Abstracts

To investigate the anatomical characteristics of the corpus callosum in a group of patients with idiopathic generalized epilepsy (IGE) using high resolution MRI volumetry. IGE subsyndromes were classified according to ILAE recommendations. MRI images were acquired in a 2T scanner. The corpus callosum was delineated in the sagital (1 mm isotropic voxels) slices of the volumetric (3D T1 gradient echo) sequence using a semi-automatic segmentation software (Neuroline, Laboratorio de Neuroimagem, UNICAMP). The callosal volumes obtained were normalized for the variation of total intracranial volume. The corpus callosum of 20 patients (13 women, mean [plusmn] SD, 24 [plusmn] 6 years) with IGE was compared to 20 healthy controls (10 women, 32 [plusmn] 14 years). Student[apos]s [italic]t[/italic] test and analysis of variance (ANOVA) were used for statistical analysis. Ten patients had juvenile myoclonic epilepsy (JME) and ten juvenile absence epilepsy (JAE). The mean callosal volume was 10149 [plusmn] 1887 mm³ in the control group and 10062 [plusmn] 1294 in the IGE group ([italic]p [/italic]= 0.8). Patients with JAE had a higher mean callosal volume (10274 [plusmn] 1717). However, there was no difference when compared to JME (9850 [plusmn] 699) and controls ([italic]p[/italic] = 0.8, 0.9 respectively). Experimental data supports that the corpus callosum is the major anatomical substratum for inter-hemispheric seizure spread and generalization. Furthermore, this structure probably is more than a pathway for transmission of seizure discharge and may also participate in a more active aspect of seizure propagation and generalization. In this preliminary evaluation there was no difference between the volumes of the corpus callosum of patients with IGE compared to controls. (Supported by CAPES, FAPESP.)