. Participants included patients from a specialty clinic for two (n = 202) or three (n = 68) total concussions. Latent class analysis (LCA) was used to identify subgroups based upon concussion symptom severity and recovery time. Risk factors (sex, age at first injury, and histories of anxiety, depression, migraine, motion sickness, ocular dysfunction, and attention-deficit/hyperactivity disorder [ADHD] or learning disability [LD]) were compared across subgroups.

RESULTS

A two-class solution yielded one group of 163 participants characterized by lower symptoms and shorter recovery times (80.7%, "normal") and 39 participants (19.3%, "miserable minority") characterized by higher symptoms and longer recovery times. Only female sex (OR = 4.91, p = 0.005) was a significant predictor of class membership. The miserable group presented for treatment nearly 4 days later (9.41 days) compared to the normal group (5.74 days) for the first injury, and almost 2 days later for the second injury (7.33 vs 5.26 days).

CONCLUSIONS

Approximately 1 in 5 patients who presented to a concussion specialty clinic for a repeat concussion were classified in the miserable minority subgroup. This subgroup was characterized by markedly higher initial symptom burdens and over double the recovery time.

LEVEL OF EVIDENCE

Retrospective cohort study, Level III evidence.

Epigenetics of concussion: A systematic review

BACKGROUND

Concussion is the most common neurological disorder affecting millions of people globally each year. Identifying epigenetic mechanisms influencing concussion incidence, severity and recovery could provide diagnostic and prognostic insight into this injury.

OBJECTIVES

This systematic review aims to identify the epigenetic mechanisms underpinning concussion.

METHODS

Seven electronic databases; PubMed, MEDLINE, CINAHL, Cochrane library, SPORTDiscus, Scopus and Web of Science were searched for studies that investigated the epigenetic mechanisms of concussion and its underlying neuropathology.

RESULTS

Based on inclusion and exclusion criteria, 772 titles were independently analysed by two of the authors to a final list of 28 studies that totaled 3042 participants. We observed separate associations between sncRNAs, methylation, histone modification and concussion. Overall, 204 small non-coding RNAs were significantly dysregulated between concussed participants and controls or between concussion participants with no post-concussive symptoms and those with post-concussive symptoms. From these, 37 were reported in more than one study and 23 of these were expressed in a consistent direction with at least one further study. Ingenuity pathway analysis identified 10 miRNAs known to regulate 15 genes associated with human neurological pathologies. Two studies found significant changes in global methylation in concussed participants and one study found a decrease in H3K27Me3 in the context of DNA damage and concussion.

CONCLUSIONS

The review findings suggest that epigenetic mechanisms may play an important role in the pathophysiological mechanisms that could influence outcome, recovery, and potential long-term consequences of concussion for individuals.

Headache after pediatric traumatic brain injury: a comparison between a post-acute sample of children and adolescents and general population

BACKGROUND

Headache is one of the most common post-concussion symptoms following pediatric traumatic brain injury (TBI). To better understand its impact on young individuals, this study aims to investigate the prevalence of headache in a German-speaking post-acute pediatric TBI sample and compare it with the general population. In addition, factors associated with the development of pediatric post-TBI headache are investigated to improve the understanding of this condition.

METHODS

A post-acute sample (3 months up to 10 years post-injury) comprising N = 463 children and adolescents aged 8 to 17 years from the TBI sample and N = 463 individuals from the general population matched for gender, age, and health status were included in the study. The Postconcussion Symptom Inventory (PCSI) item assessing headache was used as the outcome variable. Logistic regression was used to examine the association between the risk of developing headache and sociodemographic and health-related factors.

RESULTS

Slightly less than half of the participants reported the presence of headache (TBI sample: 46%; matched controls: 44%). Compared with matched controls, the odds of headache in the TBI sample were not significantly different (OR = 1.09, 95% CI 0.85 to 1.4, p = 0.49). The association between PCSI symptoms was generally stronger in adolescents than in children and in the matched controls than in the TBI sample. In the TBI sample, the probability of reporting headache increased with age.

