Narcolepsy

A chronic sleep disorder that is characterized by recurrent attacks of drowsiness and sleep. The patient is unable to control these spells of sleep, which may occur in unusual circumstances such as while eating, driving a car or having a conversation, but is easily awakened. Individuals with narcolepsy also experience intrusions of rapid eye movement (REM) sleep into the transition between sleep and wakefulness, sleep paralysis, and/or cataplexy (episodes of sudden, reversible loss of muscle tone that are precipitated by intense emotion); and may also experience intense dream-like imagery just before falling asleep or just after waking.