“He’s just lazy, he was perfectly fine the other day. He’s just trying to get out of work . . . again.”
These are some of the comments that the person with myasthenia gravis may not get to hear. They’re the type of remarks that are usually said out of earshot, and individuals with this disorder rarely get the chance to set the record straight.
Myasthenia gravis (MG) is considered one of the so-called “invisible illnesses”—chronic disorders such as lupus, rheumatoid arthritis, fibromyalgia, and chronic depression—illnesses that generally aren’t noticeable to anyone but the person who has the disease. These disorders tend not to have obvious outward signs, and in fact may be as much intentionally “hidden” by the person who has the illness (in his or her struggle for normalcy) as they are “invisible.” But unlike many of the other invisible illnesses, MG is, ironically, just conspicuous enough to permit misunderstanding, rumors, and distrust of the person with the disease. This is because some of the first symptoms of MG are a drooping of the eyelids and slurred speech. As one patient with MG remarked, “I wish I could wear a T-shirt that says ‘I’m not drunk, I have myasthenia gravis.’”
Myasthenia gravis is an autoimmune neuromuscular disease that causes skeletal muscles to become easily fatigued with ordinary activity. However, the muscle weakness of MG shouldn’t be confused with the “tired muscles” or “aches” that any of us might experience after, say, a work-out at the gym. Even after relatively mild exertion (for example, after taking a shower and getting dressed), some individuals with MG may find that they have become too weak to rise from a sitting to a standing position, to lift their arms, or to walk up a flight of stairs. What’s more, the disease is not limited to those muscles that we generally associate with physical exertion, but also attacks the neck and facial muscles, making it an effort for persons with MG to smile, speak, chew, and even to swallow. The most common symptoms, in fact, involve the optic muscles, leading to double vision and the tell-tale drooping of the eyelids (also known as “ptosis”). Most concerning, respiratory muscles may also be affected, causing breathing to become labored, and, in many patients, resulting in respiratory failure. While he was still in his sixties, billionaire Aristotle Onassis died of respiratory failure caused by MG.
With MG, symptoms occur intermittently, sometimes disappearing for weeks at a time. After a period of returned strength, the sudden unexplained recurrence of muscle weakness may baffle the undiagnosed person, while it may also make his or her claims of on-again-off-again disabling fatigue seem dubious to others. Symptoms can be temporarily alleviated by rest (making the person with MG seem “fine” to the casual observer). However, those who have MG discover that they need to carefully conserve their restored energy and stick to a strict activity “budget”—one that often precludes having a social life. One patient remarked that he feels like his body has a battery charger that never completely fills during rest, causing him to become sapped of strength at the first task. Another patient wrote, “I wanted to dust today. But I had to go to the supermarket to get a few things before the ice storm comes. So between the cold damp air and the shopping itself I’m pretty much done for the day. Looks like I’ll be staring at dust bunnies until tomorrow.”
“You’re suffering from depression.”
“You’re getting older; you’re out of shape.”
These are some of the more straightforward comments that persons with myasthenia gravis may get to hear—from family, friends, and, in some cases, from their own doctor.
In numerous youtube videos created and posted by persons who have MG, individuals affected with the disease share their personal stories—describing not only their unusual-seeming symptoms, but also their perplexity and fears before finally receiving a correct diagnosis, sometimes after being misdiagnosed a number times. In one video, a patient describes how she went to the ER for a choking episode, where she was told that it had most likely been brought on by “depression and anxiety.”
One reason that MG is often misdiagnosed is the rarity of the disease: in the United States, only 36,000 to 60,000 persons have MG. (By comparison, about 1 million Americans have Parkinson’s disease, and approximately 300,000 Americans have multiple sclerosis.) This may make it easy for non-neurologist physicians to overlook atypical symptoms (eg, signs other than the characteristic drooping eyes) or to attribute them to myopathies other than MG.
Further confounding the picture, early in the disease course patients may spontaneously experience a lengthy remission, only to have the disease recur after years of being symptom-free. The disease course varies but is usually progressive, with atrophy of the most significantly involved muscles setting in after 15 to 20 years. The disease may be limited to ocular muscles in a large percentage of patients, but in others it may progress to a generalized MG (ie, involving multiple muscle groups)—and a substantial percentage of patients will undergo the life-threatening respiratory failure of myasthenic crisis at least once in the course of their disease.
With treatment, the prognosis for persons with MG is excellent. In the majority of patients receiving treatment, symptoms may be greatly improved, allowing persons with the disease to lead normal or near-normal lives. Approximately 80% of patients will experience remission (ie, at least 6 months with no symptoms) with pharmacologic therapy, while thymectomy may allow stable, complete remission (permanent absence of symptoms) in about half of the patients who undergo the procedure.
Despite this success, there remains a smaller percentage of patients with severe MG that is refractory to conventional treatment. For those who are among this minority, intolerable medication side effects, increased suffering and debility from the disease, and the threat of death due to respiratory failure are highly urgent concerns that require solutions. Recently, efforts have been made to investigate clinical features of these patients to help address their unmet needs and to customize treatment strategies. With the results of such recent investigations in mind, alternative treatments need to be sought for these individuals whom conventional therapy has failed.