CONCLUSIONS

The results of this study suggest that the prevalence of headache in the post-acute phase of pediatric TBI is not significantly different from that in the matched non-TBI population, indicating good recovery from injury. However, due to its high prevalence, follow-up screening for this common TBI symptom, especially in adolescents, may be helpful to prevent further chronification.

TRIAL REGISTRATION

The study is retrospectively registered in German Clinical Trials Register and in International Clinical Trials Registry Platform (ID DRKS00032854).

Associations among perceived stress and mindfulness on post-concussion cognitive and mental health outcomes in young adults with a concussion history

BACKGROUND

Despite evidence suggesting perceived stress negatively impacts post-concussion outcomes and that mindfulness may improve that relationship, research has not investigated those connections.

METHODS

This cross-sectional, observational study included 80 young adults with a concussion history who completed a single study visit including the following measures: 1) demographics and concussion, mental health, and mindfulness histories; 2) perceived stress [Perceived Stress Scale (PSS-10)]; 3) mindfulness [Five Facet Mindfulness Questionnaire (FFMQ)]; and 4) post-concussion cognitive and mental health outcomes - neurocognitive performance (CNS Vital Signs), psychological symptoms [Brief Symptom Inventory-18 (BSI-18)], and QOL [Patient-Reported Outcomes Measurement Information System (PROMIS®)]. First, separate regression models determined the association among perceived stress and post-concussion cognitive and mental health outcomes. Second, linear regression models determined the association among mindfulness and post-concussion cognitive and mental health outcomes. Third, to test the moderation effect, models included a perceived stress and mindfulness interaction term.

RESULTS

Higher perceived stress was significantly associated with higher psychological symptoms (p < 0.001) and lower QOL (p < 0.05). Higher mindfulness was significantly associated with lower psychological symptoms (p < 0.001) and higher QOL (p < 0.05). No moderation models were significant.

CONCLUSION

Future research is necessary to further understand mechanisms impacting post-concussion interventions aimed to improve outcomes and life post-concussion.

Performance on the Concussion Balance Test Is Indicative of Time to Recovery in Athletes Following Sports-Related Concussion: An Exploratory Analysis

OBJECTIVE

Sports-related concussions (SRCs) are commonly occurring injuries among athletic and recreationally active populations. SRCs can result in vestibular dysfunction that should resolve before returning to activity. It has been suggested that vestibular impairment is a factor that may influence recovery time. The objective of this study was to evaluate the effect of vestibular function on recovery following SRC.

DESIGN

Retrospective chart review.

SETTING

Multidisciplinary Concussion Clinic.

INTERVENTION

A total of 32 patient charts (21 males, 15.34 [1.47] y, 171.29 [8.44] cm, 68.37 [15.47] kg) from patients diagnosed with SRC presenting to a concussion clinic between August of 2016 and July 2017 with clinician-identified vestibular involvement were included.

MAIN OUTCOME MEASURES

Scores on the Post-Concussion Symptom Scale, Dynamic Visual Acuity Test, Gaze Stabilization Test, Concussion Balance Test (COBALT), and other clinical data were used for analysis. Descriptive statistics were calculated for all variables. Pearson correlations were used to identify variables related to time to recovery. Variables were entered into a forward linear regression model.

RESULTS

Moderate to good relationships were identified between days to recovery and Dynamic Visual Acuity Test lines lost in the leftward direction (1.17 [0.52]; r = .39, P = .04), COBALT-condition 8 sway velocity (1.20 [0.18]; r = .44, P = .01), and days to successful completion of the COBALT (14.72 [8.35]; r = .63, P < .001). Patients' predicted time to recover was equal to 14.61 (0.86) (days to successful COBALT). The model was significant (P < .001, R2 = .30).

CONCLUSION

The single predictor of time to recover was the number of days to successful completion of the COBALT. Thus, the ability to complete the task may be more informative than the performance on the task in predicting recovery time.

Factors Associated with Persisting Post-Concussion Symptoms Among Collegiate Athletes and Military Cadets: Findings from the NCAA-DoD CARE Consortium

BACKGROUND

Persisting post-concussion symptoms (PPCS) is a condition characterized by prolonged recovery from a mild traumatic brain injury (mTBI) and compromised quality of life. Previous literature, on the basis of small sample sizes, concludes that there are several risk factors for the development of PPCS.

