What is myasthenia gravis?

Access guidance on key characteristics and prevalences of ocular and bulbar myasthenia gravis (MG), including limb symptoms. Emergent indicators of a myasthenic crisis as well as the impacts of MG on emotional wellbeing and social functioning are also reviewed.

Clinical presentation of myasthenia gravis

Review the hallmark clinical features of MG, from common ocular and bulbar symptoms to limb involvement and the warning signs of a myasthenic crisis.

MG, a chronic autoimmune disease, leads to fluctuating muscle weakness, fatigue, and unpredictable symptoms that significantly affect daily life^1-7

What to look for in myasthenia gravis

“When we’re teaching about myasthenia gravis, I think we always describe it as the way the doctors think about it, but it’s always important to know how the patient is going to be describing it.” Neelam Goyal (Stanford University, California, USA) highlights the importance of patient-reported functional impairments in MG assessment.  

Although MG presents with diverse and heterogeneous symptoms, common presenting features are typically identified during clinical evaluation.^2,4,6,7 These symptoms are often unpredictable and fluctuate throughout the disease course.⁷

People with MG may report symptoms that impact daily living, including:^4,7

• Visual disturbances
• Difficulty chewing or swallowing
• Hindered mobility

Myasthenia gravis subtypes

MG pathophysiology is characterized by pathogenic autoantibodies that target components of the neuromuscular junction, including acetylcholine receptors (AChR), muscle-specific kinase (MuSK), and low-density lipoprotein receptor-related protein 4 (LRP4)^8-10

While some characteristics are shared across MG subtypes, others are distinct. MG presenting with AChR autoantibodies represents the most prevalent subtype, followed by MuSK and LRP4 autoantibodies.⁸ The immunoglobulin (Ig)G1 subclass is commonly associated with both anti-AChR and anti-LRP4 MG, with additional involvement of IgG3 in anti-AChR MG and IgG4 in anti-MuSK MG.^8-10

Clinically, anti-AChR and anti-LRP4 MG differ from anti-MuSK MG in their typical presentation:^8,9,11,12

• Anti-AChR and anti-LRP4 MG are generally characterized by ocular and bulbar manifestations, along with muscle and limb weakness
• Anti-MuSK MG predominantly affects the facial-bulbar muscles and is frequently associated with respiratory compromise and myasthenic crisis

Autoantibody subtypes in myasthenia gravis

This downloadable infographic highlights key features of the most prevalent autoantibody subtypes, AChR, MuSK, and LRP4, and associated symptoms.

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Meet the experts

Neelam Goyal, MD

Neelam Goyal is Clinical Professor of Neurology and Neurological Sciences in the division of Neuromuscular Medicine at Stanford University Medical Hospital (Palo Alto, California, USA). Her research focuses on the diagnosis, management, and electrophysiological testing of neuromuscular disorders, including single-fiber electromyography. She also serves as the Interim Vice Chair of Advancement, Community and Engagement; the Wellbeing Director for the Neurology Department; and as a communication coach for the neurology residency program at Stanford University School of Medicine.

Disclosures: Consulting roles for argenx, Alexion, UCB, Janssen, Amgen, Novartis, Immunovant, Dianthus, Annexon, Seismic, Cartesian, and EMD Serono.* Research funding from argenx.

Ali Habib, MD

Ali Habib is a neuromuscular neurologist at the University of California (Irvine, USA) where he serves as Clinical Professor and Director of the Myasthenia Gravis Clinic. He is also a member of the Medical and Scientific Advisory Council of the Myasthenia Gravis Foundation of America and a board member of the Myasthenia Gravis Foundation of California.

Disclosures: Honoraria from UCB, argenx, Alexion, Immunovant, and Regeneron. Research funding from Alexion/AstraZeneca, argenx, UCB, Immunovant, Regeneron, Cabaletta Bio, Viela Bio, Pfizer, and Genentech.

*EMD Serono is the healthcare business of Merck KGaA, Darmstadt, Germany, in the US and Canada.

