A preliminary study of subsymptom threshold exercise training for refractory post-concussion syndrome

Understanding factors influencing exercise program adherence for youth with persistent post-concussive symptoms (PPCS)

BACKGROUND

A significant portion of youth sustain a concussion every year, with around 30% experiencing persistent post-concussion symptoms (PPCS). Research has shown exercising just below the exertion level that provokes symptoms can lead to more rapid recovery. However, youth often struggle to adhere to exercise recommendations following concussion.

METHODS

We conducted structured qualitative interviews (n = 32) with concussed youth and their parents to examine factors influencing motivation to engage in exercise post-concussion. Questions were framed through the lens of Self-Determination Theory (SDT) and Thematic Analysis was used to code and analyze transcripts.

RESULTS

Four primary factors appeared to motivate youth to exercise after receiving a concussion: 1) social support, 2) accountability, 3) goal setting, and 4) structure. Utilizing the lens of SDT, one could theorize that including social support and accountability helped fulfill the need of relatedness, setting goals helped fulfill the need of autonomy, and providing program structure helped fulfill the need for competence.

CONCLUSIONS

Our results suggest that Self-Determination Theory may be a useful frame for examining exercise adherence post-concussion. Incorporating social support, accountability, goal setting and structure could increase the effectiveness of exercise prescription post-concussion and should be the focus of further study.

Multimodal Assessment Battery and Heart Rate Variability Enhance Clinical Utility of Buffalo Concussion Treadmill Test

CONTEXT

The Buffalo Concussion Treadmill Test (BCTT) for exercise intolerance following concussion may highlight underlying autonomic dysfunction. Autonomic function at rest and with exertion may be predictive of neurocognitive performance for individuals with sports-related concussion. The purpose of this study is to explore the feasibility and utility of combining multimodal assessments with heart rate variability (HRV) measures during the BCTT for individuals with a remote history of concussion.

DESIGN

Prospective cohort study design, pretest/posttest.

METHODS

Participants included 5 males and 5 females (N = 10, age: 25.2 [3.3] y old, height: 173.2 [11.2] cm, mass: 73.4 [13.7] kg, body mass index: 24.5 [3.9], time since last concussion of 6.3 [4.5] y). All participants completed the multimodal assessment battery including: Concentration Reverse Digits (6 digits), Stroop Incongruent, and King-Devick Test under single- (seated) and dual-task conditions (walking on treadmill at 2.0 mph, 0% incline). Heart rate and HRV was collected at rest, during the BCTT, and during postexercise recovery. HRV data were processed and analyzed based on established protocols. Paired t tests were performed for pre- and postmeasurements separately for single- and dual-task tests of the multimodal assessment battery and HRV indices.

RESULTS

During the BCTT, HRV indices reflective of peripheral nervous system activity demonstrated a significant reduction with concomitant increase in HRV indices of sympathetic nervous system activity (P < .05). Recovery in these HRV indices toward baseline was observed during postexercise recovery. Neurocognitive performance on the Stroop task significantly improved with exercise (P < .05).

CONCLUSION

Implementation of multimodal assessments to evaluate physiological and neurocognitive responses to exercise in individuals with history of sports-related concussion is feasible. Addition of these objective measures may decrease reliance on self-reporting of exercise-induced symptom exacerbation, enabling clinicians to identify individuals whose neurocognitive performance or physiologic response to exercise on the BCTT deviates from the expected.

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.

Effect of Aerobic Exercise on Symptom Burden and Quality of Life in Adults With Persisting Post-concussive Symptoms: The ACTBI Randomized Controlled Trial

OBJECTIVE

To evaluate a 6-week sub-symptom threshold aerobic exercise protocol (AEP) versus a stretching protocol (SP) on symptom burden and quality of life (QoL) in adults with persisting post-concussive symptoms (PPCS).

DESIGN

The Aerobic exercise for treatment of Chronic symptoms following mild Traumatic Brain Injury (ACTBI) Trial was a randomized controlled trial with 2 groups.

SETTING

Outpatient brain injury, pain, and physiotherapy clinics.

PARTICIPANTS

A total of 210 participants were screened. A consecutive sample of 52 adults with PPCS and exercise intolerance after mild traumatic brain injury were enrolled. No participants withdrew because of the adverse effects of the intervention.

INTERVENTIONS

Participants were randomized to a 6-week AEP (n=27) or 6-week SP (n=25).

MAIN OUTCOME AND MEASURES

The Rivermead Post Concussion Symptoms Questionnaire was the primary outcome. Secondary outcomes included QoL using the QoL After Brain Injury Questionnaire, in addition to measures of mood, anxiety, functional impact of headache, fatigue, dizziness, exercise tolerance, and sleep.

RESULTS

Participants were a mean (SD) of 43.0 (10.9) years old (75% female) and 24.7 (14.0) months post-injury. In per-protocol analysis, between-group difference (AEP vs SP) was not significant for the Rivermead Post Concussion Symptoms Questionnaire, but QoL After Brain Injury Questionnaire between-group difference was significant (mean change=5.024; 95% Cl, 0.057-9.992; P=.047) from baseline to 6 weeks. In the intention-to-treat analysis, between-group changes in primary and secondary outcomes were not significant.

CONCLUSIONS

This trial provides preliminary data to support the prescription of aerobic exercise for adults with PPCS. Despite presenting with exercise intolerance, participants were able to engage in subsymptom threshold exercise with QoL benefits.

Documenting Compliance and Symptom Reactivity for Ambulatory Assessment Methodology Following Concussion in Adolescents and Young Adults: Feasibility of the Mobile Neurocognitive Health (MNCH) Project

OBJECTIVE

Evaluate compliance, symptom reactivity, and acceptability/experience ratings for an ecological momentary assessment (EMA) protocol involving ultra-brief ambulatory cognitive assessments in adolescent and young adult patients with concussion.

SETTING

Outpatient concussion clinic.

PARTICIPANTS

116 patients aged 13 to 25 years with concussion.

DESIGN

Prospective research design was used to examine compliance, symptom reactivity, and acceptability/experience for the Mobile Neurocognitive Health Project (MNCH); an EMA study of environmental exposures, symptoms, objective cognitive functioning, and symptom reactivity involving 4, daily EMA surveys (7:30 am , 10:30 am , 3:00 pm , 8:00 pm ) for a period of 7 days following concussion. Overall compliance rates, symptom reactivity scores, and participant acceptability/experience ratings were described. A series of non-parametric Friedman Tests with post-hoc Wilcoxon signed-rank tests were used to examine differences in compliance and reactivity related to time of day and over the course of the protocol (first 3 days [Early Week] vs last 4 days [Late Week]).

MAIN MEASURES

Compliance rates, symptom reactivity scores, participant experience/acceptability.

RESULTS

Overall median compliance was 71%, and there were significantly fewer 7:30 am surveys completed compared to the 10:30 am ( Z = -4 .88, P ≤ .001), 3:00 pm ( Z = -4 .13, P ≤ .001), and 8:00 pm ( Z = -4 .68, P ≤ .001) surveys. Compliance for Early Week surveys were significantly higher than Late Week ( Z = -2 .16, P = .009). The median symptom reactivity score was 34.39 out of 100 and was significantly higher for Early Week compared to Late Week ( Z = -4 .59, P ≤ .001). Ninety-nine percent (89/90) of the sample agreed that the app was easy to use, and 18% (16/90) indicated that the app interfered with their daily life.

CONCLUSION

Adolescents and young adults with concussion were compliant with the MNCH EMA protocol. Symptom reactivity to the protocol was low and the majority of participants reported that the app and protocol were acceptable. These findings support further investigation into applications of EMA for use in concussion studies.

The MPCETT: Assessing the Safety and Utility of Exercise Tolerance Testing in Children With Concussion Ages 6 to 12

OBJECTIVE

Treadmill test protocols for concussion assessment have been validated for patients aged 13 years and older; however, no evidence-based guidelines exist for younger children. We designed and assessed the safety and utility of the Morahan Pediatric Concussion Exercise Tolerance Test (MPCETT) for assessing exercise tolerance in symptomatic children (SC) and recovered, asymptomatic children (AC) from 6 to 12 years of age.

DESIGN

Retrospective case series.

SETTING

Secondary care center.

PARTICIPANTS

Children were diagnosed with concussion using consensus guidelines. At assessment, SC [n = 17; median (range) 10 (6-12) years; 18% female; 28 (13-50) days since injury] had persistent concussive symptoms, while AC [n = 24; 9 (7-12) years; 21% female; 21 (8-37) days since injury] required assessment for return to activity.

INTERVENTIONS

The MPCETT is a modified Buffalo Concussion Treadmill Test for pediatric populations. The test was administered to establish exercise tolerance and was terminated for increased symptoms or self-reported exhaustion.

MAIN OUTCOME MEASURES

Presence of adverse events and exercise intolerance.

RESULTS

The number of adverse events was 0 in both groups. Exercise intolerance occurred in 64.7% (95% CI, 38.3%-85.8%) of children within the SC group versus 12.5% (95% CI, 2.7%-32.4%) within the AC group (P < 0.001).

CONCLUSIONS

Pediatric exercise tolerance testing is safe and effective for assessing exercise intolerance in concussed children.

