If you’ve seen TV ads recently featuring tennis legend Monica Seles discussing her treatment for myasthenia gravis (MG), you might be wondering exactly what that is.
Morgan Jordan, DO, a neurologist at Cleveland Clinic Tradition Hospital, explains that MG is a condition that happens when communication between nerves and muscles breaks down, causing a host of symptoms that affect patients’ bodies in various ways.
The Myasthenia Gravis Foundation of America estimates that 70,000 people in the United States are known to have the condition, with many more cases undiagnosed. In recent years, there has been growing concern about the increasing incidence of MG.
Dr. Jordan says that data supports a significant increase in the number of cases. “One of the reasons is that we have much better diagnoses now, based in large part on more accurate antibody testing.”
Mayo Clinic explains some other criteria used to diagnose MG. They include:
- Neurological exams that test your reflexes, muscle strength, muscle tone, senses of touch and sight, coordination and balance.
- Blood tests to check for antibodies that interrupt the receptor sites where nerves signal your muscles to move.
- Pulmonary function tests to measure whether your condition is affecting your breathing.
- Repetitive nerve stimulation. Electrodes are attached to the skin over the muscles to be tested. Small pulses of electricity are sent to the nerve going to that muscle. These pulses measure whether the nerve can send a signal to the muscle.
- Single-fiber electromyography (EMG). Measures electrical activity traveling between your brain and your muscles by inserting a fine wire electrode through your skin and into a muscle to test a single muscle fiber.
- Imaging. A CT scan or MRI to check for a tumor or other concerns with your thymus may be ordered.
MG Companion, a news and information source for myasthenia gravis, says that a study done between January 2016-June 2024 found that the annual incidence rate of MG increased from 10.6 to 13.8 per 100,000 person-years.
Put another way, if the authors had observed 100,000 people for one year, they would have expected 10.6 to be diagnosed with MG during the year, but the number turned out to be 13.8.
The overall prevalence of people living with MG was 44.1 per 100,000 people, an 18 percent increase from 2021 to 2023.
But what does myasthenia gravis do to our bodies?
“Myasthenia gravis is an autoimmune condition. These conditions happen when the immune system creates antibodies that mistakenly work against or attack healthy cells or tissue,” Dr. Jordan explains.
“Antibodies are proteins that help fight foreign substances in the body, such as bacteria or viruses. In myasthenia gravis, the immune system mistakenly makes antibodies that stop the neurotransmitter acetylcholine from communicating with muscles.”
Cleveland Clinic says that neurotransmitters are your body’s chemical messengers, carrying information from one nerve cell across a space to the next nerve, muscle or gland cell.
These messages enable you to move your limbs, feel sensations, keep your heart beating, and take in and respond to all the information that originates in the body and environment.
“People suffering from myasthenia gravis have a reduced muscle and body connection,” says Dr. Jordan.
“Effects of the reduced connection vary from person to person,” she explains. “Among the most frequently seen are droopy eyelids and additional symptoms in the face that affect your jaw muscles, chewing, speech, controlling facial muscles and swallowing.
“Some of the more serious cases affect the diaphragm and chest muscles,” she says.
About 10 percent to 15 percent of all patients experience a “myasthenic crisis” at least once, where respiratory muscle weakness becomes severe enough to require mechanical ventilation.
Mayo Clinic says the symptoms of myasthenia gravis may come and go, usually improving when the weak muscle is rested but getting worse again when the muscle is used. Symptoms often progress and may be at their worst one or two years after the disease begins.
In addition to the symptoms cited by Dr. Jordan, Mayo Clinic mentions weakness in the neck, arms and legs, which might happen later as the condition worsens.
Leg weakness can affect how you walk and weak neck muscles can make it hard to hold up the head.
Dr. Jordan says, “Myasthenia gravis is included in of one of the most active areas of FDA-drug testing activity. Many new treatments have been approved within the last five to 10 years, with others still in the pipeline.”
Healthline reports that as of December 2024, five FDA-approved therapies are available to treat myasthenia gravis symptoms that may allow partial to complete remission. There is still no cure, but modern treatments can support an average life span.
The newest options are Rystiggo and Zilbrysq, which were both approved in 2023.
Traditional and supportive treatments include acetylcholinesterase inhibitors like Mestinon, immunosuppressants, plasmapheresis, intravenous immunoglobulin and thymectomy. Five new targeted medications are on track to gain FDA approval by 2032.
“A majority of people with myasthenia gravis live relatively normal lives,” says Dr. Jordan. “One of the keys to success is frequent appointments with your healthcare professional to monitor your condition.”
Morgan Jordan, DO, specializes in neurology and neuromuscular medicine at Cleveland Clinic Tradition Hospital. She completed her undergraduate degree at Queens University of Charlotte, her medical education at Edward Via College of Osteopathic Medicine, Carolinas Campus; her internship and residency at San Antonio Uniformed Services Health Education Consortium; and a fellowship at Shands at the University of Florida. Her office is located at Tradition HealthPark Two, 10080 Southwest Innovation Way, Port St Lucie. Call 877-463-2010 for an appointment.