OBJECTIVE

We seek to identify protective and risk factors for developing slow recovery or persisting post-concussion symptoms (PPCS) by analyzing medical history, contact sport level, setting, and the Sport Concussion Assessment Tool (SCAT) and Brief Symptom Inventory (BSI-18) assessments at baseline and post-injury.

PATIENTS AND METHODS

We studied 47,860 unique collegiate athletes and Military Service Academy (MSA) cadets enrolled in the 30-site National Collegiate Athletic Association and Department of Defense (NCAA-DoD) Concussion Assessment Research and Education (CARE) Consortium prospective cohort study of baseline and post-injury data from 2014 to 2019. Medical histories and preseason baselines (n = 60,720), along with SCAT and BSI-18 examinations (n = 5379) conducted within 48 h post-injury, were analyzed. PPCS is defined as cleared for return to play (RTP) > 29 days.

RESULTS

Of 5073 concussions, the median (95% CI) and mean (SD) RTP were 15.2 (4.8-82.6) days and 22.2 (23.0) days, respectively, with 891 developing PPCS. Sex, high SCAT score, high BSI-18 score, and delayed reporting produced small effect sizes on RTP (d = 0.22-0.44). Adjusted odds ratios (OR) of developing PPCS indicated the following risk factors: SCAT total score > 45 (OR = 1.91, 95% CI: 1.58-2.30), female sex (OR = 1.80, 95% CI: 1.53-2.13), concussion history (OR = 1.80, 95% CI: 1.29-2.52), and delayed reporting (OR = 1.42, 95% CI: 1.20-1.67). In contrast, protective factors against developing PPCS were: being a limited-contact (OR = 0.34, 95% CI: 0.25-0.47), noncontact (OR = 0.35, 95% CI: 0.24-0.51) or contact sport athlete (OR = 0.34, 95% CI: 0.28-0.41); and receiving the concussion at practice (OR = 0.64, 95% CI: 0.53-0.77) or in competition (OR = 0.44, 95% CI: 0.34-0.56). Athletes diagnosed with a learning disability and taking a neurostimulant were more protected than those who were not (OR = 0.44, 95% CI: 0.26-0.76 versus OR = 0.72, 95% CI: 0.49-1.05, respectively). A prognostic model using these variables offers poor sensitivity (9%) but high specificity (98%) in identifying PPCS (AUC = 0.72).

CONCLUSIONS

This study of 5073 concussions indicates that female sex, high symptom burden, and prior concussion are risk factors for slow recovery. In addition, learning disability, contact sport, and concussion in competition are protective against slow recovery. The neurostimulant results suggest that clinicians should keep their attention deficit disorder (ADD) and attention-deficit/hyperactivity disorder (ADHD) patients on their current neurostimulant medication after a concussion. A prognostic logistic regression model based on behavioral clinical findings did a poor job of identifying PPCS.

Recovery, interrupted: persisting symptoms after concussion and the power of iatrogenesis

Persisting symptoms after concussion (PSaC) affect up to 30% of children, adolescents, and young adults beyond 1 month post-injury, posing challenges in clinical care. This retrospective study examined 54 patients referred for neuropsychological evaluation due to PSaC, exploring factors contributing to symptom persistence. Results showed that 75.9% of patients experienced symptoms attributable to non-concussion factors, with 90.7% lacking evidence-based care post-injury. Pre-existing conditions, including migraines, anxiety, depression, and other psychiatric disorders, correlated with symptom burden. Linear regression models indicated that these psychiatric factors and the absence of evidence-based recommendations predicted symptom severity [R2 = .314, p = .002], with other psychiatric disorders showing a significant effect [β = 2.28, p = .008]. History of any psychiatric disorder predicted current symptom count [R2 = .121, p = .010]. Logistic regression identified migraines (Nagelkerke R2 = .389, p = .000) and depression (Nagelkerke R2 = .124, p = .033) as predictors of non-concussion etiology. Anxiety, depression, migraines, psychiatric disorders, and lack of evidence-based care predicted non-concussion symptoms (Nagelkerke R2 = .575, p = .000). These findings highlight the importance of holistic, individualized care in concussion. Early neuropsychological involvement may improve diagnosis, reduce iatrogenic effects, and optimize recovery through tailored evidence-based interventions.

