The use of an intensive physical exertion test as a final return to play measure in concussed athletes: a prospective cohort

A Multimodal Exertional Test for concussion: a pilot study in healthy athletes

Introduction

Exertional tests have become a promising tool to assist clinicians in the management of concussions, however require expensive equipment, extensive spaces, and specialized clinician expertise. As such, we developed a test with minimal resource requirements encompassing key elements of sport and physical activity. The purpose of this study was to pilot test the Multimodal Exertional Test (MET) protocol in a sample of healthy interuniversity athletes.

Methods

The MET comprises four stages, each featuring three distinct tasks. The test begins with engaging in squats, alternating reverse lunges, and hip hinges (Stage 1). The next stage progressively evolves into executing these tasks within specified time limits (Stage 2). Following this, the test advances to a stage that incorporates cognitive tasks (Stage 3), and the final stage demands greater levels of physical exertion, cognition, and multi-directional movements (Stage 4). Heart rate (HR) was obtained during each stage of the MET and participants' symptom severity scores were recorded following each task.

Results

Fourteen healthy interuniversity athletes (n = 8 female, n = 6 male) participated in the study. HR was obtained for 10 of the 14 athletes (females: n = 6, males: n = 4). Increases in average and maximum HR were identified between pre-MET and Stage 1, and between Stages 3 and 4. Consistent with the tasks in each stage, there were no increases in average and maximum HR observed between MET Stages 1 to 3. Female athletes exhibited higher average and maximum HRs compared to male athletes during all four stages. All 14 athletes reported minimal changes in symptom severity following each task.

Conclusion

Among healthy athletes, the MET elicits an increase in average and maximum HR throughout the protocol without symptom provocation. Female athletes exhibit higher HRs during all four stages in comparison to male athletes.

Concussion Rehabilitation and the Application of Ten Movement Training Principles

Concussion awareness continues to grow in all aspects of healthcare, including the areas of prevention, acute care, and ongoing rehabilitation. Most of the concussion research to date has focussed on the challenges around screening and diagnosing what can be a complex mix of brain impairments that overlay with additional pre-existing comorbidities. While we expect further progress in concussion diagnosis, progress also continues to be made around proactive rehabilitation, with the emergence of interventions that can enhance the recovery process, maximise function and independence with a return to study, work, and play. Traditionally, optimal multimodal assessments of concussion have treated the physical, cognitive, and psychological domains of brain injury separately, which supports diagnosis, and informs appropriate follow-up care. Due to the complex nature of brain injury, multimodal assessments direct care toward professionals from many different disciplines including medicine, physiotherapy, psychology, neuropsychology, ophthalmology, and exercise physiology. In addition, these professionals may work in different fields such as sports, neurorehabilitation, vestibular, musculoskeletal, community, vocational, and general practice clinical settings. Rehabilitation interventions for concussions employed in practice are also likely to use a blend of theoretical principles from motor control, cognitive, and psychological sciences. This scale of diversity can make information dissemination, collaboration, and innovation challenging. The Ten Movement Training Principles (MTPs) have been proposed as a usable and relevant concept to guide and support clinical reasoning in neurorehabilitation. When applied to concussion rehabilitation, these same 10 principles provide a comprehensive overview of key rehabilitation strategies for current and future practice. Future collaborations can use these training principles to support clinical and research innovations including the rapid rise of technologies in this growing field of rehabilitation practice.

Association Between First Attempt Buffalo Concussion Treadmill Test and Days to Recovery in 855 Children With Sport-Related Concussion: A Historical Cohort Study and Prognostic Factors Analysis

OBJECTIVE

Little is known about the prognostic value of the Buffalo Concussion Treadmill Test (BCTT) after the acute phase of sport-related concussion (SRC). We examined the added prognostic value of the BCTT performed 10 to 21 days after SRC in children, in addition to participant, injury, and clinical process characteristics on days to recovery.

DESIGN

Historical clinical cohort study.

SETTING

Network of approximately 150 Canadian multidisciplinary primary-care clinics.

PARTICIPANTS

855 children (mean age 14 years, range 6-17 years, 44% female) who presented between January 2016, and April 2019 with SRC.

ASSESSMENT OF RISK FACTORS

Participant, injury, and clinical process characteristics, with focus on BCTT exercise intolerance assessed 10 to 21 days after injury.

OUTCOME

Days to clinical recovery.