Factors Affecting Sport-Related Concussion Non-Disclosure in Women's Rugby-A Multi-Country Qualitative Analysis

Background and Objectives: Collision-sport athletes, such as rugby players, are at risk of sport-related concussion (SRC). Women are known to be at higher risk of SRC and may experience more severe and chronic symptomology than men. Knowledge of the factors that affect a player's disclosure of their concussive symptoms could help to inform strategies to improve compliance with reporting and management of head injuries. The aim of this study was to investigate the factors that may impact women rugby players' disclosure of a concussion. Methods: Twenty-eight adult (≥18 years of age) elite and semi-elite women rugby players from the UK and Ireland (n = 17) and the United States (n = 11) were interviewed on their playing background and SRC experience in women's rugby via one-on-one interviews (UK and Ireland) or an online questionnaire (US). Results: SRC data were analysed inductively using a thematic analysis approach to determine the potential reasons for SRC non-disclosure in women's rugby. Four main themes were identified which may influence a player's SRC non-disclosure: 1. women rugby players are self-managing SRC; 2. work-related concerns impact on SRC disclosure; 3. players and support staff lack knowledge on SRC management; and 4. poor internal and external communication affect the support players receive when injured. Conclusions: The findings were consistent across players from different countries. This research highlighted several factors that may impact on women rugby players' disclosure of SRC regardless of country of origin (UK, Ireland, or US) and access to concussion care. Coaches and management teams should be aware of these reasons, which may enhance how they discuss and manage concussion. There is a clear need for further education on concussion for players and support staff and for strategies to create environments where women can openly discuss their concussion concerns.

Adaptive Approaches to Exercise Rehabilitation for Postural Tachycardia Syndrome and Related Autonomic Disorders

Exercise is a well-documented, nonpharmacologic treatment for individuals with autonomic dysfunction and associated orthostatic intolerance, such as postural tachycardia syndrome and related disorders. Exercise has been shown to increase blood volume, reverse cardiovascular deconditioning, and improve quality of life. Current first-line standard of care treatment for autonomic dysfunction combines graded approaches to exercise with medications and lifestyle modifications. However, current exercise rehabilitation protocols for postural orthostatic tachycardia syndrome contain rigid timelines and progression paradigms that often threaten tolerability and adherence. In addition, they fail to account for clinical variables potentially critical to care and lack guidance for individualization, limiting accessibility to patients with co-morbidities that affect exercise appropriateness and safety. Therefore, we introduce an adaptive approach to exercise prescription for orthostatic intolerance that allows patient-specific modifications to meet functional goals for a wider spectrum of patients, thus improving adherence. The proposed approach integrates iterative physiological and symptomatic assessments to provide flexible, yet structured, exposure to aerobic exercise and strength training to improve functional capacity and tolerance of daily activities for patients with postural tachycardia syndrome and related autonomic disorders.

Clinically feasible dual-task detects residual post-concussion deficits after return-to-play

Dual-task (DT) has been shown to detect post-concussion deficits even after traditional measures returned to normal. However, previous studies were conducted in laboratory settings that were not feasible in the clinical setting. Prospective Cohort Study. Two groups (concussion and control groups) completed two testing sessions. The concussion group was tested at 7-10 days post-concussion (subacute) and after Return-to-Play (RTP). The control group was tested with similar time windows. Participants completed 2 single task (ST): Expanded Timed Get Up and Go (ETGUG) as a physical task and Auditory Pure Switch Task (APST) as a cognitive task. After completing STs, participants completed DT performing ETGUG and APST simultaneously. A mixed method ANOVA was conducted to analyze the effects of concussion on ST and DT performance. Another mixed method ANOVA was conducted to examine the effect of concussion recovery time. The concussion group took significantly longer to complete ST and DT than controls at the subacute phase (p = 0.018, p = 0.014, respectively). At RTP timepoint, the concussion group took significantly longer to complete ST and DT than the controls (p=0.007, p < 0.001, respectively). The deficits were more clearly shown for DT. Clinically feasible DT detected subtle and residual post-concussion deficits after athletes were cleared to RTP.

Cardiorespiratory fitness assessment and training in the early sub-acute phase of recovery following traumatic brain injury: a systematic review

OBJECTIVES

To examine the safety of cardiorespiratory fitness (CRF) assessment and training in the early sub-acute phase of recovery (≤3 months) following moderate-to-extremely severe traumatic brain injury (TBI).

METHODS

A systematic review was completed in accordance with the PRISMA guidelines. Studies investigating adults and adolescents ≥15 years with moderate-to-extremely severe TBI were considered for inclusion. The methodological quality of the included studies was evaluated according to the McMaster Guidelines for Critical Review Form - Quantitative Studies.

RESULTS

Eleven studies with a total of 380 participants were included in the review. Adverse events (AEs) and symptom monitoring were poorly reported. Only four studies reported on the occurrence of AEs, with a total of eight AEs reported. Three of the reported AEs were concussion-like symptoms with no further exercise-induced symptom exacerbation reported. No serious AEs were reported.

CONCLUSION

There is no evidence to suggest that CRF assessment and training is unsafe in the early sub-acute phase of recovery following moderate-to-extremely severe TBI. However, despite the low AE and symptom exacerbation rates identified, a timeframe for safe commencement was unable to be established due to poor reporting and/or monitoring of exercise-induced symptoms and AEs in the current literature.

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

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

Identifying the Cerebral Physiologic Response to Aerobic Exercise Following Concussion: A Scoping Review

OBJECTIVE

The purpose of this study was to identify the cerebral physiologic response to aerobic exercise in individuals with a symptomatic concussion, highlighting available knowledge and knowledge gaps in the literature.

DESIGN

A systematic scoping review was conducted and reported in keeping with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews. A search of EMBASE, MEDLINE, SCOPUS, BIOSIS, and Cochrane libraries was conducted on June 15, 2023 (from database inception). An online systematic/scoping review management system was used to remove duplicates, and the remaining articles were screened for inclusion by 2 researchers. Inclusion criteria required articles to be original research published in peer-reviewed journals. Additionally, studies were required to have an aerobic exercise component, include a measure of cerebral physiology during a bout of aerobic exercise, exclude moderate and/or severe traumatic brain injury (TBI) populations, and be in the English language. Both human and animal studies were included, with participants of any age who were diagnosed with a mild TBI/concussion only (ie, Glasgow Coma Scale score ≥ 13). Studies could be of any design as long as a measure of cerebral physiologic response to a bout of aerobic exercise was included.

RESULTS

The search resulted in 1773 articles to be screened and data from 3 eligible studies were extracted.

CONCLUSIONS

There are currently too few studies investigating the cerebral physiologic response to aerobic exercise following concussion or mild TBI to draw definitive conclusions. Further research on this topic is necessary since understanding the cerebral physiologic response to aerobic exercise in the concussion and mild TBI populations could assist in optimizing exercise-based treatment prescription and identifying other targeted therapies.

Exercise as a behavioral approach to improve mood in persons with traumatic brain injury

Mood disturbance is a common, long-term, negative consequence of traumatic brain injury (TBI) that is insufficiently addressed by most traditional treatment modalities. A large body of evidence supports the efficacy of exercise training (ET) to broadly improve mood, as measured most often by the Profile of Mood States (POMS). However, this behavioral approach is not used nearly enough in the TBI population, and when it is, mood is rarely measured. This scoping review will evaluate the use of POMS as a mood measure in TBI research and to establish a rationale for using ET as a behavioral approach to broadly improve mood in persons with TBI.

The Evaluation and Management of Concussion to Optimize Safe Recovery

Concussion is a mild traumatic brain injury causing temporary neurologic dysfunction. Symptoms following concussion are variable and generally are expected to resolve within about 1 month, but some patients experience persistent and prolonged symptoms. An early return to safe, symptom-limited activity is now favored, using targeted rehabilitation and treatments. Accommodations may be needed to facilitate return-to-school and work following concussion. Athletes should not be cleared for a full return to sport until they have recovered from a concussion and completed a return-to-play progression, in addition to returning to work/school fully.

Effectiveness of biomedical interventions on the chronic stage of traumatic brain injury: a systematic review of randomized controlled trials

Traumatic brain injury (TBI), in any form and severity, can pose risks for developing chronic symptoms that can profoundly hinder patients' work/academic, social, and personal lives. In the past 3 decades, a multitude of pharmacological, stimulation, and exercise-based interventions have been proposed to ameliorate symptoms, memory impairment, mental fatigue, and/or sleep disturbances. However, most research is preliminary, thus limited influence on clinical practice. This review aims to systematically appraise the evidence derived from randomized controlled trials (RCT) regarding the effectiveness of pharmacological, stimulation, and exercise-based interventions in treating chronic symptoms due to TBI. Our search results indicate that despite the largest volume of literature, pharmacological interventions, especially using neurostimulant medications to treat physical, cognitive, and mental fatigue, as well as daytime sleepiness, have yielded inconsistent results, such that some studies found improvements in fatigue (e.g., Modafinil, Armodafinil) while others failed to yield the improvements after the intervention. Conversely, brain stimulation techniques (e.g., transcranial magnetic stimulation, blue light therapy) and exercise interventions were effective in ameliorating mental health symptoms and cognition. However, given that most RCTs are equipped with small sample sizes, more high-quality, larger-scale RCTs is needed.

