Structural Connectivity Related to Persistent Symptoms After Mild TBI in Adolescents and Response to Aerobic Training: Preliminary Investigation.

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 (γ), normalized characteristic path length (λ), and small-worldness (σ). (2) The self-reported Post-Concussion Symptom Inventory score.

RESULTS

At initial enrollment, adolescents with mTBI had significantly lower Eglob and higher γ, λ, and σ (all P < .05) than healthy peers. After the intervention, significantly increased Eglob and decreased λ (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 λ decrease in the aerobic training and λ 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.