Myasthenia gravis (MG) is a debilitating condition that occurs when the immune system mistakenly attacks receptors required to transmit nerve signals to muscles. It leads to lack of muscle control and muscle weakness.
There is no cure for MG, but some treatments can help manage the symptoms. In some cases, improvement can occur regardless of treatment.
A number of approved drugs can help manage MG, either by altering or suppressing immune response or by improving nerve signal transmission to muscles.
Cholinesterase inhibitors or anticholinesterases, such as Mestinon (pyridostigmine), are often the first type of medication that a doctor prescribes to an MG patient.
Mestinon can improve the transmission of signals to muscles by increasing levels of the neurotransmitter acetylcholine. Neurotransmitters act as chemical messengers between nerves and muscles.
Cholinesterase inhibitors do not alter the immune system, so they do not address the underlying damage that causes MG. But they are effective in controlling symptoms.
Corticosteroids such as prednisone suppress the immune system by reducing the production of antibodies, or proteins that attack or block a specific invader or other target. This results in less damage to receptors at nerve-muscle junctions, reducing symptoms of MG.
A problem with corticosteroids is that they can have severe side effects, especially if used long-term.
Other immunosuppressants can also be used treat MG. They include Imuran (azathioprine), CellCept (mycophenolate), cyclosporine, Trexall (methotrexate), cyclophosphamide, and Prograf (tacrolimus). They may be prescribed in place of prednisone, or to reduce doses of it.
Plasmapheresis, or plasma exchange, is a process that involves drawing blood out of the body, filtering it and returning it over several hours. This can remove antibodies that prevent normal signal transmission to muscles.
The process has no impact on abnormal immune response, which means the immune system will continue to make the antibodies. This means the benefits of plasma exchange are temporary.
The procedure is also expensive and time-consuming. As a result, doctors do not usually recommend it as a routine treatment unless a patient has very severe symptoms.
Intravenous immunoglobulin infusion
The object of intravenous immunoglobulin infusion (IVIG) is to alter the immune response by replacing the damaging antibodies that cause MG with antibodies pooled from healthy donor blood.
As with plasmapheresis, this treatment is generally used for patients with very severe symptoms, patients who are not responding well to other treatments, or patients who are about to undergo surgery.
In some cases, MG can be caused by an abnormality of the thymus gland, which helps regulate the immune system. The abnormalities can include a tumor, called a thymoma, or an unusally large thymus.
Such patients may benefit from thymectomy, or surgery to remove the thymus. A clinical trial (NCT00294658) carried out in 126 MG patients suggested that a thymectomy could improve symptoms and reduce the need for medication even in patients without a tumor.
Changes in lifestyle can help some MG patients reduce symptoms or avoid triggering symptoms. For example, maintaining a healthy diet, staying well-rested and avoiding stress may help prevent symptoms from occurring as frequently.
Myasthenia Gravis News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.