[Juvenile myoclonic epilepsy].

Juvenile myoclonic epilepsy is an age-related form of idiopathic generalized epilepsy (mean age of onset: 12-14 years). The diagnosis is based on a cluster of clinical features: types of seizures, namely myoclonic jerks associated with generalized tonic-clonic or clonic-tonic-clonic seizures in 90% of the cases, absence seizures in one third of the cases; triggering factors and circadian rhythm of seizures on awakening or after sleep deprivation; a characteristic EEG pattern, i.e. bilateral symmetrical polyspike-waves. The clinical pattern is so suggestive that in clinical practice EEG is not necessary. Seventy percent of the patients are seizure-free with one-drug therapy. Treatment must be life-long, as relapse occurs in most cases after drug withdrawal, whatever the duration of control.