References

1. Gilhus and Breiner, 2025. Chapter eight - Epidemiology of myasthenia gravis. https://doi.org/10.1016/bs.irn.2025.04.028
2. Dresser, 2021. Myasthenia gravis: Epidemiology, pathophysiology and clinical manifestations. https://doi.org/10.3390/jcm10112235
3. Bubuioc, 2021. The epidemiology of myasthenia gravis. https://doi.org/10.25122/jml-2020-0145
4. NIH, 2025. Myasthenia gravis. https://www.ninds.nih.gov/health-information/disorders/myasthenia-gravis
5. Kaminski, 2024. Myasthenia gravis: The future is here. https://doi.org/10.1172/JCI179742
6. Fichtner, 2025. Chapter five - Autoantibodies in myasthenia gravis. https://doi.org/10.1016/bs.irn.2025.04.024
7. Jackson, 2023. Understanding the symptom burden and impact of myasthenia gravis from the patient’s perspective: A qualitative study. https://doi.org/10.1007/s40120-022-00408-x
8. Lazaridis and Tzartos, 2020. Myasthenia gravis: Autoantibody specificities and their role in MG management. https://doi.org/10.3389/fneur.2020.596981
9. Iorio, 2024. Myasthenia gravis: The changing treatment landscape in the era of molecular therapies. https://doi.org/10.1038/s41582-023-00916-w
10. Fichtner, 2020. Autoimmune pathology in myasthenia gravis disease subtypes is governed by divergent mechanisms of immunopathology. https://doi.org/10.3389/fimmu.2020.00776
11. Rodolico, 2020. MuSK-associated myasthenia gravis: Clinical features and management. https://doi.org/10.3389/fneur.2020.00660
12. Rivner, 2020. Clinical features of LRP-4/agrin–antibody-positive myasthenia gravis: A multicenter study. https://doi.org/10.1002/mus.26985
    
    

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Myasthenia gravis: Mechanism of disease

Review the physiological mechanisms underlying myasthenia gravis, including the autoimmune processes that lead to autoantibody production and disrupted neuromuscular signaling, resulting in muscle fatigue and weakness.

Myasthenia gravis (MG) is a rare autoimmune disease characterized by neuromuscular dysfunction.^1,3 Under normal physiological conditions, cholinergic motor neurons innervate muscle fibers, where the neuromuscular junction (NMJ) serves as the synaptic interface between the presynaptic axon terminal and the postsynaptic muscle membrane.^1-3 In MG, autoreactive T cells activate B cells, which differentiate into memory B cells, plasmablasts, and plasma cells.^2,4,5 Plasmablasts and plasma cells produce pathogenic autoantibodies that target acetylcholine receptors (AChRs), muscle-specific kinase (MuSK), and lipoprotein receptor-related protein 4 (LRP4), resulting in impaired muscle contraction, fatigability, and muscle weakness.^2-4

Pathophysiology of myasthenia gravis

This downloadable infographic summarizes the B-cell–mediated, T-cell–dependent pathophysiology of MG, including upstream immune dysregulation, pathogenic autoantibody–mediated disruption of NMJ signaling, and downstream mechanisms such as complement activation and impaired receptor clustering that compromise muscle contraction.^6,7

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References

1. Howard, 2018. Myasthenia gravis: The role of complement at the neuromuscular junction. https://doi.org/10.1111/nyas.13522
2. Kaminski, 2024. Myasthenia gravis: The future is here. https://doi.org/10.1172/JCI179742
3. Dresser, 2021. Myasthenia gravis: Epidemiology, pathophysiology and clinical manifestations. https://doi.org/10.3390/jcm10112235
4. Yi, 2018. B cells in the pathophysiology of myasthenia gravis. https://doi.org/10.1002/mus.25973
5. Uzawa, 2021. Roles of cytokines and T cells in the pathogenesis of myasthenia gravis. https://doi.org/10.1111/cei.13546
6. Cavalcante, 2024. Targeting autoimmune mechanisms by precision medicine in myasthenia gravis. https://doi.org/10.3389/fimmu.2024.1404191
7. He, 2024. Immune repertoire profiling in myasthenia gravis. https://doi.org/10.1111/imcb.12825

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Early and accurate diagnosis of myasthenia gravis

What are common diagnostic pitfalls in myasthenia gravis? Ali Habib (University of California Irvine, USA) and Neelam Goyal (Stanford University, California, USA) discuss the potential barriers to an accurate diagnosis of myasthenia gravis, including conditions that may mimic it, and strategies to reduce misdiagnosis.

