A - 03 Association of Prior Concussion and Contact Sport Exposure With Cortical Surface Metrics in Collegiate Athletes

Abstract Purpose Prior studies have suggested that concussion and repetitive head impacts may be associated with abnormalities in cortical structure, though most work has been in retired football athletes. We examined the relationship between prior concussion and years of contact sport exposure with macrostructural and microstructural cortical gray matter metrics in collegiate athletes. Method Athletes completed interviews to capture concussion and contact sport participation history. Cortical surface area (CSA) and cortical thickness (CT) were estimated from anatomical MRI scans; cortical mean diffusivity (CMD) was measured using diffusion tensor imaging. CSA, CT, and CMD were extracted from regions-of-interest derived from the Desikan-Killiany Atlas. Bayesian multilevel modeling characterized associations of prior concussions and contact sport exposure with each cortical metric, controlling for sex and intracranial volume (CSA only). Results A total of 207 and 205 participants had CT/CSA data and CMD data, respectively. There was strong evidence for a positive association of number of prior concussions with CSA in multiple regions. For CT, there was a strong, inverse association of number of prior concussions with CT in bilateral temporal pole and entorhinal cortex, right parahippocampal gyrus, and right middle temporal gyrus. There was strong evidence for a widespread, positive association of prior concussion with CMD across the cortex. Contact sport exposure was not strongly associated with any cortical metric. Conclusions Current results suggest that a history of prior concussion, but not years of contact sport exposure, is associated with differences in macro and microstructural cortical surface metrics in otherwise healthy collegiate athletes.