Diffusion tensor imaging and volumetric analysis of the ventral striatum in adults with traumatic brain injury

Objectives: The aim was to determine if there are changes in the integrity and volume of the ventral striatum following severe traumatic brain injury (TBI) and if these changes relate to executive functioning. Methods: This study recruited 14 participants with severe TBI (mean age: 22 years) and 15 demographically-matched controls. All participants underwent magnetic resonance imaging with diffusion tensor imaging (DTI) and volumetric analysis at 6 months post-injury. Participants with TBI underwent neuropsychological testing and the relation between imaging data and cognitive performance was examined. Results: Differences in DTI parameters (fractional anisotropy (FA) and apparent diffusion coefficient (ADC)) were found between participants with TBI and controls. Correlations between right and left ventral striatum ADC and the executive functioning factor of the Neurobehavioural Rating Scale-Revised (NRS-R) were found. Correlations between right ventral striatum FA and the Controlled Oral Word Association Test, Trails Making Test Part B (TMT-B) time and NRS-R executive functioning factor were also found. Volumetric analysis showed a difference only in left nucleus accumbens between TBI and control groups. Conclusions: The integrity of the ventral striatum is affected following severe TBI. Decreases in executive functioning are related to damage to the ventral striatum and its associated structures.