West syndrome and its related epileptic syndromes.

The purpose of this project was to study the relationship between West syndrome (WS) and its related epileptic syndromes, and reconsider the nosological limits of WS. The electroclinical features of 45 patients who experienced spasms in series were investigated, as well as some features not common in patients with WS. All patients were mentally retarded. The patients were divided into three groups: Group 1 consisted of 12 patients with refractory epilepsies with onset in early infancy, group 2 consisted of 5 patients with symptomatic localization-related epilepsies associated with spasms in series, and group 3 consisted of 28 patients with generalized epilepsies who had spasms in series after age 2 years. Partial seizures were the dominant symptom throughout the clinical course and spasms in series associated with atypical hypsarrhythmia appeared transiently during infancy in a significant number of the patients in group 1. In group 2, complex partial seizures (CPS) were the main seizure type and hypsarrhythmia was not observed during the clinical course. The EEGs in group 3 patients showed diffuse slow spike-waves or multifocal epileptic discharges in all but 1 patient. The EEG of the remaining patient still showed hypsarrhythmia at age 8 years. Therefore, group 1 patients should be classified as having WS although cortical mechanisms play a critical role in the occurrence of their seizures. Group 2 patients should be considered as having a type of localization-related epilepsy even though they share a similar pathophysiological mechanism with group 1. In group 3, 1 patient whose EEG still showed hypsarrhythmia was classified as having WS. The other patients should be classified as having generalized epilepsies other than WS.