Abstracts

Rationale: The proposed new classification of the ILAE believes that "generalized" crises exhibit focal onset with rapid propagation, and absence seizures with SWD present generally greater amplitude in the midline of the frontal region. The aim of this study is to evaluate the cortical thickness and white matter (WM) integrity on high-resolution T1-weighted and diffusion tensor (DTI) MR images in patients with epilepsy with absence seizures and generalized spike-wave complexes discharge (SWD). Methods: We studied 19 patients (11 female, 24.6 - 12.1 years) with electro-clinical diagnosis of epilepsy with absence seizures associated with generalized SWD of 3 to 4 Hz and 19 healthy controls matched by sex and age. All patients underwent MRI (1.5 T) with advanced sequences (high-resolution 3D isotropic T1-WI and DTI). The assessment of cortical thickness was performed semi-automatically through the sorftware FreeSurfer. The study of the integrity of the WM (DTI) was performed with TBSS (tract-based spatial statistics), which is part of the FSL. Results: Patients with absence seizures showed areas of significant reduction of cortical thickness at the right pre-central gyrus (area 4) and precuneus (area 7), and left transverse temporal gyrus (areas 41 and 42). Furthermore, we observed increased cortical thickness in the rostral portion of the left middle frontal gyrus (area 46). A voxel-based analysis of fractional anisotropy maps showed a significant reduction in the right frontal WM and anterior portions of the corpus callosum of patients with CA. Conclusions: Our results in humans with absence seizures and SWD show changes in the corpus callosum and frontal WM, as well as at the frontal, parietal and temporal cortical regions, supporting the hypothesis of focal network participation in patients with absence seizures and generalized SWD.