A Diffusion Tensor Imaging Study: Relation of Wisconsin Card Sorting Covariates to White Matter Abnormalities in Traumatic Brain Injury

New brain imaging modalities and neuropsychological testing tools are used to study neuronal changes in brain injuries such as mild traumatic brain injury (mTBI). Here we utilized diffusion tensor imaging (DTI) parameters and Wisconsin Card Sorting Test (WCST) variables to investigate patients with chronic mTBI. Neuropsychological assessments for mTBI evaluate impairments across a broad spectrum of executive functions. Our study aims to examine the relationship between fractional anisotropy (FA) and WCST covariates in patients with chronic mTBI. We hypothesize that patients who suffered chronic mTBI have significantly reduced FA in frontal white matter regions in association with significant deviation from standard percentile scores in WSCT. Utilizing multi-linear regression models alongside analyzing DTI scans, WCST covariates were linearly regressed to produce positive and negative contrasts to identify specific regions of interest (ROIs) with reduced FA. Results show that WCST covariates (such as percentile perseverative responses (Ep), non-perseverative responses (Enp), and conceptual response (CResp)) significantly deviate beyond standard percentile scores and correlate with lower FA in white matter regions in the frontal cortex, demonstrating executive function deficits. These frontal regions include the inferior frontal, superior frontal, and corpus callosum (CC), correlated with greater errors in WCST percentile scores. This study investigates the correlation between WCST covariates and DTI parameters as valuable tools in the diagnosis and prognosis of persistent cognitive impairment for patients with a history of chronic traumatic brain injury.