[3 min read]
In this article:
- Myasthenia gravis (MG) is a condition in which the body's immune system attacks the connections between nerves and muscles.
- Many patients will experience drooping eyelids as the first sign they may have MG.
- MG is a treatable condition that can be managed with a host of therapies and medications.
- A Providence Swedish neuromuscular medicine expert shares more about the disease and where to start if you suspect you may have it.
Myasthenia gravis (MG) is a chronic autoimmune disorder that impairs communication between nerves and muscles, leading to muscle weakness and fatigue. Characterized by its unpredictable nature, the condition often affects voluntary muscles, including those responsible for eye movement, facial expressions, and swallowing, resulting in a significant impact on daily life. The hallmark symptom is muscle weakness that worsens with activity and improves with rest, posing unique challenges to those affected. Tennis legend Monica Seles recently shared her own battle with myasthenia gravis, bringing renewed attention to the complexities of the disease. To learn more, we spoke with Christyn Edmundson, M.D., a neurologist who specializes in neuromuscular medicine at Providence Swedish.
What is myasthenia gravis, or MG?
It's a disease that happens when the immune system attacks the body itself. The immune system is designed to help protect us against infection or cancer, but there are times when the immune system attacks a part of the body, as with autoimmune diseases such as multiple sclerosis, rheumatoid arthritis or myasthenia gravis (MG). In MG, the immune system attacks the neuromuscular junction (shown in image at top), which is the connection between the nerve and the muscle. For our bodies to move, our brain sends signals down our spinal cord to our nerves, then to neuromuscular junction, which tells the muscle to contract or move. In MG, the body develops antibodies that attack the connection between nerves and muscles.
What are the symptoms of MG?
Generally, MG causes muscle weakness. People with MG might develop weaknesses in the eyes or other parts of the body, and typically that weakness gets worse with activity or over the course of the day. People often develop double vision or drooping eyelids that get worse as you use your eyes. It can also affect muscles that help with chewing, swallowing and breathing, as well as muscles in the arms and legs. It’s the disrupted connection between the neuron and the muscle that produces these feelings of fatigue and weakness. Symptoms can vary a lot, but in many cases, people will develop eye symptoms first.
Most autoimmune diseases affect more women than men. MG is interesting because we see what we call “bimodal distribution”, with two different ‘peaks’ of diagnosis: There's a peak that happens early in life, around the 20s and 30s. But then there's also a peak later in life, in the 60s or 70s. In those younger cases, there's a female predominance. But then that later peak actually has a male predominance. There are a variety of factors that can make MG symptoms better or worse, like stress, hormones, medications, infections or temperature. Often in the heat, people with MG have a lot more symptoms. Hormones can also affect MG severity, so some women experience fluctuations in their MG symptoms with menstruation or pregnancy.
Why do people get MG?
Like other autoimmune diseases, we don't really understand why it happens. The caveat to that is that about 15% of people with myasthenia gravis have something called a thymoma, which is a tumor on the thymus gland just behind the sternum. Thymomas are usually benign, but we almost always take these tumors out, because they might be driving MG in some cases. We sometimes also recommend removing the thymus from people with MG who do not have a tumor, since it is possible that abnormal activity in the thymus could be driving MG, even without a tumor.
What are the differences between MG, multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS)?
MS is also an autoimmune disease, but in contrast to MG, which attacks the neuromuscular junction, MS attacks the central nervous system, which is the brain and the spinal cord. Both MS and MG have a lot of treatments available for them.
ALS is a very different disease. It’s a progressive fatal neurodegenerative disease. In contrast to MS and MG, there are not as many treatments available for ALS. MG and ALS are sometimes confused by each other because they cause weakness without causing numbness or pain.
With ALS, people get progressively weaker and weaker, whereas in myasthenia there are times where weakness may be better or worse.
How do you work with Providence Swedish patients diagnosed with MG?
The first step in managing MG is to ensure we’re dealing with the correct diagnosis. There are a variety of tests that we might do to diagnose MG, including blood tests and electrical tests. There might be scans that exclude other issues. Once we actually make a diagnosis, it's a personalized process in terms of putting together a treatment plan. What the treatment ends up being depends on factors like how bad symptoms are, how often symptoms are happening and what other diseases someone with MG has. We might also consider things like whether someone is willing to take infusions or injections, or whether they prefer taking pills. Understanding someone’s, lifestyle, work and family obligations can really impact what therapies are going to be good options.
But overall, we have a host of different therapies that are available. Most of these treatments target the immune system. We are also involved in research here at Swedish and we have a couple of clinical trial protocols looking at new and advancing therapies.
How should someone proceed if they suspect that their symptoms may be MG?
Talk to your doctor, usually your primary care physician because they know you. Oftentimes talking with your physician and having them examine you will help figure out what is the best next step. Depending on your symptoms, your doctor might send you to a neurologist or neuro-ophthalmologist who can help figure out if your symptoms are from something like MG or something totally different, like an injury to an eye muscle or a problem inside the brain. So really the first thing to do is talk to your doctor for an individual evaluation and advice on the next steps.
Find a physician or advanced practice clinician (APC)
Our experts at the Swedish Neuroscience Institute offer comprehensive, progressive diagnosis and treatment for a wide range of spine, brain and central nervous system conditions. Telehealth options are available. Visit us on the web or call 206-320-3940. You can also use our provider directory to find the doctor that’s right for you.
Swedish Virtual Care connects you face-to-face with a nurse practitioner who can review your symptoms, provide instruction, and follow up as needed. If you need to find a provider, you can use our provider directory.
Additional resources
What is Guillain-Barré Syndrome?
Three sisters find hope at the Swedish Neuroscience Institute
Hope’s next chapter: three sisters continue their remarkable focused ultrasound journey
This information is not intended as a substitute for professional medical care. Always follow your health care professional’s instructions.
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