Myasthenia gravis is a disease that causes muscle weakness throughout the body. The muscles affected are the ones we can control (voluntary muscles). An example of a voluntary muscle is your hand muscles. You can control the muscles to make the hand pick something up. An example of an involuntary muscle is the heart. The heart beats without any direction from you.
Myasthenia Gravis is thought to be an autoimmune disease. That means that normal defenses of the body begin to attack the body. In this case, the immune system begins to attack cells located at the junctions of the muscles and the nerves. Women are affected more often. Women are affected at a younger age than men. Babies born to affected women frequently develop symptoms at an early age.
Initially in the disease, the facial muscles are affected first. After this, a person may develop droopy eyelids. They may have difficulty controlling facial muscles. They may have problems chewing. Swallowing and speaking may become impaired. The weakness gradually spreads to the arms and legs. It begins to affect breathing. Sometimes, the symptoms lessen or go away without any apparent cause.
Diagnosis can be made with blood tests. Tests such as electromyography may be done to examine the electrical activity in the muscle. An improvement in symptoms after having an anti-cholinesterase drug helps confirm the diagnosis.
Medicines are usually prescribed as the first treatment. These medicines help, but they do not cure the disease. A plasma cleansing procedure (plasmapheresis) can be used to treat a crisis. It can also be used to prepare a person for surgery. This procedure produces short-term improvement. Some cases are helped by removing the thymus gland. Steroids are used for short-term benefits.