Measurement of improvement on repeat exercise intolerance testing for suspected dysautonomia in protracted concussion recovery: a retrospective cohort study

BACKGROUND

Research has demonstrated concussion likely causes autonomic dysfunction leading to exercise intolerance.

OBJECTIVE

To measure improvement in exercise intolerance due to suspected dysautonomia associated with protracted concussion recovery, using objective measurements on a Buffalo Concussion Treadmill Test (BCTT) following participation in a prescribed exercise program.

METHODS

This is a retrospective cohort study of 101 patient charts post-concussion. Exercise intolerance was assessed using a BCTT to identify suspected dysautonomia and an exercise prescription was provided using guidelines for treating concussion-associated exercise intolerance. Patients without symptom improvement and/or inability to achieve 80-85% of age-expected maximum heart rate (HR) without symptom exacerbation received a repeat BCTT.

RESULTS

Twelve patient charts met inclusion criteria and were included in data analysis. There were significant improvements from pre-intervention to post-intervention testing in: maximum BCTT stage mean scores (p = .02); maximum HR mean scores (p = .01); prescription HR (RxHR) mean scores (p = .01); and HR delta (HR δ ) mean scores (p = .00).

CONCLUSIONS

Maximum stage, HR threshold, RxHR, and newly identified HR delta (HR δ ) are potential objective measurements of progress for dysautonomia treatment post-concussion. Future studies are indicated to create a tailored protocol in the management of protracted concussion-associated dysautonomia.

Changes in Physician Recommendations for Early Physical Activity After Pediatric Concussion: A Retrospective Study

OBJECTIVES

This study aimed to analyze changes in physical activity (PA) recommendations after pediatric concussions and examine the associations of patient and injury characteristics with physicians' PA recommendations.

DESIGN

Retrospective observational study.

SETTING

Concussion clinics associated with a pediatric hospital.

PATIENTS

Patients aged 10 to 18 years with a concussion diagnosis, presenting to the concussion clinic within 14 days of the injury were included. A total of 4727 pediatric concussions and corresponding 4727 discharge instructions were analyzed.

INDEPENDENT VARIABLES

The independent variables for our study were time, injury characteristics (eg, mechanism and symptom scores), and patient characteristics (eg, demographics and comorbidities).

MAIN OUTCOME MEASURES

Physician PA recommendations.

RESULTS

From 2012 to 2019, the proportion of physicians recommending light activity at an initial visit increased from 11.1% to 52.6% ( P < 0.05) within 1-week postinjury and from 16.9% to 64.0% during the second week postinjury ( P < 0.05). A significantly increased odds of recommending "light activity" (odds ratio [OR] = 1.82, 95% confidence interval [CI], 1.39-2.40) and "noncontact PA" (OR = 2.21, 95% CI, 1.28-2.05), compared with "no activity" within 1-week postinjury, was observed in each consecutive year. In addition, higher symptom scores at the initial visit were associated with lower likelihood of recommending "light activity" or "noncontact PA."

CONCLUSIONS

Physician recommendation of early, symptom-limited PA after a pediatric concussion has increased since 2012, which mirrors a shift in acute concussion management. Further research assessing how these PA recommendations may facilitate pediatric concussion recovery is warranted.

Brain changes: aerobic exercise for traumatic brain injury rehabilitation

Introduction

Traumatic Brain Injury (TBI) accounts for millions of hospitalizations and deaths worldwide. Aerobic exercise is an easily implementable, non-pharmacological intervention to treat TBI, however, there are no clear guidelines for how to best implement aerobic exercise treatment for TBI survivors across age and injury severity.

Methods

We conducted a PRISMA-ScR to examine research on exercise interventions following TBI in children, youth and adults, spanning mild to severe TBI. Three electronic databases (PubMed, PsycInfo, and Web of Science) were searched systematically by two authors, using keywords delineated from "Traumatic Brain Injury," "Aerobic Exercise," and "Intervention."

Results

Of the 415 papers originally identified from the search terms, 54 papers met the inclusion criteria and were included in this review. The papers were first grouped by participants' injury severity, and subdivided based on age at intervention, and time since injury where appropriate.

Discussion

Aerobic exercise is a promising intervention for adolescent and adult TBI survivors, regardless of injury severity. However, research examining the benefits of post-injury aerobic exercise for children and older adults is lacking.

Comparison of physiological outcomes after dynamic exertion between athletes at return to sport from concussion and controls: Preliminary findings

OBJECTIVES

Compare physiological (heart rate, heart rate variability, and blood pressure), performance (change-of-direction task completion time and errors), and clinical (symptoms and rating of perceived exertion) outcomes during dynamic exertion between athletes at return to sport after concussion to healthy athlete controls.

DESIGN

Case control.

METHODS

A sample of 23 (Female = 10; 43.5 %) athletes at medical clearance to play/activity from concussion (CONCUSS) and 23 sex-, age-, and sport-matched healthy athletes (CONTROLS) completed a 5-min seated rest before and after the dynamic exertion test. Independent sample t-tests were used to compare CONCUSS and CONTROLS for completion time, heart rate, and blood pressure; and Mann-Whitney U tests for symptoms, perceived exertion, and errors. A series of ANOVAs were conducted to compare heart rate variability between groups across pre- and post-exercise rest periods.

RESULTS

There were no differences in heart rate, blood pressure, symptoms, perceived exertion, and errors. CONCUSS were faster on Zig Zag (p = .048) and Pro Agility (p = .018) tasks, reported lower symptom severity (p = .019), and had lower post-EXiT HRV (p < .049) than CONTROLS.

CONCLUSIONS

Performance, symptoms, perceived exertion, and blood pressure outcomes from dynamic exertion were equivocal between athletes at medical clearance from concussion and healthy controls, which provide empirical support for dynamic exercise to inform medical clearance clinical decision making for sport-related concussion. However, differences in autonomic nervous system functioning indicate that additional research is needed to examine temporal changes in heart rate variability and other physiological outcomes following dynamic exertion.

Consensus statement: An evidence-based review of exercise, rehabilitation, rest, and return to activity protocols for the treatment of concussion and mild traumatic brain injury

BACKGROUND

Early diagnosis and appropriate management of concussion/mild traumatic brain injury (mTBI) is critical for preventing poor outcomes and minimizing health care burden. Current clinical guidelines for concussion management focus mostly on diagnosis and return to cognitive and physical activity but provide limited guidance on the use of specific therapeutic interventions.

OBJECTIVE

To systematically review the available evidence on therapeutic interventions for concussion/mTBI and develop an evidence-based consensus statement on the use of these interventions in clinical practice.

LITERATURE SURVEY

A systematic literature search was performed first in 2018 and 2019, and again in 2022, to identify relevant original research on these interventions. A total of 6303 articles were retrieved through the systematic literature search and screened for inclusion. Eighty articles met inclusion criteria and were included in this review and consensus process.

METHODOLOGY

A multispecialty panel was convened to explore management of concussion/mTBI. Interventions evaluated included rest, exercise, rehabilitation, and return to activity (RTA) protocols. Studies were assessed for relevance and methodologic quality and were voted upon to develop an evidence-based consensus statement on the therapeutic appropriateness of these interventions for concussion/mTBI. A meta-analysis was not performed.

SYNTHESIS

There was sufficient evidence to recommend exercise as an appropriate therapy for adolescents with acute concussion/mTBI. In other age groups and for other therapeutic modalities, although some studies demonstrated benefits for some of the interventions, mixed results and study limitations prevented the panel from drawing firm conclusions on the efficacy of those interventions. The panel found evidence of detrimental effects from strict rest and high-intensity physical activity.

CONCLUSIONS

The panel recommended exercise as an appropriate therapy for acute concussion in adolescents. The evidence on other therapeutic interventions for concussion/mTBI remains limited to small randomized controlled trials and observational studies of moderate to low quality. The panel found no strong evidence to support or recommend against the other evaluated interventions but found most interventions to be safe when used judiciously and in consideration of individual patient needs. High-quality randomized studies with sufficient power are needed to evaluate the effects of rest, rehabilitation, and RTA protocols for the management of concussion/mTBI.

Early Exercise is Associated with Faster Concussion Recovery Among Collegiate Athletes: Findings from the NCAA-DoD CARE Consortium

BACKGROUND

Growing evidence indicates early exercise may improve symptoms and reduce clinical recovery time after concussion, but research examining collegiate student-athletes is scarce.

OBJECTIVE

The aim of this study was to compare symptom recovery time, clinical recovery time, and persisting post-concussion symptom (i.e., symptoms ≥ 28 days) prevalence by the timing of light exercise initiation before the graded return to play (RTP) protocol among concussed participants.

