Natural course and predictors of spontaneous seizure remission in idiopathic generalized epilepsy: 7-27 years of follow-up.

The spontaneous course of idiopathic generalized epilepsy (IGE) is still controversial. The aim of this study was both to investigate the long-term spontaneous course and to identify factors that are predictive for epilepsy remission in a small cohort of 15 IGE patients (9 women) who refused antiepileptic drug (AED) treatment and therefore never have been treated with AED. All of them were reevaluated with a review of their medical records and direct face-to-face interview; the mean duration of follow-up was 15.3 years. Five (33.3%) of them had absence epilepsy (absence seizures, ABS), 5 had IGE with generalized tonic-clonic seizures (GTCS), and another 5 had both seizure types (IGE with ABS/GTCS). Rate of epilepsy remission was 53.3% with a mean time of seizure freedom of 13.1 years; rate of remission was highest among absence epilepsy patients (80%), followed by IGE with GTCS (60%) and IGE with ABS/GTCS (20%). The frequency of spontaneous generalized interictal epileptiform discharges in electroencephalography is not associated with the long-term seizure outcome (p=0.201) and per se does not require AED treatment. Furthermore, the occurrence of photoparoxysmal responses (p=0.020) as well as the occurrence of more than 3 GTCS during the course (p=0.029) were identified as significant predictors for a poor long-term seizure outcome which makes AED treatment indispensable in these patients. This study underlines the heterogenity of the group of IGE. AED treatment has no impact on the spontaneous course of IGE with ABS and/or GTCS. Several predictors for the long-term seizure outcome in patients with IGE were identified in this study.