Abstracts

Visual assessment of structural MRI is, by definition, normal in patients with idiopathic generalized epilepsy (IGE). Recent studies have shown increase in frontal grey matter and decrease in thalamic volume in patients with IGE, using voxel-based morphometry (VBM). VBM is a fully automated, unbiased, operator-independent MRI analysis technique that detects regionally specific differences in brain tissue composition on a voxel-wise comparison between groups of subjects. In this study, we employed an optimized VBM protocol to explore the structural difference in grey matter between a homogenous group of juvenile myoclonic epilepsy (JME) patients and control subjects., We recruited 25 JME patients (15 females; mean age at MR examination, 21 [plusmn] 6 years) and compare them with 44 control subjects (27 females; mean age 23 [plusmn] 6 years). 3D volumetric T1-weighted sagittal images were acquired from all subjects using a 1.5T MR scanner and MP-RAGE sequence, which was analyzed using SPM2 and an optimized VBM protocol. The statistical analysis with ANCOVA was employed for group comparison, and the significance was thresholded at [italic]P[/italic] [lt] 0.01, corrected for multiple comparisons using false discovery rate (FDR)., Compared with controls, JME patients showed decrease in grey matter volume in the right thalamus (MNI coordinates, -18/-16/18; Z score 5.33; voxel extent, 1203) and the left thalamus (16/-19/9; 5.20; 527). JME patients also showed increase in grey matter volume in the right medial frontal gyrus (MNI coordinates, 11/20/64; Z score, 4.46; voxel extent, 1244) and the left medial frontal gyrus (-9/-17/76; 5.23; 6176)., Using advanced technique of VBM, we demonstrated a reduction in bilateral thalamic volume and an increase in bilateral medial frontal cortical volume in patients with JME. Our results provide structural evidence of thalamocortical circuit abnormality in JME, which is considered as a fundamental pathogenesis underlying JME.,