Exercise-Induced Symptom Exacerbation and Adverse Events in Moderate-to-Severe Traumatic Brain Injury

Objective : To determine the incidence of exercise-induced symptom exacerbation and adverse events from cardiorespiratory fitness (CRF) and high-level mobility (HLM) exertional testing in the early subacute phase (≤3 months post-injury) following moderate-to-severe traumatic brain injury (TBI). Setting : Inpatient TBI subacute rehabilitation unit. Participants : One hundred fifty adults and adolescents ≥15 years with moderate-to-severe TBI completed a total of 205 exertional tests (83 participants completed CRF only, 12 HLM only, and 55 both CRF and HLM). Design : Prospective observational cohort study. Consecutive admissions were screened for recruitment between August 2017 and August 2021. Symptom ratings were recorded pre- and post-CRF and HLM exertional testing on the Sports Concussion Assessment Tool symptom scale. A summed symptom severity score (SCAT-SS) was calculated with a ≥10-point increase classified as symptom exacerbation and a ≥10-point reduction classified as symptom improvement. Main measures : SCAT symptom scale. Results : One participant experienced a ≥10-point increase in SCAT-SS (ie, symptom exacerbation) post-CRF testing (1/138 = 0.7%, 95% confidence interval [CI] = 0.01%-4.0%) and 1 post-HLM testing (1/67 = 1.5%, 95% CI = 0.04%-8.0%). Sixteen of 138 (11.6%, 95% CI = 6.8%-18.1%) CRF tests resulted in a ≥10-point decrease in SCAT-SS (ie, symptom improvement). Nine of 67 (13.4%, 95% CI = 6.3%-24.0%) HLM tests resulted in a ≥10-point decrease in SCAT-SS. Participants were more likely to experience symptom improvement than symptom exacerbation for both CRF and HLM exertion ( P ≤ .05). One adverse event, a fall, occurred during an HLM testing session. Conclusions : CRF and HLM exertional testing in the early subacute phase of recovery following moderate-to-severe TBI appears to be safe, with low rates of symptom exacerbation and adverse events identified.