Advanced mapping of the human white matter microstructure better separates elite sports participation

Collision-sport athletes, especially football players, are exposed to a higher number of repetitive head impacts. Little is known, however, regarding the effects of long-term exposure to repetitive head impacts on brain tissue structure and the locations (i.e. superficial or deep tissue structures) affected. On top of this, little is known about the effects of highly competitive, strenuous, long-term athletics on brain tissue structure. We investigated this relationship using advanced microstructural mapping techniques. Specifically, we examined the baseline differences in collegiate athletic participants by using two models of the diffusion-weighted magnetic resonance imaging signal (the Diffusion Tensor and NODDI model). DTI and NODDI parameters were mapped in both cortical and subcortical structures, as well as in the major white matter tracts. Three groups of young adults participated in our study; IU football players, cross country runners, and non-athlete students. For both models, athletes were found to have consistently higher measures of microstructure than controls. The NODDI model parameters showed stronger results indicating that it might be more sensitive to capturing differences in brain white matter tissue microstructure than the DTI model. This was the first investigation into the effects of repetitive head impacts to use an open-source data processing platform brainlife.io. Data and analyses for this study are available at https://doi.org/10.25663/brainlife.pub.14.