Neurology Conditions

Myasthenia Gravis

Myasthenia gravis is characterized by weakness and rapid fatigue of any of the voluntary muscles, typically when the muscles are being used. Myasthenia gravis is caused by an autoimmune response to the affected areas, disrupting the normal communication at the neuromuscular junction (the connection between the nerve and the muscle) and rendering the patient weak.

Signs and symptoms of myasthenia gravis are weakness of arm or leg muscles, double vision, drooping eyelids, and difficulties with speech, chewing, swallowing and breathing. There is no cure for myasthenia gravis. However, there are many treatments designed to help acutely when a patient is in Omyasthenic crisis, and to keep patients feeling well for long periods of time. Treatments are geared towards alleviating the symptoms and reducing the body's immune attack on the acetylcholine receptor.

While myasthenia gravis can affect people of any age, it's most common in women younger than 40 and in men older than 60. Myasthenia gravis occurs in two or three people per 10,000.

Diagnosing Myasthenia Gravis

A key symptom indicating myasthenia gravis as a possibility is extreme muscle weakness and fatigue that improves with rest. Tests to help confirm the diagnosis of myasthenia gravis may include:

  • Blood analysis - Physicians diagnosing myasthenia gravis may order a blood test, which could reveal the presence of abnormal antibodies that disrupt the receptor sites that respond to nerve impulses which signal muscles to move.
  • Repetitive nerve stimulation involves electrodes that are attached to the patients skin over the muscles to be tested. Small pulses of electricity delivered to your nerves, and the responses are recorded through the electrodes to measure the nerve's ability to send a signal to your muscle. To diagnose myasthenia gravis, the nerve will be tested repeatedly to see if nerve ability to send signals worsens with fatigue.
  • Single-fiber electromyography (EMG) measures the electrical activity traveling between your brain and your muscle. It involves inserting a very fine wire electrode through your skin and into a muscle. In single-fiber EMGs, a single muscle fiber is tested. Most people find this test to be somewhat uncomfortable.
  • Imaging scans - Doctors diagnosing myasthenia gravis may order a CT scan or an MRI to see if the patient may have a thymus tumor or abnormality.

Myasthenia Gravis Treatments

Symptomatic therapy is usually accomplished with oral pyridostigmine (Mestinon), which improves strength by improving nerve and muscle communication for a short time.

Immune suppression is the cornerstone of therapy, and often involves the use of steroids such as prednisone, and steroid sparing agents including azathioprine, methotrexate, cyclosporin, mycophenylate mofetil, and cyclophosphamide.

Other forms of immune suppression used in the treatment of myasthenia gravis are intravenous immunoglobulin (IVIg) and plasmapheresis. IVIg is a medication that is given usual over two to five days every six to twelve weeks depending on response. Plasma exchange is a more invasive treatment that involves clearing the patient's blood of the abnormal antibody.

If a patient is found to have a thymoma, surgical removal of the thymoma is recommended.

About the Neuromuscular Division

The Neuromuscular Division of the Department of Neurology offers full diagnostic and treatment services for myasthenia gravis.

The Neuromuscular Division of the Department of Neurology consists of physicians, nurses, and technical staff that focus on the diagnosis and treatment of people with diseases of the anterior horn cells, nerve roots, brachial plexus, lumbosacral plexus, peripheral nerves, muscles and the neuromuscular junction. Expert care Is provided for neuromuscular diseases including myasthenia gravis, peripheral neuropathies, Guillain-Barre syndrome, the muscular dystrophies, and ALS (Lou Gehrig's Disease). We are nationally recognized as a center for patients with Neuromuscular diseases, and serve as the major referral center for the Atlanta area.