Abstract
Research on patients with mild traumatic brain injury (mTBI) has reported that discourse-level impairments are associated with decreased global cognitive functioning. The global cognitive disorganization potentially emerges from poor connectivity across nodes comprising dispersed cortical networks. A likely source of this functional disconnectivity in mTBI is a post-trauma deterioration in the white matter integrity. In mTBI patients and matched controls, we used diffusion tensor tractography (DTI) to compare the integrity of inter-hemispheric commissural, limbic, and association fibers. Relative to controls, patients showed lower fractional anisotropy (FA) and higher mean diffusivity (MD) values in a majority of tracts. Decreases in fiber count, volume and density suggest a large-scale white matter deterioration not restricted to language tracts. FA of several tracts correlated with performance of a language judgment task. These suggest that the abnormalities in the integrity of inter- and intrahemispheric tracts are related to linguistic deficits in these patients.