Lambert-Eaton Myasthenic Syndrome

  • Michael Benatar


The Lambert-Eaton myasthenic syndrome (LEMS) is a rare autoimmune presynaptic disorder of neuromuscular transmission in which antibodies are directed against the voltage-gated calcium channel. The classic clinical features include proximal muscle weakness, depressed deep tendon reflexes, and prominent symptoms of autonomic dysfunction. The hallmark electrophysiological finding is a reduction in the size of the compound muscle action potential with facilitation (i.e., increased in amplitude) following brief sustained muscle contraction. In many patients, LEMS may occur in association with an underlying malignancy as a paraneoplastic disorder. How frequently are these clinical and electrophysiological features encountered in patients with LEMS? How specific is the finding of compound muscle action potential facilitation for the diagnosis? Is the presence of antibodies against voltage-gated calcium channels specific for LEMS? Should patients with LEMS be treated with immunosuppressive therapy notwithstanding the frequency with which underlying malignancies are detected? What is the long-term prognosis of LEMS, and does the presence of LEMS affect the prognosis for patients with small cell lung carcinoma? These and other questions are the subject of this chapter.


Amyotrophic Lateral Sclerosis Maximal Voluntary Contraction Plasma Exchange Small Cell Lung Carcinoma Compound Muscle Action Potential 
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  1. 1.
    O’Neill J, Murray N, Newsom-Davis J_The Lambert-Eaton myasthenic syndrome. Brain 1988;111:577–596.CrossRefPubMedGoogle Scholar
  2. 2.
    Nakao Y, Motomura M, Fukudome T, et al Seronegative Lambert-Eaton myasthenic syndrome. Study of 110 Japanese patients. Neurology 2002;59:1773–1775.CrossRefPubMedGoogle Scholar
  3. 3.
    Wirtz PW, Smallegange TM, Wintzen AR, Verschuuren JJ. Differences in clinical features between the Lambert-Eaton myasthenic syndrome with and without cancer: an analysis of 227 published cases. Clin Neurol Neurosurg 2002;104:359–363.CrossRefPubMedGoogle Scholar
  4. 4.
    Burns TM, Russell JA, LaChance DH, Jones HR. Oculobulbar involvement is typical with Lambert-Eaton myasthenic syndrome. Ann Neurol 2003;53:270–273.CrossRefPubMedGoogle Scholar
  5. 5.
    Wirtz P, Sotodeh M, Nijnuis M, et al. Difference in distribution of muscle weakness between myasthenia gravis and the Lambert-Eaton myasthenic syndrome. J Neurol Neurosurg Psychiatry 2002;73:766–768.CrossRefPubMedGoogle Scholar
  6. 6.
    O’Suilleabhain P, Low PA, Lennon VA. Autonomic dysfunction in the Lambert-Eaton myasthenic syndrome. tiSerologic and clinical correlates. Neurology 1998;50:88–93.CrossRefPubMedGoogle Scholar
  7. 7.
    Motomura M, Johnston I, Lang B, Vincent A, Newsom-Davis J. An improved diagnostic assay for Lambert-Eaton myasthenic syndrome. J Neurol Neurosurg Psychiatry 1995;58:85–87.CrossRefPubMedGoogle Scholar
  8. 8.
    Motomura M, Lang B, Johnston I, Palace J, Vincent A, Newsom-Davis J_Incidence of serum anti-P/Q and anti-N-type calcium channel autoantibodies in the Lambert-Eaton myasthenic syndrome. J Neurolog Sci 1997;147:35–42.CrossRefGoogle Scholar
  9. 9.
    Lennon VA, Kryzer TJ, Griesmann GE, et al. Calcium-channel antibodies in the Lambert-Eaton syndrome and other paraneoplastic syndromes. N Engl J Med 1995;332:1467–1474.CrossRefPubMedGoogle Scholar
