the naturally occurring chemical hypocretin, which promotes wakefulness and regulates REM sleep. Hypocretin levels are usually normal in people who have narcolepsy without cataplexy.
Although the cause of narcolepsy is not completely understood, current research suggests that narcolepsy may be the result of a combination of factors working together to cause a lack of hypocretin. These factors include:
Autoimmune disorders. When cataplexy is present, the cause is most often the loss of brain cells that produce hypocretin. Although the reason for this cell loss is unknown, it appears to be linked to abnormalities in the immune system.
Autoimmune disorders occur when the body’s immune system turns against itself and mistakenly attacks healthy cells or tissue. Researchers believe that in individuals with narcolepsy, the body’s immune system selectively attacks the hypocretin-containing brain cells because of a combination of genetic and environmental factors.
A number of factors may increase a person’s risk of narcolepsy or