Graded aerobic treadmill testing in pediatric sports-related concussion: safety, clinical use, and patient outcomes

OBJECTIVE The objectives of this study were 2-fold: 1) to evaluate the safety, tolerability, and clinical use of graded aerobic treadmill testing in pediatric patients with sports-related concussion (SRC), and 2) to evaluate the clinical outcomes of treatment with a submaximal aerobic exercise program in patients with physiological post-concussion disorder (PCD). METHODS The authors conducted a retrospective chart review of pediatric patients (age < 20 years) with SRC who were referred to a multidisciplinary pediatric concussion program and underwent graded aerobic treadmill testing between October 9, 2014, and February 11, 2016. Clinical assessments were carried out by a single neurosurgeon and included clinical history taking, physical examination, and recording specific patient-reported concussion-related symptoms using the Post-Concussion Symptom Scale (PCSS). Graded aerobic treadmill testing using a modified Balke protocol for incremental increases in intensity was used as a diagnostic tool to assess physiological recovery, classify post-concussion syndrome (PCS) subtype, and reassess patients following treatment. Patients with a symptom-limited threshold on treadmill testing (physiological PCD) were treated with an individually tailored submaximal exercise prescription and multidisciplinary targeted therapies. RESULTS One hundred six patients (mean age 15.1 years, range 11-19 years) with SRC underwent a total of 141 treadmill tests. There were no serious complications related to treadmill testing in this study. Overall, 138 (97.9%) of 141 tests were well tolerated and contributed valuable clinical information. Treadmill testing confirmed physiological recovery in 63 (96.9%) of 65 patients tested, allowing successful return to play in 61 (93.8%). Treadmill testing was used to diagnose physiological PCD in 58 patients and cervicogenic PCD in 1 patient. Of the 41 patients with physiological PCD who had complete follow-up and were treated with tailored submaximal exercise prescription, 37 (90.2%) were classified as clinically improved and 33 (80.5%) successfully returned to sporting activities. Patients who did not respond or experienced an incomplete response to submaximal aerobic exercise treatment included 7 patients with migraine headaches and 1 patient with a postinjury psychiatric disorder. CONCLUSIONS Graded aerobic treadmill testing is a safe, tolerable, and clinically valuable tool that can assist in the evaluation and management of pediatric SRC. Future research is needed to confirm the clinical value of this tool in return-to-play decision making. Studies are also needed to understand the pathophysiology of physiological PCD and the effects of targeted treatment.