  10. 10.
    Nakao YK, Motomura M, Suenaga A, et al. Specificity of omega-conotoxin MVIIC-binding and blocking calcium channel antibodies in Lambert-Eaton myasthenic syndrome. J Neurol 1999;246:38–44.CrossRefPubMedGoogle Scholar
  11. 11.
    Voltz R, Carpentier AF, Rosenfeld MR, Posner JB, Dalmau J. P/Q-Type voltage gated calcium channel antibodies in paraneoplastic disorders of the central nervous system. Muscle Nerve 1999;22:119–122.CrossRefPubMedGoogle Scholar
  12. 12.
    Tim RW, Sanders DB. Repetitive nerve stimulation studies in the Lambert-Eaton myasthenic syndrome. Muscle Nerve 1994;17:995–1001.CrossRefPubMedGoogle Scholar
  13. 13.
    Oh SJ, Kurokawa K, Classen GC, Ryan HF. Electrophysiological diagnostic criteria of Lambert-Eaton myasthenic syndrome. Muscle Nerve 2005;32:515–520.CrossRefPubMedGoogle Scholar
  14. 14.
    Tim RW, Massey JM, Sanders DB. Lambert-Eaton myasthenic syndrome: Electrodiagnostic findings and response to treatment. Neurology 2000;54:2176–2178.CrossRefPubMedGoogle Scholar
  15. 15.
    Lambert EH, Rooke D. Myasthenic state and lung cancer. In: Brain W, Norris F, eds. The remote effects of cancer on the nervous system. Grune and Stratton, New York:1965;pp. 67–79.Google Scholar
  16. 16.
    Trontelj J, Stalberg E. Single motor end-plates in myasthenia gravis and LEMS at different firing rates. Muscle Nerve 1991;14:226–232.CrossRefPubMedGoogle Scholar
  17. 17.
    Sanders DB. The effect of firing rate on neuromuscular jitter in Lambert-Eaton myasthenic syndrome. Muscle Nerve 1992;15:256–258.PubMedGoogle Scholar
  18. 18.
    Trontelj JV, Stalberg E. The effect of firing rate on neuromuscular jitter in Lambert-Eaton myasthenic syndrome. A reply_Muscle Nerve 1992;15:258.Google Scholar
  19. 19.
    McEvoy K, Windebank AJ, Daube JR, LowPA. 3,4-Diaminopyridine in the treatment of Lambert-Eaton myasthenic syndrome. N Engl J Med 1989;321:1567–1571.CrossRefPubMedGoogle Scholar
  20. 20.
    Sanders DB, Massey JM, Sanders LL, Edwards LJ. A randomized trial of 3,4-diaminopyridine in Lambert-Eaton myasthenic syndrome. Neurology 2000;54:603–607.CrossRefPubMedGoogle Scholar
  21. 21.
    Bain P, Motomura M, Newsom-Davis J, et al. Effects of intravenous immunoglobulin on muscle weakness and calcium-channel autoantibodies in the Lambert-Eaton myasthenic syndrome. Neurology 1996;47:678–683.CrossRefPubMedGoogle Scholar
  22. 22.
    Newsom-Davis J, Murray NM. Plasma exchange and immunosuppressive drug treatment in the Lambert-Eaton myasthenic syndrome. Neurology 1984;34:480–485.CrossRefPubMedGoogle Scholar
  23. 23.
    Chalk C, Murray N, Newsom-Davis J, O’Neill J, Spiro S. Response of the Lambert-Eaton myasthenic syndrome to treatment of associated small cell lung carcinoma. Neurology 1990;40:1552–1556.CrossRefPubMedGoogle Scholar
  24. 24.
    Maddison P, Lang B, Mills K, Newsom-Davis J. Long term outcome in Lambert-Eaton myasthenic syndrome without lung cancer. J Neurol Neurosurg Psychiatry 2001;70:212–217.CrossRefPubMedGoogle Scholar

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© Humana Press Inc., Totowa, NJ 2006

Authors and Affiliations

  • Michael Benatar
    • 1
  1. 1.Department of NeurologyEmory University School of MedicineAtlanta

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