Stress testing in nerve compression.

Peripheral nerve compression syndromes most often produce neuropathic changes that are recordable by conventional electrophysiologic testing techniques. Occasionally, a patient exhibits all the appropriate clinical signs, symptoms, and history of a compartment syndrome, such as a carpal tunnel syndrome, but electrophysiologic testing procedures will be normal, thus seeming to identify no neuropathic component to the syndrome. Researchers have reasonably concluded that wrist position or hand activity can have an adverse affect on intracompartmental carpal pressures, with resultant ischemic changes in epineural blood supply and subsequent compromise in nerve conduction parameters during and for a short time after the ischemic event. The stress testing protocol presented here identifies such changes, which would otherwise go undetected or undocumented and which may lead to unsuccessful clinical decisions regarding management. Sample tracings of actual cases are presented to demonstrate actual changes produced by the use of the protocol. This test protocol is used only when conventional testing is normal in the presence of appropriate clinical symptomatology.