Diagnosis and Management of Mild Traumatic Brain Injury (mTBI): A Comprehensive, Patient-centered Approach

PURPOSE OF REVIEW

The purpose of this review is to provide an update regarding recent research and recommendations in the care of mild traumatic brain injury (mTBI).

RECENT FINDINGS

New diagnostic criteria for mTBI have recently been developed by the American Congress of Rehabilitation Medicine through the Delphi method and this will help to standardize assessment, diagnosis, and treatment. Symptoms of mTBI are diverse and can sometimes become persistent. Treatment of mTBI should be patient-centered and may require subspeciality referral and coordinated, inter-disciplinary, or multi-disciplinary treatment.

Evolution of dizziness-related disability in children following concussion: a group-based trajectory analysis

OBJECTIVE

This study aimed to identify Dizziness-Related Disability (DRD) recovery trajectories in pediatric concussion and assess clinical predictors of disability groups.

MATERIALS AND METHODS

In this prospective cohort study, 81 children (8-17 years) diagnosed with an acute concussion took part in 3 evaluation sessions (baseline, 3-month, and 6-month). All sessions included the primary disability outcome, the Dizziness Handicap Inventory (DHI) to create the DRD recovery trajectories using group-based multi-trajectory modeling analysis. Each independent variable included general patients' characteristics, premorbid conditions, function and symptoms questionnaires, and clinical physical measures; and were compared between the trajectories with logistic regression models.

RESULTS

Low DRD (LD) trajectory (n = 64, 79%), and a High DRD (HD) trajectory (n = 17, 21%) were identified. The Predicting and Preventing Postconcussive Problems in Pediatrics (5P) total score (Odds Ratio (OR):1.50, 95% Confidence Interval (CI): 1.01-2.22), self-reported neck pain (OR:7.25, 95%CI: 1.24-42.36), and premorbid anxiety (OR:7.25, 95%CI: 1.24-42.36) were the strongest predictors of belonging to HD group.

CONCLUSIONS

Neck pain, premorbid anxiety, and the 5P score should be considered initially in clinical practice as to predict DRD at 3 and 6-month. Further research is needed to refine predictions and enhance personalized treatment strategies for pediatric concussion.

The Influence of Race on Time to Symptom Resolution Following Sport Concussion in Collegiate Athletes

CONTEXT

Race has been shown to influence computerized neurocognitive test scores, motor function test scores, and reported symptomology following sport-related concussion (SRC). However, the effect race may have on recovery time following SRC remains unknown. The objective of this study was to determine the influence of race on days until symptom free from SRC in NCAA Division 1 collegiate athletes.

DESIGN

Prospective cohort study.

METHODS

Participants were Black (n = 53 [28% female]) and White (n = 150 [43.3% female]) who were on average 19.0 (1.21) and 20.2 (1.3) years of age, respectively. Data were collected from the 2015-2016 to 2020-2021 collegiate sport seasons. Participants were evaluated before and after an SRC at empirically derived time points. The primary outcome measure was time until symptom free (days). Additional outcomes included baseline and postinjury Immediate Postconcussion Assessment and Cognitive Test and Sensory Organization Test (SOT) scores. A Mann-Whitney U test compared days to symptom free between groups. Immediate Postconcussion Assessment and Cognitive Test and SOT outcome scores were analyzed using a 2 (group) × 2 (time) analysis of variance.

RESULTS

White participants had a longer median recovery time (9 d) to symptom free compared with Black participants (6 d [P = .04]). Statistically significant differences were observed between Black 87.3 (9.84) and White 90.4 (8.30) groups for Immediate Postconcussion Assessment and Cognitive Test's verbal memory composite score (P = .03). Postinjury, White participants scored significantly higher 44.5 (5.63) on visual motor speed compared with Black participants (42.4 (5.90) [P = .02]). Within-group SOT differences between baseline and postinjury testing were observed in both groups (all P < .001).

