Narcolepsy

Narcolepsy is a long term neurological problem caused when the brain has trouble regulating sleep and wake cycles properly. 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 is not usually diagnosed in most patients until 10 to 15 years after the first symptoms appear. The cause of narcolepsy remains unknown.  It is likely that narcolepsy involves multiple factors interacting to cause neurological dysfunction and sleep disturbances.

Management

There is no cure for narcolepsy unfortunately. A drug known as ‘modafinil’ was approved over a decade ago to help with the symptom of excessive daytime sleepiness, but it doesn’t address the entire problem.

Two other drugs (both being antidepressants) have proved useful in controlling cataplexy in many patients: Tricyclics (including imipramine, desipramine, clomipramine, and protriptyline) and selective serotonin reuptake inhibitors (including fluoxetine and sertraline).

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 night time 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.

What’s next?

None of the currently available medications enables people with narcolepsy to consistently maintain a fully normal state of alertness. But EDS and cataplexy, the worst of the symptoms, can be helped in most patients by drug treatment. Often the treatment regimen is modified as symptoms change.