Ohtahara syndrome: Early infantile epileptic encephalopathy

Abstract

DEFINITION Ohtahara syndrome (early infantile epileptic encephalopathy with suppression bursts), is the earliest developing form of epileptic encephalopathy. ETHIOLOGY It considered to be a result of static structural developing brain damage. CLINICAL PICTURE Variable seizures develop mostly within the first 10 days of life, but may occur during the first hour after delivery. The most frequently observed seizure type are epileptic spasms, which may be either generalized and symmetrical or lateralized. The tonic spasms may occur in clusters or singly, while awake and during sleep alike. The duration of spasms is up to 10 seconds, and the interval between spasms within cluster ranges from 9 to 15 seconds. In one third of cases, other seizure types include partial motor seizures or hemiconvulsions The disorder takes a progressively deteriorating course with increasing frequency of seizures and severe retardation of psychomotor development. DIAGNOSTIC WORKUP In the initial stage of Ohtahara syndrome, interictal EEG shows a pattern of suppression-burst with high-voltage paroxysmal discharges separated by prolonged periods of nearly flat tracing that last for up to 18 seconds. PROGNOSIS AND THREATMENT Half of the reported children having Ohtahara syndrome die in infancy. Anticonvulsant helps little in controlling the seizures and halting the deterioration of psychomotor development. Severe psychomotor retardation is the rule. With time, the disorder may evolve into West syndrome or partial epilepsy. Psychomotor development may be slightly better if the infants do not develop West and later Lennox-Gastaut syndrome.