CONCLUSIONS

Black collegiate athletes achieved symptom resolution sooner than White athletes. We did not explore underlying sociocultural factors such as socioeconomic status or previous concussion education, which may have influenced our results. Future studies should explore factors that may contextualize these findings.

Influence of Preexisting Conditions and Concussion History on Postconcussion Symptom Severity and Recovery Time in Collegiate Athletes

Mental health conditions and concussion history reported by a collegiate athlete may contribute to prolonged recovery and symptom severity after concussion. This work examined the potential associations among concussion history, preexisting conditions, and sex relative to initial symptom severity and recovery duration following sport-related concussion (SRC) in a cohort of Division 1 National Collegiate Athletic Association athletes. This prospective cohort study analyzed symptom severity, recovery, and return-to-play (RTP) times reported post-SRC using data collected as part of the Pac-12 Concussion Assessment, Research and Education Affiliated Program and Health Analytics Program. Health history questionnaires that included self-reported history of preexisting conditions were completed at baseline. When consented athletes were diagnosed with a concussion, daily postconcussion symptom scores were evaluated until an athlete was clinically determined to be asymptomatic. Generalized linear and Cox proportional hazards models were used to determine associations between preexisting conditions and recovery and RTP times. Ninety-two concussions met inclusion criteria. Notable differences in initial symptom severity existed between females and males who had mood disorders (effect size [d] = 0.51) and attention-deficit hyperactivity disorder (ADHD; d = 0.93). The number of previous concussions was a strong predictor of athletes reporting preexisting mood disorders, depression, anxiety, and ADHD (p = 0.008-0.04). Females with ≥2 previous concussions required more days to RTP than males (d = 0.31-0.72). Weekly recovery and RTP probabilities substantially differed between athletes who did or did not have learning disorders (LDs; hazard ratio [HR]Recovery = 0.32, HRRTP = 0.22, d = 1.96-2.30) and ADHD (HRRecovery = 3.38, HRRTP = 2.74, d = 1.71-4.14). Although no association existed between concussion history and acute symptom severity, collegiate athletes with a history of concussion had higher probabilities of reporting depression, mood disorders, anxiety, and ADHD. Having ADHD or LDs likely strongly affects time to recovery and RTP for collegiate athletes.

Current Evidence for the Use of Jugular Vein Compression Collars in Sport: A Systematic Review

ABSTRACT

Sport-related concussions are a common type of brain injury, and the best treatment is prevention. Recently, external jugular vein compression collars have been worn by National Football League players, but the current evidence is limited. To the best of the authors' knowledge, this is the first comprehensive, up-to-date systematic review addressing the use of jugular vein compression collars for decreasing concussion incidence in high-impact sports and activities. Overall, when compared to control, the results indicated that jugular vein compression collars resulted in significantly reduced white matter alteration, improved short-term neurocognitive outcomes, increased internal jugular vein cross-sectional area, decreased internal carotid artery cross-sectional area, and moderating effects on peak pulse pressure. There was no significant difference in concussion incidence rate between groups. While promising, these findings warrant future research to assess jugular vein compression collar's role in concussion prevention, brain injury, and long-term neurocognitive outcomes. The authors are hopeful for the role jugular vein compression collars will play in the future.

Post-concussion symptom burden and dynamics: Insights from a digital health intervention and machine learning

