Aerobic Exercise and Cognitive Function in Chronic Severe Traumatic Brain Injury Survivors: A Within-Subject A-B-A Intervention Study

Abstract

Background Following acute and sub-acute rehabilitation from severe traumatic brain injury (TBI), minimal to no efficacious interventions to treat ongoing cognitive deficits are available. Aerobic exercise is a non-invasive behavioral intervention with promise to treat cognitive deficits in TBI populations. Methods In this within-subject A-B-A study design, we incorporated 20-weeks of supervised aerobic exercise interventions delivered three times per week (Phase B) between participants typical rehabilitation schedules (Phases A). We further tested if participation in supervised aerobic exercise increased participants daily physical activity (PA) levels using waist-worn actigraphy. Results Five of six participants increased trail-making test part B by more than 10% pre-to-post phase B, with three of six making a clinically meaningful improvement (+ 1SD in normative scores). Linear mixed effects models showed a significant main effect of time at the group level with significant improvement in TMT-B pre-to-post exercise and no significant effect in other planned comparisons (pre-exercise to baseline nor follow-up to post-exercise) indicating that the addition of the intervention improved performance that was not due to practice effects. Statistically significant increases in daily moderate-to-vigorous PA were also seen during phase B compared to Phase A with three of six individuals making a significant behavior changes when analyzed at the individual level. Conclusions The addition of supervised aerobic exercise to typical rehabilitation strategies in chronic survivors of severe TBI can improve executive set shifting abilities and increase voluntary daily PA levels. Trial Registration ISRCTN17487462.