Myasthenia Gravis

Myasthenia gravis (grave weakness) is a chronic autoimmune neuromuscular disease characterized by weakness of the voluntary muscles of the body. In most cases it’s the result of circulating auto-antibodies that block nerve transmission between the nerve and the muscle. Patients with myasthenia gravis can have associated abnormalities in the thymic gland such as enlargement (hyperplasia in 70 percent) or a tumor (thymoma in 15 percent).

Our highly skilled thoracic surgeons at UT Southwestern Medical Center have been performing minimally invasive or robotic thymectomy to treat myasthenia gravis for more than 15 years, longer than any other group in North Texas. Thymectomy and medical treatment can result in complete remission of the disease in more than 40 to 60 percent of patients within five years after surgery.

Our surgeons work closely with UT Southwestern’s dedicated myasthenia gravis neurologists to deliver comprehensive care – all in one location, and usually on the same day.

Symptoms

Symptoms of myasthenia gravis depend upon the muscles affected by the disease. Most patients will first notice weakness in the muscles that control the movement of the eye and eyelids, resulting in double vision and droopy eyelids. Other symptoms include:

• Changes in facial expression
• Difficulty chewing
• Difficulty speaking
• Difficulty swallowing
• Difficulty walking or doing repetitive work with arms and hands
• Shortness of breath

Diagnosis

Because the diagnosis may be difficult to make, symptoms suggestive of myasthenia gravis must be investigated by an experienced neurologist. Diseases associated with myasthenia gravis may include thymoma, thyroid diseases, collagen vascular diseases, and dysfunction of red blood cells.

If we suspect that you have myasthenia gravis, we will conduct a physical examination and order tests to confirm the diagnosis.

Tests and imaging techniques used to diagnose myasthenia gravis might include:

• Blood testing to identify circulating antibodies
• Electromyography (EMG), including single-fiber electromyography (SFEMG) to determine the response of your muscles to stimulation
• Pulmonary function testing to determine the strength of your breathing muscles
• Thoracic imaging, including computed tomography (CT) and magnetic resonance imaging (MRI) to detect enlargement or a tumor of the thymic gland

Treatments

Once diagnosed, the initial treatment includes medications to control the symptoms under the care of an experienced neurologist in the Neuromuscular Disorders Program. In about 6 percent of patients, the disease may go into natural spontaneous remission. If symptoms recur, additional treatment will be necessary.

Treatments for myasthenia gravis include:

• Immunotherapy to reduce inflammation and production of autoantibodies
• Medication to improve nerve transmission
• Plasma exchange (PLEX) or intravenous immunoglobulin administration (IVIG) to remove or counteract the autoantibodies
• Thymectomy: Surgery to remove the thymus gland, which is frequently abnormal in people with myasthenia gravis (enlarged or presence of a tumor)

Clinical Trials

In addition to standard treatments for myasthenia gravis, UT Southwestern gives patients access to the most promising new therapies through clinical trials. Talk with your doctor to see if a clinical trial may be right for you.