Electrophysiologic approaches to the diagnosis of entrapment neuropathies.

Identifying and localizing nerve entrapments is a major problem in electrodiagnosis. Pathophysiology in the different conditions is diverse; a common but not invariable situation is focal demyelination with consequent focal slowing of nerve conduction. Many techniques of nerve conduction and electromyography (EMG) are available. The precise anatomy and the behavior of each syndrome has to be understood in order to develop appropriate strategies to use these techniques to best advantage.