Individuals who sustain a concussion can experience a range of symptoms which can significantly impact their quality of life and functional outcome. This study aims to understand the nature and recovery trajectories of post-concussion symptomatology by applying an unsupervised machine learning approach to data captured from a digital health intervention (HeadOn). As part of the 35-day program, patients complete a daily symptom diary which rates 8 post-concussion symptoms. Symptom data were analysed using K-means clustering to categorize patients based on their symptom profiles. During the study period, a total of 758 symptom diaries were completed by 84 patients, equating to 6064 individual symptom ratings. Fatigue, sleep disturbance and difficulty concentrating were the most prevalent symptoms reported. A decline in symptom burden was observed over the 35-day period, with physical and emotional symptoms showing early rates of recovery. In a correlation matrix, there were strong positive correlations between low mood and irritability (r = 0.84), and poor memory and difficulty concentrating (r = 0.83). K-means cluster analysis identified three distinct patient clusters based on symptom severity. Cluster 0 (n = 24) had a low symptom burden profile across all the post-concussion symptoms. Cluster 1 (n = 35) had moderate symptom burden but with pronounced fatigue. Cluster 2 (n = 25) had a high symptom burden profile across all the post-concussion symptoms. Reflecting the severity of the clusters, there was a significant relationship between the symptom clusters for both the Rivermead (p = 0.05) and PHQ-9 (p = 0.003) questionnaires at 6-weeks follow-up. By leveraging digital ecological momentary assessments, a rich dataset of daily symptom ratings was captured allowing for the identification of symptom severity clusters. These findings underscore the potential of digital technology and machine learning to enhance our understanding of post-concussion symptomatology and offer a scalable solution to support patients with their recovery.

Recovery Is Similar Between Black and White College Athletes Following Sport-Related Concussion

CONTEXT

Racial identity may associate with clinical outcomes following sport-related concussion (SRC). This study compared clinical outcome scores before and after recovery from a SRC between Black or White college athletes.

DESIGN

Prospective cohort.

METHODS

Participants were self-reported White (n = 61, 18.5 [1.1] y of age) and Black (n = 24, 18.3 [1.1] y of age) NCAA Division 1 college athletes. The revised Head Injury Scale (HIS-r), the Immediate Postconcussion and Cognitive Test (ImPACT) battery, and the Sensory Organization Test (SOT) at baseline (T1), upon symptom resolution (T2) following a diagnosed SRC, and upon establishing a new baseline assessment (T3). Race was collected from paper and electronic medical records. The revised Head Injury Scale total symptom severity, ImPACT's Verbal Memory, Visual Memory, Visual Motor Speed (VMS), and Reaction Time, and the SOT Equilibrium Score, were compared between groups at each time point. Multivariate analyses of variance (2 [group] × 3 [time]) were used to compare revised Head Injury Scale, ImPACT, and SOT outcome scores. Post hoc analyses consisted of independent and paired sample t tests.

RESULTS

A significant main effect for time (λ = 0.66, F2,82 = 21.55, P < .001, ηp2=.34) was observed for the SOT. White athletes significantly improved on the Equilibrium Score between all time points (all P < .006). Similarly, Black athletes significantly improved on the Equilibrium Score between T1-T2 and T1-T3 (all P < .001). A significant main effect of time was observed for ImPACT's Verbal Memory, Visual Memory, and VMS outcome scores (all P < .001). VMS improved for White athletes between T1-T2 (P = .02) and T3 (P = .006). Black athletes had improved VMS scores between T1-T3 (P = .015) and T2-T3 (P = .005). A between-group difference was observed for VMS at T2 (P = .004).

CONCLUSIONS

There was 1 small and not clinically significant difference between groups for the VMS score at T2. Overall, groups performed consistently or improved upon their baseline balance, cognition, and symptom outcome scores at clinically relevant time points following a SRC.

Determinants of symptom presentation and resolution following concussions in high school sports

Sport-related concussions (SRCs) are prevalent in high school (HS) sports, though the determinants of, and relationships between concussion symptoms in this population remain relatively unknown. We analysed SRC data captured within the HS RIO injury surveillance system during 2014/15-2018/19. We used Generalized Estimating Equations to simultaneously assess covariate predictors of symptom presentations and identify pairwise symptom associations and employed multivariable ordinal logistic regressions to determine symptom resolution time (SRT) predictors. Among the 8,969 concussions assessed, headaches (94.3%) and dizziness (73.3%) were the most prevalently reported symptoms. In 5,953 boys' concussion assessed, class year, event type and injury mechanism emerged as determinants of various concussion symptoms, while in 3,016 girls' concussions assessed, class year, event type, injury mechanism, and sport type emerged as significant symptom determinants. In both groups, difficulty concentrating, sensitivity to light, sensitivity to noise, and disorientation were symptoms with the strongest associations with other symptoms. Odds of longer SRT were higher with greater endorsement (i.e. counts) of the subset of symptoms with strongest cross-domain associations (ORadj. = 1.35; 95% CI = [1.30, 1.40]). Our findings provide valuable information for informing sideline and follow-up clinical concussion assessment algorithms in high school athletes.

