Myasthenia Gravis Questions & Answers

Updated: Aug 27, 2018
  • Author: Abbas Jowkar, MD; Chief Editor: Nicholas Lorenzo, MD, MHA, CPE  more...
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Questions & Answers

Overview

What is myasthenia gravis (MG)?

What is the diagnostic accuracy of the anti–acetylcholine receptor (AChR) antibody test for myasthenia gravis (MG)?

What are the clinical characteristics of myasthenia gravis (MG)?

What factors trigger or worsen exacerbations in myasthenia gravis (MG)?

What are the main classes of myasthenia gravis (MG)?

What may cause false-positive anti-acetylcholine receptor (AChR) antibody test results in the evaluation of myasthenia gravis (MG)?

Which antibody assays are useful in the evaluation of myasthenia gravis (MG)?

Which imaging studies are performed in the evaluation of myasthenia gravis (MG)?

What is the approach to treatment of myasthenia gravis (MG)?

What is included in the treatment of myasthenia gravis (MG)?

What is the role of long-term immunosuppression therapy in the treatment of myasthenia gravis (MG)?

What is the role of eculizumab in the treatment of myasthenia gravis (MG)?

Which agents are being investigated as possible treatments for myasthenia gravis (MG)?

What is the role of thymectomy in the treatment of myasthenia gravis (MG)?

What is myasthenia gravis (MG)?

What is the anatomy of myasthenia gravis (MG)?

What is the role of the pre-synaptic region in myasthenia gravis (MG)?

What are the primary, secondary, and tertiary groups of synaptic vesicles for myasthenia gravis (MG)?

What is the role of synaptic space in myasthenia gravis (MG)?

What is the role of the post-synaptic membrane in myasthenia gravis (MG)?

What is the role of the acetylcholine receptor for myasthenia gravis (MG)?

How are the subunits in the acetylcholine receptor (AChR) organized in myasthenia gravis (MG)?

What is the role of neureregulin in myasthenia gravis (MG)?

How does neuromuscular transmission occur in myasthenia gravis (MG)?

What is the role of acetylcholine receptor (AChR) molecules in the pathogenesis of myasthenia gravis (MG)?

What is the role of voltage-gated calcium channels (VGCCs) in the pathogenesis of myasthenia gravis (MG)?

What is the role of endplate potential (EPP) in the pathogenesis of myasthenia gravis (MG)?

What is the safety factor in the pathogenesis of myasthenia gravis (MG)?

What leads to insufficient endplate potentials (EPP) in the pathophysiology of myasthenia gravis (MG)?

When do patients become symptomatic with myasthenia gravis (MG)?

What is the role of type-II hypersensitivity reactions in the pathophysiology of myasthenia gravis (MG)?

What leads to impairment of neuromuscular transmission in the pathophysiology of myasthenia gravis (MG)?

What is seronegative myasthenia gravis (MG)?

Why does myasthenia gravis (MG) affect the extraocular muscles first?

What causes myasthenia gravis (MG)?

Which drugs induce or exacerbate symptoms of myasthenia gravis (MG)?

What is the prevalence of thymic abnormalities in myasthenia gravis (MG)?

What is the incidence of myasthenia gravis (MG)?

How does the incidence of myasthenia gravis (MG) vary by age?

How does the incidence of myasthenia gravis (MG) vary by sex?

What are the racial predilections of myasthenia gravis (MG)?

What is the prognosis of myasthenia gravis (MG)?

What should be included in patient education about myasthenia gravis (MG)?

Presentation

What history is characteristic of myasthenia gravis (MG)?

What is the appearance of a patient with myasthenia gravis (MG)?

What are oropharyngeal symptoms of myasthenia gravis (MG)?

What are the muscle weakness symptoms of myasthenia gravis (MG)?

Which factors can cause myasthenia gravis (MG) symptoms worsen?

What are less common symptoms of myasthenia gravis (MG)?

What history is characteristic of anti-MuSK-positive myasthenia gravis (MG)?

What are the classifications of myasthenia gravis (MG)?

Which physical findings suggest myasthenia gravis (MG)?

How is weakness characterized in myasthenia gravis (MG)?

How is extraocular muscle weakness characterized in patients with myasthenia gravis (MG)?

What is the prevalence of palatal muscle weakness in patients with myasthenia gravis (MG)?

How is jaw muscle weakness characterized in myasthenia gravis (MG)?

How is limb muscle weakness characterized in myasthenia gravis (MG)?

How is respiratory muscle weakness characterized in myasthenia gravis (MG)?

Which maneuvers should be included in the physical exam of suspected myasthenia gravis (MG)?

Which comorbid autoimmune diseases may be present in patients with myasthenia gravis (MG)?

DDX

Which conditions should be included in the differential diagnoses of myasthenia gravis (MG) in older patients?

What are the differential diagnoses for Myasthenia Gravis?

Workup

What is the role of anti- receptor (AChR) antibody testing in the evaluation of myasthenia gravis (MG)?

What is the significance of finding modulating anti-acetylcholine receptor (AChR) ab in the evaluation of myasthenia gravis (MG)?

What is the role of anti-striated muscle (anti-SM) ab in the evaluation of myasthenia gravis (MG)?

What is the role of anti-agrin antibodies in the evaluation of myasthenia gravis (MG)?

Which lab test is used to determine severity of myasthenia gravis (MG)?

What is the significance of finding binding anti-acetylcholine receptor (AChR) ab in the evaluation of myasthenia gravis (MG)?

What is the significance of finding blocking anti-acetylcholine receptor (AChR) ab in the evaluation of myasthenia gravis (MG)?

