Altered Functional and Structural Connectomes in Female High School Soccer Athletes After a Season of Head Impact Exposure and the Effect of a Novel Collar.

Background: Characterization of, and evaluation of strategies to mitigate, the effects of sub-concussive impacts (SCI) on brain structure and function are crucial to understanding potential long-term neurological risks associated with sports participation. Objectives: To evaluate the efficacy of a jugular vein compression collar for preserving functional and structural measures of brain network organization in a cohort of female high school soccer players throughout a season of competitive play. Methods: Athletes were assigned to a collar (N = 72) or non-collar (N = 56) group before engaging in a season of play, during which head impact data were recorded via accelerometer for every practice and competition. Participants completed neuroimaging sessions before and following the season. A graph theoretical framework was applied to the functional and structural connectivity measures computed from resting state functional magnetic resonance imaging (rs-fMRI) and diffusion tensor imaging (DTI) data. Results: Non-collar-wearing athletes exhibited significantly increased rs-fMRI-derived global clustering coefficients (p = 0.032) and DTI-derived modularity (p = 0.042), compared to collar-wearing athletes. No longitudinal changes in any graph measures were observed for the collar group (p > 0.05). Conclusion: The observed increase in graph measures in the non-collar group is congruent with previous studies of SCI and is similar to graph theoretical studies of traumatic brain injury. The absence of alterations in graph metrics in the collar group indicates a potential ameliorating effect of the collar device against network reorganization, in line with previous literature.