[Effect of different stages of physiological nocturnal sleep on interseizure discharges in patients with various forms of epilepsy].

All-night EEG records were obtained in 100 patients aged 14-48 years staying at a neurosurgical centre for various forms of focal epilepsy. In 84 cases discharges were observed during the nocturnal investigation. The morphology of the discharges depended on the phase of sleep during which they appeared. Discharges occurring in phases of light sleep had greater activity and more focal character in relation to the remaining NREM phases. On the other hand, discharges in deep sleep phases had a greater tendency for generalization. In half the cases focal discharges disappeared in the REM sleep phase. Intraseizure changes depended on the phase of sleep, focal or generalized character, and localization of pathological focus. Seiture activity during sleep was never observed in the REM phase of sleep.