My 29-year-old daughter has had Narcolepsy for 10 years. Is there anything new about this condition?

Yes. Narcolepsy is a condition that causes severe sleepiness and may also be accompanied by sudden episodes of weakness lasting a few minutes, often during periods of emotion such as surprise or laughter. There are two new developments in understanding narcolepsy. The first is the recent finding that genetic abnormalities in some animals can produce a condition that greatly resembles human narcolepsy. A gene called the Orexin-hypocretin gene can be experimentally deleted from the DNA of a mouse; this results in the mouse having episodes of loss of muscle activity and sleep attacks that mimic the cataplexy and sleep attacks experienced by a person with narcolepsy. This animal condition has been called the "Orexin-hypocretin knock-out" mouse, because the gene is knocked out or deleted. Whether human narcoleptics actually have the specific defect of the Orexin-hypocretin knockout mouse is being studied at several research centers. Such studies may lead to a better understanding of why and how humans develop narcolepsy.

The second development is the 1999 approval by the U.S. Food and Drug Administration (FDA) of a new medication, Modafinil, specifically for the treatment of patients with narcolepsy. Modafinil is the first new medication for this condition in over 50 years. Modafinil has the advantage over the older amphetamine-type stimulants of not being habit-forming or addictive, not causing the feeling of "speeding" and not producing high blood pressure or sweating. Almost all my patients with narcolepsy who have switched from amphetamine and Ritalin to Modafinil prefer it to the older medications.

Recently the FDA approved Xyrem (gamma-hydroxy butyrate or GHB) for the treatment of narcolepsy. This is taken at bedtime and after four hours of sleep in order to counter act the fragmented sleep that narcoleptics often experience.

Lawrence W. Kneisley, M.D.
Diplomate, American Board of Sleep Medicine
Member, South Bay Independent Physicians Medical Group, Inc.