Tammy Cairo, age 15, of Columbus, Ohio, for her question:

WHAT IS NARCOLEPSY?

Narcolepey is a disorder in which the person may suddenly drop off to sleep without warning and at inappropriate moments, such as while talking with another person or even while driving a car.

In some cases, narcolepsy stems from an abnormality in the reticular activating system, the brain's so called "sleep center." In other cases it is suspected that the difficulty is emotional. For some persons, doctors provide brain stimulation through amphetamines to prevent sudden dropping off to sleep.

Occasionally, narcoleptic attacks are accompanied by feelings of body paralysis, weakness, or collapse while angry or laughing. The person may drop helplessly to the ground on such occasions. There also may be a compulsion to eat enormous quantities of food, a condition called Klein Levine syndrome.

The condition in which a person loses muscular power and control without loss of consciousness is called cataplexy. It often occurs in persons who have attacks of narcolepsy. Cataplectic attacks usually last only a few seconds and in most cases are caused by a sudden emotional disturbance.