eMedicine Specialties > Obstetrics and Gynecology > Medical Problems in Pregnancy

Myasthenia Gravis and Pregnancy: Differential Diagnoses & Workup

Author: Idan Sharon, MD, Consulting Staff, Departments of Neurology and Psychiatry, Cornell New York Methodist Hospital; Private Practice
Contributor Information and Disclosures

Updated: Dec 13, 2007

Differential Diagnoses

Other Problems to Be Considered

The differential diagnosis of myasthenia gravis includes conditions associated with weakness of muscles, such as Lambert-Eaton myasthenic syndrome, botulism, hyperthyroidism, neurasthenia, intracranial mass lesion, progressive external ophthalmoplegia, and drug-induced MG.

Workup

Laboratory Studies

Screen for other autoimmune disorders, including rheumatoid arthritis, systemic lupus erythematosus, pemphigus, Hashimoto thyroiditis, scleroderma, dermatitis herpetiformis, autoimmune hemolytic anemia, polymyositis, and sarcoidosis.

Imaging Studies

Obtain CT scans to study the thymus, or obtain MRIs to evaluate the mediastinum.

Other Tests

  • Diagnosis is based on clinical history and signs, improvement with anticholinesterase injection, serum anti-AChR antibody titers, and electromyographic signs of impaired neuromuscular transmission. The combination of test results helps the physician confirm the diagnosis.
  • Intravenous injection of edrophonium (Tensilon) is a routine test when symptoms and signs suggest MG. This cholinesterase inhibitor increases the amount of acetylcholine available, which increases the probability of acetylcholine binding to the receptor. It is the test of choice because it is fast and inexpensive. Initially, the patient is injected with 1-2 mg of edrophonium. If this dose does not yield expected results and no adverse effects are observed, another 4-5 mg is administered. Clinical improvement occurs in 10-60 seconds and lasts for approximately 10 minutes. Test muscles that do not require patient cooperation so that results are more reliable. Edrophonium test results are positive in approximately 90% of myasthenic patients.
  • Anti-AChR antibody titration is usually performed by radioimmunoassay. This is the most specific test for MG. High antibody titers usually correlate with severe disease.
  • Low-rate repetitive nerve stimulation is also used to demonstrate problems with neuromuscular transmission. A decremental pattern (>10% difference in compound muscle action potential amplitude between the first and fourth or fifth stimulus) is the usual finding. Single-fiber electromyography produces the most sensitive data to support the diagnosis. Findings are abnormal in more than 90% of patients. This test shows abnormalities in neuromuscular transmission as increased jitter and blocking.

More on Myasthenia Gravis and Pregnancy

Overview: Myasthenia Gravis and Pregnancy
Differential Diagnoses & Workup: Myasthenia Gravis and Pregnancy
Treatment & Medication: Myasthenia Gravis and Pregnancy
Follow-up: Myasthenia Gravis and Pregnancy
References
[ CLOSE WINDOW ]

References

  1. Mitchell PJ, Bebbington M. Myasthenia gravis in pregnancy. Obstet Gynecol. Aug 1992;80(2):178-81. [Medline].

  2. Plauche WC. Myasthenia gravis in mothers and their newborns. Clin Obstet Gynecol. Mar 1991;34(1):82-99. [Medline].

  3. Batocchi AP, Majolini L, Evoli A, et al. Course and treatment of myasthenia gravis during pregnancy. Neurology. Feb 1999;52(3):447-52. [Medline].

  4. Rolbin WH, Levinson G, Shnider SM, Wright RG. Anesthetic considerations for myasthenia gravis and pregnancy. Anesth Analg. Jul-Aug 1978;57(4):441-7. [Medline].

  5. Ip MS, So SY, Lam WK, et al. Thymectomy in myasthenia gravis during pregnancy. Postgrad Med J. Jun 1986;62(728):473-4. [Medline].

  6. Batashki I, Markova D, Milchev N, Terzhumanov R, Uchikova E, Uchikov A. [Myasthenia gravis and pregnancy--a case report and review of the literature]. Akush Ginekol (Sofiia). 2006;45(7):59-61. [Medline].