An early and accurate diagnosis of myasthenia gravis (MG) is key to avoiding unnecessary treatment and limiting the risk of neuromuscular damage or fixed weakness.^1-6 Barriers to timely diagnosis of MG include:^7-10

• Mild or fluctuating symptomatology
• Comorbidities
• Symptom communication challenges

Diagnostic considerations for myasthenia gravis

Accurate diagnosis is a cornerstone of effective MG management, yet the fluctuating nature of the disease means symptoms can be subtle or easily overlooked.^7-9 A typical diagnostic workup includes clinical examination, serologic testing, and additional assessments as required.^9-11

Diagnosis of myasthenia gravis

What questions should be asked during a clinical evaluation, and which serologic tests are most appropriate for each MG subtype? Download this clinician-informed infographic about considerations for clinical assessment, serologic testing, and electrophysiological evaluation for individuals presenting with symptoms of MG.

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Meet the experts

Neelam Goyal, MD

Neelam Goyal is Clinical Professor of Neurology and Neurological Sciences in the division of Neuromuscular Medicine at Stanford University Medical Hospital (Palo Alto, California, USA). Her research focuses on the diagnosis, management, and electrophysiological testing of neuromuscular disorders, including single-fiber electromyography. She also serves as the Interim Vice Chair of Advancement, Community and Engagement; the Wellbeing Director for the Neurology Department; and as a communication coach for the neurology residency program at Stanford University School of Medicine.

Disclosures: Consulting roles for argenx, Alexion, UCB, Janssen, Amgen, Novartis, Immunovant, Dianthus, Annexon, Seismic, Cartesian, and EMD Serono.* Research funding from argenx.

Ali Habib, MD

Ali Habib is a neuromuscular neurologist at the University of California (Irvine, USA) where he serves as Clinical Professor and Director of the Myasthenia Gravis Clinic. He is also a member of the Medical and Scientific Advisory Council of the Myasthenia Gravis Foundation of America and a board member of the Myasthenia Gravis Foundation of California.

Disclosures: Honoraria from UCB, argenx, Alexion, Immunovant, and Regeneron. Research funding from Alexion/AstraZeneca, argenx, UCB, Immunovant, Regeneron, Cabaletta Bio, Viela Bio, Pfizer, and Genentech.

*EMD Serono is the healthcare business of Merck KGaA, Darmstadt, Germany, in the US and Canada.

References

1. Pesa, 2025. Factors associated with increased severity of generalized myasthenia gravis among patients in the United States and Europe. https://doi.org/10.1038/s41598-025-93464-w
2. Falso, 2025. Assessing the rate and causes of myasthenia gravis misdiagnosis. https://doi.org/10.1212/WNL.0000000000210780
3. Li, 2019. Do early prednisolone and other immunosuppressant therapies prevent generalization in ocular myasthenia gravis in Western populations: A systematic review and meta-analysis. https://doi.org/10.1177/1756286419876521
4. Velonakis, 2021. MRI evidence of extraocular muscle atrophy and fatty replacement in myasthenia gravis. https://doi.org/10.1007/s00234-021-02753-4
5. Cejvanovic and Vissing, 2014. Muscle strength in myasthenia gravis. https://doi.org/10.1111/ane.12193
6. Vesperinas, 2026. Challenges in myasthenia gravis diagnosis: An analysis of the diagnostic process of myasthenia gravis in a specialized clinic. https://doi.org/10.1016/j.nmd.2025.106284
7. Beaupark, 2024. Myasthenia gravis misunderstood - identifying the historical misinterpretations, miscommunication, and misconceptions. https://doi.org/10.17161/rrnmf.v5i3.21137
8. Mahic, 2022. Physician-reported perspectives on myasthenia gravis in the United States: A real-world survey. https://doi.org/10.1007/s40120-022-00383-3
9. Oguz-Akarsu, 2025. Unusual presentations of myasthenia gravis and misdiagnosis. https://doi.org/10.1038/s41598-025-91470-6
10. Reyes Acosta, 2025. What patients don’t say and physicians don’t ask: A needs assessment in myasthenia gravis integrating patient and healthcare professional perspectives. https://doi.org/10.1007/s40120-025-00751-9
11. NIH, 2025. Myasthenia gravis. https://www.ninds.nih.gov/health-information/disorders/myasthenia-gravis
12. Rousseff, 2021. Diagnosis of myasthenia gravis. https://doi.org/10.3390/jcm10081736

