Caudate atrophy and impaired frontostriatal connections are linked to executive dysfunction in temporal lobe epilepsy

摘要

This study tests the hypothesis that executive dysfunction, common in temporal lobe epilepsy (TLE), is associated with an abnormal frontostriatal network. Structural and diffusion tensor MR scans, Wisconsin Card Sorting Test (WCST) targeting cognitive flexibility and Trails B test examining parallel sequencing were obtained from 9 left TLE and 17 healthy controls. The five major findings are: 1) Caudate volume is reduced on the left side in TLE. 2) The atrophy involves dorsal and ventral head of caudate. 3) These atrophic caudate regions have corresponding high probability of connections to dorsal prefrontal, anterior cingulate, and orbitofrontal cortex. 4) Smaller caudate volumes are linked to greater numbers of WCST perseverative errors. 5) Reduced connections between caudate and dorsal prefrontal cortex correlated with poorer scores on Trails B test. The results suggest that atrophy in the dorsal head of caudate might disrupt frontostriatal networks that are critical for executive functioning in TLE.