eMedicine Specialties > Neurology > Neuromuscular Diseases

Myasthenia Gravis: Follow-up

Author: Aashit K Shah, MD, Associate Professor of Neurology, Wayne State University; Program Director, Clinical Neurophysiology Fellowship, Department of Neurology, Detroit Medical Center
Contributor Information and Disclosures

Updated: Jan 15, 2009

Follow-up

Further Outpatient Care

  • Patients with myasthenia gravis require close follow-up care in cooperation with the primary care physician.
  • Myasthenia gravis is a chronic disease that may worsen acutely over days or weeks (and on rare occasions, over hours).
  • Treatment requires scheduled reevaluation and a close doctor/patient relationship.

Inpatient & Outpatient Medications

See Medication.

Complications

  • Respiratory failure may occur if respiratory muscle weakness is severe.
  • Dysphagia due to pharyngeal muscle weakness may occur and may lead to aspiration pneumonia.
  • Complications secondary to drug treatment: Long-term immunomodulating therapies may predispose patients with myasthenia gravis to various complications.
    • Long-term steroid use may cause or aggravate osteoporosis, cataracts, hyperglycemia, weight gain, avascular necrosis of hip, hypertension, and other complications.
    • Long-term steroid use increases the risk of gastritis or peptic ulcer disease. Patients on such therapy also should take an H2 blocker or antacid.
    • Some complications are common to any immunomodulating therapy, especially if the patient is on more than 1 agent. These would include infections such as tuberculosis, systemic fungal infections, and Pneumocystis carinii pneumonia.
    • Risk of lymphoproliferative malignancies may be increased with chronic immunosuppression.
    • Immunosuppressive drugs may have teratogenic effects.

Prognosis

  • Untreated myasthenia gravis carries a mortality rate of 25-31%. With current treatment (especially pertaining to acute exacerbations), the mortality rate has declined to approximately 4%.
  • The disease frequently presents (40%) with only ocular symptoms. However, the EOM almost always are involved within the first year. In patients with only ocular involvement at onset, only 16% remain ocular exclusively at the end of 2 years.
  • In patients with generalized weakness, the nadir of maximal weakness usually is reached within the first 3 years of the disease. Half of the disease-related mortality also occurs during this time period. Those who survive the first 3 years of disease usually achieve a steady state or improve. Worsening of disease is uncommon after 3 years.
  • Important risk factors for poor prognosis include age older than 40 years, a short history of progressive disease, and thymoma.

Patient Education

  • Educate patients to recognize impending respiratory crisis.
    • Intercurrent infection may worsen symptoms of myasthenia gravis temporarily.
    • Mild exacerbation of weakness is possible in hot weather.
  • Risk of congenital deformity (arthrogryposis multiplex) is increased in offspring of women with severe myasthenia gravis.
    • Neonates born to women with myasthenia gravis need to be monitored for respiratory failure for 1-2 weeks after birth.
    • Certain immunosuppressant drugs have teratogenic potential.
    • Discuss these aspects with women in reproductive years prior to beginning therapy with these drugs.
  • Certain medications such as the aminoglycosides, ciprofloxacin, chloroquine, procaine, lithium, phenytoin, beta-blockers, procainamide, and quinidine may exacerbate symptoms of myasthenia gravis. Many other drugs have been associated only rarely with exacerbation of myasthenia gravis.
  • Medications that induce the hepatic microsomal cytochrome P-450 system (eg, corticosteroids) may render oral contraceptives less effective.
  • Statins may cause worsening of myasthenia without regard to type of myasthenia gravis or brand of statin. Worsening of weakness can occur independently of myalgic syndrome and usually involves oculobulbar symptoms within 1-16 weeks of onset of statin treatment.13

Miscellaneous

Medicolegal Pitfalls

  • Rapid respiratory failure may occur if the patient is not monitored properly. Patients should be watched very carefully, especially during exacerbation, by measuring negative inspiratory force (NIF) and vital capacity (VC).
  • Transient neonatal MG occurs in 10-30% of neonates born to myasthenic mothers. It may occur any time during the first 7-10 days of life, and infants should be monitored closely for any signs of respiratory distress.
 


More on Myasthenia Gravis

Overview: Myasthenia Gravis
Differential Diagnoses & Workup: Myasthenia Gravis
Treatment & Medication: Myasthenia Gravis
Follow-up: Myasthenia Gravis
Multimedia: Myasthenia Gravis
References
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References

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Further Reading

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Keywords

myasthenia gravis, autoimmune neuromuscular disease, skeletal muscle weakness, fatigability on exertion, muscle weakness, acetylcholine receptor, AChR, seronegative myasthenia gravis, SNMG, muscle-specific kinase, MuSK, MG

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Contributor Information and Disclosures

Author

Aashit K Shah, MD, Associate Professor of Neurology, Wayne State University; Program Director, Clinical Neurophysiology Fellowship, Department of Neurology, Detroit Medical Center
Aashit K Shah, MD is a member of the following medical societies: American Academy of Neurology, American Clinical Neurophysiology Society, and American Epilepsy Society
Disclosure: Nothing to disclose.

Medical Editor

Donald B Sanders, MD, EMG Laboratory Director, Professor of Medicine (Neurology), Division of Neurology, Duke University Medical Center
Donald B Sanders, MD is a member of the following medical societies: American Academy of Neurology, American Association of Neuromuscular and Electrodiagnostic Medicine, American Neurological Association, and New York Academy of Sciences
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Glenn Lopate, MD, Associate Professor, Department of Neurology, Division of Neuromuscular Diseases, Washington University School of Medicine; Chief of Neurology, St Louis ConnectCare, Consulting Staff, Barnes Jewish Hospital
Glenn Lopate, MD is a member of the following medical societies: American Academy of Neurology, American Association of Neuromuscular and Electrodiagnostic Medicine, and Phi Beta Kappa
Disclosure: Nothing to disclose.

CME Editor

Selim R Benbadis, MD, Professor, Director of Comprehensive Epilepsy Program, Departments of Neurology and Neurosurgery, University of South Florida School of Medicine, Tampa General Hospital
Selim R Benbadis, MD is a member of the following medical societies: American Academy of Neurology, American Academy of Sleep Medicine, American Clinical Neurophysiology Society, American Epilepsy Society, and American Medical Association
Disclosure: Nothing to disclose.

Chief Editor

Nicholas Lorenzo, MD, Chief Editor, eMedicine Neurology; Consulting Staff, Neurology Specialists and Consultants
Nicholas Lorenzo, MD is a member of the following medical societies: Alpha Omega Alpha and American Academy of Neurology
Disclosure: Nothing to disclose.

 
 
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