NINDS Lambert-Eaton Myasthenic Syndrome Information Page

Table of Contents (click to jump to sections)

What is Lambert-Eaton Myasthenic Syndrome?
Is there any treatment?
What is the prognosis?
What research is being done?
Clinical Trials
Organizations

What is Lambert-Eaton Myasthenic Syndrome?

Lambert-Eaton myasthenic syndrome (LEMS) is a disorder of the neuromuscular junction-the site where nerve cells meet muscle cells and help activate the muscles. It is caused by a disruption of electrical impulses between these nerve and muscle cells. LEMS is an autoimmune condition; in such disorders the immune system, which normally protects the body from foreign organisms, mistakenly attacks the body's own tissues. The disruption of electrical impulses is associated with antibodies produced as a consequence of this autoimmunity. Symptoms include muscle weakness, a tingling sensation in the affected areas, fatigue, and dry mouth. LEMS is closely associated with cancer, in particular small cell lung cancer. More than half the individuals diagnosed with LEMS also develop small cell lung cancer. LEMS may appear up to 3 years before cancer is diagnosed.

Is there any treatment?

There is no cure for LEMS. Treatment is directed at decreasing the autoimmune response (through the use of steroids, plasmapheresis, or high-dose intravenous immunoglobulin) or improving the transmission of the disrupted electrical impulses by giving drugs such as di-amino pyridine or pyridostigmine bromide (Mestinon). For patients with small cell lung cancer, treatment of the cancer is the first priority.

What is the prognosis?

The prognosis for individuals with LEMS varies. Those with LEMS not associated with malignancy have a benign overall prognosis. Generally the presence of cancer determines the prognosis.

What research is being done?

The NINDS supports research on neuromuscular disorders such as LEMS with the ultimate goal of finding ways to treat, prevent, and cure them.

NIH Patient Recruitment for Lambert-Eaton Myasthenic Syndrome Clinical Trials

Organizations

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American Autoimmune Related Diseases Association 22100 Gratiot Avenue Eastpointe, MI 48021-2227 aarda@aarda.org http://www.aarda.org Tel: 586-776-3900 800-598-4668 Fax: 586-776-3903	Muscular Dystrophy Association 3300 East Sunrise Drive Tucson, AZ 85718-3208 mda@mdausa.org http://www.mda.org Tel: 520-529-2000 800-572-1717 Fax: 520-529-5300
National Organization for Rare Disorders (NORD) 55 Kenosia Avenue Danbury, CT 06810 orphan@rarediseases.org http://www.rarediseases.org Tel: 203-744-0100 Voice Mail 800-999-NORD (6673) Fax: 203-798-2291

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Office of Communications and Public Liaison
National Institute of Neurological Disorders and Stroke
National Institutes of Health
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Last updated February 13, 2007