Myasthenia gravis is an autoimmune disorder. It causes severe muscle weakness. Usually, the weakness occurs in the eyes and face, but it can happen in the neck, fingers, arms, legs, chest and elsewhere. The weakness gets worse after activity and better after rest. Although it can be serious, most people with myasthenia gravis have a good quality of life, respond well to treatments and have a normal life expectancy.
What Is Myasthenia Gravis?
Myasthenia gravis, sometimes just referred to as MG, is an autoimmune neuromuscular disorder. The body’s immune system blocks the signals sent from the brain to the muscles, and then the muscles can’t respond correctly. (1) It is a rare, long-term (chronic) condition that affects at least 20 in every 100,000 people worldwide. It peaks in women in their 20s and 30s and in men when they reach their 50s and 60s, and women are more likely to be diagnosed than men.
Myasthenia gravis results in weakness of skeletal muscles — the muscles the body uses to move. It typically gets better after rest and worse after activity. Although it most often affects the eyes (called ocular myasthenia when it doesn’t affect other muscles as well), it can affect the face, neck, speech, throat, arms and legs. In about 10 percent of people with myasthenia gravis, the condition affects the muscles that help them breathe, forcing them to use a ventilator for help breathing. (2) When this happens, it is called a myasthenic crisis.
What is the prognosis for people with myasthenia gravis?
There is no known cure for myasthenia gravis, but there are many treatments that help most people with the disorder manage symptoms fairly well. In general, symptoms get worse, particularly for the first three years after diagnosis. However, most people have an improvement in symptoms with treatment.