Abstract
Objective: To quantify structural connectivity abnormalities in adolescents with mild traumatic brain injury (mTBI) and to investigate connectivity changes following aerobic training using graph theory and diffusion tensor imaging tractography.
Setting: Outpatient research setting.
Participants: Twenty-two children (age: 15.83 +/- 1.77 years, 10 females) with 4 to 16 weeks of persistent symptoms after mTBI and a matched healthy comparison group.
Design: Randomized clinical trial of aerobic training and stretching comparison combined with case-control comparison.
Main Measures: (1) Five global network measures: global efficiency (Eglob), mean local efficiency, modularity, normalized clustering coefficient ([gamma]), normalized characteristic path length ([lambda]), and small-worldness ([sigma]). (2) The self-reported Post-Concussion Symptom Inventory score.
Results: At initial enrollment, adolescents with mTBI had significantly lower Eglob and higher [gamma], [lambda], and [sigma] (all P < .05) than healthy peers. After the intervention, significantly increased Eglob and decreased [lambda] (both P < .05) were found in the aerobic training group. Improvement in Post-Concussion Symptom Inventory scores was significantly correlated with the Eglob increase and [lambda] decrease in the aerobic training and [lambda] decrease in the stretching comparison group (all P < .05).
Conclusion: This pilot study showed initial evidence that structural connectivity analysis was sensitive to brain network abnormalities and may serve as an imaging biomarker in children with persistent symptoms after mTBI.