Myasthenia Gravis

Admit and urgently involve neurology and critical care for progressive dysphagia, dysarthria, weak cough, dyspnea, or rapidly worsening generalized weakness, because respiratory-muscle involvement defines the life-threatening end of the MG spectrum. Myasthenic crisis and severe exacerbations are treated with rapid immunomodulation using plasma exchange (PLEX) or intravenous immunoglobulin (IVIG); pyridostigmine can worsen airway secretions in at least some ventilated crisis presentations. BMJ+2BMJMyasthenia gravis - Symptoms, diagnosis and treatment | BMJ Best Practice USScienceDirectRescue therapy in myasthenia gravis - ScienceDirectScienceDirectEmergent role of complement inhibitors in myasthenic crisis: Understanding why, when and how - ScienceDirect

If symptoms emerge during or after immune checkpoint inhibitor (ICI) therapy, treat MG as a possible myositis-myocarditis-MG overlap syndrome rather than isolated ocular or limb weakness. Obtain cardiac troponin and skeletal-muscle biomarkers including creatine phosphokinase, and assess for conduction disease, ventricular arrhythmia, reduced left-ventricular function, and myocarditis-directed cardiac magnetic resonance findings when clinically indicated. Overlap syndromes carry higher mortality, and respiratory failure from respiratory-muscle myositis is a recognized cause of death. jacc+1jaccDiagnosis and Management of Cardiovascular Adverse Effects of Targeted Oncology Therapies: Bruton’s Tyrosine Kinase, Immune Checkpoint, and Vascular Endothelial Growth Factor Inhibitors: 2025 ACC Concise Clinical Guidance: A Report of the American College of Cardiology Solution Set Oversight CommitteeASCOManagement of Immune-Related Adverse Events in ...

For ICI-associated MG, early PLEX or IVIG in addition to corticosteroids should be favored when weakness is clinically significant, particularly with bulbar, respiratory, or concurrent cardiac or myositis features. In a systematic review and single-center experience, first-line PLEX or IVIG plus steroids was associated with improvement in 95% of patients versus 63% with steroids alone. jaccjaccSteroids in Immune Checkpoint Inhibitor Myocarditis

Order anti-AChR binding antibody as the initial serologic test in clinically suspected MG; it is highly specific, exceeding 90%, and has sensitivity up to approximately 85% in generalized MG. A positive result confirms an autoimmune postsynaptic neuromuscular-junction disorder in the appropriate clinical setting and identifies the phenotype most relevant to thymectomy and complement-directed treatment discussions. ccjm+1ccjmMyasthenia gravis: Frequently asked questions | Cleveland Clinic Journal of medicineNeurologyComparison of Fixed and Live Cell-Based Assay for the Detection of AChR and MuSK Antibodies in Myasthenia Gravis

If AChR testing is negative, obtain MuSK antibody testing. MuSK antibodies are detected by radioimmunoassay in approximately 5% to 7% of MG cases; in patients who remain antibody-negative by routine testing, live cell-based assays can identify low-affinity clustered AChR or MuSK antibodies in a proportion of double-seronegative cases. LRP4 antibodies are another recognized antibody target, but a negative routine panel does not exclude MG. BMJ+1BMJMyasthenia gravis - Symptoms, diagnosis and treatment | BMJ Best Practice USNeurologyComparison of Fixed and Live Cell-Based Assay for the Detection of AChR and MuSK Antibodies in Myasthenia Gravis

Use repetitive nerve stimulation (RNS) and single-fiber EMG (SFEMG) to demonstrate neuromuscular transmission failure when antibodies are absent, symptoms are atypical, or objective confirmation is needed before committing to chronic immunotherapy. A decremental RNS response or increased SFEMG jitter supports MG; in reported double-seronegative cohorts, diagnosis incorporated a characteristic syndrome plus RNS or SFEMG evidence of transmission impairment. BMJ+1BMJMyasthenia gravis - Symptoms, diagnosis and treatment | BMJ Best Practice USNeurologyComparison of Fixed and Live Cell-Based Assay for the Detection of AChR and MuSK Antibodies in Myasthenia Gravis

Document disease burden longitudinally with a reproducible clinical scale such as MG Activities of Daily Living (MG-ADL), Quantitative Myasthenia Gravis (QMG), or Myasthenia Gravis Composite (MGC). These measures were used at baseline and follow-up in comparative generalized-MG treatment studies and provide an objective anchor for escalation, tapering, or determination of inadequate response. BMJ+1BMJC5 complement inhibition versus FcRn modulation in generalised myasthenia gravisScienceDirect474PTemporal trends in management of myasthenia gravis in a tertiary centre in north India - ScienceDirect

Obtain chest imaging to evaluate for thymoma after MG is diagnosed or strongly suspected, because thymoma is a clinically important MG-associated condition and thymectomy is a key therapeutic intervention in thymoma-associated MG. Computed tomography or magnetic resonance imaging can identify thymoma for preoperative risk assessment and surgical planning. ScienceDirect+1ScienceDirectManaging myasthenic crisis after video-assisted thoracoscopic thymectomy with therapeutic plasma exchange - ScienceDirectWileyNomogram for predicting the risk of postoperative myasthenic crisis in patients with thymectomy - Ruan - 2023 - Annals of Clinical and Translational Neurology - Wiley Online Library

