Sleep and EEG interictal epileptiform abnormalities in partial epilepsy

The relationship between sleep and EEG interictal epileptiform abnormalitie s (IEA) has been studied from different perspectives. One of the most follo wed orientations regards the investigation of the effects of IEA on sleep o rganization, while another approach considers the modulation of IEA caused by sleep. Only the latter approach, for its practical diagnostic implicatio ns, is covered by the present review. In particular, on the basis of the li terature and of personal studies, we review some relevant aspects of the re lationship between the different stages of the sleep and the EEG epileptic abnormalities in partial epilepsy. Tn addition, the modulation of IEA by fl uctuations of the level of arousal and by sleep microstructure is reviewed. Finally, the information obtained on localization of epileptic foci From r ecordings during wakefulness and different sleep stages is discussed. (C) 2 000 Elsevier Science Ireland Ltd. All rights reserved.