Juvenile myoclonic epilepsy (JME) is an idiopathic generalized epileptic syndrome characterized by myoclonic jerks, generalized tonic-clonic seizures (GTCSs), and sometimes absence seizures. JME is relatively common and responds well to treatment with appropriate anticonvulsants.
Other features suggestive of the diagnosis include normal intelligence, onset around adolescence, and a family history of the condition. GTCSs occur shortly after awakening or after precipitating factors such as sleep deprivation, alcohol use, or psychological stress. Patients usually require lifelong anticonvulsant therapy, but their overall prognosis is generally good.
Definition of juvenile myoclonic epilepsy
Since the first description of a probable case of JME in 1867,
various names have been applied to this condition.
The term “juvenile myoclonic epilepsy” was proposed in 1975
and has been adopted by the International League Against Epilepsy (ILAE). Under the proposal for revised classification of epilepsies and epileptic syndromes, in 1989 the ILAE Commission on Classification and Terminology defined JME (impulsive petit mal) as follows.
“Impulsive petit mal appears around puberty and is characterized by seizures with bilateral, single or repetitive, arrhythmic, irregular myoclonic jerks, predominantly in the arms. Jerks may cause some patients to fall suddenly. No disturbance of consciousness is noticeable. Often, there are GTCS and, less often infrequent absences. The seizures usually occur shortly after awakening and are often precipitated by sleep deprivation.”
“Interictal and ictal EEG have rapid, generalized, often irregular spike-waves (SW) and polyspike-waves (PSW); there is no close phase correlation between EEG [electroencephalographic] spikes and jerks. Frequently the patients are photosensitive. The disorder may be inherited and sex distribution is equal. Response to appropriate drugs is good.”
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