What is myasthenia gravis?

Myasthenia gravis is a neurological condition characterized by weakness of the skeletal muscles. In myasthenia gravis, only the muscles used for movement (not involuntary muscles such as the heart) are affected. Myasthenia gravis arises because the body’s own immune system attacks the point at which the nerves signal the muscles to move. Over time, the nerves lose their ability to stimulate muscles.

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Myasthenia gravis is a result of impaired communication between nerves and muscles. In particular, in myasthenia gravis, the body makes antibodies (autoantibodies) that block the receptors for an important neurotransmitter chemical at the point where nerves join muscles. As with many other autoimmune disorders, you are more likely to get myasthenia gravis if you have other autoimmune conditions. A significant number of individuals diagnosed with myasthenia gravis have an abnormal growth in their thymus, a lymphoid organ that processes immune-regulating cells.

Symptoms of myasthenia gravis, in addition to muscle weakness, include difficulty breathing, difficulty eating, eyelid droop, facial paralysis, fatigue, and difficulty with vision. Most of these symptoms worsen with physical activity. While these symptoms generally can be controlled, in some cases a myasthenic attack can occur. These attacks impair the function of breathing muscles and can be life threatening if not immediately treated.

There is no cure for myasthenia gravis, but it can be treated. Certain lifestyle factors can be changed to improve symptoms, such as decreasing physical activities and avoiding stress. Medications for myasthenia gravis include drugs to help with nerve signaling and suppress the autoimmune response. In some situations, plasmapheresis (a blood purification process) or an immunoglobulin infusion (infusion of helpful antibodies) can be used to alleviate symptoms. In patients with severe symptoms, surgery may be required to remove all or part of the thymus, an organ that is important in the development of immune system cells. In many cases, these treatments can cause myasthenia gravis to go into remission.

Seek immediate medical care (call 911) for serious symptoms of a myasthenic attack such as severe difficulty breathing. Myasthenic attacks can be life threatening.

Seek prompt medical care for any symptoms of myasthenia gravis, as this is a serious condition which can be alleviated with medical treatment.


What are the symptoms of myasthenia gravis?

Symptoms of myasthenia gravis mainly include muscle weakness, specifically of the voluntary muscles. This includes weakness in the muscles of the eye, which can lead to vision difficulties. Muscle weakness can also affect muscles involved with breathing, which can cause breathing difficulties. The symptoms of myasthenia gravis generally worsen with physical activity. In very serious cases, symp... Read more about myasthenia gravissymptoms


What causes myasthenia gravis?

Myasthenia gravis is not passed down in families, nor is it contagious. Myasthenia gravis occurs when the immune system attacks acetylcholine receptors (important binding sites for the chemical involved in signaling from nerves to muscles), which are components of the neuromuscular junction (the point where nerves join muscles). When the neuromuscular junction stops functioning, signals from th... Read more about myasthenia graviscauses


How is myasthenia gravis treated?

While there is no cure for myasthenia gravis, it can be treated with lifestyle modifications, medication, and, in some cases, surgery. In many cases, myasthenia gravis can go into remission (period of time without symptoms) with treatment. It is possible for people with myasthenia gravis to lead normal lives, including having children, so long as appropriate medical monitoring and treatment are... Read more about myasthenia gravistreatments

Medical Reviewer: William C. Lloyd III, MD, FACS Last Annual Review Date: Sep 6, 2013 Copyright: © Copyright 2014 Health Grades, Inc. All rights reserved. May not be reproduced or reprinted without permission from Health Grades, Inc. Use of this information is governed by the HealthGrades User Agreement.

This Article is Filed Under: Bones, Joints and Muscles

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