Why Is Myasthenia Gravis So Difficult to Diagnose?

Beth Stein, M.D., is the Chief of Neurology at St. Joseph’s Regional Medical Center, and works closely with the Myasthenia Gravis Foundation of America (MGFA).

Myasthenia gravis can be difficult to diagnose, and in this video, she discusses why the clinical presentation, disease course, and symptoms of the condition make it that way.

Stein: Patients with myasthenia gravis tend to have a fluctuating disease course and I think that’s the hardest part of the disease. Their symptoms fluctuate from minute-to-minute, hour-to-hour and day-to-day, which makes it very difficult for them and for physicians to diagnose. They can present with symptoms as minimal as double vision or blurry vision, and trouble swallowing, and [symptoms] can change throughout the day. Those are some of the clinical symptoms that make it very difficult for them.

Every patient is different, and each patient is different from day-to-day, which limits the ability to actually diagnose them accurately for a long period of time. Patients can come in with symptoms as mild as trouble swallowing and trouble breathing and it can go undiagnosed because they go to the wrong physicians. They’ll go to an ear, nose and throat doctor, or they’ll go to a lung doctor, and these symptoms keep changing. Patients won’t even pay attention to these symptoms because they can fluctuate, and they think they’re getting better when they’re getting worse.

In general, it starts in the second or third decade of life for women, or the fifth, sixth, or seventh decade of life for men. Now that the population is aging, it happens to be more common in women than men, though there are rare instances where it affects young children and young adults, as well. The disease tends to be mild at first, as it presents with double vision and blurry vision, but it can rapidly escalate to shortness of breath where they need to be intubated and managed in a hospital. It has a relapsing, remitted course where it can be well-controlled with medication, but there can be times where it can be exacerbated and they can get very weak. In the end stages of the disease, they can develop long-standing weaknesses.

Patients often come in with fluctuating symptoms; fluctuation is a hallmark of the disease. Because it’s fluctuating, sometimes physicians will mistake them as being psychotic or crazy. “How can you have double vision in the morning, and be perfect during a physician’s appointment? How can you have weakness or shortness of breath and then be completely fine when you go to the pulmonologist?”

Unfortunately, sometimes [patients] are diagnosed as having psychiatric illness. Sometimes, they’ll come in with weakness in an arm or a leg, or trouble swallowing, and they’ll think they had a stroke. They’re worked up for stroke, or other neurologic disorders like multiple sclerosis, and they can be misdiagnosed in the beginning stages. It takes an astute doctor who is well-versed in myasthenia or other autoimmune diseases to hone in on the nature of the disease in order to accurately diagnose it.