RESULTS

Children who were exercise intolerant experienced an increase of 13 days to recovery (95% CI, 9-18 days). Each additional day between SRC and first BCTT was associated with a recovery delay of 1 day (95% CI, 1-2 days), and prior history of concussion was associated with a recovery delay of 3 days (95% CI, 1-5 days). Participant, injury, and clinical process characteristics, and the first attempt BCTT result explained 11% of the variation in recovery time, with 4% accounted for by the BCTT.

CONCLUSION

Exercise-intolerance assessed 10 to 21 days after SRC was associated with delayed recovery. However, this was not a strong prognostic factor for days to recovery.

Does Sleep Quality Influence Recovery Outcomes After Postconcussive Injury in Children and Adolescents?

OBJECTIVE

To determine whether objective parameters of sleep quality differ throughout recovery between children and adolescents who experienced an early return to school (RTS) and those who had a delayed RTS or did not return at all during the study period.

SETTING

Sleep parameters reflective of sleep quality were evaluated in participants' natural sleeping habitat throughout 9 weeks postinjury.

PARTICIPANTS

Ninety-four children and adolescents (aged 5-18 years) with diagnosed concussion.

DESIGN

Prospective cohort. Participants followed RTS protocols.

MAIN MEASURES

Actigraphy-derived estimates of total sleep time (TST), sleep efficiency (SE), wake after sleep onset (WASO), average arousal length (AAL), and number of arousals (NOAs) per hour were assessed. The length of time from injury until RTS was determined for each participant. Participants were categorized into an early RTS or delayed RTS group based on their time to RTS.

RESULTS

Both TST and SE were significantly greater in the early RTS group. WASO duration, AAL, and NOAs were significantly greater in the delayed RTS group. Differences between RTS groups were most apparent during weeks 1 to 5 postinjury.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Participants who returned to school earlier had significantly better objective sleep quality than participants who experienced a delayed RTS. This study provides evidence in support of a relationship between sleep quality and time to RTS in children and adolescents with concussion. Considering early monitoring of sleep, education regarding sleep hygiene, and access to age-appropriate sleep interventions may be helpful in pediatric concussion recovery.

Psychological Contributions to Symptom Provocation Testing After Concussion

OBJECTIVE

Following concussion, symptoms such as headache, dizziness, and fatigue may transiently worsen or reemerge with increased exertion or activity. Standardized tests have been developed to assess symptom increases following aerobic, cognitive, or vestibular/oculomotor challenge. Although neurophysiological mechanisms are proposed to underlie symptom increases following exertion, psychological factors such as anxiety and misinterpretation of normal bodily sensations may also play a role. In this study, we examined the contribution of psychological factors to symptom provocation testing outcomes.

SETTING

Two outpatient concussion clinics in British Columbia, Canada.

PARTICIPANTS

Adults with persistent symptoms following concussion ( N = 79; 62% women).

DESIGN

In a single session, participants completed self-report questionnaires measuring the psychological factors of interest and underwent symptom provocation testing including aerobic (Buffalo Concussion Bike Test; BCBT), cognitive (National Institutes of Health Toolbox-Cognition Battery; NIHTB-CB), and vestibular/oculomotor (Vestibular/Ocular Motor Screening for Concussion; VOMS) challenge.

MAIN MEASURES

Psychological factors of interest included premorbid and current anxiety (Generalized Anxiety Disorder-7; GAD-7), catastrophizing (Pain Catastrophizing Scale-Adapted; PCS-A), fear avoidance behavior (Fear Avoidance Behavior after Traumatic Brain Injury; FAB-TBI), and somatization (Patient Health Questionnaire-15; PHQ-15). Our primary outcome variables were self-reported symptom change during each symptom provocation test.

RESULTS

We found that current anxiety ( B = 0.034; 95% CI = 0.003, 0.065), symptom catastrophizing ( B = 0.013; 95% CI = 0.000, 0.026), fear avoidance behavior ( B = 0.029; 95% CI = 0.008, 0.050), and somatization ( B = 0.041; 95% CI = 0.007, 0.075) were associated with increased symptoms during the VOMS in univariate models adjusted for time postinjury but not in a multivariable model that included all covariates. The psychological variables of interest were not significantly related to symptom change during the BCBT or NIHTB-CB.

CONCLUSION

Our findings suggest that symptom provocation test failure should be interpreted with caution because it might indicate psychological maladjustment rather than lingering brain injury or incomplete neurophysiological recovery.

The Role of Age, Sex, Body Mass Index, and Sport Type on the Dynamic Exertion Test in Healthy Athletes: A Cross-Sectional Study

BACKGROUND

The dynamic exertion test (EXiT) was developed to help inform return to play after sport-related concussion, but some factors may threaten the internal validity of EXiT and affect clinical interpretation.