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Overview of diagnostic tools

Ali Habib (University of California, Irvine, USA) and Neelam Goyal (Stanford University, California, USA) review the diagnostic pathway for myasthenia gravis, covering clinical evaluation, electrophysiological studies, and key considerations in serologic testing across subtypes.

A diagnosis of myasthenia gravis (MG) often begins with a clinical suspicion of the disease based on fatigable muscle weakness and fluctuating symptoms.^1,2 Physical and neurological examination, serologic testing, and electrophysiology are used to confirm a diagnosis of MG³:

• Clinical examination and assessments can be used in the initial evaluation to determine fatigability and ocular symptoms^2,4-6 
• Serologic assessment supports disease subtyping and guides appropriate therapy^7,8
• Electrophysiological testing provides additional diagnostic confirmation, particularly in seronegative cases⁸

Serologic testing in myasthenia gravis

Most patients with MG have autoantibodies to the acetylcholine receptor (AChR), while smaller subsets have autoantibodies to muscle-specific kinase (MuSK) or low-density lipoprotein receptor-related protein 4 (LRP4); others may not have any of the three autoantibodies, known as triple seronegative disease⁹

Serologic testing plays a central role in diagnosing and classifying MG by identifying autoantibodies that interfere with neuromuscular function.^7-9 Common techniques for the detection of autoantibodies in plasma include the radioimmunoprecipitation assay (RIPA), enzyme-linked immunosorbent assay (ELISA), and cell-based assay.^7,10

Common serologic tests for MG diagnosis

What common serologic tests are used in diagnosing MG? Download this infographic for a visual overview of the common methods used to detect anti-AChR, anti-MuSK, and anti-LRP4 antibodies, including the benefits and limitations of each assay.

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Meet the experts

Neelam Goyal, MD

Neelam Goyal is Clinical Professor of Neurology and Neurological Sciences in the division of Neuromuscular Medicine at Stanford University Medical Hospital (Palo Alto, California, USA). Her research focuses on the diagnosis, management, and electrophysiological testing of neuromuscular disorders, including single-fiber electromyography. She also serves as the Interim Vice Chair of Advancement, Community and Engagement; the Wellbeing Director for the Neurology Department; and as a communication coach for the neurology residency program at Stanford University School of Medicine.

Disclosures: Consulting roles for argenx, Alexion, UCB, Janssen, Amgen, Novartis, Immunovant, Dianthus, Annexon, Seismic, Cartesian, and EMD Serono.* Research funding from argenx.

Ali Habib, MD

Ali Habib is a neuromuscular neurologist at the University of California (Irvine, USA) where he serves as Clinical Professor and Director of the Myasthenia Gravis Clinic. He is also a member of the Medical and Scientific Advisory Council of the Myasthenia Gravis Foundation of America and a board member of the Myasthenia Gravis Foundation of California.

Disclosures: Honoraria from UCB, argenx, Alexion, Immunovant, and Regeneron. Research funding from Alexion/AstraZeneca, argenx, UCB, Immunovant, Regeneron, Cabaletta Bio, Viela Bio, Pfizer, and Genentech.

