Frequently Asked Questions

What is myasthenia gravis and what are common symptoms?

Myasthenia gravis (MG) is an autoimmune neuromuscular disorder that affects voluntary muscles. Common symptoms can include a drooping eyelid, blurred or double vision, slurred speech, difficulty chewing and swallowing, weakness in the arms and legs, chronic muscle fatigue and difficulty breathing. The weakness tends to increase with continued activity and can be improved with periods of rest. Not everyone will display all symptoms, and symptoms can fluctuate.

I think I have MG. What do I do?

We can provide you with general information regarding MG, but you should consult with your doctor if you think you have MG. Request an information packet here.

How does the doctor test for MG?

• Acetylcholine Receptor Antibody— a blood test for the abnormal antibodies can be performed to see if they are present. Approximately 85% of MG patients have this antibody and, when detected with an elevated concentration the AChR antibody test is strongly indicative of MG.

• Anti-MuSK Antibody testing—-a blood test for the remaining 15% of MG patients who have tested negative for the acetylcholine antibody. These patients have seronegative (SN) MG. About 40% of patients with SNMG test positive for the anti-MuSK antibody. The remaining patients have unidentified antibodies causing their MG.

• Office Tests—Sleep, Ice Pack and Edrophonium tests are examinations performed by specialists to evaluate an improvement in strength that may be consistent with MG.

• Electromyography— (EMG) studies can provide support for the diagnosis of MG when characteristic patterns are present. Repetitive Nerve Stimulation is used to check for a pattern of response that is characteristic of MG.

• Single Fiber EMG— studies can provide support for the diagnosis of MG when characteristic patterns are present. The single fiber EMG and AChR antibody test are primary tests used to confirm a clinical diagnosis of MG.

How is MG treated?

The goal of MG treatment is to remove antibodies, reduce antibodies, and inhibit the binding of antibodies through the various medications and treatments available. (from Summer 2006 newsletter article by K. Sivakumar, MD)

There is no known cure for MG, but there are effective treatments that allow many people with MG to lead full lives.

Common treatments include medications such as Mestinon® (pyridostigmine), prednisone, Cellcept® (mycophenolate mofetil), Imuran® (azathioprine), cyclosporine, and treatments such as thymectomy, plasmapheresis, and intravenous immunoglobulin (IvIg) infusions.

Spontaneous improvement and even remission may occur without specific therapy. Rest and a well-balanced diet can help.

Are there medications a patient with MG should not take?

There are certain drugs that patients with MG should avoid or only use with caution. You should always discuss these concerns with your doctor or neurologist; make sure these professionals know every drug you are taking, including over-the-counter medications. Your pharmacist may be another good resource.

Why aren’t my medications working?

Will my MG go away?

In some cases, MG may go into remission for a time, during which no treatment is necessary.

Is it safe to switch to generic Mestinon® (pyridostigmine)?

The generic form of Mestinon® has been on the market since February 2003 and to our knowledge, no studies have been conducted as to the relative effectiveness of the medication in relation to the brand version. By law the generic medications must have the same active ingredients as the brand name medication; however, the “fillers” or excipients may differ.

Can people with MG receive the flu shot?

How did I get MG?

Often, the cause of MG contraction is not known for the particular patient. It is possible to contract MG from Penicillamine, which is used to treat Wilson’s disease, rheumatoid arthritis, other chronic autoimmune diseases, and cystinuria. It is also possible to contract MG by being treated with interferon alpha, or through a bone marrow transplant. (From “Medication and Myasthenia Gravis”).

Is MG hereditary?

Researchers are uncertain of the cause of MG, but do not believe that it is hereditary. A genetic predisposition to autoimmune diseases can run in families, but MG is not thought to be directly hereditary.

Is MG contagious?

Researchers are uncertain of the cause of MG, but do not believe that it is contagious.

How many people have MG?

Approximately 20 out of 100,000 individuals in the U.S. have been diagnosed with MG. However, MG is considered under-diagnosed and the prevalence is thought to be much higher.

At what age do most patients get MG?

The most common age at onset is the second and third decades in women and the seventh and eighth decades in men. As the population ages, the average age at onset increases correspondingly; now males are more often affected than females, and the onset of symptoms is usually after age 50.

Will my children get MG?

Researchers are uncertain of the cause of MG, but do not believe that it is hereditary or contagious. A genetic predisposition to autoimmune diseases can run in families, but MG is not thought to be directly hereditary.

There is a 12% to 20% incidence of neonatal myasthenia in infants born to mothers with MG. Neonatal myasthenia is a temporary condition of general weakness in a baby and usually occurs within the first 24 to 48 hours after birth and may last days or weeks. It is usually self-limited, lasting three to five weeks, but occasionally lasts longer.

Will I be able to have children?

Will I be able to continue working?

This partially depends on the nature of your job and your MG, but most MG patients continue working successfully.

Can you refer me to a specialist in myasthenia gravis?

MAA cannot provide referrals. In general, we suggest that people see a neurologist who focuses on neuromuscular conditions.