Myasthenia gravis (MG) causes weakness that gets worse with exertion and improves with rest. The disease first appeared in medical reports in 1672 but didn’t earn its name, which literally means “grave muscular weakness,” until the 1880s. Physicians in 19th-century Germany, the first to begin systematic studies of the disease, noted that it produces weakness that fluctuates but generally progresses with time. Lacking crucial insights into the properties of nerve and muscle, they weren’t able to do much for their patients, many of whom lost strength rapidly and eventually died from respiratory failure. Even in the early 20th century, the mortality rate of MG was around 70 per cent.
Fortunately, over the past 100 years, the origins of MG have gradually unfolded, and the outlook for people with the disease has improved dramatically. MG is an autoimmune disease — a disease that occurs when the immune system attacks the body’s own tissues. In MG, that attack interrupts the connection between nerve and muscle — the neuromuscular junction.
Muscles that control the eyes, face, neck, and limbs are commonly affected. Thanks to this understanding of the mechanism behind MG, physicians can now treat it with drugs that suppress the immune system or boost the signals between nerve and muscle. Surgeries and other procedures are also helpful in many cases.
Physicians now estimate, that when MG is properly treated, the mortality rate is near zero. Most people with the disease are able to manage their symptoms and lead active lives, and a few experience remission lasting many years. This fact sheet provides essential information about MG and two related diseases that affect the neuromuscular junction, Lambert-Eaton myasthenic syndrome (LEMS) and congenital myasthenic syndrome (CMS).
