Brain Structural And Functional Connectivity In Roller Derby Athletes.

Sport participation can have immense health benefits. However, mechanical loading of the head that is common in contact and collision sports could change brain structure and function in a way that accelerates the onset of cognitive decline later in life. The generalizability of most research on athlete brain health is limited by a primary focus on collegiate male athletes. PURPOSE: We sought to compare brain connectivity between Women's Flat Track Roller Derby (RD) athletes and female non-athletes (NA). METHODS: RD athletes (n=19, 24-41 years old) and NA (n=14, 20-49 years old) underwent structural, functional, and diffusion-weighted MR imaging. After preprocessing of the functional data, a surface-based cortical parcellation was used to group dense timeseries (32k 'greyordinates' per hemisphere) into 500 areas corresponding to 7 widely studied intrinsic brain networks. Functional connectivity (FC) was estimated by elastic-net regularization of the areal BOLD signals. After diffeomorphic reconstruction of pre-processed diffusion data, fiber tracking was performed until 1 million streamlines had been constructed for each individual. Structural connectivity (SC) was defined as the number of streamlines connecting each pair of 500 cortical areas. Group differences in structural and functional connectivity were tested using the network based statistic (5000 permutations) with a primary threshold t>2.04. In whole-brain networks that were observed to be larger ('intensity') than 95% of the permuted networks, 'edges' that passed the initial threshold were averaged within and between 7 intrinsic brain networks. The resulting graphs (7 x 7 networks) were inspected to characterize group differences. RESULTS: RD athletes exhibited a pattern of lower FC (p=.032) and lower SC (p = .046) than NA. The greatest differences in FC were observed within the limbic, ventral attention, and dorsal attention networks. The greatest differences in SC were observed within the visual and frontoparietal networks and between the frontoparietal and attention networks. CONCLUSIONS: Compared to non-athletes, brain structural and functional connectivity was lower in women competing in Roller Derby. Further research is needed to understand the antecedents to and consequences of these patterns. [ABSTRACT FROM AUTHOR]