Functional magnetic resonance and diffusion tensor imaging analysis of verbal working memory in patients with temporal lobe epilepsy.

OBJECTIVE This study aimed to investigate the relationships between brain functions and verbal working memory (VWM) impairments in patients with temporal lobe epilepsy (TLE). METHODS Functional magnetic resonance imaging was performed on 15 healthy controls and 15 patients with TLE while they performed the N-back task in order to compare the brain areas that were activated during VWM. Diffusion tensor imaging was then performed to examine the integrity of the VWM-related fiber bundles. RESULTS The patient group exhibited a significant reduction in the activation of the brain areas that were negatively activated in the VWM task in the control group (P < 0.05), and no activation was observed in the patient group in the brain areas that were positively activated in the VWM task in the control group. The fractional anisotropy values of both cingulate bundles were significantly reduced in the patient group compared with those in the control group (P < 0.05), and these values were positively correlated with the number of activated pixels in the ipsilateral prefrontal areas (left: r = 0.790, P < 0.05; right: r = 0.852, P < 0.05). CONCLUSIONS Patients with TLE exhibited impaired VWM functions that were related to subtle alterations in the cingulate bundles.