Interictal EEG prediction of response to antiepileptic drug monotherapy

Forty-eight patients had sleep-deprived EEGs prior to antiepileptic drug monotherapy. The majority were seizure-free after one year, or had more than 50% reduction in seizure frequency. Among those with normal EEGs 50% were seizure-free, while 75% with diffuse slowing, 44% with focal abnormality, and 83% with generalized epileptiform discharges were fully controlled. Freedom from seizures was achieved in 13% taking phenobarbital, 50% taking phenytoin, 63% taking carbamazepine, and 100% taking valproate. The sleep-deprived interictal EEG should be an integral part of initial assessment and drug selection in patients with clinical histories of convulsive seizure.