The Effect of Social Determinants of Health on Clinical Recovery Following Concussion: A Systematic Review

CONTEXT

Concussion evaluations include a multifaceted approach; however, individual differences can influence test score interpretations and validity. Social determinants of health (SDoH) differentially affect disease risk and outcomes based upon social and environmental characteristics. Efforts to better define, diagnose, manage, and treat concussion have increased, but minimal efforts have focused on examining SDoH that may affect concussion recovery.

OBJECTIVE

This review examined previous research that examined the effect of SDoH on concussion recovery of athletes.

EVIDENCE ACQUISITION

CINAHL, MEDLINE, PsycInfo, and SPORTDiscus databases were used to search the terms "concussion" AND "recovery," "youth, adolescent, teen and/or adult," and "social determinants of health" and variations of these terms. The evidence level for each study was evaluated using the 2011 Oxford Center for Evidence-Based Medicine Guide.

EVIDENCE SYNTHESIS

Seven thousand nine hundred and twenty-one articles were identified and screened for inclusion. Five studies met the inclusion criteria and were included in this systematic review. Using the Downs and Black Quality Index, the studies included in this review were deemed high quality.

CONCLUSION

Though limited literature exists, there is preliminary evidence to suggest that SDoH (specifically, economic stability, education access and quality, and social and community context) may have an impact on the clinical recovery from concussion. The dimensions evaluated varied between studies and the results were inconsistent. No single factor consistently affected clinical recovery; however, private insurance and race appear to have an association with the speed of recovery. Unfortunately, the potential intersection of these variables and other preinjury factors limits the ability to make clear recommendations. While most of the studies in this review are retrospective in nature, future efforts should focus on training clinicians to prospectively evaluate the effect of SDoH on concussion recovery and injury outcomes. Funding and registration for this systematic review were not obtained nor required.

Comparing Time to Recovery Between Initial and Repeat Concussion in Athletes

OBJECTIVE

Compare time to recovery between initial and repeat concussions.

DESIGN

Retrospective review of electronic medical record.

SETTING

An interdisciplinary concussion clinic.

PATIENTS

Fifty patients (14.4 years old [±2.5]; 24 [48%] female) who sustained >1 concussion between 2016 and 2020 and were evaluated within 30 days of their concussion.

INTERVENTION

Injuries were divided into first, second, and/or last concussions.

MAIN OUTCOME MEASURES

The primary outcome was time to recovery, as defined by clearance for return to sport. This was compared between first versus second concussion (primary analysis) and first versus last concussion (secondary analysis) using Cox regression. Multivariable models accounted for time from concussion to initial clinic visit and Sport Concussion Assessment Tool symptom severity score at initial encounter. Sensitivity analyses explored potential influences of initial encounter timing and interval between concussions.

RESULTS

Time to recovery did not differ between initial and repeat concussion in univariate or multivariable models (HR = 1.02, 95% CI, 0.65-1.62, P = 0.92; HR = 1.01, 95% CI, 0.64-1.62, P = 0.91 for multivariable models comparing first (ref) versus second and first (ref) versus last concussion, respectively). Similar results were obtained in sensitivity analyses stratifying by time to initial visit (≤7 days vs >7 days) or time between injuries (≤1 year vs >1 year).

CONCLUSIONS

There were no differences in time to recovery between initial and repeat concussions sustained by the same athlete. A nonsignificant trend of shorter recovery after repeat concussions was observed for patients presenting within 1 week of injury and when repeat injuries occurred within 1 year.