METHODS

Collegiate student-athletes (n = 1228; age 18.4 ± 0.9 years; 56.5% male, 76.3% division I; 33.7% ≥ 1 prior concussion) across 30 institutions enrolled in the CARE Consortium completed post-concussion assessments and were monitored over time. Symptom recovery (days from injury to symptom resolution) and clinical recovery (days from injury to return to play protocol completion) was determined by the student-athletes' clinicians. Student-athletes were categorized by timing of light exercise initiation. Early (< 2 days post-concussion; n = 161), typical (3-7 days post-concussion; n = 281), and late exercise (≥ 8 days post-concussion; n = 169) groups were compared with the no-exercise group (n = 617; i.e., did not exercise prior to beginning the RTP protocol) for all analyses. Multivariable Cox regression models with hazard ratios (HR) and survival curves and a multivariable binomial regression model with prevalence ratios (PR) compared recovery outcomes between exercise groups while accounting for covariates.

RESULTS

Compared to the no-exercise group, the early exercise group was 92% more probable to experience symptom recovery (HR 1.92; 95% CI 1.57-2.36), 88% more probable to reach clinical recovery (HR 1.88; 95% CI 1.55-2.28) and took a median of 2.4 and 3.2 days less to recover, respectively. The late exercise group relative to the no-exercise group was 57% less probable to reach symptom recovery (HR 0.43; 95% CI 0.35-0.53), 46% less probable to achieve clinical recovery (HR 0.54; 95% CI 0.45-0.66) and took 5.3 days and 5.7 days more to recover, respectively. The typical exercise group did not differ in hazard for symptom or clinical recovery (p ≥ 0.329) compared with the no-exercise group. The prevalence of persisting post-concussion symptoms in the combined sample was 6.6%. Early exercise had 4% lower prevalence (PR 0.96, 95% CI 0.94-0.99) and typical exercise had 3% lower prevalence (PR 0.97, 95% CI 0.94-0.99) of persisting post-concussion symptoms, while the late exercise group had an elevated prevalence (PR 1.11, 95% CI 1.04-1.18) compared with the no-exercise group.

CONCLUSION

Exercise < 2 days post-concussion was associated with more probable and faster symptom and clinical recovery, and lower persisting post-concussion symptom prevalence. When considering our findings and existing literature, qualified clinicians may implement early exercise into their clinical practice to provide therapeutic treatment and improve student-athlete recovery.

The association between sleep and physical activity with persisting postconcussion symptoms among adolescent athletes

BACKGROUND

Both sleep duration and physical activity following concussion may influence subsequent recovery. Objective measurement of sleep and physical activity behavior via wearable technology may provide insights into their association with concussion recovery.

OBJECTIVE

To determine whether sleep behavior (eg, duration, timing) and/or physical activity (steps/day, or exercise frequency, duration, intensity) in the first month after adolescent sports-related concussion are associated with developing persisting postconcussion symptoms (PPCS).

DESIGN

Case-control.

SETTING

Outpatient sports medicine clinic.

PARTICIPANTS

The study prospectively enrolled adolescent athletes who sustained a concussion (N = 49, age = 14.8 ± 1.8 years; 51% female) who were evaluated within 14 days of concussion (mean = 6.7 ± 2.7 days) and followed uvia sleep/physical activity monitoring for the subsequent 2 weeks.

MAIN OUTCOME MEASURES

Participants wore a monitor to track sleep (sleep time, wake time, and time spent awake in bed at night) and physical activity (average steps/day, exercise frequency, exercise duration) behavior for 2 weeks after initial assessment. Participants were followed until symptom resolution, and the main outcome of interest was development of PPCS (symptom duration >28 days). A multivariable logistic regression model was used to examine associations between physical activity and sleep behavior with PPCS.

RESULTS

Of the 49 participants, 47% (n = 23, mean symptom resolution = 57 ± 23 days post injury) developed PPCS and 53% (n = 26, mean symptom resolution = 15 ± 7 days post injury) did not. Univariable analysis showed that the PPCS group took fewer steps/day (7526 ± 2975 vs. 9803 ± 3786 steps/day; p = .02), exercised less frequently (2.5 ± 2.2 vs. 4.4 ± 2.1 days/week; p = .005), and spent more time in bed awake (1.2 ± 0.3 vs. 0.8 ± 0.3 h/night; p = .03) than the no PPCS group. Multivariable results indicated the odds of developing PPCS significantly increased with fewer exercise session/week (adjusted odds ratio = 1.96, 95% confidence interval = 1.09, 3.51, p = .024).

CONCLUSIONS

More exercise sessions that were longer than 15 minutes during concussion recovery was associated with a lower risk of developing PPCS, whereas sleep and other physical activity measures were not. Further studies regarding exercise duration and intensity are needed. Clinicians may consider advising patients to optimize sleep and physical activity during concussion recovery.

An At-Home, Virtually Administered Graded Exertion Protocol for Use in Concussion Management: Preliminary Evaluation of Safety and Feasibility for Determining Clearance to Return to High-Intensity Exercise in Healthy Youth and Children With Subacute Concussion

Graded exertion testing (GXT) is an important tool for concussion management, as it is used to personalize post-concussion exercise prescription and return athletes to sport. However, most GXT requires expensive equipment and in-person supervision. Our objective was to assess the safety and feasibility of the Montreal Virtual Exertion (MOVE) protocol, a no-equipment, virtually compatible GXT, in healthy children and children with subacute concussion. The MOVE protocol consists of seven stages of bodyweight and plyometric exercises performed for 60 sec each. Twenty healthy (i.e., non-concussed) children completed the MOVE protocol virtually over Zoom Enterprise. Next, 30 children with subacute concussion (median: 31.5 days post-injury) were randomized to the MOVE protocol or Buffalo Concussion Treadmill Test (BCTT), which increases the incline or speed of the treadmill every minute until maximum exertion. Out of an abundance of caution, all concussed participants completed the MOVE protocol in an in-person clinical space. However, the test evaluator was stationed in a different room within the clinic and administered the MOVE protocol using Zoom Enterprise software to mimic telehealth conditions. Safety and feasibility outcomes were recorded throughout GXT, including heart rate, rate of perceived exertion (RPE), and symptom outcomes. No adverse events were recorded, and all feasibility criteria were successfully met in healthy youth and youth with concussion. Among concussed youth, increases in heart rate (MOVE: 82.4 ± 17.9 bpm, BCTT: 72.1 ± 23.0 bpm; t(28) = 1.36, p = 0.18), RPE (MOVE: 5.87 ± 1.92, BCTT: 5.07 ± 2.34, t(28) = 1.02, p = 0.32), and overall symptom presentation were similar between the MOVE and BCTT protocols. The MOVE protocol is a safe and feasible GXT in healthy youth and youth with subacute concussion. Future studies should assess the fully virtual administration of the MOVE in children with concussion, MOVE protocol tolerability in children with acute concussion, and whether the MOVE protocol can be used to guide individualized exercise prescription.

Sensitivity and Specificity of Exercise Intolerance on Graded Exertion Testing for Diagnosing Sport-Related Concussion: A Systematic Review and Exploratory Meta-Analysis

Abstract There is no single gold standard test to diagnose sport-related concussion (SRC). Concussion-related exercise intolerance, that is, inability to exercise to the individual's appropriate level due to exacerbation of concussion-like symptoms, is a frequent finding in athletes early after SRC that has not been systematically evaluated as a diagnostic test of SRC. We performed a systematic review and proportional meta-analysis of studies that evaluated graded exertion testing in athletes after SRC. We also included studies of exertion testing in healthy athletic participants without SRC to assess specificity. Pubmed and Embase were searched in January 2022 for articles published since 2000. Eligible studies included those that performed graded exercise tolerance tests in symptomatic concussed participants (> 90% of subjects had an SRC, seen within 14 days of injury), at the time of clinical recovery from SRC, in healthy athletes, or both. Study quality was assessed using the Newcastle-Ottawa Scale. Twelve articles met inclusion criteria, most of which were of poor methodological quality. The pooled estimate of incidence of exercise intolerance in participants with SRC equated to an estimated sensitivity of 94.4% (95% confidence interval [CI]: 90.8, 97.2). The pooled estimate of incidence of exercise intolerance in participants without SRC equated to an estimated specificity of 94.6% (95% CI: 91.1, 97.3). The results suggest that exercise intolerance measured on systematic testing within 2 weeks of SRC may have excellent sensitivity for helping to rule in the diagnosis of SRC and excellent specificity for helping to rule out SRC. A prospective validation study to determine the sensitivity and specificity of exercise intolerance on graded exertion testing for diagnosing SRC after head injury as the source of symptoms is warranted.

Targeted multidomain intervention for complex mTBI: protocol for a multisite randomized controlled trial in military-age civilians

Background

Mild traumatic brain injury (mTBI) affects ~18,000 military personnel each year, and although most will recover in 3-4 weeks, many experience persisting symptoms and impairment lasting months or longer. Current standard of care for U.S. military personnel with complex mTBI involves initial (<48 h) prescribed rest, followed by behavioral (e.g., physical activity, sleep regulation, stress reduction, hydration, nutrition), and symptom-guided management. There is growing agreement that mTBI involves different clinical profiles or subtypes that require a comprehensive multidomain evaluation and adjudication process, as well as a targeted approach to treatment. However, there is a lack of research examining the effectiveness of this approach to assessing and treating mTBI. This multisite randomized controlled trial (RCT) will determine the effectiveness of a targeted multidomain (T-MD) intervention (anxiety/mood, cognitive, migraine, ocular, vestibular; and sleep, autonomic) compared to usual care (behavioral management) in military-aged civilians with complex mTBI.

