Narcolepsy.

Focuses on narcolepsy, a neurological disorder marked by daytime drowsiness that causes people to fall asleep at dangerous or inappropriate times. Role of cataplexy, the loss of skeletal muscle tone without loss of consciousness, as a defining symptom of narcolepsy; Sleep paralysis and hypnagogic hallucinations; The absence of a non-REM sleep stage in narcoleptic sleep patterns; Studies based on the frequency of narcolepsy in dogs.