Improving symptom burden in adults with persistent post-concussive symptoms: a randomized aerobic exercise trial protocol

Background Persistent post-concussive symptoms (PPCS) affect up to 30% of individuals following mild traumatic brain injury. PPCS frequently includes exercise intolerance. Sub-symptom threshold aerobic exercise has been proposed as a treatment option for symptom burden and exercise intolerance in this population. The primary aim of this study is to evaluate whether a progressive, sub-symptom threshold aerobic exercise program can alleviate symptom burden in adults with PPCS. Methods Fifty-six adults (18-65) with PPCS (>3mos-5 yrs) will be randomized into two groups: an immediate start 12-week aerobic exercise protocol (AEP) or delayed start 6-week placebo-like stretching protocol (SP), followed by AEP. Aerobic or stretching activities will be completed 5x/week for 30 mins during the intervention. Online daily activity logs will be submitted. Exercise prescriptions for the AEP will be 70-80% of heart rate at the point of symptom exacerbation achieved on a treadmill test with heart rate monitoring. Exercise prescription will be updated every 3-weeks with a repeat treadmill test. The Rivermead Post-concussion Symptom Questionnaire will be the primary outcome measure at 6 and 12-weeks of intervention. Secondary outcomes include assessments of specific symptoms (headache, quality of life, mood, anxiety, fatigue, dizziness, sleep parameters, daytime sleepiness) in addition to blood biomarkers and magnetic resonance imaging and spectroscopy data for quantification of brain metabolites including gamma-aminobutyric acid (GABA), glutathione, glutamate and N-acetyl aspartate (NAA) all measured at 6 and 12-weeks of intervention. Discussion This trial will evaluate the use of aerobic exercise as an intervention for adults with PPCS, thus expanding our knowledge of this treatment option previously studied predominantly for adolescent sport-related concussion.