Conventional Medical Treatments for Myasthenia Gravis (MG)

What is myasthenia gravis?

Myasthenia gravis (MG) is a rare, lifelong autoimmune disease that involves disruption of normal communication between nerves and muscles. Nerves release a specific neurotransmitter, acetylcholine, that binds to muscle receptor sites at the neuromuscular junction of skeletal muscles. When working properly, this signals the muscles to contract. MG causes the immune system to create antibodies that block these receptor sites, resulting in communication disruption between the nerves and muscles. As fewer nerve signals are received by the muscles, muscle fatigue and weakness occur. Voluntary muscles of the body, especially the mouth, eyes, throat and limbs, are typically affected by MG.

Treatments for myasthenia gravis

Although there is no known cure for MG, certain treatments may help relieve symptoms. Specific treatment options usually depend on the individual's age, overall health, muscles affected, and MG severity and progression.

Medication treatment options

MG medication treatment options include the following:

• Cholinesterase inhibitors, such as pyridostigmine, can enhance communication between nerves and muscles. This can improve muscle strength and contraction.
• Corticosteroids, such as prednisone, decrease antibody production by suppressing the immune system. However, prolonged use of corticosteroids may cause serious side effects.
• Immunosuppressants, such as azathioprine, mycophenolate mofetil, cyclosporine, methotrexate, or tacrolimus, may be prescribed to alter the immune system. These medications can take months to work and may be combined with corticosteroids.

Intravenous therapy treatments

Intravenous (IV) therapies are typically used for short periods to ease worsening symptoms. They may also be used prior to other therapies or surgery. IV therapies include the following:

• Intravenous immunoglobulin (IVIg) provides the body with normal donor antibodies over a period of two to five days. It can be used to treat an MG crisis and generalized MG. Benefits are seen within one week and can last three to six weeks.
• Monoclonal antibodies, such as rituximab and eculizumab, are biologically engineered proteins that suppress an overactive immune system. They can cause serious side effects and are typically used for individuals that do not respond to other treatments.

Plasmapheresis treatment option

Also known as plasma exchange, plasmapheresis is usually a treatment option for severe MG. It is similar to the dialysis filtering process. As a machine filters the blood, it removes abnormal antibodies that block communication between the nerve endings and muscle receptor site. Lessened symptoms may be experienced within a few days, but only last two to three weeks.

Thymectomy surgery

Thymectomy is a surgical procedure that removes the thymus gland, which plays an important role in the development of the immune system. This surgery is typically recommended for individuals with a thymoma (tumor on the thymus gland) or under 60 years of age with moderate to severe MG. A thymectomy may reduce symptoms by altering the immune system response; however, improvement is uncertain and may take months to years to occur.

Additional source: Conquer Myasthenia Gravis