Abstracts

RATIONALE: MRI and pathological studies have indicated both focal and diffuse patterns of cerebral volume change in patients with focal epilepsy. To further delinate cerebral changes in such patients a method of determining cortical lobar volumes was established along with normative ranges. This was then compared with a group of patients with primary generalised epilepsy (PGE), and another group of patients with hippocampal sclerosis (HS)
METHODS: 97 neurologically normal controls with 3D T1 MRI aquisitions had brains previously extracted. A group of 89 HS patients(pathologically proven and selected through a surgical treatment program) and 21 PGE (cognitively normal with typical clinical features and 3Hz spike-wave discharges on EEG) patients were employed A 3D morphometric process was used to extract cortical shells from the segmented brains. These cortical shells were then subdivided into frontal, parietal, temporal and occipital cortical regions via an interactive editing process. Reliable landmarks were determined from 3D reconstructions which could be rotated to ensure accurate placement.
RESULTS: Cortical volumes total and for both hemispheres were significantly reduced (p[lt]0.01) in both patients with HS and PGE to controls, and there was no significant difference between the 2 patient groups. Hemisphere cortical volumes were reduced in PGE and HS in all regions except frontal lobes (p[lt]0.01). Table below provides normative values for male and female controls for specified cortical structures.
CONCLUSIONS: This study demonstrates focal and primary generalised epilepsies are associated with widespread cortical volume changes. This has significant implications for our understanding of the pathogenesis of these epilepsies. It also provides normative values for cortical lobar volumes for future comparison against other epilepsy patient groups.[table]