Adam Todd MD is a Board Certified Neurologist with Noran Neurological Clinic. As a certified electromyographer, he additionally performs EMGS for both his own patients and for other providers’ patients when ordered. He has special interests in neuromuscular disorders, epilepsy, and stroke. In this Question and Answer session, Dr. Todd answers some common questions about Myasthenia Gravis.
Question: What is myasthenia gravis?
Answer: Myasthenia gravis is an autoimmune disorder affecting the neuromuscular junction. As the name suggests, the neuromuscular junction is link between nerve and muscle. This link is established through chemical transmission. To move your muscles, a specific chemical neurotransmitter by the name of acetylcholine is secreted by the nerve. Acetylcholine clings to receptors on the muscle cell, stimulating them and resulting in muscle contraction. In myasthenia gravis, an antibody, a protein made by our own immune system blocks the receptors, effectively disconnecting the nerve from the muscle. This leads to weakness.
Question: What are the symptoms?
Answer: Premature fatigue, weakness, droopy eyelids and double vision are common presentations. Symptoms can be severe enough to cause weakness in muscles associated with breathing and swallowing. These symptoms are potentially life-threatening and require immediate medical attention.
Question: How is it diagnosed?
Answer: The diagnosis is based on a combination of clinical, laboratory and neurodiagnostic tests. When the clinical history is suggestive, a blood test is often obtained to look for antibodies specifically associated with myasthenia gravis. Electrodiagnostic testing is sometimes performed which can include nerve conduction studies and, less commonly, single fiber EMG. There is a close association between myasthenia gravis and tumors of the thymus gland. Therefore, a CT scan of the chest is often performed.
Question: How is it treated?
Answer: Myasthenia gravis is treated based on its severity. Milder symptoms may only require symptomatic treatment with an oral medicine called Mestinon (pyridostigmine). When generalized symptoms are present, daily steroids are often administered for a time. When long-term steroid use is anticipated, a steroid-sparing immunomodulating agent is used such as azathioprine, mycophenalate mofetil or cyclosporine . Some people can experience a “myasthenic crisis” which involves severe worsening of symptoms that is potentially life-threatening. This requires hospitalization and close medical monitoring. It is typically treated with either intravenous IVIG or plasmapheresis.
Question: What is the prognosis? How does it affect a person’s life in the long run?
Answer: In the past, myasthenia gravis had a mortality rate as high 20-30%. With today’s medical knowledge and treatments, the prognosis is much better and most people can expect a normal life span. Some cases can go into remission with return of strength and can be safely taken off medications.
Thank you Dr. Todd for providing us with some great information!
To learn more about Dr. Adam Todd and how he works with his patients, visit his bio page.
If you have additional questions about myasthenia gravis and would like to schedule an appointment with a neurologist experienced in the management of your condition, please contact Noran Neurological Clinic at 612-879-1500.