~1% to 2% of epilepsies that start before the age of 3 years.
Age at onset
6 months to 3 years but also earlier (4 months) or later (4 years).
Males (66%) predominate.
Neurological and mental state
Probably genetic. It is the earliest form of idiopathic generalized epilepsy (IGE).
Myoclonic jerks, singular or clusters. Consciousness is intact but mild clouding may occur during cluster of jerks.
There are no other types of seizures other than simple febrile seizures in 10%.
Photosensitivity (20%), unexpected acoustic or tactile stimuli (10%).
Awakening or during the first hours of sleep.
Generalized polyspike or spike and slow-wave discharges.
Remission usually occurs within 1 year (6 months to 5 years) from onset. 10% to 20% develop infrequent generalized tonic-clonic seizures in their early teens. 10% to 20%, if untreated, may develop mild cognitive, behavioral, or motor deficits. EEG photosensitivity may persist after remission of seizures.
(1) Non-epileptic conditions (hypnagogic jerks and benign non-epileptic myoclonus) and (2) Dravet syndrome and West syndrome.
Excellent response to valproate, which should be withdrawn 3 to 5 years from onset. Patients with acoustic and somatosensory evoked myoclonus may not need treatment.
*Expert opinion, please check FDA-approved indications and prescribing information
This page was adapted from:
The educational kit on epilepsies
The epileptic syndromes
By C. P. Panayiotopoulos
Originally published by MEDICINAE
21 Cave Street, Oxford OX4 1BA
First published 2006 and reprinted in 2007
Reviewed and revised June 2008 by Steven C. Schachter, MD
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