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

Does early exercise intolerance effect time to return to play, symptom burden, neurocognition, Vestibular-Ocular-Motor (VOM) function and academic ability in acutely concussed student-athletes?

INTRODUCTION

Early Exercise Intolerance (EEI) is associated with delayed recovery and longer time to Return To Play (RTP), but this has not been established.Participants; (n = 52, male n = 30) UK university-aged rugby-union student-athletes.

METHODS

Student-athletes completed baseline screening (July-October 2021 and 2022). The test battery was repeated within 48 h, 4, 8 and 14 days after a Sports-Related Concussion (SRC) with the Buffalo Concussion Bike or Treadmill Test to set sub-symptom heart rate threshold. Student-athletes then completed a controlled early exercise protocol in-between reassessment (days 3, 5-7 and 9-13). Those with EEI were compared to those with early-exercise tolerance.

OUTCOME MEASURES

Post-Concussion Symptom Scale, Immediate Post-Concussion and Cognitive Test, Vestibular-Ocular Motor Screening Tool and the Revised Perceived Academic Impact Tool.

RESULTS

EEI was seen throughout the initial 14-days post-SRC (23.8%, 22.4%, 25.5%. 25.0%). EEI was associated with a slower reaction time within 48 h (-0.01 (-0.030-0.043) Vs 0.06 (0.033-0.24), p = 0.004) and greater VOMS scores within 48 h; (0.00 (0.00-4.00) Vs 5.50 (2.75-9.00), p = 0.016) and 4 days (0.00 (0.00-2.00) Vs 5.00 (0.00-6.00), p = 0.044). RTP was 12.5 days longer in those with EEI at 14-days post-SRC.

CONCLUSION

EEI is prevalent following an SRC in university-aged student-athletes and was associated with delayed recovery and RTP.

Can the Buffalo Concussion Treadmill Test Be Used as a Prognostic Indicator for Patients With Sport-Related Mild Traumatic Brain Injury?

OBJECTIVE

To establish whether time to exercise cessation using the Buffalo Concussion Treadmill Test (BCTT) protocol can be used as a prognostic indicator of recovery after sport-related mild traumatic brain injury (SR-mTBI).

DESIGN

Retrospective analysis of prospectively collected data.

SETTING

Specialist Concussion Clinic.

PARTICIPANTS

Three hundred and twenty one patients presenting between 2017 and 2019 who underwent BCTT for SR-mTBI.

INTERVENTIONS

Participants who remained symptomatic at a 2-week follow-up appointment after SR-mTBI underwent BCTT to develop a progressive subsymptom threshold exercise program with fortnightly follow-up until clinical recovery.

MAIN OUTCOME MEASURES

Clinical recovery was the primary outcome measure.

RESULTS

A total of 321 participants were eligible to participate in this study (mean age 22.94% and 46% female). The BCTT test duration was divided into 4-minute intervals and those who completed full 20 minutes. There was higher probability of clinical recovery in those who finished the entire 20-minute BCTT protocol compared with those who managed 17-<20 minutes (Hazard Ratio, HR 0.57), 13 to 16 minutes (HR 0.53), 9 to 12 minutes (HR 0.6), 5 to 8 minutes (HR 0.4), and 1 to 4 minutes (HR 0.7), respectively. Those seen earlier after injury ( P = 0.009), male patients ( P = 0.116), younger patients ( P = 0.0003), and those with physiological or cervical dominant ( P = 0.416) symptom clusters were more likely to achieve clinical recovery. Fifty percent of those who completed the full BCTT protocol achieved clinical recovery at day 19 post-injury.

CONCLUSIONS

The group completing full 20 minutes of BCTT achieved clinical recovery more quickly than those who did not complete full BCTT.

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.

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.

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.

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.

Rehabilitation of Sport-Related Concussion

This article provides a summary of clinical assessment methods and nonpharmacologic rehabilitation techniques used for concussed patients. It describes concussion-relevant physical examination methods to identify underlying symptom generators. This approach allows practitioners to prescribe targeted rehabilitation therapies to treat postconcussion symptoms. Evidence-based rehabilitation approaches include cervical rehabilitation, vestibulo-ocular rehabilitation, and sub-symptom threshold aerobic exercise.