OBJECTIVE

To compare age, sex, BMI, and sport types across EXiT physiological [pre-EXiT and post-EXiT percentage of maximum heart rate (HR %max) and blood pressure (BP)], performance (change-of-direction task completion time and committed errors), and clinical [symptoms and rating of perceived exertion (RPE)] outcomes among healthy adolescents and adults.

STUDY DESIGN

Cross-sectional.

METHODS

Eighty-seven participants ( F = 55, 37.4%) reported symptoms and RPE during the EXiT, which consists of a 12-minute treadmill running protocol, and the dynamic circuit, ball toss, box shuffle (SHUF) and carioca (CAR), zig zag (ZZ), proagility (PA), and arrow agility (AA) tasks. Independent samples t tests were conducted for pre-EXiT and post-EXiT HR %max and BP and change-of-direction task completion time and Mann-Whitney U tests for errors, symptoms, and RPE. A series of 1-way analysis of variance (ANOVAs) and Kruskal-Wallis H tests were conducted to compare collision, contact, and noncontact sport types.

RESULTS

Adolescents had lower completion time across AA ( P = 0.01) and male athletes lower than female athletes on CAR, ZZ, PA, and AA ( P < 0.04). Male athletes reported greater RPE after the SHUF, CAR, and AA ( P < 0.03). HR %max , errors, and symptoms were equivocal across all subgroups ( P > 0.05).

CONCLUSION

Age and sex should be considered in the interpretation of performance and clinical, but not physiological, EXiT outcomes. The EXiT is a standardized exercise assessment and generalizable to healthy athletes.

Test-Retest, Interrater Reliability, and Minimal Detectable Change of the Dynamic Exertion Test (EXiT) for Concussion

BACKGROUND

The Dynamic Exertion Test (EXiT) was developed to inform return-to-play (RTP) decision-making following clinical recovery from sport-related concussion (SRC). The purpose of the current study was to document intrarater and test-retest reliability and minimal detectable change (MDC) scores for physiological [heart rate (HR) and blood pressure], performance (change-of-direction task completion time and errors), and clinical outcomes (endorsed symptoms, perceived exertion) of EXiT, and interrater reliability of performance outcomes.

HYPOTHESIS

Healthy athletes would exhibit stable physiological responses to the EXiT across visits, demonstrate consistent change-of-direction task completion time between consecutive trials at each visit, and the fastest time (of 2 trials) across visits, and endorse equivocal symptoms and effort across visits.

STUDY DESIGN

Cross-sectional, test-retest.

LEVEL OF EVIDENCE

Level 3.

METHODS

Seventy-nine (female: 34 [43%], 19.6 ± 5.0 years) athletes completed the EXiT at 2 study visits (8.7 ± 4.7 days between visits). Two-way, mixed, intraclass correlation coefficients (ICCs) were used to evaluate intrarater and test-retest reliability. Cronbach's alpha was used to document the internal consistency of symptoms at each visit, and MDC scores were calculated on the physiological, performance, and clinical outcomes.

RESULTS

Measured and percentage of age-estimated maximum HR were reliable following EXiT (ICC = 0.579-0.618). Change-of-direction task completion time (MDC range = 0.75-8.70 s) had good-to-excellent test-retest (ICC = 0.703-0.948) and interrater (ICC = 0.932-0.965) reliability. Symptoms had a high internal consistency at visits 1 (α = 0.894) and 2 (α = 0.805) and were reliable across visits (ICC = 0.588).

CONCLUSION

The current investigation established test-retest reliability in addition to MDC scores of an objective dynamic exercise assessment among healthy adolescent and adult athletes. The EXiT may be an objective approach to inform RTP decision-making following SRC recovery.

CLINICAL RELEVANCE

The EXiT is a clinically feasible exertion-based assessment that can be readily administered in a variety of outpatient clinical settings.

Examining how time from sport-related concussion to initial assessment predicts return-to-play clearance

OBJECTIVE

(i) To analyze data of adolescents who have sustained a sport-related concussion (SRC) through the use of Complete Concussion Management Inc. (CCMI) concussion database system; and (ii) to determine an optimal time to assess and manage an athlete with an SRC by prospectively analyzing data from CCMI concussion database system.

METHOD

A cohort of patients, ages 8-18 years, who sustained an SRC, assessed 30 days or less from injury and were treated at partnered CCMI clinics across Canada were prospectively followed. The primary outcome measure was recovery, defined as CCMI discharge, which includes an athlete having completed all return-to-school and return-to-play steps and passed the Gapski-Goodman test without symptom exacerbation.

