Table of ContentsView AllTable of ContentsSymptomsCausesDiagnosisTreatmentCopingNext in Myasthenia Gravis GuideSymptoms of Myasthenia Gravis
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Table of Contents
Symptoms
Causes
Diagnosis
Treatment
Coping
Next in Myasthenia Gravis Guide
Myasthenia gravis(MG) is a condition that causes profound muscle weakness as a result of the immune system attacking receptors (docking sites) located on muscle tissue. The muscles in the eyelids and those attached to the eyeball are commonly the first (and sometimes only) muscles affected in myasthenia gravis. Other muscles that may become weak include jaw, limb, and even, breathing muscles.
While there is no cure yet for myasthenia gravis, the upside is that there are several therapies available to improve symptoms.
Verywell / Alexandra Gordon
Myasthenia Gravis Symptoms
The primary symptom of myasthenia gravis is significant, specific muscle weakness that tends to get progressively worse later in the day, especially if the affected muscles are being used a lot.
Commonly, someone with myasthenia gravis will first experience droopy eyelids or “tired eyes” (ptosis) and/or blurry or double vision (diplopia).
While some people with MG only experience eye muscle weakness (ocular myasthenia), others progress to a more generalized form of the disease in which multiple muscles are affected.
In those individuals, besides eye-related problems, these symptoms may occur:
Keep in mind, the weakness of myasthenia gravis is different than, for example, the tiredness someone might feel in their legs after standing or working all day.Weaknessimplies only barely being able to move a particular muscle.
Due to related, severe shortness of breath,intubation(being placed on a breathing machine) and monitoring in an intensive care unit are required.
When a Loved One Is in the ICU
7:33A Day In The Life with Myasthenia Gravis (MG)
7:33
A Day In The Life with Myasthenia Gravis (MG)
It’s important to note that in some cases, instead of antibodies produced against acetylcholine receptors, a person with myasthenia gravis has antibodies produced against proteins located on the surface of the muscle membrane. These antibodies are calledmuscle-specific receptor tyrosine kinase (MuSK) antibodies.
What Is Asthenia?
Medical History and Neurological Exam
During the medical history, a healthcare provider will listen carefully to your health story and inquire about specific details. For example, they may ask the following questions if they suspect myasthenia gravis based on you noting “tired or dropping eyes.”
After these questions, your healthcare provider will perform a neurological exam in which they evaluate your muscle strength and tone. They will also check your eyes to see if there are any problems with eye movement.
Blood Tests
In addition to a medical history and physical exam, if a person has symptoms suggestive of myasthenia gravis, there are antibody blood tests that can be done to confirm the diagnosis.
The most specific test is theacetylcholine receptor antibody test, which checks the blood for the presence of abnormal antibodies.Presence of the antibodies confirms the diagnosis. Your healthcare provider may also check for the presence of MuSK antibodies.
Electrophysiological Studies
Electrophysiological studies, such as repetitive nerve stimulation studies and single-fiber electromyography (EMG), can be very helpful in diagnosing myasthenia gravis—especially if other tests (like the antibody blood test) are normal, but a practitioner’s suspicion for MG is still high based on one’s symptoms.
Understanding NCS and EMG Test Results
Edrophonium Test
Theedrophonium test, also called theTensilon test, has mostly fallen out of use due to the unavailability of the chemical required to perform it.
Historically, though, during this test, a healthcare provider injects edrophonium—a medicine that prevents the breakdown of acetylcholine—into a vein. If muscle strength improves after this medicine is given, the test is considered positive and offers strong support for the diagnosis of MG.
Imaging
Some patients with myasthenia gravis have a tumor of thethymus gland—an immune system gland that is located in your chest.Imaging tests, usually acomputed tomography (CT) scanormagnetic resonance imaging (MRI), can diagnose thymomas.
An MRI of the brain may also be ordered during the diagnostic process to evaluate for mimicking conditions likestroke,brain tumor, ormultiple sclerosis.
While there is no cure for myasthenia gravis, there aretreatments that ease symptoms and calm the disease down.
Acetylcholine Inhibitors
Drugs called acetylcholinesterase inhibitors, which block the breakdown of acetylcholine, can help increase the levels of acetylcholine at the neuromuscular junction. The main acetylcholinesterase inhibitor used to treat myasthenia gravis is Mestinon (pyridostigmine).
Potential side effects of this drug include diarrhea, abdominal cramping, and nausea, although taking it with food can reduce gastrointestinal distress.
