There may be different neural bases between subjects with epilepsy only (EP) and interictal chronic epilepsy psychosis (EPS). However, there have been few structural MRI studies of EPS. The current study was conducted to investigate the neural substrate of EPS. T1-weighted images were analyzed in 14 patients with EPS and 14 strictly-matched patients with EP. We conducted volume comparison in the whole brain using voxel-based morphometry (VBM). The VBM method revealed that EPS patients exhibited significantly reduced gray matter volumes in the left postcentral gyrus and the left supra marginal gyrus compared with EP patients (adjusted p = 0.029, FDR corrected q; k = 319 voxels). For clinical correlations, there were no significant associations between psychotic symptoms and gray matter volumes in the left postcentral gyrus and the left supra marginal gyrus. VBM analysis revealed that reduced gray matter volumes in the left postcentral gyrus and the left supra marginal gyrus may be crucial regions for EPS.
Keywords: Chronic interictal epileptic psychosis; Left postcentral gyrus; Left supra marginal gyrus; MRI.