Methods

This study employs a single-blinded, two-group repeated measures design. The RCT will enroll up to 250 military-aged civilians (18-49 yrs) with a diagnosed complex mTBI within 8 days to 6 months of injury from two concussion specialty clinics. The two study arms are a T-MD intervention and a usual care, behavioral management control group. All participants will complete a comprehensive, multidomain clinical evaluation at their first clinical visit. Information gathered from this evaluation will be used to adjudicate mTBI clinical profiles. Participants will then be randomized to either the 4-week T-MD or control arm. The T-MD group will receive targeted interventions that correspond to the patient's clinical profile (s) and the control group will receive behavioral management strategies. Primary outcomes for this study are changes from enrollment to post-intervention on the Neurobehavioral Symptom Inventory (NSI), Patient Global Impression of Change (PGIC), and functional near-infrared spectroscopy (fNIRS). Time to return to activity (RTA), and healthcare utilization costs will also be assessed.

Discussion

Study findings may inform a more effective approach to treat complex mTBI in military personnel and civilians, reduce morbidity, and accelerate safe return-to-duty/activity.

Ethics and dissemination

The study is approved by the University of Pittsburgh Institutional Review board and registered at clinicaltrials.gov. Dissemination plans include peer-reviewed publications and presentations at professional meetings.

Clinical Trial Registration

www.clinicaltrials.gov, identifier: NCT04549532.

Combined Neurocognitive and Exercise Tolerance Testing Improves Objectivity of Buffalo Concussion Treadmill Test

CONTEXT

The Buffalo Concussion Treadmill Test (BCTT) is a standard assessment of exercise tolerance utilized for exercise prescription following concussion and to inform decisions regarding return to play. One limitation of the BCTT is that interpretation of test results is dependent on individuals' self-report of symptom exacerbation with exertion. Symptoms following concussion are significantly underreported or unreported. Combining objective neurocognitive assessment with exercise tolerance testing may enable clinicians to objectively identify those requiring further assessment or rehabilitation before return to play. The purpose of this study was to investigate how performance on a neurocognitive assessment battery is affected by provocative exercise testing.

DESIGN

Prospective cohort study, pretest/posttest.

METHODS

A total of 30 participants included 13 women (43.3%), age 23.4 (1.93) years, height 173.56 (10) cm, weight 77.35 (16.3) kg, and 11 (36.7%) with history of concussion. All participants completed a neurocognitive assessment battery, including the Stroop Test and standardized assessments of working memory, attention, and information processing speed/accuracy in single-task (seated position) and dual-task conditions (walking on a treadmill at 2.0 miles per hour). The neurocognitive assessment battery was performed at baseline and after the standard BCTT test protocol.

RESULTS

BCTT: Average percentage of heart rate maximum (%HRmax) = 93.97% (4.8%); average maximum rating of perceived exertion = 18.6 (1.5). Time-based performance in single-task and dual-task conditions significantly improved from baseline (P < .05) following maximal exercise testing on the BCTT for the following neurocognitive assessments: concentration-reverse digits, Stroop congruent, and Stroop incongruent.

CONCLUSIONS

Healthy participants demonstrated improvements across multiple domains of neurocognitive performance following the exercise tolerance testing on the BCTT. Understanding normal responses in neurocognitive performance for healthy individuals following exercise tolerance testing may allow clinicians to more objectively monitor the trajectory of recovery following sports-related concussion.

Exercise Parameters for Postconcussion Symptom Rehabilitation: A Systematic Review

CONTEXT

Exercise rehabilitation for postconcussion symptoms (PCS) has shown some benefits in adolescent athletes; but a synthesis of evidence on exercise per se has been lacking.

OBJECTIVE

This systematic review aimed to determine if unimodal exercise interventions are useful to treat PCS and if so, to identify a set of clearly defined and effective exercise parameters for further research.

EVIDENCE ACQUISITION

Relevant health databases and clinical trial registries were searched from inception to June 2022. The searches used a combination of subject headings and keywords related to mild traumatic brain injury (mTBI), PCSs, and exercise. Two independent reviewers screened and appraised the literature. The Cochrane Collaboration's Risk of Bias-2 tool for randomized controlled trials was used to assess methodological quality of studies.

EVIDENCE SYNTHESIS

Seven studies were included in the review. Four studies were assessed to have a low overall risk of bias, 2 with low risk and 1 with some concerns. Participants in the studies comprised mostly adolescents with sports-related concussion. The review found exercise to be more beneficial than control conditions in 2 studies investigating acute PCS and 2 studies investigating persistent PCS. Within-group differences showing symptom improvement over time were observed in all 7 studies. In general, the review found support for programmatic exercise that commences after an initial period of rest for 24 to 48 hours. Recommendations for exercise parameters that can be explored in subsequent research include progressive aerobic exercise starting from 10 to 15 minutes at least 4 times a week, at a starting intensity of 50% HR of the subsymptom threshold, with length of program depending on recovery.

CONCLUSION

The evidence in support of exercise rehabilitation for PCSs is moderate based on the small pool of eligible studies. Further research can be guided by the exercise parameters identified in this review.

Active Rehabilitation Following Acute Mild Traumatic Brain Injury: A Systematic Review

Purpose:

Following mild traumatic brain injury (mTBI), patients are often advised to restrict physical activity until full symptom resolution followed by gradual return to activity. However, extended rest periods may prolong recovery and contribute to persistent symptoms. Emerging evidence suggests early active rehabilitation that increases heart rate without exacerbating symptoms may improve mTBI patient recovery. This review aims to: (1) appraise evidence on active rehabilitation intervention for mTBI recovery within one-month of injury (i.e., exercise type, duration, intensity, etc.); and (2) recommend evidence-based rehabilitation protocols.

Method:

Pubmed, CINAHL, PsychARTICLES, SportDISCUS, and AMED databases were searched using key terms “mild Traumatic Brain Injury”, “Rehabilitation”, “Acute”, and their synonyms. Evidence was appraised using Cochrane RoB-2 and ROBINS-I.

Results:

434 citations were initially identified with seven papers systematically reviewed. Within the reviewed articles, only three were randomized controlled trials with low risk of bias, and four were non-randomized trials with low to moderate risk of bias. Findings highlighted that a range of active rehabilitation protocols were used with different exercise modalities (primarily treadmills and static cycling), durations (9–20 min, or until symptomatic, for 30–50 days or symptoms resolved), and intensities (low, moderate or high). Active rehabilitation did not cause any serious adverse events (i.e., death, hospitalisation etc.), and six studies reported that it did not exacerbate mTBI symptoms in any participants (with one participant having symptom worsening in one study). Overall, the majority of reviewed studies ( n = 4) showed that active rehabilitation decreased time to mTBI symptom resolution compared to controls (strict rest/stretching exercises).

Conclusions:

Individualized active rehabilitation prescribed within one-month post-mTBI appears to be safe and effective at decreasing recovery time to symptom resolution in mTBI. However, there is a lack of consensus regarding specific intervention protocols that needs to be addressed before adoption within clinical practice.

Efficacy of aerobic exercise following concussion: a narrative review

Concussion is a type of mild traumatic brain injury which results in symptoms within the physical, cognitive, emotional, and sleep domains. Historically, guidelines established by expert opinion have recommended rest during the initial stages of recovery following a concussion until symptom resolution. However, recent recommendations have shifted to advise an initial period of 24-48 h of rest immediately following concussion with the gradual introduction of light-to-moderate intensity aerobic exercise thereafter. Given the relatively recent transition in recommendations, the aim of this review is to provide an overview of the current literature on the efficacy of aerobic exercise following concussion. The current literature is limited to studies assessing the impact of standardized aerobic exercise following concussion. Upon review, literature suggests participating in aerobic exercise below the point of symptom exacerbation is safe in both the acute and chronic post-concussion symptom stages of recovery and does not delay time to medical clearance. Future large-scale randomized controlled trials assessing the impact of aerobic exercise and differences between males and females would help support the current evidence suggesting aerobic exercise could improve time to recovery following concussion and identify any sex differences in response. As well, future studies with the purpose of identifying optimal aerobic exercise volume and intensity in the treatment of concussion could improve the specificity of the current guidelines.

SWOT analysis of a physical activity intervention delivered to outpatient adults with a mild traumatic brain injury

Objectives

Physical activity interventions are effective to reduce the symptoms and recovery time after a mild traumatic brain injury; such interventions are not always embedded in all interdisciplinary outpatient settings. Service providers of a specialized rehabilitation program recognized the need to implement emerging evidence-based approaches to improve physical activity delivery. Understanding the perceptions of managers, clinicians, and users regarding the strengths, weaknesses, opportunities, and threats of the current physical activity intervention delivered to outpatient adults with a mild traumatic brain injury could inform local and widespread intervention development, enhancement, and implementation of evidence-based physical activity interventions.

Methods

This study used a descriptive qualitative design using a strength, weakness, opportunity, and threat analysis framework. Managerial staff (n = 3), clinicians (n = 6), and program users (n = 5) with persisting symptoms following a mild traumatic brain injury from an outpatient specialized public rehabilitation program in Québec (Canada) participated. Individual semi-structured interviews were performed, recorded, transcribed verbatim, and analyzed using a qualitative content analysis approach.

