Abstracts

Cross-sectional and longitudinal magnetic resonance imaging studies in patients with partial epilepsies have shown progressive hippocampal and extrahippocampal atrophy, the severity of which correlated with the duration of epilepsy, seizure frequency, or lifetime seizure number, whereas others have failed to show a clear association.
Objectives: To determine factors associated with progression of hippocampal atrophy (HA) and extrahippocampal atrophy in medial temporal lobe epilepsy (MTLE)., We included 34 patients (18 women) with MTLE, as determined by clinical and electroencephalography (EEG) evaluation following the ILAE criteria. Eleven patients presented left MTLE, 10 patients right MTLE and 13 patients had bitemporal EEG foci. We also included 44 healthy controls (23 women). MRI scans were performed in a 2T scanner (Elscint Prestige, Haifa, Israel). T1-weighted gradient-echo sequence with isotropic voxel size of 1 mm was used for voxel based morphometry (VBM) analysis to determine differences in white and gray matter between controls and patients. VBM was performed using SPM 2. Follow-up images were obtained after at least six months after the first baseline MRI. Comparison between the patient[apos]s follow-up and baseline MRIs, and between patients and controls were performed using a t-test. Correlation and multiple regressions were used to determine factors associated with progression. A p value of 0.05 was set as the threshold for the statistical analysis., Follow-up MRI was performed after a mean interval of 44.6 months (SD=27.3; range 7-85 months). Ten patients had history of febrile seizure. Eighteen patients were seizure-free between the first and second MRI. We observed a progression of white matter (corpus callosum and deep white matter) (p[lt]0.05) and gray matter atrophy (hippocampi and thalami p[lt]0.05) in patients with MTLE. This progression was more intense in patients with left MTLE when compared to right MTLE. Patients with seizure control had a less intense progression of white and gray matter atrophy when compared to patients without seizure control., We observed a progression of white and gray matter atrophy in patients with MTLE, more intense in patients with left MTLE. This progression was more intense in patients with poor seizure control., (Supported by FAPESP and CNPq.)