Nocturnal seizures are one of the subtypes of epilepsy seizures. Since they occur only when sleeping they are not detected as often as daytime seizures. Therefore the diagnosis and characterization are more difficult. They might be mixed with similar conditions that occur at night and affect the sleeping. They might occur just after a person has fallen asleep, just before waking, during daytime sleep, or while in a state of drowsiness. People who experience nocturnal seizures may find it difficult to wake up or to stay awake.
The majority of people with nocturnal seizures have idiopathic epilepsy and there is evidence that sleep enhances epileptic discharges in the EEG.