Results

Participants were generally positive about the intervention but expressed that improvement was required. Strengths (n = 15), weaknesses (n = 17), opportunities (n = 12), and threats (n = 6) related to eight overarching categories: physical activity intervention, health-related outcomes, clinical expertise, knowledge translation, communication, user engagement, resources, and accessibility. Category descriptions, convergent and divergent perspectives, and salient quotes of participants are provided.

Conclusions

Participants were generally positive about the intervention (e.g., format) but identified weaknesses (e.g., need for service providers to better describe the physical activity intervention using theoretically driven approaches). Consultations of stakeholders will inform future intervention enhancement efforts and assist in ensuring interventions meet user needs.

Symptom Provocation Following Post-concussion Computerized Neurocognitive Testing and Its Relationship to Other Clinical Measures of Concussion

OBJECTIVE

The objective of this study was to document the prevalence of post-computerized neurocognitive test (post-CNT) increases in symptoms in athletes with sport-related concussion, and to examine the effect of post-CNT symptom increases on concussion neurocognitive and vestibular/ocular motor clinical outcomes.

METHODS

This was a retrospective analysis of medical records from a concussion specialty clinic. Two hundred and three athletes (M = 16.48 ± 1.97 years; 44% [90/203] female) completed a clinical visit for concussion within 30 days of injury (M = 7.73 ± 5.54 days). Computerized neurocognitive testing (the Immediate Post-concussion Assessment and Cognitive Testing: ImPACT), the Post-Concussion Symptom Scale (PCSS), and the Vestibular Ocular Motor Screening (VOMS) were the main outcome measures for the current study.

RESULTS

Sixty-nine percent (141/203) of the sample did not report significant increases in PCSS scores following post-concussion CNT and were classified into a No Provocation (NO PROV) group. Thirty-one percent (62/203) of participants did report a significant increase in symptoms following post-concussion CNT and were classified into a Provocation (PROV) group. Neurocognitive performance was similar between groups. However, the PROV group reported significantly higher scores on the VOMS symptom items than the NO PROV group.

CONCLUSIONS

The majority of adolescent athletes can complete a post-concussion CNT without experiencing significant increases in concussion symptoms. Individuals that report symptom increases from completing a post-concussion CNT are more likely to exhibit increased vestibular/ocular motor symptoms. These findings underscore the relationship between the clinical findings from both CNT and vestibular/ocular motor measures following concussion.

Interdisciplinary Rehabilitation for Concussion Recovery (i-RECOveR): protocol of an investigator-blinded, randomised, case series with multiple baseline design to evaluate the feasibility and preliminary efficacy of a 12-week treatment for persistent post-concussion symptoms

BACKGROUND

Up to 25% of concussed individuals experience persistent post-concussion symptoms (PPCSs) which may interfere with the return to pre-injury activities and cause significant stress. Given that multiple etiological factors are thought to contribute to PPCSs, an interdisciplinary approach is recommended. This pilot study aims to primarily investigate the feasibility of a novel interdisciplinary treatment for PPCSs. Given this intervention is novel, uncertainty exists in terms of potential recruitment and retention rates, adverse events, and treatment adherence and fidelity. These factors will be explored to inform the feasibility of a phase-2 randomised controlled trial. Preliminary efficacy of this intervention will also be explored.

METHODS

Fifteen individuals with mild traumatic brain injury and PPCSs will receive up to 12 weeks of interdisciplinary treatments including psychology, physiotherapy, and medical interventions. Primary feasibility outcomes including data on recruitment and retention rates and treatment adherence will be explored descriptively. The cognitive therapy rating scale will be used to assess treatment fidelity. A single-case series with multiple baseline design will be used to explore preliminary efficacy. Participants will be randomly assigned to baseline phases of 2, 4, or 6 weeks. Regarding patient-centred secondary outcomes, the Rivermead Post-Concussion Symptoms Questionnaire will be assessed three times a week during baseline and treatment phases. Secondary outcomes also include measures of mood, sleep and fatigue, physical functioning, return to activity, and health-related quality of life. Patient-centred outcomes will be assessed at baseline, pretreatment, post-treatment, and one- and three-month follow-up. Thematic analysis of participant experiences will be explored through qualitative interviews.

DISCUSSION

Results from this trial will inform the feasibility and preliminary efficacy of this interdisciplinary concussion intervention and whether proceeding to a future definitive phase-2 randomised controlled trial is worthwhile. Understanding the end-user perspective of the treatment will also enable modifications to the treatment protocol for future trials to best suit the needs of individuals with PPCSs after mTBI. Outcomes from this trial can be directly translated into community rehabilitation programmes.

TRIAL REGISTRATION

ANZCTR, ACTRN12620001111965. Registered 27 October 2020, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=379118.

The University of Kansas Health System Outpatient Clinical Concussion Comprehensive Protocol: An Interdisciplinary Approach

Objective:

The concussion team at The University of Kansas Health System outpatient rehabilitation spine center is comprised of experienced multi-disciplinary experts including physical therapists and a speech language pathologist. The team set forth with a purpose of creating and organizing an internal physical therapy clinical recommendation protocol for initial evaluations and subsequent treatments for the concussed patient. The aim of this paper is to share these recommendation protocols with other therapy teams and provide a foundational layout for treating the patient with post-concussion symptoms in an outpatient physical therapy clinical setting.

Study design:

Clinical recommendation protocol provides guidance for patients ages 10+ from initial evaluation through discharge with emphasis on evidence-based research in the areas of: oculomotor, cervical, vestibular, post-concussion migraine influence, mood disorders(such as anxiety and depression), exertion, and cognitive communicative dysfunction.

Results:

Finding a written, comprehensive clinical resource protocol for post-concussion outpatient evaluation(s) and treatment strategies can be difficult. This document serves as a resource for other outpatient concussion rehabilitation clinics, providing rationale, and objective measurement tools, for assessing and treating concussion patients. To the authors’ knowledge, no other research has produced a practical, efficient evaluation tool to be utilized at bed side, condensing evidence-based research into an easy-to-use form.

Conclusion:

The University of Kansas Health System outpatient concussion rehabilitation center developed clinical recommendation protocols for concussion care. The intent was to standardize assessment and treatment for concussion patients and to share these objective measurement tools and procedures, focused on a team approach of concussion providers, as a clinical outline for both the novice and seasoned clinician specializing in the field of concussion work in an outpatient rehabilitation setting.

A Remotely Delivered Progressive Walking Intervention for Adults With Persistent Symptoms of a Mild Traumatic Brain Injury: Feasibility and Exploration of Its Impact

Introduction

Persistent post-concussion symptoms following a mild traumatic brain injury (mTBI) can impact function and participation of adults. Physical activity is recommended to reduce symptoms and foster return to normal activities. Adults with a mTBI may have personal factors or experience accessibility issues restricting physical activity. Walking is a physical activity accessible to most that could be delivered remotely.

Objectives

Determine the feasibility, safety, and acceptability of a remotely delivered progressive walking intervention designed for adults with persistent mTBI symptoms and explore its effects on health-related outcomes.

Methodology

This feasibility study using a single-group pre-post mixed methods convergent parallel design was conducted remotely. Adults aged 18–65 years with a mTBI reporting persistent symptoms for ≥3 months were recruited. The 8-week remote progressive walking intervention aimed to increase the weekly number of steps walked by 40% based on a 1-week baseline measured by a Fitbit Inspire 2 activity monitor. Feasibility measures were about the intervention, its remote delivery, safety, and acceptability. Health-related outcomes were post-concussion symptoms, kinesiophobia, mood, sleep, fatigue, and quality of life. Semi-structured exit interviews were recorded and transcribed verbatim. Quantitative and qualitative data were analyzed separately, and results merged, compared, and contrasted. Descriptive statistics and paired samples t-tests were used. The qualitative analyses followed an iterative content analysis approach using reflexivity and triangulation of sources.

Results

Twenty adults (16 women) aged 42.5 ± 11.51 years with persisting symptoms for 9.25 ± 6.43 months participated, adhered to 94.38% of sessions, completed the intervention, and found it to be feasible, safe and acceptable. Participants increased weekly total number of steps walked (change = 14,886 ± 18,283; t = 3.55, p = 0.002). Severity of post-concussion symptoms (change = −6.42 ± 10.69; t = −2.62, p = 0.018), kinesiophobia (change = −5 ± 6.86; t = 3.18, p = 0.005), anxiety (change = −1.53 ± 3.01; t = −2.21, p = 0.04), and fatigue (change = −10.21 ± 10.20; t = −4.37, p < 0.001) were reduced, whilst quality of life improved (change = 10.58 ± 13.35; t = 3.46, p = 0.003). Participants' perceptions corroborate most quantitative results; they felt improved self-efficacy about physical activity and provided five key recommendations.

Discussion

This study demonstrates the feasibility, safety, and acceptability of the remote 8-week progressive walking intervention, a promising approach to reduce persisting symptoms, improve physical activity level health-related outcomes and quality of life of adults with persistent post-concussion symptoms following a mTBI.

Adolescent and Parent Perceptions of the Impact of Concussion/mTBI on Family Functioning and Activity Levels in Recovery

OBJECTIVE

To explore adolescent and parent perceptions of the impact of a concussion/mild traumatic brain injury (mTBI) on family functioning and activity levels in the first 4 weeks of recovery.

