Myasthenia gravis is a disorder that involves weakness in the skeletal muscles of the body. It stems from a communication problem between the body’s nerves and the muscles that they send impulses to. In Latin, the term literally means “grave muscle weakness.”
The disorder most commonly develops in adult women younger than 40 and adult men older than 60. However, it can affect people of all ages. The symptoms vary in severity from mild impairment of the facial muscles to difficulty breathing or moving the neck or limbs.
Causes of Myasthenia Gravis
Myasthenia gravis is an autoimmune disorder. This means that the immune system attacks parts of the body and causes the symptoms of the disease. In the case of myasthenia gravis, the immune system attacks the neuromuscular junction, which is the area where the nerves meet the muscles and tell them how to respond. This disrupts the communication between the nerves and muscles.
Often, the first symptoms of myasthenia gravis to appear are droopy eyes, difficulty swallowing or problems with facial muscles. Vision problems may also occur. As symptoms worsen, they may include problems with walking, impaired speech, breathing problems or trouble moving the limbs or neck. Symptoms can vary widely from person to person, but in general, people with myasthenia gravis will see their symptoms worsen during activity and improve after a period of rest.
Myasthenia gravis can often be managed with modern medical treatments. Several medications can help. For instance, drugs called anticholinesterase agents can improve communication between the nerves and muscles, and immunosuppressive drugs can help reduce the body’s autoimmune response. The thymus gland is also sometimes involved in the disease, so surgical removal of the gland (a thymectomy) can be helpful for some. A procedure called plasmapheresis is also sometimes used. It involves removing blood that contains abnormal antibodies from the body and replacing it with blood with healthy antibodies.
SOURCES: U.S. National Institute of Neurological Disorders and Stroke