Extratemporal abnormalities of brain parenchyma in young adults with temporal lobe epilepsy: a diffusion tensor imaging study.

AIM: To examine extratemporal abnormalities of the cerebral parenchyma in young adult temporal lobe epilepsy (TLE) patients using diffusion tensor imaging (DTI). MATERIALS AND METHODS: The study comprised 20 adults with unilateral TLE and 20 controls. The fractional anisotropy (FA), apparent diffusion coefficient (ADC), parallel eigenvalue (λ∥), and perpendicular eigenvalue (λ⊥) were calculated in the regions of interest (ROIs) using a 3 T MRI system. ROIs included the anterior/posterior limb of the internal capsule (AIC/PIC), external capsule (EC), head of caudate nucleus (HCN), lenticular nucleus (LN), thalamus (TL), and genu/body/splenium of the corpus callosum (GCC/BCC/SCC). RESULTS: Compared to controls, TLE patients showed lower FA in all ROIs; higher ADC in bilateral ECs, HCNs, TLs, and BCC; lower λ∥ in the ipsilateral LN and bilateral AICs, TL, and GCC; and higher λ⊥ in all ROIs except the bilateral PICs. In TLE patients, the ipsilateral TL had decreased FA compared with the contralateral TL. Pearson correlation analysis revealed a negative correlation between the ADC of the GCC and the age at onset of epilepsy; the λ∥ of the ipsilateral PIC and age at onset of epilepsy; the λ⊥ of the contralateral AIC and duration of epilepsy, respectively; and a positive correlation between the ADC of the GCC and the duration of epilepsy and the λ⊥ of the GCC and the duration of epilepsy, respectively. CONCLUSION: The study revealed bilateral extratemporal abnormalities in young adult TLE patients compared with controls. In addition, TLE patients with younger age at onset or longer duration of epilepsy may have more serious extratemporal changes.