Juvenile myoclonic epilepsy: characteristics of a primary generalized epilepsy.

Juvenile myoclonic epilepsy (JME) is a primary generalized epilepsy that affects approximately 7% of adolescent and adult epilepsy patients. JME is characterized by myoclonic seizures alone or combined with generalized tonic-clonic seizures or absence seizures. Seizures are precipitated by sudden awakening, sleep deprivation, photic stimulation, and alcohol consumption. The ictal electroencephalogram (EEG) shows a typical 4- to 6-Hz polyspike and wave pattern; the interictal EEG may be normal. Valproate controls seizures in approximately 80% of JME patients and is recommended for successful management of this disorder.