Narcolepsy is a chronic disease of the central nervous system. Excessive daytime sleepiness (EDS) is the main symptom and is present in 100% of patients with narcolepsy. Other primary symptoms of narcolepsy include: loss of muscle tone (cataplexy), istorted perceptions (hypnagogic hallucinations), and inability to move or talk (sleep paralysis).
Narcoleptics with long sleep time had a similar disease course and similar frequencies of cataplexy, sleep paralysis, hallucinations, multiple sleep onset in REM periods, short mean sleep latencies, and HLA DQB1*0602 positivity as narcoleptics with normal sleep time did. However, they had longer sleep time during 24 h, and higher sleep efficiency, lower Epworth Sleepiness Scale scores, and reported their naps were more often unrefreshing.