Narcolepsy

Narcolepsy is a life-long neurological illness, primarily characterized by sudden uncontrollable sleep attacks and persistent daytime sleepiness. Narcolepsy affects more than 500,000 Americans and symptoms may arise as early as the onset of puberty and continue throughout life.

Recently scientists have identified a genetic marker for this disease confirming that narcolepsy may be hereditary. A child with a parent having narcolepsy has one chance in twenty of being affected. The cause of narcolepsy is unknown. This disorder is characterized by excessive sleepiness that is typically associated with cataplexy, a sudden loss of muscle tone and paralysis of voluntary muscles that is associated with a strong emotion.

It is also characterized by other REM sleep abnormalities such as sleep paralysis (immobility of the body that occurs in the transition from sleep to wakefulness) and hypnagogic hallucinations (pre-sleep dreams).

Symptoms

Symptoms of narcolepsy include:

• Excessive sleepiness or sudden muscle weakness
• Cataplexy
• Sleep paralysis
• Hypnagogic hallucinations
• Automatic behaviors (like driving home and not remembering how you got there)
• Disrupted major sleep episode (disruption of the longest sleep episode that occurs on a daily basis)

Polysomnography shows one or more of the following:

• The onset of sleep is less than 10 minutes
• The onset of REM sleep is less than 20 minutes
• MSLT (multiple sleep latency test) that demonstrates an average sleep onset of less than 5 minutes with more than one REM sleep onset
• HLA typing demonstrates DR2 positivity (blood contains markers for narcolepsy)

How Serious Is This Disorder?

Narcolepsy is not a fatal disorder in itself. Narcolepsy has a great impact on the ability to function. Due to the excessive sleepiness, narcoleptics may fall asleep in very dangerous situations, such as while driving.

There are different levels of severity. Some with this disorder may have mild sleepiness or rare cataplexy (less than once per week). Others may have moderate sleepiness or infrequent cataplexy (less than daily). Yet others may experience severe sleepiness or severe cataplexy (daily). Narcolepsy is usually treated with medication to improve alertness.