[Interaction of epileptic seizures and biological rhythms]

Circadian modulation of seizure threshold is subjected to a multitude of periodical, aperiodical and stochastical influences. Epilepsies on the other hand influence the biological rhythms themselves. Epileptic seizures are activated during transient sleep stages. Nocturnal seizures lead to severe sleep disorders and therefore to hypersomnia. Partial and generalized epilepsies have a different sleep profil even without seizure manifestation. Finally antiepileptic drugs may interfere with circadian rhythms. Knowing the chronobiological context a differentiation of epileptic seizures from nonepileptic parasomnias may succeed more easily. To ensure the appropriate diagnostical proceeding multichannel EEG should be used in every polysomnography with neurological topics.