RESULTS

1213 athletes (482 female) were included for analysis. Days between injury and initial assessment (p = 0.00), male sex (p = 0.00), and previous concussion history (p = 0.00) were significant predictors of time to discharge. A log-rank test revealed a significant difference (p = 0.00) in time to discharge with athletes assessed <10 days of injury discharged at a mean of 23.5 days (95% CI, 22.5, 24.5) and those assessed at day 10 to 30 were discharged at a mean of 37.1 days (95% CI, 33.7, 40.5). Athletes who were assessed at 0 to 9 days from injury were two times more likely to be discharged sooner compared to those athletes assessed 10 to 30 days from injury (HR 2.03, p = 0.00).

CONCLUSION

Time from SRC to initial assessment significantly predicted time to discharge, with those being evaluated earlier experiencing a faster discharge. The results aid in establishing recommended timelines for evaluation following an SRC in order to prevent or mitigate athletes experiencing a prolonged recovery and encourage timely access to care and a quicker return to life post-concussive injury.

Examining the trajectory and predictors of post-concussion sleep quality in children and adolescents

OBJECTIVES

This study aimed to 1) determine if post-concussion sleep quality of children and adolescents differed from healthy sleep estimates; 2) describe the trajectory of parameters of sleep quality; 3) determine factors that predict sleep quality outcomes; and 4) compare sleep parameter outcomes between asymptomatic and symptomatic participants at 4 weeks post-concussion.

METHODS

Nightly actigraphy estimates of sleep in 79 children and adolescents were measured throughout 4 weeks post-concussion. Total sleep time (TST), sleep efficiency (SE), wake after sleep onset (WASO), number of arousals (NOA), and average arousal length (AAL) were measured.

RESULTS

Child and adolescent participants experienced significantly poorer SE and longer WASO duration throughout 4 weeks of recovery and adolescents experienced significantly longer TST. SE significantly improved with time post-injury (p = .047). Older age was associated with longer TST (p = .003) and female sex was associated with longer WASO (p = .025) and AAL duration (p = .044). Week 4 sleep parameter outcomes were not significantly different between asymptomatic and symptomatic participants.

CONCLUSIONS

The sleep quality of youth is adversely affected by concussion, particularly in females. Sleep quality appears to improve with time but may require more than 4 weeks to return to normal.

The Dynamic Exertion Test for Sport-Related Concussion: A Comparison of Athletes at Return-to-Play and Healthy Controls

PURPOSE

To describe the Dynamic Exertion Test (EXiT) by comparing physiological, performance, and clinical outcomes between athletes medically cleared following sport-related concussion (SRC) and healthy controls.

METHODS

One hundred four (female = 41, 39.4%) participants (14-21 y of age) including 52 medically cleared for return to play at 21.48 (15.40) days following SRC and 52 healthy athletes completed the EXiT involving (1) 12-minute aerobic component and (2) 18-minute dynamic component including 2 functional movement and 5 change-of-direction (COD) tasks. Physiological (heart rate and blood pressure), clinical (endorsed symptoms and rating of perceived exertion), and performance (COD-task completion time and errors) outcomes were collected throughout EXiT. Participants also completed the Postconcussion Symptom Scale and vestibular/ocular motor screening before EXiT. Independent-samples t tests were used to compare groups on resting heart rate and blood pressure, COD-task completion time, and Mann-Whitney U tests on Postconcussion Symptom Scale, vestibular/ocular motor screening, and EXiT symptoms, rating of perceived exertion, and errors.

RESULTS

COD-task completion time and resting systolic blood pressure and heart rate were similar between groups (P > .05). SRC reported greater rating of perceived exertion during the aerobic component (P < .05) and lower total dizziness (P = .003) and total symptoms (P = .021) during EXiT and had lower near point of convergence distance (P < .001) and total symptoms (P = .007) for vestibular/ocular motor screening than healthy athletes.

CONCLUSION

Physiological, performance, and clinical EXiT outcomes were equivocal between athletes at medical clearance following SRC and healthy controls. The multidomain EXiT may help to inform safe return-to-play decision making post-SRC.

Unexpected symptoms after concussion: Potential links to functional neurological and somatic symptom disorders

OBJECTIVE

Reporting of unexpected symptoms after concussion might, in some people, reflect a Functional Neurological Disorder (FND), Somatic Symptom Disorder (SSD), or exaggeration (feigning). This study aimed to determine whether reporting unexpected symptoms after concussion was associated with risk factors for FND/SSD, exaggeration, or both.

