Compression syndrome of the recurrent motor branch of the median nerve.

Carpal tunnel compression and its surgical release has been well described. Motor branch anomalies of the median nerve have also been documented in the literature. Independent recurrent motor branch compression of the median nerve appears to exist in the presence of carpal tunnel symptomatology or as an independent entity. Eight presentations of concomitant or independent compression of the recurrent motor branch of the median nerve have been reviewed. These cases can be subdivided into cases presenting with or without carpal tunnel symptomatology, as well as into two types of independent compression patterns: the first being a direct fascial penetration and entrapment and the second being an acute angulation of the recurrent branch with apparent impingement by the transverse carpal retinaculum. Attention should be directed to the inspection and decompression of the motor branch of the median nerve in those cases that present thenar muscle pathology either clinically or electrodiagnostically.