Reflex myoclonic epilepsy in infancy: a benign age-dependent idiopathic startle epilepsy

Reflex myoclonic epilepsy of infancy is an idiopathic epileptic disorder characterized by myoclonic attacks, with onset in the first 2 years of life precipitated exclusively by unexpected tactile or auditory stimuli. We report on a 9 month-old infant with myoclonic attacks, which consisted of frequent clusters of up to 10 symmetric jerks affecting mainly the arms and the head occurring as reflex responses to unexpected auditory stimuli. There was no family history of epilepsy or febrile convulsions. Ictal EEG demonstrated a typical 3 Hz spike-wave pattern, while there were no abnormalities, either in wakefulness or during sleep. The neurodevelopmental examination was unremarkable and MRI of the brain was normal. The attacks disappeared 3 weeks after initiating sodium valproate, and have not reappeared since then (follow-up 3 years and 3 months); today, at 4 years of age, the patient has normal psychomotor development. RMEI should be considered as an age-dependent, idiopathic, generalized epileptic syndrome with an apparently good prognosis [Published with video sequences].