Bilateral absence of musculocutaneous nerve with unusual communicating branch between radial and ulnar nerves

Busra CANDAN, Kenan OZTURK, So

Abstract

Variations in the course and branches of the musculocutaneous nerve and the absence of the nerve have been reported in the literature. During the routine dissection of a 65-year-old male cadaver, we observed a variant brachial plexus characterized by the absence of the musculocutaneous nerve bilaterally. The median nerve took over the area of supply of the musculocutaneous nerve by giving both the muscular and sensory branches. The coracobrachialis muscle was innervated by a branch of lateral cord bilaterally. From median nerve, two branches emerged: one to biceps brachii muscle and the other one to brachialis muscle, which continued as lateral cutaneous nerve of forearm. We also observed a communicating branch between ulnar and radial nerves at high humeral level at right side. A branch emerged from this communicating branch and innervated triceps brachii muscle. These variations have clinical significance during surgical procedures in brachial plexus block, diagnostic clinical neurophysiology.