ABSTRACT
Narcolepsy is a neurological disorder characterized by excessive daytime somnolence (EDS) and symptoms of abnormal rapid eye movement (REM) sleep, namely cataplexy, sleep paralysis, and hypnagogic hallucinations. Sleepiness is a prerequisite for diagnosing narcolepsy in international classifications, although patients occasionally experience isolated cataplexy or other abnormal symptoms of REM sleep before developing daytime sleepiness. Sleep paralysis and hypnagogic hallucinations are frequently associated with narcolepsy, but these symptoms have poor diagnostic predictive value. Since 1983, however, all attempts to demonstrate that human narcolepsy is an autoimmune disease have failed. Although all attempts to date have yielded negative results, it cannot be ruled out that narcolepsy may be an autoimmune disease. It may be that the autoimmune process is difficult to detect because it involves a discrete area of the brain or only produces neuronal degeneration without any overt sign of inflammation.
