The Rugby Connectome: A Longitudinal Analysis of Structural Connectivity in an Adolescent Cohort with Repeated Head Impacts

Motivation: Evidence suggests that repeated head impacts which do not produce conscious changes in cognition, may have detrimental effects on neurological function and brain micro-structure. Goal(s): Our study aims to quantify longitudinal changes in structural connectivity within a cohort of young rugby players throughout a rugby season. Approach: Using head impact data and advanced MRI techniques including whole brain tractography from multi-shell diffusion MRI, structural connectivity adjacency matrices were derived from tractograms and analyzed using graph theory. Results: Global clustering coefficient increased significantly from preseason to mid-season and post-season. These changes correlated with measures of cumulative head impact exposure. Impact: Data from our adolescent rugby cohort offers a rare opportunity to document the longitudinal effect of repeated head impact exposure on structural connectivity. The structural connectivity changes we observed may not be indicative of clinically relevant brain injury.