  7. Brenner T, Beyth Y, Abramsky O. Inhibitory effect of alpha-fetoprotein on the binding of myasthenia gravis antibody to acetylcholine receptor. Proc Natl Acad Sci U S A. Jun 1980;77(6):3635-9. [Medline].

  8. Carr SR, Gilchrist JM, Abuelo DN, Clark D. Treatment of antenatal myasthenia gravis. Obstet Gynecol. Sep 1991;78(3 Pt 2):485-9. [Medline].

  9. Duff GB. Preeclampsia and the patient with myasthenia gravis. Obstet Gynecol. Sep 1979;54(3):355-8. [Medline].

  10. Ellison J, Thomson AJ, Walker ID, Greer IA. Thrombocytopenia and leucopenia precipitated by pregnancy in a woman with myasthenia gravis. BJOG. Aug 2000;107(8):1052-4. [Medline].

  11. Evoli A, Batocchi AP, Tonali P. A practical guide to the recognition and management of myasthenia gravis. Drugs. Nov 1996;52(5):662-70. [Medline].

  12. Giwa-Osagie OF, Newton JR, Larcher V. Obstetric performance of patients with my asthenia gravis. Int J Gynaecol Obstet. Aug 1981;19(4):267-70. [Medline].

  13. Hoff JM, Daltveit AK, Gilhus NE. Myasthenia gravis in pregnancy and birth: identifying risk factors, optimising care. Eur J Neurol. Jan 2007;14(1):38-43. [Medline].

  14. Hoff JM, Daltveit AK, Gilhus NE. Myasthenia gravis: consequences for pregnancy, delivery, and the newborn. Neurology. Nov 25 2003;61(10):1362-6. [Medline].

  15. Igarashi S, Yamauchi T, Tsuji S, et al. [A case of myasthenia gravis complicated by cyclic thrombocytopenia]. Rinsho Shinkeigaku. Mar 1992;32(3):321-3. [Medline].

  16. Johns TR, Howard FM. Symposium on therapeutic controversies. Myasthenia gravis. Steroids and immunosuppressive drugs. Trans Am Neurol Assoc. 1978;103:278-81. [Medline].

  17. Kalidindi M, Ganpot S, Tahmesebi F, Govind A, Okolo S, Yoong W. Myasthenia gravis and pregnancy. J Obstet Gynaecol. Jan 2007;27(1):30-2. [Medline].

  18. Levine SE, Keesey JC. Successful plasmapheresis for fulminant myasthenia gravis during pregnancy. Arch Neurol. Feb 1986;43(2):197-8. [Medline].

  19. McNall PG, Jafarnia MR. Management of myasthenia gravis in the obstetrical patient. Am J Obstet Gynecol. Jun 15 1965;92:518-25. [Medline].

  20. Newsom-Davis J, Willcox N, Schluep M, et al. Immunological heterogeneity and cellular mechanisms in myasthenia gravis. Ann N Y Acad Sci. 1987;505:12-26. [Medline].

  21. Ramirez C, de Seze J, Delrieu O, et al. [Myasthenia gravis and pregnancy: clinical course and management of delivery and the postpartum phase]. Rev Neurol (Paris). Mar 2006;162(3):330-8. [Medline].

  22. Sax TW, Rosenbaum RB. Neuromuscular disorders in pregnancy. Muscle Nerve. Nov 2006;34(5):559-71. [Medline].

  23. Shehata HA, Okosun H. Neurological disorders in pregnancy. Curr Opin Obstet Gynecol. Apr 2004;16(2):117-22. [Medline].

  24. Téllez Zenteno JF. Can we consider thymectomy before pregnancy in female patients with myasthenia gravis?. Eur J Cardiothorac Surg. Aug 2006;30(2):411-2; author reply 412. [Medline].

