[The symptom of EEG-flattening accompanying psychomotor attacks, their frequency, duration, form and significance. A video-band analysis of 78 patients with 187 attacks (author's transl)].

A total of 187 psychomotor attacks in 78 epileptic patients were recorded on video band; 48 patients (61.5%) and 100 attacks (55.5%) showed signs of EEG flattening. This flattening became manifest before the clinical onset of the fit in 11.88% of patients, simultaneously with the fit in 30.5%, during the fit in 17.1%, and at the end of the attack in 4.8%. In 10.7% of the attacks, the flattening was considered as a cardinal EEG symptom of the fit, since it lasted longer than two-thirds of attack duration. Side differences in flattening occurred only in 6.4% of all attacks. The constancy of flattening varied in patients who had several attacks. Only few cases showed consistent flattening. In 50% of attacks with a remembered aura, the flattening occurred before the clinical signs of the fit. Since EEG flattening is explained by an arousal activation of the ascending reticular formation, it is assumed that the epileptic discharge of the psychomotor attack is initiated by activation of the nonspecific ascending reticular and limbic systems. This results in EEG flattening and clinically in an unconsciousness reaction.