DEAR DR. DONOHUE: I have had myasthenia gravis for the past two years. I understand there is no cure. It is somewhat rare and gets very little attention from doctors and the press. Half a year ago Barbara Bush was on television and mentioned she had myasthenia and was cured of it. Is this possible? Could you tell me how to contact her for information? – R.D.

ANSWER: Myasthenia gravis affects about one person in every 7,500, not making it common but not making it a rarity, either.

The glitch in myasthenia has to do with the transmission of nerve signals to muscles. Nerves release a chemical messenger called acetylcholine. The acetylcholine has to swim a small gap between nerve and muscle and land at a muscle receptor, a docking station. When it arrives there, the muscle contracts.

In myasthenia, the receptor docking stations are blocked with antibodies. Acetylcholine cannot activate the muscle properly. The result is a feeble muscle contraction.

As a result, eyelids can droop. Eye muscles can no longer coordinate right- and left-eye synchronous movement, so double vision often occurs. Chewing and swallowing become difficult. Arms and legs can be affected.

Myasthenia symptoms often come and go. Medicines can usually tide patients over the times when symptoms are at their height. Some of those medicines stop the breakdown of acetylcholine, and that increases the strength of muscle contraction. Often, removal of the thymus gland, located in the upper chest, can bring relief of symptoms. Cure is not commonly spoken of, but there can be long periods when the illness goes into remission.

I don’t know if Barbara Bush had myasthenia, and I don’t know how to contact her, but I can do you one better. Call the Myasthenia Gravis Foundation at 1-800-541-5454, or go to its Web site at www.myasthenia.org. The foundation can supply you with information and make you realize you are not the rarity you believe.

DEAR DR. DONOHUE: My wife just had a bypass of her abdominal arteries. In the weeks prior to her operation, she was unable to eat or drink anything. It took a great deal of time to get the problem diagnosed. The doctor tried angioplasty but was unable to unblock the artery, so he did a bypass. My wife is expected to make a full recovery. What is the problem called? – M.H.

ANSWER: Abdominal arteries, just like heart arteries, can become clogged with cholesterol and fatty buildup. The problem is called mesenteric vascular insufficiency. The mesenteric artery supplies most of the intestines with blood.

If the blockage is complete and sudden, the situation is an emergency that requires immediate surgery, or the intestines will become gangrenous.

If the blockage is partial, then the situation is less urgent but still serious. Symptoms are abdominal pain and cramping following a meal, with weight loss and diarrhea also being common.

Sometimes a blocked mesenteric artery, just like a heart artery, can be opened with a balloon-tipped catheter – angioplasty. At other times, just as with heart arteries, the blocked section of artery has to be bypassed with a graft.

DEAR DR. DONOHUE: You answered a recent letter about metabolic syndrome. The answer sounded very much like one in an earlier column on syndrome X. Are these two syndromes the same? – W.P.

ANSWER: Metabolic syndrome and syndrome X are the same. The “syndrome X” name is used less frequently because it also refers to a different condition, one where a person has angina (chest pain) with normal heart arteries.

Some of the criteria for metabolic syndrome are: insulin resistance, manifested in abnormal blood sugar; blood pressure greater than 130/85; being overweight with a waist of 35 or more inches (89 cm) for women and 40 (102) for men; low HDL cholesterol (good cholesterol); and high triglycerides (blood fats). About 20 percent of the adult population has it, and it is a fast track to heart attacks and strokes.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475.