DEAR DR. DONOHUE: My aunt died about 20 years ago. I have been told that the cause of her death was myasthenia gravis. Will you please answer some questions about it? What are the early symptoms? How is it diagnosed? What treatments are available? — E.S.

ANSWER: Myasthenia gravis, despite its unfamiliar name, isn’t a rare condition. Around six people in 100,000 have it. It’s the result of a breakdown in communication between nerves and muscles. A muscle doesn’t move until it gets a nerve signal. The signal comes in the form of a chemical messenger — acetylcholine — released by the nerve. This chemical swims across a small gap between the nerve and muscle, and lands on a muscle receptor, a docking station. Once securely moored on the muscle receptor, acetylcholine causes the muscle to contract. The muscle moves.

In myasthenia, antibodies made by the immune system clog the muscle receptor and prevent acetylcholine from attaching to it. This makes the illness an immune disease, yet another example of the immune system attacking its own body. The salient and early features are muscle weakness and muscle fatigue. Eyelids might droop, or the head might sag because neck muscles are weak. Eye muscles can’t coordinate eye movement, so double vision is often a consequence. Chewing and swallowing food become great hurdles. Repetitive movements quickly tire muscles, and walking can be impossible. Even combing the hair is a challenge.

The Tensilon test was a diagnostic test that provided good evidence of myasthenia. Tensilon, no longer being manufactured, prolongs the action of acetylcholine and improves muscle action immediately upon injection. Detecting myasthenia antibodies in the blood is another diagnostic test. So is electric stimulation of muscles. Mestinon is a popular medicine. It increases the level of acetylcholine. The cortisone drug prednisone can reverse many symptoms. Removal of the thymus gland, a gland in the upper chest, can benefit some myasthenia patients. It’s always removed if it has a tumor, and can be removed in people younger than 55 to stop myasthenia antibody production.

DEAR DR. DONOHUE: My daughter has an acoustic neuroma and is scheduled for surgery. She has gotten minimal information, and I am uncomfortable about this. She is a remarkable teacher and the mother of three. We’d appreciate some insights. — E.K.

ANSWER: An acoustic neuroma is a noncancerous tumor of the hearing nerve. It arises in a cell called the Schwann cell, which provides insulation for the nerve. Its classic sign is progressive, one-sided hearing loss. Neurosurgeons remove the tumor by operating with visualization provided by a microscope. Sometimes radiation is used, and the procedures are called gamma knife or CyberKnife. Your daughter’s doctor will recommend the therapy best suited to her condition. Results usually are gratifying. Have your daughter contact the Acoustic Neuroma Association at 877-200-8211 or on the Internet at www.ANAUSA.org.

DEAR DR. DONOHUE: Regarding the woman who sleeps with her head covered, I’d would like to say that I would sleep that way too, if I could breathe easily. If I wear a cap, my husband makes fun of me, so I don’t. What do you say? — D.B.

ANSWER: So many people wrote about this that I’m going to try it. Go ahead. Wear the cap. It makes you even more attractive than you are.

TO READERS: The fibromyalgia booklet explains this common and misunderstood illness that makes people hurt all over. To obtain a copy, write: Dr. Donohue — No. 305, Box 536475, Orlando, FL 3283-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

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. Readers may also order health newsletters from www.rbmamall.com.