The edrophonium test.

Cholinesterase inhibitors (CEIs) have been known to improve strength in patients with myasthenia gravis (MG) since the 1930s, and have been used as a diagnostic test since the early 1950s. The following review summarizes the history of edrophonium usage in myasthenia gravis, reviews the literature with regard to the method of performing the edrophonium test, and discusses the available information regarding sensitivity and specificity of the test with respect to diagnosis of MG.