[Functional relation between petit mal epilepsy and sleep].

In 24 patients with petit mal-epilepsy 54 all-night polygraphic recordings were registered. In petit mal-epilepsy the epileptic clinical manifestations as well as the electrographic discharges appear with maximal intensity in sleep stage 2. However, these electrical and clinical phenomena are not characteristic of petit mal. Therefore one may surmise that the facilitation of epileptiform phenomena in sleep stage 2 is generally applicable, and does not represent a particular characteristic of petit mal. In sleep stages 1 and REM as well as in the transitional stages well organized characteristic spike-and-wave discharges occur which are identical to those appearing during wakefulness. Sleep stages 1 and the transitional stages are functionally unstable states when bioelectrical discharges as well as clinical absences are activated. In stage REM the spike-and-wave discharges either disappear or persist, however, in comparison to the frequency of discharges during NREM-sleep they are likely to be activated during REM. This feature seems to be characteristic of petit mal and occurs in every patient in an individually set pattern. The appearance of electrographic epileptiform discharges and clinical absences bears an individual character and accordingly the following variations can be distinguished: - petit mal during wakefulness, - petit mal, when falling asleep, - petit mal in awakenings, - petit mal during transitional states, - the intense activating effect of sleep stage 2 on epileptiform patterns, however this is not characteristic of petit mal only. During NREM-sleep epileptiform discharges are easily activated by acoustic stimuli and correspond to epileptiform phenomena which occur spontaneously during the same stage.(ABSTRACT TRUNCATED AT 250 WORDS)