What is Narcolepsy?

Narcolepsy is a chronic neurological disorder characterized by the brain’s impaired ability to regulate a normal sleep-wake cycle. Narcolepsy affects roughly 40-50 people per 100,000 worldwide, but these numbers are estimated to be underinflated due to the difficulty of properly diagnosing this disorder. With the average time between symptom onset and diagnosis being seven years, estimates place up to 60% of patients being initially misdiagnosed with conditions such as depression, insomnia, or obstructive sleep apnea (“Narcolepsy Fast Facts”, 2015). Narcolepsy is not only characterized by excessive daytime sleepiness (EDS); associated symptoms include sudden loss of muscle tone and cataplexy (weakness), sleep paralysis, hallucinations, fragmented sleep, and insomnia. Narcolepsy is further classified into Type 1–narcolepsy with cataplexy–or Type 2–narcolepsy without cataplexy–as well as secondary narcolepsy, which is caused by damage to the brain’s hypothalamus, responsible for regulating sleep. Narcolepsy is known to add significant difficulties to ordinary daily-life functioning, with affected patients falling asleep unexpectedly and often in the middle of tasks like driving, eating, or engaging in conversation (Fletcher, 2023).

The causes of narcolepsy are not completely understood and ongoing research in the field is focused on uncovering the underlying genetic, autoimmune, and neurobiological factors that contribute to the development of this complex sleep disorder. It has been noted that nearly all patients with Type 1 narcolepsy (with cataplexy) display abnormally low levels of hypocretin or orexin, neuropeptide hormones produced in the hypothalamus that promote wakefulness and regulate the sleep cycle. The causes for this hypocretin deficiency remain a topic of intense research but are likely the result of a myriad of factors, including autoimmune disorders, family history, and past brain injury. Researchers have also identified human leukocyte antigen (HLA) gene markers to be present in most patients with narcolepsy; however, these variants are common in the general population, and only a small number of people within this subpopulation will develop narcolepsy (“Narcolepsy,” n.d.).

Since there is currently no cure for narcolepsy, treatments center on managing symptoms through lifestyle changes and medication. Lifestyle interventions include sticking to a strict sleep schedule, taking short naps, avoiding nicotine and alcohol, and regular exercise. Drug therapies fall into several classifications, including stimulants, antidepressants, central nervous system depressants, and histamine H3 receptor (H3R) antagonists (Mayo Clinic, 2023).

References

• “Narcolepsy Fast Facts.” NarcolepsyNetwork, June 2015, https://narcolepsynetwork.org/about-narcolepsy/narcolepsy-fast-facts/.

• Fletcher, Jenna. “What Is the Prevalence of Narcolepsy?” MedicalNewsToday, 31 Jan. 2023,https://www.medicalnewstoday.com/articles/how-common-is-narcolepsy#prevalence. Accessed 29 Aug. 2023

• “Narcolepsy.” National Institute of Neurological Disorders and Stroke, https://www.ninds.nih.gov/health-information/disorders/narcolepsy. Accessed 29 Aug. 2023.

• Mayo Clinic. “Narcolepsy.” Mayo Clinic, 14 Jan. 2023, https://www.mayoclinic.org/diseases-conditions/narcolepsy/symptoms-causes/syc-20375497.