Paroxysmal wave and spike activity and diagnostic sub-classification

Abstract

One-hundred seventy-eight cases, presenting wave and spike activity in standard EEG recording, were reviewed with respect to type or types of seizures. The wave and spike activity was descriptively subclassified on the basis of frequency per sec. of the paroxysmal discharge. It was found that: 1. 1. ( a) Only 16 per cent had seizures classified as the petit mal triad, without seizures of other types. This is in close agreement with the 1941 report of Jasper and Kershman; ( b) twenty-two and a half per cent had seizures classified as grand mal (only); ( c) seventy per cent of the total group had seizures of the petit mal triad, plus other seizures types (and, conversely, 30 per cent had no seizures classified as the petit mal triad). This is in closer agreement with the findings of Gibbs et al. than with those of Jasper and Kershman. 2. 2. Considering “variants” of the wave and spike as being slower or faster than the “classical” three per sec. paroxysmal pattern, or admixed with it, such variants were more evident in the clinical grand mal than the clinical petit mal triad group. Particularly, most cases exhibiting the fast 4 per sec. variant had grand mal epilepsy. Rarely did these cases exhibit petit mal symptomatology. 3. 3. Presumed organic etiology of seizures was found infrequently in those cases showing the classical 3 per sec. pattern. However, when slow variants are considered, the incidence of idiopathic and presumed organic etiology was equal; these data do not indicate that organic etiology can be accurately predicted from the fact that a slow wave and spike appears in the EEG. Idiopathic epilepsy does seem to be related to the 3 per sec. paroxysmal wave and spike.