Definition of Lambert-Eaton syndrome:

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

Causes, incidence, and risk factors:

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.