People with myasthenia gravis (MG) experience weakness that can affect their lives in various ways. Newer treatments can help control symptoms, so people are better able to live their lives and enjoy the activities they love.
MG is a chronic disease that affects about 36,000 to 60,000 people in the United States, and it can strike people of any age, gender or race. “It’s relatively rare, but one of the more common conditions I treat,” said Christina Chrisman, MD, a neuromuscular neurologist with Banner Brain & Spine.
What is myasthenia gravis?
It’s an autoimmune condition that affects a part of the nervous system where a nerve and a muscle connect, called the neuromuscular junction. With it, your immune system goes awry and attacks neurotransmitter receptor sites at this junction. It’s usually caused by certain types of antibodies, called acetylcholine receptor antibodies (AchR), which can show up on a blood test.
If you have MG, it’s hard for your nerves to communicate with your muscles. That’s what leads to muscle weakness. The weakness can strike different parts of your body:
- In the muscles of the eyes, it can lead to double vision or drooping eyelids
- In the throat, it can cause trouble speaking or swallowing
- In the diaphragm, it can lead to shortness of breath
- In the arms, legs or neck, it can lead to reduced strength
The weakness usually fluctuates throughout the day—it can worsen with activity and afternoons or evenings.
Myasthenia gravis can often be underdiagnosed or misdiagnosed. Some people complain of fatigue and weakness for years before their health care provider orders the blood test that can diagnose it. On the other hand, some people are misdiagnosed with myasthenia gravis and are prescribed aggressive treatments that have side effects. “Seeing a specialist is important due to the lack of awareness about this disease,” Dr. Chrisman said.
Treatment for myasthenia gravis
There is no cure for myasthenia gravis, but many effective treatments can reduce symptoms and help control the disease. One is a medication called pyridostigmine, which increases acetylcholine, an important neurotransmitter. This medication can be taken several times a day to help minimize symptoms.
And various therapies can act on the immune system in different ways to help control the disease in the long-term. “In some people, these treatments almost resolve all of their symptoms,” Dr. Chrisman said. Options include:
- Steroids
- Oral non-steroidal immunosuppressants
- Intravenous (IV) infusion therapies, such as intravenous immunoglobulin
- Plasma exchange, which is similar to dialysis and removes harmful myasthenia gravis antibodies from the circulation
If you have myasthenia gravis, your doctor should check for a tumor of the thymus gland called a thymoma, which is found in about 15% of people with MG and should be surgically removed. Removing the thymus gland even if there’s no tumor may also help with the disease long-term in some people.
What new treatments are available?
“There are a few new treatments for myasthenia gravis that have been FDA-approved in the past several years, which are exciting and life-changing for a lot of people,” Dr. Chrisman said. They work in specific and targeted ways, and they all require IV infusions.
One class of medication is called complement inhibitors and includes eculizumab (Soliris) and ravulizumab (Ultomiris). These monoclonal antibodies inhibit a part of the immune system involved in the myasthenia gravis antibody attack.
The other new type of medication, efgartigimod alfa (Vyvgart), works by reducing the number of certain antibodies circulating in the body.
“For the right people, these treatments may be life-changing,” Dr. Chrisman said. “In the past few years, it has been exciting to offer these new therapies and really make a difference in people’s lives.” Many people can return to golf, tennis, travel and other activities they enjoyed before their diagnosis. People may also be able to taper off other therapies, like steroids, that can have bothersome side effects.
With these treatments, the risk of infection is usually quite low, and side effects are minimal. And some people can go two months or longer between infusions.
“Of course, not every medication is right for everyone. Treatment needs to be tailored to the individual, so please talk with your doctor if you are wondering if you may be a candidate for these new therapies,” Dr. Chrisman said.
What are the downsides of these treatments?
Like any therapy for myasthenia gravis, these treatment options suppress the immune system. “When treating autoimmune diseases we affect the immune system, so there may be trade-offs like a slightly higher risk of infections,” Dr. Chrisman said. Some of the treatments require vaccinations to prevent these infections.
IV treatments require a needle stick, which some people would rather avoid. And people either need to travel to an infusion center or have a nurse come to their home to administer the treatment, so they need to plan and schedule their infusions.
What else should people with myasthenia gravis know?
Those with myasthenia gravis should know how to recognize a myasthenic crisis when symptoms that affect breathing can be severe enough to require a ventilator. An infection, stress, surgery or a medication reaction can trigger a myasthenia crisis.
If you experience extreme difficulty breathing with myasthenia gravis, you should go to the ER or call 911.
The bottom line
Myasthenia gravis, an autoimmune disorder, can cause weakness in various parts of the body. But newer treatment options can help minimize symptoms and stop the disease from progressing.
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