[Differentiation of 2 paroxysmal reaction types in the EEG after sleep deprivation]

In the EEG after sleep deprivation paroxysms with spikes and spike wave-complexes as well as paroxysms with slow waves can be seen. The paroxysms occur either spontaneously (it means at any time during the record) or at moments of shifting vigilance. These moments are characterized by sudden changes of the EEG frequency for instance by transition from one sleep stage to another. Paroxysms with spikes or spike wave-complexes occur mainly at the transition from lower to higher levels of vigilance and are accompanied by abnormal K-complexes and abnormal photosensibility. Paroxysms of slow waves occur mainly at the transition from higher to lower levels of vigilance, abnormal K-complexes and abnormal photosensitivity are lacking but in some cases the before diffuse abnormal EEG is improved after sleep deprivation. It assumed that we are dealing with two different types of reaction.