LAUSR

OBJECTIVE To determine whether graded exercise testing can predict recovery trajectory of concussion in children and adolescents. DESIGN Prospective study. SETTING Children's Hospital, Westmead, Australia. PARTICIPANTS One hundred thirty-nine children aged 12 to 16 years at 5 to 7 days after an acute concussive injury. INTERVENTION Graded exercise testing on a treadmill at the subacute phase to assess symptom provocation and determine clinical recovery indicating readiness to commence a return to activity (RTA) protocol. Exercise time to symptom exacerbation and clinical recovery were measured. MAIN OUTCOME MEASURES Standard concussion assessment and clinical testing (neurocognitive, vestibular/ocular, and balance) were conducted to determine major clinical drivers/indicators. RESULTS Participants (mean age 12.4 ± 2.8 years, 73% male) had a confirmed sport-related concussion. The main clinical drivers identified on exercise testing were headache, balance, and vestibular dysfunction. Participants fell into 1 of 2 groups, exercise-tolerant (54%) and exercise-intolerant (46%). Exercise-tolerant patients showed mild clinical indicators, no symptom exacerbation during 10.3 ± 3.3 minutes of exercise, were safely transitioned to a RTA protocol, and recovered within 10 days. Exercise-intolerant patients had high clinical indicators, significant symptom exacerbation at 4.2 ± 1.6 minutes of exercise, and prolonged recovery of 45.6 days. No adverse effects from exercise were reported in either group. Combined use of provocative exercise and clinical testing was 93% predictive of outcome. CONCLUSIONS Exercise testing during the subacute phase after a concussion can predict longer recovery. Exercise testing can identify a unique window where patients can be safely transitioned to activity, enabling clinicians to better inform patients and families, allocate resources and streamline care.