Clinical and electroencephalographic findings prior to the onset of juvenile myoclonic epilepsy: A case series.

The four patients had transitioned to juvenile myoclonic epilepsy from other epileptological preconditions. Patients with juvenile myoclonic epilepsy may show generalized electroencephalographic abnormality many years prior to the onset of symptoms. Generalized spike-waves on electroencephalogram during the course of any type of epilepsy or febrile seizure may be a risk factor for developing juvenile myoclonic epilepsy.