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.