DEAR DR. DONOHUE - Is cerebral palsy related to some birth injury? - W.W.

ANSWER - Cerebral palsy is really a group of disorders affecting the brain's control of muscles. I can state that it is not related to any injury occurring during delivery.In general, the symptoms of cerebral palsy are stiff, jerky, uncoordinated movements. This can involve the muscles of speech, so that talking becomes difficult. However, CP appears in all degrees of seriousness, from the barely recognizable to the very pronounced, disabling forms. Many people with CP lead very active lives. I know physicians who have it.

Early detection is important so that physical therapy can begin promptly. In most instances, CP progresses to about age 5, when it reaches a plateau.

DEAR DR. DONOHUE - Would like your opinion of narcolepsy, excessive daytime sleepiness. I have it. Every day, I feel like someone who has gone without sleep for 48 hours. But my medicine helps me. I've had it for years, but I understood my problem was low thyroid. It wasn't diagnosed until I was 50. I am secretary of a support group. We go to different places and show a film we obtained from the American Narcolepsy Association in California. I guess you know the group. I sure wish there was a cure, but no hope yet. - H.A.R.

ANSWER - Narcolepsy is one of those conditions that was once thought to be rare. But now we know it isn't so rare at all. Somewhere between 100,000 and 250,000 Americans have it.

It's the occurrence of daytime sleep in episodes lasting from seconds to as long as half an hour. The danger times to watch for are those when you are engaged in activities done almost automatically, such as driving a car. More men than women have it.

In narcolepsy, sleep attacks are coupled with one or another of several symptoms, which include sudden weakness (sometimes to the point of collapse), brief paralysis, or hypnagogic hallucination, i.e., hearing of words or sounds not there.

It is nice to know what's wrong. In narcolepsy that leads to helpful control with drugs. Methylphenidate, pemoline and amphetamines all are used with good effect. Yes, I know of the American Narcolepsy Association, whose address is Box 1187, San Carlos, CA 94070.

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