I'm going to take a wild guess and say that most of you have never heard of myasthenia gravis. Don't worry. Until about two years ago, I had no idea what it was either. It is considered a rare disease and only affects about one in 5,000 people in the United States. No one in my family had heard of it, except for a distant cousin who works as a veterinarian and had treated it in dogs. But needless to say, it is diagnosed in humans as well. In all honesty, other than the brief paragraph or two in my neuroscience textbooks, I probably never would have heard of the disease, had I not been diagnosed with it in August of 2014.
Myasthenia gravis (MG) is a chronic autoimmune disorder that essentially causes an interruption in the communication between nerves and muscles. Normally, the neuron meets the muscle at the neuromuscular junction. The neuron releases a molecule, acetylcholine, which binds to receptors on the muscle, telling it to contract. However, in MG, these receptors are blocked, destroyed, or otherwise altered, preventing muscle contraction. Although this can occur at any neuromuscular junction, it is most commonly presented in facial muscles, especially those surrounding the eye. Some forms of MG remain localized on the face and eyes, while others can become generalized so that many muscles, including those that affect breathing and voluntary limb movement, are affected.
Because the disease presents itself differently in everyone, MG has been nicknamed the Snowflake Disease. No two cases are the same. Additionally, nearly anyone can be diagnosed. It is most common in young adult women, or men over the age of 60. It is neither contagious nor hereditary. However, children of mothers with MG can acquire the antibodies that compromise the acetylcholine receptors, in what is known as neonatal myasthenia gravis. The symptoms of neonatal MG typically disappear a few months after birth. Myasthenia gravis is treatable with medication, but at the moment, there is no cure. Patients can go into remission, but relapses can occur at any time.
Because many of the early symptoms are also symptoms of other more common diseases, MG is often misdiagnosed. Just from WebMD, there were about 30 conditions that matched my symptoms. When I first went to the doctor with double vision and a drooping eyelid, she assumed that, being a teenager in New England during the summer, I likely had Lyme Disease. A blood test determined it was not Lyme, and an MRI ruled out several other possibilities. A couple of blood tests later, I was diagnosed with MG. As confirmation, I underwent an electromyography (EMG) and pulmonary function testing, which measure nerve-to-muscle transmission and breathing strength, respectively. These are the most common diagnostic methods for MG, with the blood test being the most successful.
June is MG Awareness Month. Throughout the spring, the MGFA has sponsored several walks across the country, and continue to do so throughout the summer. If you are interested in learning more or donating, visit the MGFA website. It might be a rare disease, but it could also be one that changes your life.
