Long-Term Abnormalities in the Corpus Callosum of Female Concussed Athletes

Concussion is an injury affecting millions of individuals annually that can be associated with long-term sequelae. Recent studies have reported long-term abnormalities in the white matter (WM) tracts of male athletes. The corpus callosum (CC) and corticospinal tract (CST) have been shown to be particularly vulnerable to concussion, which may be related to abnormal interhemispheric functional connectivity and motor impairments. These anatomical pathways, however, have not been investigated in female athletes despite the functional significance of the CC and CST to adequate sports performance. In the present study, 8 healthy, unconcussed female athletes (soccer, hockey) were compared with 10 female athletes (soccer, hockey, water polo) 6 months post-concussion. Diffusion tensor imaging (DTI) of the CC and CST was conducted in a 3T magnetic resonance imaging (MRI) scanner. DTI analysis showed no significant differences between groups within the CST but revealed differences between groups in the CC. The concussed group had lower mean diffusivity (t = 2.14; p = 0.048) and lower radial diffusivity (t = 2.91; p = 0.010) in the region of the CC projecting to the prefrontal cortex. A lower volume of WM fibers was found in the region projecting to the premotor and supplementary motor areas (t = 2.14; p = 0.048). Finally, lower axial diffusivity (AD) was observed in the CC area projecting mainly to the parietal and temporal area (t = 2.23; p = 0.041). Long-term alterations in the CC of female athletes appear to affect mostly the anterior part of the CC projecting to the prefrontal and premotor areas. Further studies are needed to determine whether these alterations are associated with a higher risk of sustaining a subsequent concussive injury.