Immunosuppressants
Glucocorticoids, such as prednisone, are often used to suppress the abnormal production of antibodies in people with myasthenia gravis.
Other immune-system suppressing drugs sometimes used to treat myasthenia gravis include:
Plasmapheresis
Plasma exchange (plasmapheresis), in which blood plasma containing the abnormal antibodies is removed and fresh plasma is put back in, is used to treat an acute myasthenic crisis. This procedure may also be done before surgery in an effort to head off a myasthenic crisis.
The caveat about plasmapheresis is that while it works within days, the benefits are short-lived (usually just weeks). In addition, plasmapheresis is expensive and complications may arise, such as:
Intravenous Immunoglobulin
Intravenous immunoglobulin (IVIG) entails giving a person (through their vein) a high concentration of antibodies collected from healthy donors. The administration of IVIG is usually done over a period of two to five days. While possible side effects of IVIG are generally mild, serious complications may occur including kidney failure,meningitis, and allergic reactions.
Just like plasmapheresis, intravenous immunoglobulin (IVIG) may be used to treat a myasthenic crisis or administered prior to surgery. Likewise, the effects of IVIG are short-lived.
Thymectomy
Surgery to remove the thymus gland (thymectomy) can reduce and possibly even resolve myasthenia gravis symptoms.
While surgery is definitely indicated in people with a thymus gland tumor, whether thymectomy is indicated in other cases is less clear. In these instances, it’s important to have a thoughtful discussion with a neurologist who has experience treating myasthenia gravis.
A key strategy for preventing myasthenic attacks is to avoid/minimize possible triggers.
Potential triggers for myasthenic attacks include:
Certain medications can also trigger an attack, such as:
Individuals with myasthenia gravis should be careful before starting any new medication and watch carefully after taking it for signs of muscle weakness.
Infection, such as with the flu or pneumonia, can also trigger a myasthenia flare. With that, be sure to obtain all recommended vaccines, such as your yearly flu shot.
A Word From Verywell
The future of myasthenia gravis is bright, as researchers work tirelessly to find therapies that target and perhaps fix the immune system abnormality that lies at the root of myasthenia gravis. Until then, continue to remain active in your health care: See your healthcare provider regularly, report any new symptoms right away, and take medication as advised.
7 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Sieb JP.Myasthenia gravis: an update for the clinician.Clin Exp Immunol. 2014;175(3):408-18. doi:10.1111/cei.12217Wendell LC, Levine JM.Myasthenic crisis.Neurohospitalist. 2011;1(1):16-22. doi:10.1177/1941875210382918Berrih-Aknin S, Frenkian-Cuvelier M, Eymard B.Diagnostic and clinical classification of autoimmune myasthenia gravis.J Autoimmun. 2014;48-49:143-8. doi:10.1016/j.jaut.2014.01.003NIH National Institute of Neurological Disorders and Stroke.Myasthenia gravis.Colović MB, Krstić DZ, Lazarević-Pašti TD, Bondžić AM, Vasić VM.Acetylcholinesterase inhibitors: pharmacology and toxicology.Curr Neuropharmacol. 2013;11(3):315-35. doi:10.2174/1570159X11311030006Szczeklik W, Wawrzycka K, Włudarczyk A, et al.Complications in patients treated with plasmapheresis in the intensive care unit.Anaesthesiol Intensive Ther. 2013;45(1):7-13. doi:10.5603/AIT.2013.0002Guo Y, Tian X, Wang X, Xiao Z.Adverse effects of immunoglobulin therapy.Front Immunol. 2018;9:1299. doi:10.3389/fimmu.2018.01299Additional ReadingMyasthenia Gravis Foundation of America.What is myasthenia gravis?Trouth AJ, Dabi A, Solieman N, Kurukumbi M, Kalyanam J.Myasthenia gravis: a review.Autoimmune Dis. 2012;2012:874680. doi:10.1155/2012/874680