  25. Vincent A, Newsom-Davis J. Acetylcholine receptor antibody as a diagnostic test for myasthenia gravis: results in 153 validated cases and 2967 diagnostic assays. J Neurol Neurosurg Psychiatry. Dec 1985;48(12):1246-52. [Medline].

[ CLOSE WINDOW ]

Further Reading

[ CLOSE WINDOW ]

Keywords

MG, autoimmune neuromuscular disease, human acetylcholine receptors, AChRs, pregnancy complications, pregnancy comorbidity, autoimmune neuromuscular disease, rheumatoid arthritis, systemic lupus erythematosus, SLE, pemphigus, Hashimoto thyroiditis, Hashimoto's thyroiditis, thymic abnormality, scleroderma, dermatitis herpetiformis, autoimmune hemolytic anemia, polymyositis, sarcoidosis, MG and pregnancy

[ CLOSE WINDOW ]

Contributor Information and Disclosures

Author

Idan Sharon, MD, Consulting Staff, Departments of Neurology and Psychiatry, Cornell New York Methodist Hospital; Private Practice
Idan Sharon, MD is a member of the following medical societies: American Academy of Neurology, American Medical Association, and Medical Society of the State of New York
Disclosure: Nothing to disclose.

Medical Editor

Bryan D Cowan, MD, Professor and Chairman, Department of Obstetrics and Gynecology, University of Mississippi College of Medicine; Consulting Staff, Department of Obstetrics and Gynecology, Veterans Affairs Medical Center; Medical Director, Wiser Hospital for Women, University of Mississippi Medical Center
Bryan D Cowan, MD is a member of the following medical societies: American Association of Gynecologic Laparoscopists, American College of Obstetricians and Gynecologists, American Gynecological and Obstetrical Society, American Medical Association, American Society for Reproductive Medicine, Association of Professors of Gynecology and Obstetrics, Central Association of Obstetricians and Gynecologists, Endocrine Society, Sigma Xi, Society for Assisted Reproductive Technologies, Society for Gynecologic Investigation, Society for the Study of Reproduction, and Society of Laparoendoscopic Surgeons
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Gail F Whitman-Elia, MD, Professor, Department of Obstetrics and Gynecology, University of South Carolina School of Medicine
Gail F Whitman-Elia, MD is a member of the following medical societies: American Association of Clinical Endocrinologists, American College of Clinical Endocrinologists, American College of Obstetricians and Gynecologists, American Institute of Ultrasound in Medicine, American Medical Association, American Medical Women's Association, American Public Health Association, American Society for Reproductive Medicine, Endocrine Society, and South Carolina Medical Association
Disclosure: Nothing to disclose.

CME Editor

Frederick B Gaupp, MD, Consulting Staff, Department of Family Practice, Assumption Community Hospital
Frederick B Gaupp, MD is a member of the following medical societies: American Academy of Family Physicians
Disclosure: Nothing to disclose.

Chief Editor

David Chelmow, MD, Professor of Obstetrics and Gynecology, Tufts University School of Medicine; Program Director, Tufts University Affiliated Hospitals OB/GYN Residency Program; Chair, Tufts University Health Sciences Campus Institutional Review Board
David Chelmow, MD is a member of the following medical societies: American College of Obstetricians and Gynecologists, American Medical Association, Association of Professors of Gynecology and Obstetrics, Massachusetts Medical Society, Phi Beta Kappa, Sigma Xi, Society for Gynecologic Investigation, and Society for Medical Decision Making
Disclosure: Nothing to disclose.

 
 
HONcode

We subscribe to the
HONcode principles of the
Health On the Net Foundation

All material on this website is protected by copyright, Copyright© 1994- by Medscape.
This website also contains material copyrighted by 3rd parties.

DISCLAIMER: The content of this Website is not influenced by sponsors. The site is designed primarily for use by qualified physicians and other medical professionals. The information contained herein should NOT be used as a substitute for the advice of an appropriately qualified and licensed physician or other health care provider. The information provided here is for educational and informational purposes only. In no way should it be considered as offering medical advice. Please check with a physician if you suspect you are ill.