Abstract

Hypnagogic and hypnopompic hallucinations are visual, tactile, auditory or other sensory events, usually brief but sometimes prolonged, that occur at the transition from wakefulness to sleep (hypnagogic) or from sleep to wakefulness (hypnopompic). Hypnagogic and hypnopompic hallucinations are often associated with sleep paralysis. Sleep paralysis occurs immediately prior to falling asleep (hypnagogic paralysis) or upon waking (hypnopompic paralysis). In 1664, the Dutch physician Isbrand Van Diemerbroeck (1609-1674) published a collection of case histories. One history with the title 'Of the Night-Mare' describes the nightly experiences of the 50-year-old woman. This case report is subject of this article. The experiences in this case could without doubt be diagnosed as sleep paralysis accompanied by hypnagogic hallucinations. This case from 1664 should be cited as the earliest detailed account of sleep paralysis associated with hypnagogic illusions and as the first observation that sleep paralysis and hypnagogic experiences occur more often in supine position of the body.