Electrodiagnostic approach to the patient with suspected mononeuropathy of the upper extremity.

Upper extremity mononeuropathies are common. Most are due to compression, whereas others occur in the setting of systemic disorders (e.g., diabetes) or with coexistent polyneuropathies. Electrophysiologic studies are essential in most cases, and provide critical information regarding localization, severity, activity, chronicity, and underlying pathophysiological mechanisms. Insights gleaned from the electrodiagnostic report guide clinicians in the optimal management of mononeuropathies of the upper extremity.