Diffusion MRI as a complementary assessment to cognition, emotion, and motor dysfunction after sports-related concussion: a systematic review and critical appraisal of the literature.

Sports-related concussion (SRC) is a complex and heterogeneous injury with psychological, cognitive and functional consequences. Advances in diffusion magnetic resonance imaging (dMRI) allow sensitive measurement of white matter pathology post-SRC and may provide insight into injury and recovery. We systematically reviewed and meta-analyzed the literature examining dMRI alongside cognitive, emotional or motor assessments to determine relationships between these analyses. Sixteen studies examining young athletes (n = 6) or retired professionals (n = 10) met the inclusion criteria, with 12 emotional, 10 cognitive and four motor assessments. Studies had heterogeneous methodology, moderate quality and modest sample sizes. Fractional anisotropy (FA) was the most frequent dMRI metric, with SRC-induced changes described most commonly in the frontal lobe and least in the cerebellum and brainstem. There is an emerging complementary role for dMRI as part of a comprehensive assessment battery for SRC. However, larger-scale studies with broader subject populations (specifically, in females and in the 30-45 year age range) are needed to corroborate findings and determine the true diagnostic utility of dMRI post-SRC.