Reduction of rapid eye movement sleep by diurnal and nocturnal seizures intemporal lobe epilepsy

Background: Patients with brief, complex partial seizures frequently suffer from tiredness and decreased productivity that continue well beyond the po stictal period. A possible explanation is that seizures, even when occurrin g during the day, disrupt sleep the following night. Objective: To determine the effect of temporal lobe complex partial seizure s on sleep structure and daytime drowsiness. Methods: Patients with temporal lobe epilepsy were admitted for video-elect roencephalography monitoring. All night polysomnography was recorded under the following 3 conditions: seizure free, seizure during the day before the recording, and seizure during the recording. Percentage of time in each sl eep stage, sleep efficiency, and time to first and second rapid eye movemen t (REM) period were compared for seizure vs control conditions. Daytime dro wsiness was also measured, using a modified maintenance of wakefulness test and 2 subjective drowsiness tests. Results: Daytime seizures reduced REM from 18% +/- 1% to 12% +/- 2% (P = .0 03). Night seizures reduced REM from 16% +/- 1% to 6.8% +/- 2% (P<.001). Ni ght seizures also significantly reduced stages 2 and 4 while increasing sta ge 1 sleep. Night seizures, but not day seizures, significantly reduced sle ep efficiency, increased time to first REM period, and increased drowsiness as measured by the maintenance of wakefulness test. Conclusions: Temporal lobe complex partial seizures decrease REM sleep, par ticularly when occurring during sleep but also when occurring on the previo us day. This may, in part, be responsible for the prolonged impairment of f unctioning that some patients report following seizures.