Volumetric magnetic resonance imaging in patients with primary generalized epilepsy

We studied 21 patients with primary generalized epilepsy (PGE), using volumetric magnetic resonance imaging (MRI) measurements of the amygdala and hippocampus. Subtypes of PGE included juvenile myoclonic epilepsy in 9 patients, primary generalized tonic-clonic seizures (GTCS) in 4, childhood absence epilepsy in 3, juvenile absence epilepsy in 2, unclassified PGE in 2, and photosensitive epilepsy in 1. Seizure types included GTC in 14 patients, absence onset myoclonic in 7, atypical absence in 6, and atonic in 2. Age of seizure onset ranged from 6 months to 46 years, and duration of epilepsy ranged from 1 to 26 years. No patient experienced febrile seizures during childhood. Fourteen patients (67%) had a family history of seizures. Interictal (19 patients) and ictal (8 patients) EEG recording showed bursts of generalized spike and wave and/or polyspike and wave activity consistent with PGE. Hippocampal and amygdaloid volumes and ratios were within the normal range as compared with that of our normal control population. Significant reduction in hippocampal and amygdaloid volumes is a specific marker for hippocampal and amygdaloid sclerosis.