Epileptic spasms in clusters without hypsarrhythmia in infancy.

Abstract

Spasms are defined as epileptic seizures characterized by brief axial contraction, in flexion, extension or mixed, symmetric or asymmetric, lasting from a fraction of a second to 1-2s, and are associated with a slow-wave transient or sharp and slow-wave complex, followed or not by voltage attenuation. Epileptic spasms usually appear in clusters and are age-dependent. This type of epileptic spasms associated with the particular EEG pattern, hypsar rhythmia, constitutes the basis for the diagnosis of West syndrome. The question is, how to nosologically define those patients who clearly present epileptic spasms in clusters without modified or typical hypsarrhythmia and with or without focal paroxysmal discharges on the interictal EEG. In the present series, the four patients show that epileptic spasms in clusters may occur in infancy, without hypsarrhythmia. They all presented the following features: normal neuropsychological development before onset of epileptic spasms, clusters of epileptic spasms, focal clinical and/or EEG abnormalities, normal neuroradiological imaging, neurometabolic investigations and karyotypes. In three of the patients, seizures were refractory to AEDs. Epileptic spasms in clusters without hypsarrhythmia that start in the first year of life represent a subtype of infantile spasms that generally are refractory to AEDs. It is not yet clear whether it should be considered as a variant of West syndrome or not [Published with Video sequence].