Myasthenia gravis causes skeletal muscles to weaken


Dear Doctors: Can you please talk about myasthenia gravis? Our oldest daughter has been diagnosed with it. She’s 33 and lives with her family in another state, but we want to understand what she’s dealing with. I just read about Chinese herbs that can be helpful. Do you know if that’s true?

Dear Reader: Myasthenia gravis is a long-term disease that adversely affects the skeletal muscles. These are the muscles that, with the help of tendons and ligaments, make it possible for the body to move and perform a wide range of functions.

Skeletal muscles are known as voluntary muscles, which means they are under a person’s direct control. Myasthenia gravis does not affect the involuntary muscles, such as the heart, or those that line the blood vessels, organs, stomach and intestines. When someone has myasthenia gravis, their skeletal muscles become weak and quickly grow fatigued when in use.

The name of the disease is drawn from Greek and Latin and means grave or serious muscle weakness. The condition is caused by a glitch in the immune system that mistakenly blocks the pathways of communication between the muscles and the nerves that animate them. Taken together, and in more scientific terms, myasthenia gravis is a chronic neuromuscular autoimmune disease.

Symptoms include drooping eyelids, weakness in the eye muscles, difficulty swallowing, impaired speech, difficulty breathing, and weakness in the neck, arms, hands, fingers or legs. Since each case is different, symptoms vary in type and intensity. Some individuals have mild disease in which treatment isn’t necessary. In severe cases, weakness in the muscles of the chest and diaphragm impairs the ability to breathe effectively. This is known as myasthenic crisis, and it is a medical emergency.

The disease can occur at any age, but it is more frequently seen in young women in their 20s and 30s and men aged 50 and older. There is no cure for myasthenia gravis at this time. Treatment focuses on improving muscle function and preventing problems with swallowing and breathing. This can include the use of steroids, immunoglobulin or monoclonal antibodies, each of which modulate immune response. The thymus, a small gland located in the upper part of the chest between the lungs, appears to play a role in the disease. Surgical removal of the thymus can sometimes lessen the need for medication and prevent more severe symptoms.

Elizabeth Ko, MD and Eve Glazier, MD

As to your question about Chinese herbs, we think you are referring to a small study that was recently reported in the news. The results, published in the medical journal Frontiers in Neurology, found that a blend of herbs used in traditional Chinese medicine, known as Fufang Huangqi Decoction, can have a beneficial effect on certain imbalances common to the gut microbiomes of people with myasthenia gravis. This echoes the findings of previous studies.

While this research suggests the potential benefits of new treatment pathways, it’s important to note the studies only looked at the effects of the herbs on the gut microbes of people living with myasthenia gravis. They did not explore their effect, good or ill, on the patients themselves and made no recommendations regarding their use.

(Send your questions to [email protected], or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)