SETTING

Outpatient research setting.

PARTICIPANTS

Twenty-seven adolescents (aged of 13-17 years) within 1 week of a concussion/mTBI and a parent/guardian were enrolled in the study.

DESIGN

Prospective ecological study with qualitative, semistructured interviews.

MAIN MEASURES

Adolescents reported symptoms electronically every 2 days for 28 days via the Post-Concussion Symptom Inventory. Semistructured interviews were completed with each adolescent-parent dyad at the end of the 28-day period. Interview questions focused on perceptions of recovery progress and study procedures.

RESULTS

Symptom trajectories were variable across participants. Three main themes emerged from thematic analysis, including: (1) disruption of routines and activities, (2) injury management considerations, and (3) positive and negative influential factors (eg, school and coach support, timing of injury, and recovery expectations). Results highlighted nuances of recovery challenges that families specifically face and help emphasize the potential benefits of shared decision-making and where more guidance would be appreciated such as more specific self-management of symptoms and physical activity reintegration strategies.

CONCLUSIONS

Study findings support a shared decision-making approach with the identified themes as potential topics to help consider social and environmental influences on recovery. The themes presented in the results could be topics emphasized during intake and follow-up visit processes to help guide plans of care and return-to-activity decisions.

Ambulatory Assessment in Concussion Clinical Care and Rehabilitation

Concussion is a mild traumatic brain injury that is characterized by a wide range of physical, emotional, and cognitive symptoms as well as neurocognitive, vestibular, and ocular impairments that can negatively affect daily functioning and quality of life. Clinical consensus statements recommend a targeted, clinical profile-based approach for management and treatment. This approach requires that clinicians utilize information obtained via a clinical interview and a multi-domain assessment battery to identify clinical profile(s) (e.g., vestibular, mood/anxiety, ocular, migraine, cognitive fatigue) and prescribe a corresponding treatment/rehabilitation program. Despite this comprehensive approach, the clinical picture can be limited by the accuracy and specificity of patient reports (which often conflate timing and severity of symptomology), as well as frequency and duration of exposure to symptom exacerbating environments (e.g., busy hallways, sitting in the back seat of a car). Given that modern rehabilitation programs leverage the natural environment as a tool to promote recovery (e.g., expose-recover approach), accurate characterization of the patient clinical profile is essential to improving recovery outcomes. Ambulatory assessment methodology could greatly benefit concussion clinical care by providing a window into the symptoms and impairments experienced by patients over the course of their daily lives. Moreover, by evaluating the timing, onset, and severity of symptoms and impairments in response to changes in a patient's natural environment, ambulatory assessments can provide clinicians with a tool to confirm clinical profiles and gauge effectiveness of the rehabilitation program. In this perspective report, we review the motivations for utilizing ambulatory assessment methodology in concussion clinical care and report on data from a pilot project utilizing smart phone-based, ambulatory assessments to capture patient reports of symptom severity, environmental exposures, and performance-based assessments of cognition for 7 days following their initial evaluation.

The impact of the COVID-19 pandemic on the well-being of individuals with persistent post-concussive symptoms: a qualitative study

Background

In response to the COVID‐19 pandemic, public health measures were implemented that closed essential businesses, mandated social distancing, and imposed substantial changes to the routine care experienced by patients with mild traumatic brain injury (mTBI) and persistent postconcussive symptoms (PPCS). Patients with PPCS often rely on a comprehensive care team, requiring in‐person treatments and consistent care. Little information exists regarding how access to these services have been affected by public health measures and what outcome the measures have had on the recovery of patients with PPCS.

Objective

To explore the impact of the restriction of in‐person treatments, shifts to virtual care, and global public health measures on the recovery and psychological well‐being of patients with PPCS.

Design

Qualitative interviews were recorded, transcribed, and analyzed using a reflexive thematic analysis approach to identify the main impacts of the public health measures on participants with PPCS.

Setting

Participant interviews were completed remotely via telephone or video‐calling software during province‐wide shutdowns.

Participants

20 individuals with PPCS who attended the institution's Brain Injury Program consented to participate.

Interventions

Not applicable.

Results

The impacts of the public health measures emerged most prominently in three main categories: (1) day‐to‐day lived experiences, (2) personal health status, and (3) health service experiences and barriers.

Conclusions

This in‐depth investigation of the lived experiences of patients with PPCS outlines how the COVID‐19 public health measures negatively affected their care and well‐being. The analysis identified that through increasing social support systems, providing better access to standard or remote treatment, and developing more effective telehealth strategies, this population could be better supported in the event of future public health measures.

Overview of Traumatic Brain Injury in American Football Athletes

OBJECTIVE

The aim of this review is to provide a summary of the epidemiology, clinical presentation, pathophysiology, and treatment of traumatic brain injury in collision athletes, particularly those participating in American football.

DATA SOURCES

A literature search was conducted using the PubMed/MEDLINE and Google Scholar databases for publications between 1990 and 2019. The following search phrases were used: "concussion," "professional athletes," "collision athletes," "mild traumatic brain injury," "severe traumatic brain injury," "management of concussion," "management of severe traumatic brain injury," and "chronic traumatic encephalopathy." Publications that did not present epidemiology, clinical presentation, pathophysiology, radiological evaluation, or management were omitted. Classic articles as per senior author recommendations were retrieved through reference review.

RESULTS

The results of the literature review yielded 147 references: 21 articles discussing epidemiology, 16 discussing clinical presentation, 34 discussing etiology and pathophysiology, 10 discussing radiological evaluation, 34 articles for on-field management, and 32 articles for medical and surgical management.

CONCLUSION

Traumatic brain injuries are frequent in professional collision athletes, and more severe injuries can have devastating and lasting consequences. Although sport-related concussions are well studied in professional American football, there is limited literature on the epidemiology and management of severe traumatic brain injuries. This article reviews the epidemiology, as well as the current practices in sideline evaluation, acute management, and surgical treatment of concussions and severe traumatic brain injury in professional collision athletes. Return-to-play decisions should be based on individual patient symptoms and recovery.

Mobile Subthreshold Exercise Program (MSTEP) for concussion: study protocol for a randomized controlled trial

BACKGROUND

Subthreshold exercise, defined as aerobic exercise below the level that causes symptoms, has been utilized as a treatment for youth with persistent postconcussive symptoms (PPCS), but there is currently little evidence to guide use. In addition, prior studies of exercise for PPCS have all required multiple in-person visits. We developed a virtual approach for delivering subthreshold exercise to youth with PPCS called the Mobile Subthreshold Exercise Program (MSTEP), and we have now been funded to conduct a large national randomized controlled trial (RCT) to test its efficacy for reducing concussive symptoms and improving health-related quality of life.

METHODS

This investigation is an RCT comparing MSTEP to an active control. We will recruit 200 adolescents 11-18 years old with postconcussive symptoms persisting for at least 1 week but less than 1 year. Youth will be randomized to receive either 6 weeks of subthreshold exercise (MSTEP) or a stretching condition (control). Youth and parents will complete surveys of concussive symptoms at baseline, weekly during the intervention, and at 3 and 6 months. The primary outcomes will be trajectory of concussive symptoms and health-related quality of life over the 6 months of the study. Secondary outcomes will include depression, anxiety, and sleep quality. We will also assess potential mediators of treatment effects including moderate-vigorous physical activity and fear avoidance of concussive symptoms.

DISCUSSION

This multisite RCT of MSTEP will provide vital information regarding the efficacy of a virtually delivered subthreshold exercise program for youth with PPCS, and insight regarding potential mediators of treatment effects, including objectively measured physical activity and fear avoidance of concussive symptoms.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04688255. Registered on December 29, 2020.

Tele-Active Rehabilitation for Youth With Concussion: Evidence-Based and Theory-Informed Intervention Development

BACKGROUND

Active rehabilitation involving subsymptom threshold exercise combined with education and support promotes recovery in youth with concussion but is typically delivered in person, which may limit accessibility for families because of a lack of services in their communities or logistical challenges to attending in-person sessions.

OBJECTIVE

This paper describes the evidence-based and theory-informed development of the Tele-Active Rehabilitation (Tele-AR) intervention for pediatric concussion, which was specifically designed for remote service delivery.

METHODS

The intervention was designed by clinician-researchers with experience in pediatric concussion rehabilitation following the Medical Research Council guidance for developing complex interventions. Development involved a critical review of the literature to identify existing evidence, the expansion of the theoretical basis for active rehabilitation, and the modeling of the intervention process and outcomes.

RESULTS

Tele-AR is a 6-week home exercise and education and support program facilitated through weekly videoconferencing appointments with a clinician. Exercise consists of low- to moderate-intensity subsymptom threshold aerobic activity and coordination drills that are individualized to participant needs and interests (prescribed for 3 days per week). Education includes the evidence-supported Concussion & You self-management program, which covers topics related to energy management, nutrition, hydration, sleep hygiene, and return to activity. Elements of self-determination theory are incorporated to support motivation and engagement. We present a logic model describing predicted intervention effects using a biopsychosocial conceptualization of outcomes after concussion.