Refer patients with radiologic thymoma for multidisciplinary thoracic surgical and oncology assessment. Thymectomy is not rescue therapy for acute weakness; stabilize active crisis or severe exacerbation first with rapid immunomodulation and respiratory support before elective operative planning. ScienceDirect+1ScienceDirectRescue therapy in myasthenia gravis - ScienceDirectScienceDirectManaging myasthenic crisis after video-assisted thoracoscopic thymectomy with therapeutic plasma exchange - ScienceDirect

Before thymectomy, reassess current bulbar symptoms, MG severity classification, prior crisis, and recent IVIG use because each has been incorporated into postoperative myasthenic-crisis prediction models. Postoperative myasthenic crisis is defined in one registry model as crisis occurring within 30 days after thymectomy. WileyWileyNomogram for predicting the risk of postoperative myasthenic crisis in patients with thymectomy - Ruan - 2023 - Annals of Clinical and Translational Neurology - Wiley Online Library

Use pyridostigmine as symptomatic therapy for patients seeking medical treatment, particularly in ocular MG; it is generally more effective for ptosis than diplopia. If adequate pyridostigmine treatment does not meet functional goals, add corticosteroids or a nonsteroidal immunosuppressive drug rather than continuing ineffective symptomatic treatment alone. Wolters Kluwer+1Wolters KluwerTreatment of Ocular Myasthenia Gravis : The Asia-Pacific Journal of OphthalmologyccjmMyasthenia gravis: Frequently asked questions | Cleveland Clinic Journal of medicine

Corticosteroids benefit most MG subtypes, with improvement beginning at approximately 2 weeks on average and marked improvement reported in more than 80% of patients in retrospective evidence. Reassess response and toxicity early: among patients treated with high-dose corticosteroids, approximately 5% to 20% have inadequate benefit or prohibitive adverse effects after several weeks to 3 months, prompting use of nonsteroidal immunosuppression and avoidance of prolonged high-dose exposure. ccjm+1ccjmMyasthenia gravis: Frequently asked questions | Cleveland Clinic Journal of medicineccjmWhat are the treatment options for myasthenia gravis if first-line agents fail? | Cleveland Clinic Journal of medicine

Use a nonsteroidal immunosuppressive agent when corticosteroid toxicity, steroid dependence, or insufficient response makes steroid-sparing treatment necessary. Agents used in standard generalized-MG treatment include azathioprine, mycophenolate mofetil, cyclosporine, methotrexate, and tacrolimus; selection should reflect prior treatment response and patient-specific toxicity risk. BMJ+2BMJC5 complement inhibition versus FcRn modulation in generalised myasthenia gravisccjmMyasthenia gravis: Frequently asked questions | Cleveland Clinic Journal of medicineccjmWhat are the treatment options for myasthenia gravis if first-line agents fail? | Cleveland Clinic Journal of medicine

Define treatment success prospectively. Complete stable remission is generally no MG signs or symptoms without therapy for 1 year, but minimal manifestation status or better with only mild adverse effects is a more realistic target for many patients; minimal manifestation status permits mild examination weakness without functional limitation. ccjmccjmWhat are the treatment options for myasthenia gravis if first-line agents fail? | Cleveland Clinic Journal of medicine

At each treatment decision, document ocular, bulbar, limb, and respiratory function and compare MG-ADL, QMG, or MGC with baseline. In generalized-MG studies, MG-ADL was collected at baseline and approximately 1, 3, and 6 months, illustrating a practical framework for objectively tracking early and intermediate treatment response. BMJBMJC5 complement inhibition versus FcRn modulation in generalised myasthenia gravis

Monitor corticosteroid toxicity proactively, especially weight gain, osteoporosis, dysglycemia, psychiatric effects, and infection risk; these complications were documented drivers of treatment escalation in high-risk MG cohorts. A patient with improved strength but unacceptable steroid toxicity has not achieved an acceptable long-term treatment outcome and should be considered for steroid-sparing therapy. BMJ+1BMJInduction cyclophosphamide with maintenance immunosuppression in high-risk myasthenia gravis: long-term follow-up and safety profileccjmWhat are the treatment options for myasthenia gravis if first-line agents fail? | Cleveland Clinic Journal of medicine

Patients receiving ICI therapy require a low threshold for reassessment of dyspnea, diplopia, ptosis, weakness, chest symptoms, palpitations, presyncope, or syncope. Neurologic ICI toxicities have a median onset of 4 weeks but may occur from 1 to 68 weeks after exposure; concurrent myocarditis or MG is associated with high mortality. jacc+1jaccDiagnosis and Management of Cardiovascular Adverse Effects of Targeted Oncology Therapies: Bruton’s Tyrosine Kinase, Immune Checkpoint, and Vascular Endothelial Growth Factor Inhibitors: 2025 ACC Concise Clinical Guidance: A Report of the American College of Cardiology Solution Set Oversight CommitteeASCOManagement of Immune-Related Adverse Events in ...