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What is Myasthenia Gravis?

Tricia Christensen
Tricia Christensen
Tricia Christensen
Tricia Christensen

Myasthenia gravis, which translates to grave muscle weakness, is an autoimmune condition that causes the voluntary muscles of the body to gradually weaken. Most often the muscles of the face, such as those that control the movement of the eyelids, speaking, and chewing, are first affected. These muscles may show involuntary movement or droopiness, or may make speaking or swallowing very difficult.

Myasthenia gravis is not inherited, though there have been some cases where there is more than one affected member of a family. Its advent is most common in women under the age of 40, and men over 60. The condition is primarily related to the thymus gland, which abnormally secretes immune cells that may attack the body’s nerve transmission signals and cut them off or distort them.

Steroids such as prednisone are used to improve muscle strength, though these steroids can have extreme side effects.
Steroids such as prednisone are used to improve muscle strength, though these steroids can have extreme side effects.

Symptoms progress from muscle weakness in the face to weakness in the extremities, which may affect movement range. Weakness is often exhibited most during activity. The most serious aspect of myasthenia gravis is its ability to cause a myasthenic crisis. During a crisis, the muscles that support breathing become too weak and those undergoing a crisis generally require emergency services and/or hospitalization to provide breathing assistance, such as with ventilators.

Myasthenia gravis causes extreme muscle weakness in the voluntary muscles of the body.
Myasthenia gravis causes extreme muscle weakness in the voluntary muscles of the body.

Methods for diagnosing myasthenia gravis are not perfect, and some with the condition can wait several years prior to receiving a positive diagnosis. Since these symptoms do not fail to go unnoticed, a physician will usually begin with taking a complete medical history. Physical examination may include the patient demonstrating the ability to grasp objects or move certain muscles. Sometimes blood tests can detect the presence of abnormal immune cells.

Treatment for myasthenia gravis may include the surgical removal of the thymus gland.
Treatment for myasthenia gravis may include the surgical removal of the thymus gland.

Two other tests that can possibly be performed are single fiber electromyography (EMG), and an edrophonium test. EMG tests single strands of muscles with electrical pulses to identify any damage of neural transmission to muscles. An edrophonium test uses intravenous administration of edrophonium to temporarily block the actions of immune cells. During the test, when symptoms of myasthenia gravis improve, this can be considered as a positive test.

Myasthenia gravis is most common in men over 60.
Myasthenia gravis is most common in men over 60.

Once diagnosed, there are several treatments for myasthenia gravis. In some cases, medications that block immune responses, specifically those autoimmune cells produced in the thymus are administered. These include daily doses of medications like neostigmine. Occasionally, steroids like prednisone are used to improve muscle strength, though these steroids can have extreme side effects.

Myasthenia gravis is primarily related to the thymus gland.
Myasthenia gravis is primarily related to the thymus gland.

When possible, a surgical procedure called a thymectomy removes the thymus gland. This is by far the most effective treatment for myasthenia gravis, with 70% of patients having complete remission of symptoms. Since this option does not completely eliminate the illness in some, continued research by the National Institute of Neurological Disorders and Stroke hopes to find both better treatments and ultimately a cure. For now, with current treatment, many with myasthenia gravis can be expected to live a healthy and normal life.

Tricia Christensen
Tricia Christensen

Tricia has a Literature degree from Sonoma State University and has been a frequent WiseGEEK contributor for many years. She is especially passionate about reading and writing, although her other interests include medicine, art, film, history, politics, ethics, and religion. Tricia lives in Northern California and is currently working on her first novel.

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Tricia Christensen
Tricia Christensen

Tricia has a Literature degree from Sonoma State University and has been a frequent WiseGEEK contributor for many years. She is especially passionate about reading and writing, although her other interests include medicine, art, film, history, politics, ethics, and religion. Tricia lives in Northern California and is currently working on her first novel.

Learn more...

Discussion Comments

msingh

Dose of Cellcept is 1500 mg daily and not 155 mg as typed earlier. sorry

msingh

I am diagnosed as a Musk Myasthenia patient. I had an attack in July 2006 and had to undergo plasmapheresis. I have been taking Cellcept for more than three years. I was told my thymus gland is OK. What is the cause of this disease and how long will I have to take this medicine? I am doing fine with 155mg dose of cellcept.

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    • Steroids such as prednisone are used to improve muscle strength, though these steroids can have extreme side effects.
      By: Thirteen Of Clubs
      Steroids such as prednisone are used to improve muscle strength, though these steroids can have extreme side effects.
    • Myasthenia gravis causes extreme muscle weakness in the voluntary muscles of the body.
      By: Ambrose
      Myasthenia gravis causes extreme muscle weakness in the voluntary muscles of the body.
    • Treatment for myasthenia gravis may include the surgical removal of the thymus gland.
      By: designua
      Treatment for myasthenia gravis may include the surgical removal of the thymus gland.
    • Myasthenia gravis is most common in men over 60.
      By: wildworx
      Myasthenia gravis is most common in men over 60.
    • Myasthenia gravis is primarily related to the thymus gland.
      By: reineg
      Myasthenia gravis is primarily related to the thymus gland.
    • Blood tests can detect the presence of abnormal immune cells.
      By: Von Schonertagen
      Blood tests can detect the presence of abnormal immune cells.
    • Migraines may occur as a side effect of prednisone.
      By: Tyler Olson
      Migraines may occur as a side effect of prednisone.
    • Hospitalization may be required during a myasthenia gravis crisis.
      By: cappui
      Hospitalization may be required during a myasthenia gravis crisis.
    • An edrophonium test uses intravenous administration of edrophonium to block actions of immune cells.
      By: Tyler Olson
      An edrophonium test uses intravenous administration of edrophonium to block actions of immune cells.