ABSTRACT
In childhood, there are several epileptic encephalopathies in which excessive neuronal activity may not only cause clinical seizures but also lead to a stagnation or regression in the development of cognitive and motor function. Early-infantile epileptic encephalopathy with suppression-burst, Ohtahara syndrome and early myoclonic encephalopathy (EME) present in the neonatal or early infantile period, a time when seizure-susceptibility is low and only a few epileptic syndromes are observed.1-3 Both syndromes are characterized by a suppression-burst pattern on EEG and by frequent intractable seizures. They are inclusively called early infantile epileptic syndromes or encephalopathies with suppression-burst.4,5
Ohtahara syndrome has the earliest presentation of the three age-dependent epileptic encephalopathies, which include Ohtahara syndrome, West syndrome and LennoxGastaut syndrome. Although each of these three syndromes has specific clinical and electroencephalographic features, they have the following common characteristics:
Transition is often observed with age between these syndromes; approximately three-quarters of patients with Ohtahara syndrome develop West syndrome in middle infancy, and more than half of patients with West syndrome develop Lennox-Gastaut syndrome, usually in early childhood.8-10 Their common characteristics and the
frequent transition between syndromes led Ohtahara to inclusively name each of these three syndromes as an agedependent epileptic encephalopathy.6,7 Despite their common features, each of the three syndromes usually presents at a certain age and has particular clinical and EEG features. In that each syndrome may be due to a wide variety of etiologies, the age at presentation is probably a major factor in the manifestation of the specific electroclinical features of each. Thus, these syndromes may be the age-specific epileptic response to various brain insults.