*EMD Serono is the healthcare business of Merck KGaA, Darmstadt, Germany, in the US and Canada.

References

1. Jackson, 2023. Understanding the symptom burden and impact of myasthenia gravis from the patient’s perspective: A qualitative study. https://doi.org/10.1007/s40120-022-00408-x
2. Gilhus, 2019. Myasthenia gravis. https://doi.org/10.1038/s41572-019-0079-y
3. NIH, 2025. Myasthenia gravis. https://www.ninds.nih.gov/health-information/disorders/myasthenia-gravis
4. Jacob, 2024. Treating myasthenia gravis beyond the eye clinic. https://doi.org/10.1038/s41433-024-03133-x
5. Mihara, 2016. Fixation stability of the upward gaze in patients with myasthenia gravis: An eye-tracker study. https://doi.org/10.1136/bmjophth-2017-000072
6. Liu, 2016. Diagnosing myasthenia gravis with an ice pack. https://doi.org/10.1056/NEJMicm1509523
7. Li, 2023. Serological diagnosis of myasthenia gravis and its clinical significance. https://doi.org/10.21037/atm-19-363
8. Pesa Jacqueline, 2026. Serological testing patterns among individuals newly diagnosed with myasthenia gravis. https://doi.org/10.1016/j.jns.2025.125700
9. Lazaridis, 2020. Myasthenia gravis: Autoantibody specificities and their role in MG management. https://doi.org/10.3389/fneur.2020.596981
10. Zisimopoulou, 2013. Serological diagnostics in myasthenia gravis based on novel assays and recently identified antigens. https://doi.org/10.1016/j.autrev.2013.03.002

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Measuring myasthenia gravis

Symptoms of myasthenia gravis (MG) are heterogeneous and can fluctuate during the same day or from one day to another, ranging from visual disturbances to widespread muscle weakness^1,2

Accurate assessment and classification of MG are essential for understanding disease severity, monitoring progression, and guiding treatment decisions.^1,3-5 Functional deficits and symptom severity can be measured using validated clinical scales and patient-reported outcomes:^1,3-5

• The Myasthenia Gravis Foundation of America (MGFA) classification categorizes people with MG based on clinical features and severity, helping to distinguish differences in prognosis and therapeutic response⁴
• The MG Activities of Daily Living (MG-ADL), Quantitative MG (QMG), MG Composite (MGC), and Revised MG Quality of Life-15 (MG-QOL15r) scales are widely used to assess MG symptoms and quality of life^1,4,5

Although no measure fully reflects a patient’s lived experience yet, available tools and rating systems can help clinicians better evaluate symptom burden, monitor response to therapy, and align care with individual patient needs.¹

Assessing myasthenia gravis

This downloadable infographic provides a visual overview of the clinical tools used to assess and monitor MG, including measures for symptoms, disease severity, and quality of life.

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Classification of myasthenia gravis

Take a visual tour of the MGFA classification system – used for evaluating disease severity in MG – and review the spectrum of ocular and generalized symptoms to support consistent clinical assessment and monitoring.

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References

1. Thomsen and Andersen, 2020. Outcome measures in clinical trials of patients with myasthenia gravis. https://doi.org/10.3389/fneur.2020.596382
2. Jackson, 2023. Understanding the symptom burden and impact of myasthenia gravis from the patient’s perspective: A qualitative study. https://doi.org/10.1007/s40120-022-00408-x
3. Ruzhansky, 2025. Standardization of myasthenia gravis outcome measures in clinical practice: A report of the MGFA task force. https://doi.org/10.1002/mus.28417
4. Jaretzki, 2000. Myasthenia gravis: Recommendations for clinical research standards. https://doi.org/10.1212/wnl.55.1.16
5. Guptill, 2023. Addressing outcome measure variability in myasthenia gravis clinical trials. https://doi.org/10.1212/WNL.0000000000207278

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