During the physical exam, your doctor will ask about your medical history and symptoms. A common way to diagnose myasthenia gravis is to test how you respond to certain medicines.
Muscle weakness often dramatically improves for a brief time when you are given an anticholinesterase medicine. If you respond to the medicine, it confirms myasthenia gravis. Blood tests. These tests look for antibodies that may be present in people with myasthenia gravis. Genetic tests. These tests are done to check for conditions that run in families. Nerve conduction studies.
A test called repetitive nerve stimulation is used to diagnose myasthenia gravis. Electromyogram EMG. A test that measures the electrical activity of a muscle. An EMG can detect abnormal electrical muscle activity due to diseases and neuromuscular conditions. Specific treatment for myasthenia gravis will be determined by your healthcare provider based on:.
There is no cure for myasthenia gravis, but the symptoms can often be controlled. Myasthenia gravis is a lifelong medical condition. Early detection is the key to managing the condition. Although myasthenia gravis is rarely seen in infants, the fetus may acquire antibodies from a mother affected with myasthenia gravis—a condition called neonatal myasthenia. Rarely, children of a healthy mother may develop congenital myasthenia. This is not an autoimmune disorder but is caused by defective genes that produce abnormal proteins in the neuromuscular junction and can cause similar symptoms to myasthenia gravis.
Because weakness is a common symptom of many other disorders, the diagnosis of myasthenia gravis is often missed or delayed sometimes up to two years in people who experience mild weakness or in those individuals whose weakness is restricted to only a few muscles.
Today, myasthenia gravis can generally be controlled. There are several therapies available to help reduce and improve muscle weakness. With treatment, most individuals with myasthenia can significantly improve their muscle weakness and lead normal or nearly normal lives. Some cases of myasthenia gravis may go into remission—either temporarily or permanently— and muscle weakness may disappear completely so that medications can be discontinued.
Stable, long-lasting complete remissions are the goal of thymectomy and may occur in about 50 percent of individuals who undergo this procedure. The mission of the National Institute of Neurological Disorders and Stroke NINDS is to seek fundamental knowledge about the brain and nervous system and to use that knowledge to reduce the burden of neurological disease.
Although there is no cure for myasthenia gravis, management of the disorder has improved over the past 30 years. There is a greater understanding about the causes, structure and function of the neuromuscular junction, the fundamental aspects of the thymus gland and of autoimmunity. Technological advances have led to more timely and accurate diagnosis of myasthenia gravis and new and enhanced therapies have improved treatment options.
Researchers are working to develop better medications, identify new ways to diagnose and treat individuals, and improve treatment options. Some people with myasthenia gravis do not respond favorably to available treatment options, which usually include long-term suppression of the immune system. New drugs are being tested, either alone or in combination with existing drug therapies, to see if they are more effective in targeting the causes of the disease.
In addition to developing new medications, researchers are trying to find better ways to diagnose and treat this disorder. For example, NINDS-funded researchers are exploring the assembly and function of connections between nerves and muscle fibers to understand the fundamental processes in neuromuscular development. The goal of treatment is to manage symptoms and control the activity of your immune system.
Corticosteroids and immunosuppressants can be used to suppress the immune system. These medications help minimize the abnormal immune response that occurs in MG. Additionally, cholinesterase inhibitors, such as pyridostigmine Mestinon , can be used to increase communication between nerves and muscles. Removal of the thymus gland, which is part of the immune system, may be appropriate for many patients with MG.
Once the thymus is removed, patients typically show less muscle weakness. According to the Myasthenia Gravis Foundation of America , between 10 and 15 percent of people with MG will have a tumor in their thymus. Tumors, even those that are benign, are always removed because they may become cancerous. Plasmapheresis is also known as a plasma exchange. This process removes harmful antibodies from the blood, which may result in an improvement in muscle strength. Plasmapheresis is a short-term treatment.
The body continues to produce the harmful antibodies and weakness may recur. Plasma exchange is helpful before surgery or during times of extreme MG weakness. Intravenous immune globulin IVIG is blood product that comes from donors. These treatments cannot cure MG. Some individuals may go into remission, during which treatment is not necessary. Tell your doctor about any medications or supplements you take. Some drugs can make MG symptoms worse. One of the most dangerous potential complications of MG is myasthenic crisis.
This consists of life-threatening muscle weakness that can include breathing problems. Request an Appointment at Mayo Clinic. Receptors Open pop-up dialog box Close. Receptors Chemicals messengers, called neurotransmitters, fit precisely into receptor sites on your muscle cells.
Thymus gland Open pop-up dialog box Close. Thymus gland The thymus gland, a part of your immune system situated in the upper chest beneath the breastbone, may trigger or maintain the production of antibodies that result in the muscle weakness. Share on: Facebook Twitter. Show references AskMayoExpert.
Myasthenia gravis. Rochester, Minn. Clinical overview of MG. Myasthenia Gravis Foundation of America. Accessed April 1, Jameson JL, et al. Myasthenia gravis and other diseases of the neuromuscular junction. In: Harrison's Principles of Internal Medicine.
New York, N. Myasthenia gravis fact sheet. National Institute of Neurological Disorders and Stroke. Simon RP, et al.
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