Myasthenia Gravis (MG)

Myasthenia gravis (MG) is an autoimmune condition in which antibodies attack the communication between nerves and muscles (neuromuscular junction). This results in weakness and fatigue in muscles.

Weakness in the eye muscles, arms, hands, fingers, legs, and neck

Droopy eyelids (ptosis)

Shortness of breath

Changes in facial control and expressions

Difficulty speaking, swallowing, or chewing

Double vision (diplopia)

There are two main types of autoimmune myasthenia gravis: ocular and generalized.

  • Ocular MG: Causes weakness in the muscles that control the eyelids and other eye movements.
  • Generalized MG: Causes weakness in the eye muscles and other muscles throughout the body. Generalized MG is the most common type, accounting for 85% of MG cases.

There are additional specific subtypes of MG based on different aspects of the disease such as the cause, antibodies, age of onset, and tumor on the thymus gland (thymoma).

For individuals showing signs and symptoms that are consistent with myasthenia gravis, doctors may conduct the following tests to confirm a diagnosis:

  • Neurological Exam: Measures the function of an individual’s reflexes, muscle strength, muscle tone, senses of touch and sight, coordination, and balance. If a person has any difficulty moving their eyes or muscles, a medical professional may decide to conduct additional evaluations.
  • Ice Pack Test: Placing an ice pack on a muscle that is not functioning properly for a few minutes, and testing whether the patient has improved control of that muscle after the ice pack is removed. This test is often used for individuals who have a drooping eyelid, therefore, the ice pack would be placed on the person's eye.
  • Blood Tests: Checks if there are abnormal antibodies present in the blood.
  • Repetitive Nerve Stimulation: Measures the connections between muscles and nerves by using electrodes attached to nerves to detect the response to an electrical stimulus.
  • Single-Fiber Electromyography (EMG): Tests a single muscle fiber by inserting an electrode through the skin and into a muscle to measure activity between the brain and muscles.
  • Imaging: CT scans and MRI scans help visualize and check for abnormal growth in the thymus or a thymus gland tumor (thymoma).

Although there is no known cure for MG, treatments and medications can effectively reduce its signs and symptoms.

Medications

Here’s a list of medications that may help manage MG:

  • Cholinesterase inhibitors: Cholinesterase inhibitors improve communication between nerves and muscles, supporting muscle contraction and strength. An example of this type of medication is pyridostigmine.
  • Immunosuppressants:  Immunosuppressants decrease inflammation, alter the immune system, and can reduce the body's production of abnormal antibodies. Examples of immunosuppressants include azathioprine, mycophenolate mofetil, cyclosporine, methotrexate and tacrolimus.
  • Corticosteroids: Corticosteroids suppress the immune system which can limit antibody production. An example of this type of medication is prednisone
Intravenous Therapy

Intravenous therapy can be used for a short period of time to address sudden worsening of MG symptoms.‍

  • Plasmapheresis: Runs blood from the body through a machine that filters out the ACh and MuSK antibodies, and then sends the filtered blood back into the body.
  • Intravenous Immunoglobulin (IVIg): Adds normal antibodies to a patient’s blood to alter the immune response.
  • Monoclonal Antibodies: Man-made proteins that behave like human antibodies to alter immune response.
Surgery
  • Individuals with myasthenia gravis may have an enlarged thymus gland and/or a tumor (thymoma) on it. The thymus gland, located in the upper chest beneath the breastbone, is part of the immune system. When the thymus gland is enlarged or has tumors, it can cause the production of antibodies that lead to muscle weakness. Therefore, people with MG may require a thymectomy, which entails removing the thymus gland. In some cases, even if tests on the thymus gland do not indicate a problem, surgical removal of the gland may improve symptoms.

Ongoing Research

Myasthenia gravis is a rare disease that requires more effective treatment options. To find these new treatments for MG, further research is necessary.

Current Research Studies

There are over 70 myasthenia gravis research studies that are actively recruiting participants. Visit Clinicaltrials.gov to find MG research studies near you.

Featured Study

Resources

Find an online community of fellow patients, caregivers, and advocates below
as well as some other general resources!

Myasthenia Gravis Support Group
This is a support group for all Myasthenia Gravis sufferers, friends, and family members looking for answers.
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Myasthenia Gravis
A group intended to be an informative and supportive group for people with MG.
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Myasthenia Gravis Support Group
A support group for MG patients, family members and friends looking for support and answers.
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Reddit Group: r/MyastheniaGravis
A subreddit community for all discussions and questions regarding myasthenia gravis.
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Myasthenia Gravis Foundation of America
An organization committed to enhancing lives and improving care for myasthenia gravis.
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Myasthenia Gravis Association
A group dedicated to helping patients, families, friends and communities affected by myasthenia gravis.
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MG United
A group that aims to support individuals with myasthenia gravis, as well as their caregivers, by offering various resources and information about the condition.
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Living with MG Stories
Visit the Living with MG Stories page on the Myasthenia Gravis Foundation of America website to read people's different stories and experiences with MG.
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My Myasthenia
A podcast to share stories, journeys, and discoveries regarding the crazy disease Myasthenia Gravis.
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Myasthenia Gravis and Social Security Disability
Check out this website for more information on disability resources for individuals with myasthenia gravis.
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Finding Support for Your MG Journey
Read this article to learn more about ways to find support and cope with myasthenia gravis.
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Myasthenia Gravis Treatments Transforming Outcomes for Debilitating Neuromuscular Disease Under Investigation at Houston Methodist
Learn more about a clinical trial gathering real-world data on the effectiveness and safety of C5 inhibitors, a groundbreaking new class of drugs offering renewed hope to people with myasthenia gravis (MG).
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