[Narcolepsy].

Narcolepsy is a disorder of sleep with uncontrolled sleepiness and cataplexy. Its prevalence in Japanese is estimated to be 0.16-0.59%. The handicap of narcoleptic patients is even larger than that of epileptic patients. The etiology is still unknown, however, a tight association between specific HLA (DR15 and QQ6) or its genotypes (DRB11501, DRB50101, DQB10602, DQA10102) and narcolepsy was recently established. This finding raises the possibility that narcolepsy might be an immunological disorder. At present, any concrete evidence supporting this possibility is lacking. Methylphenidate and pemoline are used for controlling excessive daytime sleepiness. Some tricyclic antidepressant such as clomipramine and imipramine are effective in controlling cataplexy, sleep paralysis and hypnagogic hallucination.