The Co-Occurrence of Vestibular/Ocular Motor Provocation and State Anxiety in Adolescents and Young Adults with Concussion

Vestibular/ocular motor provocation and state anxiety are both independently linked to poor recovery outcomes following concussion. However, the relationship between these two clinical presentations and their co-occurring effects on concussion recovery outcomes is understudied. The purpose was to examine the co-occurring effects of vestibular/ocular motor provocation and state anxiety following concussion. There were 532 participants (15-25 years) with concussions who completed the vestibular/ocular motor screening (VOMS), State-Trait Anxiety Inventory, and the Post-Concussion Symptom Scale within 30 days of injury. Participants were classified into provocation (PROV) and no provocation (NO PROV) groups based on exceeding/not exceeding VOMS cutoffs. An analysis of covariance was used to examine between-group comparisons on state anxiety scores; and logistic regressions, with adjusted odds ratios (Adj OR), were used to evaluate predictors of clinical levels of state anxiety and protracted recovery. A total of 418 participants (78.6%; age = 17.2 ± 2.6; 65% female) exceeding VOMS cutoffs were in the PROV, and 114 (21.4%; age = 16.6 ± 2.2; 53% female) participants were in the NO PROV group. The PROV group (mean [M] = 39.50, standard deviation [SD] = 12.05) exhibited significantly higher state anxiety scores than the NO PROV group (M = 32.45, SD = 10.43) (F[1, 532] = 15.36, p < 0.001, η2= 0.03). Vestibular/ocular motor provocation (Adj OR =3.35, p < 0.001, 95% confidence interval [CI]: 1.42-3.88) was the most robust predictor of clinical state anxiety following concussion (χ2 [4, 532] = 86.78, p < 0.001). Participants exhibiting vestibular/ocular motor provocation with clinical levels of state anxiety were at 2.47 times (p < 0.001, 95% CI: 1.53-3.99) greater odds of experiencing a protracted concussion recovery than participants with vestibular/ocular motor provocation without clinical state anxiety. Vestibular/ocular motor provocation is associated with increased state anxiety following concussion, and the addition of clinical state anxiety to vestibular/ocular motor provocation increases the odds for protracted recovery. Clinicians should assess vestibular/ocular motor function and anxiety following concussion.

Sport-related concussion research agenda beyond medical science: culture, ethics, science, policy

The Concussion in Sport Group guidelines have successfully brought the attention of brain injuries to the global medical and sport research communities, and has significantly impacted brain injury-related practices and rules of international sport. Despite being the global repository of state-of-the-art science, diagnostic tools and guides to clinical practice, the ensuing consensus statements remain the object of ethical and sociocultural criticism. The purpose of this paper is to bring to bear a broad range of multidisciplinary challenges to the processes and products of sport-related concussion movement. We identify lacunae in scientific research and clinical guidance in relation to age, disability, gender and race. We also identify, through multidisciplinary and interdisciplinary analysis, a range of ethical problems resulting from conflicts of interest, processes of attributing expertise in sport-related concussion, unjustifiably narrow methodological control and insufficient athlete engagement in research and policy development. We argue that the sport and exercise medicine community need to augment the existing research and practice foci to understand these problems more holistically and, in turn, provide guidance and recommendations that help sport clinicians better care for brain-injured athletes.

Race/ethnicity, sex, and age differences in pediatric SCAT-5 concussion symptoms

OBJECTIVE

To examine sociodemographic differences in concussion symptom reporting, among young children by race/ethnicity, sex, and age at initial presentation to guide potential interventions for children from different backgrounds.

METHOD

Participants were elementary-age children (ages 5 to 12 years; n = 392) who sustained a concussion within 30 days of specialty concussion clinic visit. Independent variables were self-defined race/ethnic group, participants' sex, and age. Dependent variables were number and severity of 22 post-concussion symptoms as measured by the Sport Concussion Assessment Tool5® (SCAT-5) Symptom Evaluation.

RESULTS

Analyses of variance (ANOVAs) showed no differences in reporting of symptoms across race/ethnic or age groups. There was no interaction between race/ethnic, sex and age groups. Females in this sample reported a greater number and severity of concussion symptoms than males.

CONCLUSIONS

Concussion symptom endorsement on the SCAT-5 Symptom Evaluation did not appear to be affected by race/ethnicity or age. However, consistent with existing literature, females reported higher endorsement of concussion symptoms than males and therefore may merit special consideration in evaluation of symptoms. Future research should examine the intersection of other sociodemographic variables with race/ethnicity and should consider the influence of respondent (child vs. parent) in studies of this age cohort.