People diagnosed with NPC may experience a variety of neurologic symptoms, including cognitive impairment, dementia, and cataplexy. Niemann-Pick type C Disease (NPC): NPC is a rare genetic disorder characterized by the body’s inability to transport lipids such as cholesterol within cells, leading to accumulations of fatty substances in body tissues. Around 30% of cataplexy episodes are related to other disorders, including: There is increasing evidence that type 1 narcolepsy may be caused by the immune system attacking cells that produce orexin.įamily history: While potential genetic links aren’t fully understood, around 10% of people with type 1 narcolepsy have a close relative with similar symptoms.īrain injury: Some people with type 1 narcolepsy lose orexin-containing brain cells due to brain injuries, tumors, and other acquired diseases.Ĭataplexy isn’t always linked to narcolepsy.

In autoimmune disorders, the body attacks its own healthy tissue by mistake. This research suggests that several factors may contribute to a loss of orexin in people with type 1 narcolepsy.Īutoimmune disorders: A loss of cells that produce orexin may be related to dysfunction in the immune system. Much of what we know about the relationship between orexin (hypocretin) and cataplexy comes from type 1 narcolepsy research. Orexin plays an important role in the sleep-wake cycle. While the cause of cataplexy is still being investigated, most people with cataplexy show a loss of certain brain cells that produce the hormone orexin (also called hypocretin). While type 1 and type 2 narcolepsy both have the name “narcolepsy” in it, the cause for type 1 narcolepsy is well understood (loss of a neurotransmitter, orexin), whereas the cause for type 2 narcolepsy is not well understood. For people with type 1 narcolepsy, episodes of cataplexy typically begin after the onset of excessive sleepiness. People diagnosed with type 1 narcolepsy experience episodes of cataplexy, while people with type 2 narcolepsy do not. There are two major types of narcolepsy: type 1 and type 2, differentiated by whether or not a person experiences cataplexy. Narcolepsy is a sleep disorder characterized by excessive daytime sleepiness, sleep paralysis, hallucinations, and, in some cases, cataplexy. Episodes typically last a couple of minutes and resolve on their own. Unlike other conditions that cause a loss of muscle control, like fainting or seizures, people experiencing cataplexy remain conscious and aware. During more severe episodes, a person collapses and cannot move or speak. Less severe episodes involve momentary sensations of weakness in a few muscles, while more severe episodes involve a total loss of voluntary muscle control. Episodes may also be triggered by anger, but rarely by stress, fear, or physical exertion.Įpisodes of cataplexy can vary in severity. The triggering experiences are usually positive, like laughter, witty conversations, and pleasant surprise. We will continue to monitor and revise this article as new literature is published on cataplexy.Ĭataplexy is a sudden muscle weakness that occurs while a person is awake. Our medical review team has recently evaluated this page to ensure accuracy.

Examples of cataplexy