What is the role of anti-muscle-specific kinase (MuSK) antibodies in the evaluation of myasthenia gravis (MG)?

What is the role of anti-lipoprotein-related protein 4 (LRP4) antibodies in the evaluation of myasthenia gravis (MG)?

Which autoantibodies may be present in myasthenia gravis (MG)?

Which lab tests are performed to rule out specific differential diagnoses of myasthenia gravis (MG)?

What is the role of imaging studies in the evaluation of myasthenia gravis (MG)?

How does tetanic contraction affect repetitive nerve stimulation (RNS) for myasthenia gravis (MG)?

What is the role of electrodiagnostic studies in the evaluation of myasthenia gravis (MG)?

Which electrodiagnostic studies are performed in the evaluation of myasthenia gravis (MG)?

What is the role of repetitive nerve stimulation (RNS) in the evaluation of myasthenia gravis (MG)?

How does temperature affect the results of repetitive nerve stimulation (RNS) in the evaluation of myasthenia gravis (MG)?

What follows a tetanic contraction in the evaluation of myasthenia gravis (MG)?

How is tetanic contraction of the muscle used in repetitive nerve stimulation (RNS) for myasthenia gravis (MG)?

What is the role of single-fiber electromyography (SFEMG) in the evaluation of myasthenia gravis (MG)?

What are the benefits of single-fiber electromyography (SFEMG) in the evaluation of myasthenia gravis (MG)?

What is the role of pharmacological testing in the evaluation of myasthenia gravis (MG)?

How is pharmacological testing performed in the evaluation of myasthenia gravis (MG)?

What is the role of edrophonium in the evaluation of myasthenia gravis (MG)?

What is the role of the ice pack test in the evaluation of myasthenia gravis (MG)?

Which histologic findings are characteristic of myasthenia gravis (MG)?

Treatment

What is the basis for treatment selection in myasthenia gravis (MG)?

What are the Myasthenia Gravis Foundation of America operational definitions of myasthenia gravis (MG)?

What are the treatment options for myasthenia gravis (MG)?

When is inpatient care indicated for myasthenia gravis (MG)?

What is included in pharmacologic therapy for myasthenia gravis (MG)?

What is the role of anticholinesterase (AChE) inhibitors in the treatment of myasthenia gravis (MG)?

What is the role of pyridostigmine in the treatment of myasthenia gravis (MG)?

What is the role of corticosteroids in the treatment of myasthenia gravis (MG)?

What is the efficacy of corticosteroid therapy for the treatment of myasthenia gravis (MG)?

What is the role of nonsteroidal immunosuppressant agents in the treatment of myasthenia gravis (MG)?

Which medications are used in the pharmacologic therapy of myasthenia gravis (MG)?

What is the efficacy of immunosuppressive therapy for myasthenia gravis (MG)?

What is the importance of immunosuppressant tapering for myasthenia gravis (MG)?

What is the role of plasma exchange (PLEX) and IV immune globulin (IVIg) in the treatment of myasthenia gravis (MG)?

What is the treatment regimen for refractory myasthenia gravis (MG)?

How is IV immune globulin (IVIg) used in maintenance therapy for myasthenia gravis (MG)?

What is the role of rituximab in the treatment of myasthenia gravis (MG)?

What are the rituximab regimens used in the treatment of myasthenia gravis (MG)?

How is prednisone used in the treatment of myasthenia gravis (MG)?

How is myasthenia gravis (MG) induced by cancer immunotherapy treated?

What is neonatal myasthenia gravis (MG) and how is it managed?

What are the complications of myasthenia gravis (MG)?

What is the role of plasmapheresis in the treatment of myasthenia gravis (MG)?

What is the role of thymectomy in the treatment of myasthenia gravis (MG)?

When is thymectomy indicated in the treatment of myasthenia gravis (MG)?

In which patients is thymectomy contraindicated for the treatment of myasthenia gravis (MG)?

What is the possible outcome of thymectomy for myasthenia gravis (MG)?

What are the remission rates following thymectomy for myasthenia gravis (MG)?

What is the role of robotic thymectomy in the treatment of myasthenia gravis (MG)?

What is the preferred thymectomy technique for myasthenia gravis (MG)?

What is the Myasthenia Gravis Foundation of America (MGFA) thymectomy classification?

What is efficacy of thymectomy in the treatment of myasthenia gravis (MG)?

What is the role of diet and activity in the treatment of myasthenia gravis (MG)?

How is myasthenia gravis (MG) managed during pregnancy?

What is the role of plasma exchange (PLEX) and IV immune globulin (IVIg) in the treatment of pregnant patients with myasthenia gravis (MG)?

What is the risk for babies born to mothers with myasthenia gravis (MG)?

What is juvenile myasthenia gravis (MG)?

How is IV immune globulin (IVIg) administered in the treatment of myasthenia gravis (MG)?

What are the advantages and disadvantages of IV immune globulin (IVIg) in the treatment of myasthenia gravis (MG)?

Medications

Which medications are used in the treatment of myasthenia gravis (MG)?

Which medications in the drug class Anticholinergic agents are used in the treatment of Myasthenia Gravis?

Which medications in the drug class Beta2 Agonists are used in the treatment of Myasthenia Gravis?

Which medications in the drug class Monoclonal Antibodies are used in the treatment of Myasthenia Gravis?

Which medications in the drug class Immune Globulins are used in the treatment of Myasthenia Gravis?

Which medications in the drug class Immunomodulators are used in the treatment of Myasthenia Gravis?

Which medications in the drug class Corticosteroids are used in the treatment of Myasthenia Gravis?

Which medications in the drug class Anticholinesterase Inhibitors are used in the treatment of Myasthenia Gravis?