METHOD

Adults with persistent symptoms following concussion (N = 77; 61% women) rated the presence and severity of unexpected neurological symptoms (from the Screening for Somatoform Symptoms scale, e.g., paralysis) and somatic symptoms (from the Patient Health Questionnaire-15, e.g., stomach pain) that did not overlap with post-concussion symptom scale items. The independent variables were risk factors for exaggeration (neuropsychological performance validity test failure and personal injury litigation) and predisposing and perpetuating factors for developing FND and/or SSD (e.g., fear avoidance behavior).

RESULTS

When adjusting for all covariates, fear avoidance behavior was most strongly related to unexpected neurological symptoms (B = 0.11, 95% confidence interval = 0.05-0.18, p < .001), while current anxiety scores were most strongly related to unexpected somatic symptoms (B = 0.34, 95% confidence interval = 0.15-0.52, p < .001). Performance validity test failure and litigation were not significant predictors in either model.

CONCLUSION

Unexpected neurological and other somatic symptoms after concussion should not be dismissed as exaggeration. Psychological factors thought to perpetuate FND and SSD (e.g., fear avoidance behavior) may contribute to unexpected symptoms following concussion. More research is needed at the intersection of FND, SSD, and persistent post-concussive symptoms.

Does Exercise Increase Vestibular and Ocular Motor Symptom Detection After Sport-Related Concussion?

BACKGROUND AND PURPOSE

Postconcussive vestibular and ocular motor symptoms are common and contribute to longer recovery. The Vestibular/Ocular Motor Screening (VOMS) is used to detect such symptoms, but a VOMS performed at rest may miss symptoms that are only provoked by exertion. Supervised exercise challenges (SECs) have been shown to detect concussion-related symptoms provoked by physical exertion. The purpose of this study was to determine whether athletes undergoing an SEC will exhibit greater symptom provocation with the VOMS compared to a VOMS performed at rest prior to an SEC.

METHODS

Thirty-six athletes (58.3% male) between ages 10 and 18 years and within 30 days of concussion were included. All participants completed VOMS assessments at rest and immediately after an SEC. VOMS total symptom score increases were calculated for both pre- and post-SEC assessments compared using Wilcoxon ranked sum tests. The frequencies of positive assessments for each VOMS item were compared using McNemar's test.

RESULTS

There were significant increases in post-SEC symptom provocation scores compared with pre-SEC scores for all VOMS items. The post-SEC VOMS identified 29 participants (80.6%) as positive in at least 1 VOMS item compared with 21 participants (58.3%) identified as positive pre-SEC (P = 0.008). For all VOMS items, the post-SEC VOMS identified participants who were previously negative on a pre-SEC VOMS but became positive after the SEC.

DISCUSSION AND CONCLUSIONS

An SEC performed prior to a VOMS assessment may increase the detection of vestibular and ocular motor symptoms that may be missed if the VOMS was performed only at rest.Video Abstract available for more insight from the authors (see the Video Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A342).

Post-exercise cognitive testing to assess persisting alterations in athletes with a history of concussion

Primary Objective: To determine whether a physical exercise protocol could reveal persistent cognitive alterations in university athletes with a history of concussion (HOC). Thirty-four HOC and 34 controls participated in this study.Research Design: Cross-sectional.Methods and Procedures: The exercise protocol consisted of a 20-min bout on a stationary bike at 80% of the theoretical maximal heart rate. Before and after the exercise, participants performed a computerized switch task designed specifically to recruit executive functions. Group × Condition (pre- and post-exercise) repeated measures of ANCOVAs for accuracy, reaction time, and inverse efficiency score on the switch task were conducted. Chi-square tests were run to determine if the proportion of HOC and controls who underperformed (at least 2SD lower than the control group's average score) at rest and post-exercise were similar. Whilst no interaction or main effects were found with ANCOVAs, significantly more HOC athletes (21%) underperformed following exercise than at rest (3%) on the switch task, p = .02. The current results indicate that an acute bout of exercise can reveal persistent alterations that are not present at rest in the protracted phase of concussion. They also highlight the importance of considering inter-individual differences in recovery trajectories.

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

CONTEXT

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

OBJECTIVE

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

DESIGN

Retrospective case series.

SETTING

Multidisciplinary sport concussion clinic at a tertiary care center.

PATIENTS OR OTHER PARTICIPANTS

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

MAIN OUTCOME MEASURE(S)

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

RESULTS

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

CONCLUSIONS

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