Can you imagine waking up one morning to find your eyelids drooping and your vision blurred? This is not something Myasthenia gravis patients have to imagine. It’s something very real and very frightening. Myasthenia gravis is a progressive autoimmune disorder that is characterized by muscle weakness. Myasthenia gravis comes from Greek and Latin words that mean “grave muscular weakness”. The disease tends to strike more women than men. It usually affects women between 20 and 40 years of age and usually strikes men over 60 years of age. However, it can occur at any age and children can also develop the disease.

Myasthenia gravis is not directly inherited or contagious and it can occur in more than one person in a family. If a woman with Myasthenia gravis becomes pregnant the baby can acquire the antibodies from the mother and will have the symptoms of the disease for a few weeks or months after birth. This is referred to as neonatal myasthenia and the symptoms can be treated.

The onset of Myasthenia gravis is usually sudden and the symptoms are usually not recognized as the disease in the beginning. The first noticeable symptom is weakness of the eye muscles which cause drooping of one or both eyelids and blurred or double vision. Other symptoms include an unstable or waddling gait, weakness in the arms, hands, fingers and neck, changes in facial expressions, difficulty in swallowing and shortness of breath and impaired speech.

Diagnosis can be confirmed several ways.

• Acetylcholine Receptor Antibody-This is a blood test that is used to detect abnormal antibodies. Approximately 85% of Myasthenia gravis patients have this antibody and if it is detected a guaranteed diagnosis can be made.
• Anti-mu SK antibody testing-This is a blood test for the remaining 15% of seronegative Myasthenia gravis patients. These patients have tested negative for the acetylcholine antibody. Approximately 40-75% test positive for the anti-mu SK antibody. The remaining patients have an unknown antibody that is causing the disease.
• Tensilon Test-This test is performed by injecting edorphonium chloride or Tensilon into a vein. The injection provides strong support for diagnosis if there is an improvement in muscle strength immediately after the injection.
• Electromyography (EMG)-This test provides support for the diagnosis if characteristic patterns are present.
• Single Fiber EMG-This test also supports diagnosis with characteristic patterns present.

Myasthenia gravis is caused when there is a breakdown in communication between the nerves and muscles. This is caused by the immune system. It is unknown as to why the disease causes the immune system to produce antibodies that block or destroy many receptor sites of acetylcholine in the muscles. Fewer receptor sites cause the muscles to receive fewer nerve signals. This results in weakness. The thymus gland, part of the immune system located beneath the breastbone is suspected to trigger or maintain the production of these antibodies. Some adults who have Myasthenia gravis have an abnormally large thymus.

There are many factors that can make Myasthenia gravis worse. They include fatigue, illness, stress, extreme heat and medications that include beta blockers, calcium, channel blockers, quinne and some antibiotics.

There are a few treatments and therapies for Myasthenia gravis.
• Medications-Cholinesterase inhibitors improve the nerve signals to muscles and increase strength. Immunosuppressive drugs are used to suppress the production of abnormal antibodies.
• Thymectomy-This is the surgical removal of the thymus gland. This may cure some people with Myasthenia gravis by possibly re-balancing the immune system.
• Plasma Exchange-This is a procedure to remove abnormal antibodies from the blood.
• High dose intravenous immune globulin-This therapy temporarily interferes with the ability of the immune system to damage nerve muscle junction.

The prevalence of Myasthenia gravis in the United States is estimated at about 20 out of 100,000 of the population. However, the prevalence may be higher because of the possibility that it is under diagnosed. Most cases of Myasthenia gravis today are not as “grave” as the name implies. Most people with the disease can expect to live normal lives for the most part.