Lambert-Eaton syndrome is a disorder in which faulty communication between nerves and muscles leads to muscle weakness.

Myasthenic syndrome; Eaton-Lambert syndrome; Lambert-Eaton myasthenic syndrome; LEMS

Lambert-Eaton syndrome occurs when nerves cells do not release enough of a chemical called acetylcholine. This chemical transmits impulses between nerves and muscles.

The result is muscle weakness and other symptoms similar to myasthenia gravis. However, unlike myasthenia gravis, as the muscles continue to contract, acetylcholine can build up in large enough amounts for strength to improve slightly. Instead of the muscle getting quickly weaker as it contracts repeatedly, it gets stronger for a short period of time.

Lambert-Eaton syndrome may occur with cancers such as small-cell lung cancer or autoimmune disorders such as vitiligo, which leads to a loss of skin pigment

Images

Superficial anterior muscles

Review Date: 08/27/2010
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Daniel B. Hoch, PhD, MD, Assistant Professor of Neurology, Harvard Medical School, Department of Neurology, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)