White Matter Changes and Confrontation Naming in Retired Aging National Football League Athletes

Abstract

Using diffusion tensor imaging (DTI), we assessed the relationship of white matter integrity and performance on the Boston Naming Test (BNT) in a group of retired professional football players and a control group. We examined correlations between fractional anisotropy (FA) and mean diffusivity (MD) with BNT T-scores in an unbiased voxelwise analysis processed with tract-based spatial statistics (TBSS). We also analyzed the DTI data by grouping voxels together as white matter tracts and testing each tract's association with BNT T-scores. Significant voxelwise correlations between FA and BNT performance were only seen in the retired football players (p < 0.02). Two tracts had mean FA values that significantly correlated with BNT performance: forceps minor and forceps major. White matter integrity is important for distributed cognitive processes, and disruption correlates with diminished performance in athletes exposed to concussive and subconcussive brain injuries, but not in controls without such exposure.

Keywords: DTI; National Football League; TBSS; concussion; naming; white matter.

FIG. 1.

Voxelwise correlation for retired professional athletes’ fractional anisotropy (FA) values and Boston Naming Test (BNT) T-scores. Blue voxels are significant at p < 0.02 corrected for multiple comparisons. Axial slices are in radiological orientation with the results thickened for better visibility using the “tbss_fill” script.

FIG. 2.

Tractwise correlation between fractional anisotropy (FA) and fractional anisotropy (BNT) T-scores in both controls and retired profession athletes. Each circle represents a cognitively normal control or athlete depending on the panel. The squares represent athletes with MCI. Pearson correlations are displayed in each quadrant in the top right corner.