Frequently Asked Questions (FAQs) About Myasthenia Gravis
Whether you are living with myasthenia gravis (MG) or know someone who is, here is a guide to the basics of MG.
What is myasthenia gravis?
Myasthenia gravis is a chronic autoimmune disease. Autoimmune means that the body’s immune system cannot tell the difference between healthy cells and invaders like viruses, fungi, or bacteria.1
Because it cannot tell the difference, the body begins to attack and damage healthy cells. Chronic means that it lasts for a long time or never goes away completely.1
With myasthenia gravis, the body attacks areas where nerves communicate with muscles. This communication is what makes muscles work. Without the ability to communicate properly, the muscles become weak and tire easily.1
What are the different types?
There are 2 main types of MG:2,3
- Ocular – In ocular MG, the muscles that control the eyes and eyelids are weak and become tired with use. This can lead to droopy eyelids and double vision. About 15 percent of all people with MG have the ocular form.
- Generalized – Symptoms often begin in the eye and gradually spread to other muscle groups. When this happens it is called generalized MG. The muscles in the face and arms or legs are the areas most often affected.
Learn more about other subtypes of myasthenia gravis.
What are the symptoms?
The most common symptoms of myasthenia gravis include:1,4,5
- Weakness of the eye muscles that leads to blurred or double vision
- Drooping of 1 or both eyelids
- Changes in facial expressions
- Trouble swallowing or chewing
- Trouble speaking
- Weakness in the arms, hands, fingers, or legs
- Shortness of breath
How is it diagnosed?
Myasthenia gravis is diagnosed using a combination of health history, physical exam, and a variety of tests. If your doctor suspects you have MG, the most common tests used to confirm this include:2,6-8
- Pre-testing (also called bedside testing)
- Blood tests
- Nerve conduction studies and electromyography
What are the MG antibodies?
In MG, the body creates chemicals called antibodies. These chemicals attack healthy parts of the muscle that communicate with nerves. This keeps the muscles from working correctly and leads to weakness. Doctors have found that people with MG create antibodies including:9
- Acetylcholine receptor (AChR)
- Muscle-specific kinase (MUSK)
- Lipoprotein-related protein 4 (LRP4)
Roughly 6 out of every 100 people with MG will have seronegative myasthenia gravis, meaning they have none of the common antibodies. People with ocular MG are more likely to have seronegative MG.6
How is it treated?
The goal of treating MG is to reduce or improve muscle weakness without the treatment causing side effects. Some people’s symptoms can improve to the point that they may only feel weakness on occasion. But some people struggle to find a treatment that works for them. Some people even go into remission, which means they have no signs or symptoms of MG.
There are several ways to treat MG. These treatments help control muscle weakness and calm the immune system. These treatments include:10
- Acetylcholinesterase inhibitors
- Steroids and other immunosuppressants
- Intravenous immunoglobulin (IVIG)
- Lifestyle and alternative treatments
What is the life expectancy?
There is no cure for MG, but most people with the condition have a normal lifespan. Only 3 to 4 out of every 100 people with MG die because of MG. Years ago, early death occurred in over a third of people with MG. Today, if someone dies of MG, death is usually due to a myasthenic crisis or a thymoma.2
Up to 4 out of 10 people with MG go into remission, which means their muscle weakness disappears completely. Remission is usually temporary and may come with occasional flares, but it is permanent in some people. During remission, some people can stop taking all of their MG drugs.11
Between 4 and 6 out of 10 people who have a thymectomy achieve remission. Thymectomy is a surgery to remove the thymus gland. The chances of remission increase for 7 to 10 years after the surgery.2
Am I a candidate for thymectomy?
Surgery to remove the thymus, or thymectomy, is not right for everyone. A small international study looked at 126 people with MG and found thymectomy was most likely to improve symptoms for people:12-15
- With generalized MG
- Who had had symptoms for less than 3 to 5 years (called early thymectomy)
- Younger than ages 60 to 65
- For whom anticholinesterase drugs do not work
Thymectomy generally is not recommended for people with:13,15
- Ocular MG
- MuSK or LRP4 antibodies
- Seronegative MG
- Late-onset MG if they are older than 65
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