Use of diffusion tension imaging in the evaluation of pediatric concussions

Objective: To evaluate whether quantitative metrics of white matter fractional anisotropy (FA) and mean diffusivity (MD) were different in patients presenting to our clinic with persistent symptoms after a concussion.

Design: Matched control retrospective study.

Setting: Primary not-for-profit Institution.

Patients: Consecutive patients seen at a primary care institution's Sports Concussion Clinic for sport-related concussion that underwent diffusion tensor imaging. Interventions (Independent variables): Type of sports, days from Injury, number of symptoms, weeks out when Magnetic Resonance Imaging (MRI) ordered, history of psychological issues, length of symptoms, age, sex, MRI imaging data.

Main outcome measure: Difference in white matter FA and MD.

Results: Seventeen concussion patients, ages 9 and 17 (average = 12.5 years; median = 13 years, 11 males and 6 females), were matched with age and gender controls who had an MRI following a complaint of headache. Patients reported an average of 11.5 concussion symptoms, out of a total possible 22 and were seen at an average of 30 days post injury. No region met tract based spatial statistics criteria for significant differences between concussed and healthy control groups (all p > 0.05). Similarly, when comparing group averages from the atlas based regional summaries, no region met the 0.2 false discovery rate (FDR) threshold for significant differences (the smallest unadjusted p-values were 0.02 for MD and 0.14 for FA).

Conclusions: Our results did not show measurable diffusion tensor imaging (DTI) changes with standard clinical data acquisition and quantitative processing for the individual patient. At this time DTI should not be considered a technique that can diagnose concussion within an individual subject.