Impact of subconcussive head acceleration on brain microstructure: Longitudinal diffusion MRI findings and symptom correlation

Motivation: Subconcussive head acceleration is correlated with brain microstructural changes accompanied with long-term cognitive sequelae which pose serious health concerns. Goal(s): To determine if subconcussive head acceleration affects the brain microstructure of contact sports athlete and evaluate if it is correlated with clinical symptom scores. Approach: Diffusion MRI was used to study white matter changes over a season of rugby in athletes, relative to controls and own baseline. Results: Increased cluster size of significant difference identified in contact sport athletes compared with non-contact sport controls suggest axonal damage and is correlated with symptom count and severity even without concussion diagnosis. Impact: Findings raise importance of integrating neuroimaging in clinical tests of subconcussive head acceleration to determine extent of alteration, design removal from play to allow brain microstructure recovery, and prevent long-term neurologic effects, neuropsychological sequelae, and possible disability.