Narcolepsy
What is narcolepsy?
Narcolepsy is a chronic neurological disorder caused by the brain’s inability to regulate sleep-wake cycles normally. At various times throughout the day, people with narcolepsy experience irresistible bouts of sleep. If the urge becomes overwhelming, individuals will fall asleep for periods lasting from a few seconds to several minutes. In rare cases, some people may remain asleep for an hour or longer. In addition to excessive daytime sleepiness (EDS), three other major symptoms frequently characterize narcolepsy: cataplexy, or the sudden loss of voluntary muscle tone; vivid hallucinations during sleep onset or upon awakening; and brief episodes of total paralysis at the beginning or end of sleep. Narcolepsy often is not definitively diagnosed until 10 to 15 years after the first symptoms appear. In many cases, the cause of narcolepsy remains unknown. It is likely that narcolepsy involves multiple factors interacting to cause neurological dysfunction and sleep disturbances.
Is there any treatment?
There is no cure for narcolepsy. In 1999, after successful clinical trial results, the U.S. Food and Drug Administration (FDA) approved a drug called modafinil for the treatment of EDS. Drug therapy should be supplemented by behavioral strategies. For example, many people with narcolepsy take short, regularly scheduled naps at times when they tend to feel sleepiest. Improving the quality of nighttime sleep can combat EDS and help relieve persistent feelings of fatigue. Among the most important common-sense measures people with narcolepsy can take to enhance sleep quality are actions such as maintaining a regular sleep schedule, and avoiding alcohol and caffeine-containing beverages before bedtime.
The drug Xyrem (sodium oxybate or gamma hydroxybutyrate, also known as GHB) was approved in July 2002 for treating cataplexy and in November 2005 for EDS in people who have narcolepsy. Due to safety concerns associated with the use of this drug, the distribution of Xyrem is tightly restricted. Xywav, a lower sodium formulation of oxybate, was FDA-approved for narcolepsy in July 2020.
Wakix (pitolisant) is an unscheduled medication which increases wakefulness in narcolepsy patients by modifying the histamine system. It was FDA-approved for the treatment of excessive daytime sleepiness in August 2019 and for cataplexy in October 2020.
What is the prognosis?
Excessive daytime sleepiness and cataplexy, the most disabling symptoms of narcolepsy, can be controlled in most patients with drug treatment. Oftentimes, multiple medications are used to treat the symptoms, and the treatment regimen is modified as symptoms change. Whatever the age of onset, patients find that the symptoms tend to get worse over the two to three decades after the first symptoms appear. Many older patients find that some daytime symptoms decrease in severity after age 60.