Ethosuximide-induced conversion of typical childhood absence to Rolandic spikes.

Coexistence of 2 idiopathic epilepsy syndromes (ie, childhood absence and Rolandic epilepsy), as evidenced by electroencephalographic (EEG) findings with or without clinical features of the 2 conditions, is uncommon and remains controversial. Few case reports support this coexistence either as a continuum or drug-induced conversion, whereas a large sample case review did not find such co-occurrence. The authors report a case of conversion of typical absence to Rolandic spikes after treatment with ethosuximide. An 11-year-old girl was diagnosed with typical childhood absence epilepsy at the age of 6 years with classic clinical and EEG features. She became seizure-free on ethosuximide but her follow-up EEGs consistently recorded right centrotemporal and centroparietal spikes without associated clinical seizures. This case may suggest simultaneous presence of these 2 common childhood idiopathic epilepsies either as a continuum or a drug-induced conversion.