CONCLUSIONS

The Tele-AR intervention may help to increase access to care that improves recovery and promotes a timely return to activity in youth with concussion. Future research is needed to evaluate the feasibility and efficacy of this approach.

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

Objective:

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

Subjects:

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

Methods:

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

Results:

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

Conclusions:

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

The acute, systemic effects of aerobic exercise in recently concussed adolescent student-athletes: preliminary findings

OBJECTIVES

Examine the acute effects (pre-, during, post-intervention) of two different intensities of aerobic exercise or rest on autonomic, oculomotor, and vestibular function and symptom burden in patients with a recent sport-related concussion (SRC) and compare their responses to sex-matched, age-stratified, non-concussed (HEALTHY) student-athletes.

METHODS

Student-athletes between the ages of 13 and 18 that presented to the sports medicine clinic within Day 3-7 post-SRC and from local schools were recruited for a randomized controlled trial (RCT). The participants were administered the Vestibular/Ocular Motor Screening (VOMS), King-Devick (K-D), and Post-Concussion Symptom Scale (PCSS) before and after the intervention. Heart rate variability (HRV) and mean arterial pressure (MAP) were collected before, during, and after the intervention. The intervention was either a single, 20-min session of treadmill walking at 40% (40HR) or 60% of age-predicted max heart rate (60HR), or seated, rest (NOEX).

RESULTS

30 participants completed the intervention with the SRC group treated 4.5 ± 1.3 days post-injury. Pre-exercise HRV and MAP were significantly different (p's < 0.001) during treatment but returned to pre-exercise values within 5 min of recovery in both the SRC and HEALTHY groups. Both the SRC and HEALTHY groups exhibited similar reductions pre- to post-intervention for symptom severity and count (p's < 0.05), three VOMS items (p's < 0.05) but not K-D time.

CONCLUSIONS

To date, this is the first adolescent RCT to report the acute, systemic effects of aerobic exercise on recently concussed adolescent athletes. The interventions appeared safe in SRC participants, were well-tolerated, and provided brief therapeutic benefit.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier NCT03575455.

Association Between Symptom Burden at Initiation of a Graduated Return to Activity Protocol and Time to Return to Unrestricted Activity After Concussion in Service Academy Cadets

BACKGROUND

Current consensus and position statements recommend that concussed patients be asymptomatic upon the initiation of the graduated return to activity (RTA) protocol. However, a significant number of concussed patients are beginning their RTA protocols while endorsing symptoms.

PURPOSE

To characterize symptom endorsement at the beginning of the RTA protocol and examine the association between symptom endorsement and RTA protocol duration in service academy cadets.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

A prospective cohort study was conducted with cadets at 3 US service academies. Postconcussion symptom inventories were recorded upon the initiation of an RTA protocol. The Sport Concussion Assessment Tool Symptom Inventory was used to classify participants into 3 groups (0 symptoms, 1 symptom, and ≥2 symptoms) upon the initiation of the RTA protocol. The primary outcome of interest was RTA protocol duration. Kaplan-Meier survival estimates were calculated to estimate RTA protocol duration by symptom endorsement, sex, varsity status, academic break, and time to graduated RTA initiation. Univariate and multivariable Cox proportional hazards models were used to estimate the association between symptom endorsement at the initiation of the RTA protocol and RTA protocol duration (α < .05).

RESULTS

Data were analyzed from 966 concussed cadets (36% women). Headache (42%) and faintness/dizziness (44%) were the most commonly endorsed symptoms on the Sport Concussion Assessment Tool-Third Edition and the Brief Symptom Inventory-18, respectively. Univariate results revealed a significant association between endorsing ≥2 symptoms and RTA protocol duration. In the multivariable model, endorsing ≥2 symptoms maintained a statistically significant association with RTA protocol duration. Significant associations were observed between RTA protocol duration and nonvarsity status (27% longer), women (15% longer), academic breaks (70% longer), and time to the initiation of the RTA protocol (1.1% longer daily incremental increase) after controlling for covariates.

CONCLUSION

Symptom endorsement at the initiation of an RTA protocol was associated with RTA protocol duration. Cadets who had returned to preinjury baseline symptom burden or improved from baseline symptom burden and endorsed ≥2 symptoms at the initiation of the RTA protocol took longer to RTA.

Neuropsychological and neuropsychiatric recovery from mild traumatic brain injury

PURPOSE OF REVIEW

Mild traumatic brain injury (mTBI) is a significant public health concern for children. This review summarizes recent literature on early symptoms and neuropsychiatric and neuropsychological outcomes following pediatric mTBI and highlights factors that predict prolonged recovery. Evidence-based recommendations for assessment and treatment are also discussed.

RECENT FINDINGS

Whereas most children recover within 1 month after mTBI, 10-30% of children experience lingering neuropsychiatric or neuropsychological symptoms 3 months or more after injury. For the subset who experience prolonged recovery, new or worsening emotional and behavioral symptoms are the most frequent concerns. Recent research has suggested that specific factors, including preinjury mental health concerns, female sex, and family characteristics, are associated with increased risk of experiencing prolonged recovery. Early management includes reassurance, brief rest (1-3 days), and gradual return to typical activities. When symptoms linger for more than 4 weeks, evaluation in a specialty clinic is recommended and multimodal therapies are considered. Active recovery models, which include gradual return to aerobic exercise and cognitive behavioral approaches, are promising for the management of prolonged symptoms.

SUMMARY

A minority of children with mTBI experience prolonged neuropsychiatric or neuropsychological concerns. While our understanding of pediatric mTBI is growing, and recommendations for assessment and management have been developed, many gaps remain.

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

OBJECTIVE

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

SUBJECTS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Autonomic dysfunction in adults following mild traumatic brain injury: A systematic review

BACKGROUND

Increasing evidence suggests autonomic nervous system (ANS) dysfunction may occur following mild traumatic brain injury (mTBI). Measures of heart rate, heart rate variability, blood pressure and baroreceptor sensitivity can be used to evaluate ANS dysfunction following mTBI.

OBJECTIVE

Summarize the evidence for ANS dysfunction in adults following mTBI.

METHODS

A search of Embase, MEDLINE, Cochrane Central Register, PsycINFO, CINAHL and SPORTDiscus databases was conducted. Search topics included: mTBI and ANS. Identified abstracts were independently reviewed by 2 reviewers followed by full text screening. Risk of bias was assessed using a modified SIGN checklist. A structured synthesis was performed.

RESULTS

Thirty-nine studies (combined 1,467 participants diagnosed with mTBI) evaluating ANS function were included. ANS function was evaluated under various conditions including: rest, during exertion, cold pressor test, Valsalva maneuver, using face cooling and eyeball pressure paradigms. Short-term or ultra-short-term recordings were most common. The majority of studies (28/39) were rated as "unacceptable" for quality of evidence.

CONCLUSIONS

Altered parameters of ANS function have been reported in multiple conditions following mTBI, both acutely and in the post-acute/chronic stages of recovery. However, due to methodological limitations, conclusions regarding the severity and timing of ANS dysfunction following mTBI cannot be drawn.

Refined Analysis of Chronic White Matter Changes after Traumatic Brain Injury and Repeated Sports-Related Concussions: Of Use in Targeted Rehabilitative Approaches?

Traumatic brain injury (TBI) or repeated sport-related concussions (rSRC) may lead to long-term memory impairment. Diffusion tensor imaging (DTI) is helpful to reveal global white matter damage but may underestimate focal abnormalities. We investigated the distribution of post-injury regional white matter changes after TBI and rSRC. Six patients with moderate/severe TBI, and 12 athletes with rSRC were included ≥6 months post-injury, and 10 (age-matched) healthy controls (HC) were analyzed. The Repeatable Battery for the Assessment of Neuropsychological Status was performed at the time of DTI. Major white matter pathways were tracked using q-space diffeomorphic reconstruction and analyzed for global and regional changes with a controlled false discovery rate. TBI patients displayed multiple classic white matter injuries compared with HC (p < 0.01). At the regional white matter analysis, the left frontal aslant tract, anterior thalamic radiation, and the genu of the corpus callosum displayed focal changes in both groups compared with HC but with different trends. Both TBI and rSRC displayed worse memory performance compared with HC (p < 0.05). While global analysis of DTI-based parameters did not reveal common abnormalities in TBI and rSRC, abnormalities to the fronto-thalamic network were observed in both groups using regional analysis of the white matter pathways. These results may be valuable to tailor individualized rehabilitative approaches for post-injury cognitive impairment in both TBI and rSRC patients.

Designing research on concussion treatment in the military setting: Important challenges to consider

Traumatic brain injury (TBI) is highly prevalent on a global scale with concussion being the most common of all TBIs. Concussion research on rehabilitation and symptom resolution is well-established, particularly among athletes, but less is known about the recovery of active duty service members (ADSMs). In a population whose occupational environment increases risk for such injury, it is imperative that treatment is optimized to achieve successful rehabilitation. The military setting, however, has challenges that must be accounted for when developing proposals to study the benefits of new interventions or treatment. This review will provide a discussion on those challenges to better understand the considerations that are essential during the developmental phase of concussion studies within the military setting. This review aims to provide investigators novice to the military setting an overview of considerations when researching concussion among ADSMs.