hypnogogic seizure http://www.case.edu/EpSO.owl#HypnogogicSeizure http://www.columbianeurology.org/sites/default/files/nocturnal_seizures_SemNeurol_2004.pdf Seizures due to Hypnogogic hallucination. Hypnogogic (or hypnopompic) hallucinations also occur while falling asleep (or waking up). Cataplexy, hypnagogic hallucinations, and sleep paralysis can occur in the absence of narcolepsy, and in these cases are more likely to be mistaken for epilepsy. Modified definition special seizure