Sleep and epilepsy

The differential diagnosis of ''things that go bump in the night'' includes parasomnias, sleep-related movement disorders, psychiatric conditions, and epilepsy. This article focuses on the interactions between sleep, epilepsy, and the effects of antiepileptic medication, with an emphasis on avoiding misinterpretation of primary sleep disorders and epilepsies presenting during sleep. There are important effects of sleep state on seizure activity, and there are equally important effects of epilepsy on sleep maintenance with implications on daytime alertness. Pointers to elicit appropriate history and examination are described; appropriate investigations including polysomnography and different electroencephalographic techniques can clarify difficult clinical dilemmas.