Goal-Oriented Attentional Self-Regulation Training in Chronic Mild Traumatic Brain Injury Leads to Microstructural Plasticity in Prefrontal White Matter

Abstract

Impaired attention is one of the most common, debilitating, and persistent consequence of traumatic brain injury (TBI), which impacts overall cognitive and executive functions in these patients. Previous neuroimaging studies, trying to understand the neural mechanism underlying attention impairment post TBI, have highlighted the role of prefrontal white matter tracts in attentional functioning in mild TBI. Goal-Oriented Attentional Self-Regulation (GOALS) is a cognitive rehabilitation training program that targets executive control functions in participants by applying mindfulness-based attention regulation and goal management strategies. GOALS training has been demonstrated to improve attention and executive functioning in patients with chronic TBI. However, its impact on microstructural integrity of attention-associated prefrontal white matter tracts is still unclear. Here, using diffusion MRI in a pilot randomized controlled trial, we investigated the effect of GOALS training on prefrontal white matter microstructure in US military veterans with chronic mild TBI (mTBI), compared to a matched control group of veterans with chronic mTBI who received standard of care brain health education. We also tested for an association between microstructural white matter changes and sustained attention ability in these patients pre- and post-GOALS training. Our results show significantly better white matter microstructural integrity in left and right anterior corona radiata in the GOALS group compared to the control group post-training. Moreover, we found a significant correlation between sustained attention ability of GOALS training participants and white matter integrity of their right anterior corona radiata pre- and post-training. Finally, our findings indicated that the improved white matter integrity of the anterior corona radiata in GOALS training participants was the result of increased neurite density and decreased fiber orientation dispersion within this tract.