Occipital intermittent rhythmic delta activity in absence epilepsy.

Occipital intermittent rhythmic delta activity (OIRDA) is considered good prognostic factor in typical absences (TA). We report electroclinical evolution in 14 patients with TA and OIRDA, which performed video-EEG. Seven patients were female; 9 had childhood absence epilepsy and the others did not present electroclinical characteristics for syndromic classification according to ILAE's classification (1989). Pyknolepsy was referred to in 13; TA was the only seizure type in 13; one had generalized tonic-clonic seizures (GTCS) and three had myoclonic jerks during TA. VPA monotherapy controlled seizures in 11, diVPA and ESM, in one each. After seizure control EEG normalized in 10 while in three, spike-wave complexes (SWC) persisted, accompanied by OIRDA in one. Finally in another, seizures were not controlled and SWC and OIRDA persisted. In conclusion, we observed in this series of TA and OIRDA with onset before 10 years, pyknolepsy as common finding and few GTCS. VPA controlled seizures in most cases and EEG normalized in 76.92%. We suggest that OIRDA could be considered good prognostic factor in TA associated with SWC and of epileptiform nature leading to appropriate investigation.