What’s going on with your eyes?
You’re working at your computer when you start seeing double and it feels like one of your eyelids is drooping. Figuring your eyes are strained, you take a break, close your eyes, and everything is fine a few minutes later. Over the next few days, you notice that this keeps happening. Why? Is there anything you can do to fix it? How can you prevent it?
Definition
Myasthenia gravis is a disorder that causes weakening and rapid fatigue in muscles that you voluntarily control, which occurs due to a breakdown in the communication of your nerves and muscles. Usually, your nerves “speak” to your muscles by releasing chemicals, neurotransmitters, which fit into specific receptor sites. For those with myasthenia gravis, their immune system creates antibodies that destroy or block the receptor sites for a particular neurotransmitter, usually acetylcholine. The antibodies can also inhibit the function of proteins, such as muscle-specific receptor tyrosine kinase, that help form the nerve-muscular junction. In either case, it results in your muscles receiving fewer nerve signals. Your thymus gland, which resides in the upper part of your chest beneath the breastbone, is thought to trigger or maintain the production of the antibodies that impede acetylcholine. Sometimes, this results from a tumor (thymoma); typically, they aren’t cancerous. Some individuals with myasthenia gravis don’t have antibodies against acetylcholine or muscle-specific receptor tyrosine kinase. This type is called antibody-negative myasthenia gravis, even though they have antibodies against another protein, lipoprotein-related protein 4. Neonatal myasthenia gravis occurs when a child is born with the condition because their mother has it. This is rare. If treated quickly, the child will usually recover within two months. Other children are born with a hereditary form of the disease, congenital myasthenia syndrome. This is also rare. While myasthenia gravis can occur in anyone, it’s more common in women under 40 and men over 60.
Symptoms of myasthenia gravis are related to muscle weakness since the nerve signals don’t get through. Often it’s made worse by use and improves with resting the affected muscles. The disease progresses over time, with it reaching its worst within the first few years. While it can affect any muscles that you voluntarily control, it does tend to affect specific muscle groups more than others. Over half of the people who have the condition start by having eye problems. The two most common issues are the drooping of one or both eyelids and double vision that improves when one eye is closed. For about 15% of people who have the disorder, their first symptoms are related to their face and throat muscles. This results in impaired speech, difficulty swallowing, difficulty chewing, and changes in facial expressions. Myasthenia gravis can also cause your neck and limb muscles to be weak, making it challenging to keep your head up, hard to use your arms, and affect your ability to walk.
Certain things can make your myasthenia gravis worse, such as fatigue, illness, stress, pregnancy, menstrual periods, and certain medications (ex. beta blockers, quinidine gluconate, quinidine sulfate, quinine, phenytoin, certain anesthetics, and some antibiotics). There is one concerning complication because it’s life-threatening, known as a myasthenic crisis. This condition involves the muscles that control breathing becoming too weak to do their job. The affected person needs mechanical assistance to breathe and other treatments to help them do this on their own again. Individuals with myasthenia gravis are more likely to have an overactive/underactive thyroid or other autoimmune conditions.
Treatment
There’s no cure for myasthenia gravis, so treatment concentrates on relieving symptoms. How that is achieved depends on your age, the severity of your condition, and how fast the disease is progressing. Commonly, this involves some form of medication. You might take a cholinesterase inhibitor, such as pyridostigmine or neostigmine, to enhance the communication between your nerves and muscles, thereby improving muscle strength/contraction. Corticosteroids, like prednisone, can impede your immune system by limiting antibody production. The only problem is that long-term use can result in serious side effects. Other immunosuppressants can take months to work but are effective. These include azathioprine, mycophenolate mofetil, cyclosporine, methotrexate, and tacrolimus.
Sometimes, if your symptoms suddenly worsen or you’re going to have surgery, your doctor may recommend intravenous (IV) therapy. One option is plasmapheresis, which filters your blood in a manner that is similar to dialysis. During the process, the antibodies that block nerve transmission are removed. Unfortunately, the effects only last a few weeks. Another solution is intravenous immunoglobulin (IVIg), which provides your body with normal antibodies, altering your immune system response. The benefits only last three to six weeks. Monoclonal antibody treatments, like rituximab or eculizumab, are only used for people who don’t respond to other therapies because the side effects can be dangerous.
For those with thymomas, your doctor will probably want to remove your thymus gland. In some cases, they might want to remove it even if you don’t have a tumor because it’s thought that doing this could improve symptoms. However, the benefits can take years to develop. The procedure is done as an open one or minimally invasive. Your doctor will help you decide which one is best for you.
The best way to manage your symptoms and make the most of your energy is through changes in your daily life. To preserve energy, use electric appliances and power tools whenever possible, including an electric toothbrush, electric can opener, and dishwasher. Adjust your daily routine to do important things when you have good muscle strength. For instance, when it comes to eating, take your time chewing, take breaks between bites of food, select food that is mainly soft (it won’t require as much chewing), and have several smaller meals throughout the day. When it comes to chores, shopping, or errands, do those at the time of day when you have the most energy. If you have issues with double vision, try wearing an eye patch. Just remember to switch eyes occasionally to prevent eyestrain. It’s also essential to create a safe environment to live in. This means installing grab bars or railings where you need them for support, keep floors clear of clutter, and remove area rugs. Since stress can worsen your symptoms, find ways to relax. Don’t be afraid to ask for help when you need it. Learn as much as you can about your condition and maintain a support network of family and friends.
Prevention
While the mechanism of how the disease affects your body is known, the reason why your body starts producing antibodies that impact your nerves and muscles is not. This signifies it’s not preventable yet. The best thing you can do is prevent complications of the disorder to the best of your ability.
Myasthenia gravis is a challenging disease to have, but doing everything you can to live your life in a way that allows you to participate as much as possible, means you won’t miss out. If you have any questions or concerns about myasthenia gravis, please speak with your doctor. If you would like more information, please visit the Myasthenia Gravis Foundation of America at https://myasthenia.org/