J Clin Neurol.  2012 Sep;8(3):235-237. 10.3988/jcn.2012.8.3.235.

A Patient with Coexisting Myasthenia Gravis and Lambert-Eaton Myasthenic Syndrome

• Kim JA
• Lim YM
• Jang EH
• Kim KK

• KMID: 2287597
• DOI: http://doi.org/10.3988/jcn.2012.8.3.235

Abstract

BACKGROUND
The coexistence of myasthenia gravis (MG) and Lambert-Eaton myasthenic syndrome (LEMS) is very rare and remains controversial.
CASE REPORT
A 48-year-old woman initially presented with noticeable right ptosis and intermittent diplopia. She then developed fluctuating proximal limb weakness and difficulty in swallowing. The serum titer of anti-acetylcholine-receptor antibody was elevated and the edrophonium (Tensilon) test was positive. However, repetitive nerve stimulation revealed abnormalities typical of LEMS. The patient exhibited a good response to treatment with anticholinesterase inhibitors and steroids, and long-term evaluation disclosed that she presented with the clinical, electrophysiological, and immunological characteristics of both diseases.
CONCLUSIONS
The reported clinical and electrophysiological features suggest that this patient was a very rare case of combined MG and LEMS.

Keyword

myasthenia gravis; Lambert-Eaton myasthenic syndrome; overlap syndrome; repetitive nerve stimulation tests

MeSH Terms

Deglutition
Diplopia
Edrophonium
Extremities
Female
Humans
Lambert-Eaton Myasthenic Syndrome
Middle Aged
Myasthenia Gravis
Steroids
Edrophonium
Steroids

Figure

• 

  Fig. 1 "LEMS triad" on RNS. A: Low CMAP amplitude and decremental response on low-frequency (3 Hz) stimulation of the ulnar nerve. B: Marked incremental response on high-frequency (50 Hz) stimulation of the ulnar nerve. CMAP: compound muscle action potential, LEMS: Lambert-Eaton myasthenic syndrome, RNS: repetitive nerve stimulation.

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