Ulnar dominant hand and forearm: an electrophysiologic approach

An ulnar-to-median anastomosis in the forearm is a rare condition, but may be present in any electromyographic case. A thorough approach to this condition is required to avoid misinterpretation of the electrodiagnostic report and confusion during the test. Prior to concluding that an anomaly is present, technical reason should be taken into consideration. The presence of volume-conducted potentials from various nearby muscles may confuse the electromyographer. Therefore, instead of using surface electrodes with unintended supramaximal intensity of stimulation, the needle electrodes may be used (in some cases) to localize specific muscles and to minimize volume-conducted potentials by not utilizing supramaximal stimulation intensity. The authors will discuss ulnar-to-median anastomosis in the forearm. This is the first attempt to put together all the information available in the literature about such an anastomosis.