7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Sieb JP.Myasthenia gravis: an update for the clinician.Clin Exp Immunol. 2014;175(3):408-18. doi:10.1111/cei.12217Wendell LC, Levine JM.Myasthenic crisis.Neurohospitalist. 2011;1(1):16-22. doi:10.1177/1941875210382918Berrih-Aknin S, Frenkian-Cuvelier M, Eymard B.Diagnostic and clinical classification of autoimmune myasthenia gravis.J Autoimmun. 2014;48-49:143-8. doi:10.1016/j.jaut.2014.01.003NIH National Institute of Neurological Disorders and Stroke.Myasthenia gravis.Colović MB, Krstić DZ, Lazarević-Pašti TD, Bondžić AM, Vasić VM.Acetylcholinesterase inhibitors: pharmacology and toxicology.Curr Neuropharmacol. 2013;11(3):315-35. doi:10.2174/1570159X11311030006Szczeklik W, Wawrzycka K, Włudarczyk A, et al.Complications in patients treated with plasmapheresis in the intensive care unit.Anaesthesiol Intensive Ther. 2013;45(1):7-13. doi:10.5603/AIT.2013.0002Guo Y, Tian X, Wang X, Xiao Z.Adverse effects of immunoglobulin therapy.Front Immunol. 2018;9:1299. doi:10.3389/fimmu.2018.01299Additional ReadingMyasthenia Gravis Foundation of America.What is myasthenia gravis?Trouth AJ, Dabi A, Solieman N, Kurukumbi M, Kalyanam J.Myasthenia gravis: a review.Autoimmune Dis. 2012;2012:874680. doi:10.1155/2012/874680
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Sieb JP.Myasthenia gravis: an update for the clinician.Clin Exp Immunol. 2014;175(3):408-18. doi:10.1111/cei.12217Wendell LC, Levine JM.Myasthenic crisis.Neurohospitalist. 2011;1(1):16-22. doi:10.1177/1941875210382918Berrih-Aknin S, Frenkian-Cuvelier M, Eymard B.Diagnostic and clinical classification of autoimmune myasthenia gravis.J Autoimmun. 2014;48-49:143-8. doi:10.1016/j.jaut.2014.01.003NIH National Institute of Neurological Disorders and Stroke.Myasthenia gravis.Colović MB, Krstić DZ, Lazarević-Pašti TD, Bondžić AM, Vasić VM.Acetylcholinesterase inhibitors: pharmacology and toxicology.Curr Neuropharmacol. 2013;11(3):315-35. doi:10.2174/1570159X11311030006Szczeklik W, Wawrzycka K, Włudarczyk A, et al.Complications in patients treated with plasmapheresis in the intensive care unit.Anaesthesiol Intensive Ther. 2013;45(1):7-13. doi:10.5603/AIT.2013.0002Guo Y, Tian X, Wang X, Xiao Z.Adverse effects of immunoglobulin therapy.Front Immunol. 2018;9:1299. doi:10.3389/fimmu.2018.01299
Sieb JP.Myasthenia gravis: an update for the clinician.Clin Exp Immunol. 2014;175(3):408-18. doi:10.1111/cei.12217
Wendell LC, Levine JM.Myasthenic crisis.Neurohospitalist. 2011;1(1):16-22. doi:10.1177/1941875210382918
Berrih-Aknin S, Frenkian-Cuvelier M, Eymard B.Diagnostic and clinical classification of autoimmune myasthenia gravis.J Autoimmun. 2014;48-49:143-8. doi:10.1016/j.jaut.2014.01.003
NIH National Institute of Neurological Disorders and Stroke.Myasthenia gravis.
Colović MB, Krstić DZ, Lazarević-Pašti TD, Bondžić AM, Vasić VM.Acetylcholinesterase inhibitors: pharmacology and toxicology.Curr Neuropharmacol. 2013;11(3):315-35. doi:10.2174/1570159X11311030006
Szczeklik W, Wawrzycka K, Włudarczyk A, et al.Complications in patients treated with plasmapheresis in the intensive care unit.Anaesthesiol Intensive Ther. 2013;45(1):7-13. doi:10.5603/AIT.2013.0002
Guo Y, Tian X, Wang X, Xiao Z.Adverse effects of immunoglobulin therapy.Front Immunol. 2018;9:1299. doi:10.3389/fimmu.2018.01299
Myasthenia Gravis Foundation of America.What is myasthenia gravis?Trouth AJ, Dabi A, Solieman N, Kurukumbi M, Kalyanam J.Myasthenia gravis: a review.Autoimmune Dis. 2012;2012:874680. doi:10.1155/2012/874680
Myasthenia Gravis Foundation of America.What is myasthenia gravis?
Trouth AJ, Dabi A, Solieman N, Kurukumbi M, Kalyanam J.Myasthenia gravis: a review.Autoimmune Dis. 2012;2012:874680. doi:10.1155/2012/874680
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