Epileptic activity during sleep and wakefulness.

In 23 untreated patients the temporal distribution of generalized spike-wave activity was investigated by means of mobile long-term EEG recordings. Distribution classes (S, A, W) were defined if the relative amount of epileptic activity within the phases sleep, awakening and waking exceeded a threshold, otherwise a diffuse distribution (D) was scored. A, S and D distributions were found approximately with the same frequency. In no patient was the middle part of the night most prominent. In one patient, it was shown by micro-hypnograms that 'micro-arousals' are closely related to spike-wave activity.