William C. Dement

Genetically Determined Animal Models of Narcolepsy, A Disorder of REM Sleep

Narcolepsy is a neurological condition that affects 0.02% to 0.09% of Caucasians, North American blacks, and Japanese populations. It is seen in all races, although the percentage of affected subjects has not been investigated in all continents, and it involves both sexes. It was first described in humans by Gelineau (1880). Narcolepsy is a life-long disease that is characterized by abnormal sleep tendencies, including excessive daytime sleepiness, often disturbed nocturnal sleep, and pathological manifestations of rapid eye movement (REM) sleep. The REM sleep abnormalities include sleep-onset REM periods and the dissociated REM sleep inhibitory processes—cataplexy and sleep paralysis (pathological equivalents of REM sleep atonia). Excessive daytime sleepiness, cataplexy (abrupt loss of motor tone induced by emotions) and, less often, sleep paralysis and hypnagogic hallucinations are the major symptoms of the disease. The causes of human narcolepsy are currently unknown but may involve a defect of the specific mechanisms regulating REM sleep and wakefulness.