An Unusual Formation of Median Nerve with Absence of Musculocutaneous Nerve

The Musculocutaneous nerve arises from the lateral cord of the brachial plexus, passes inferiorly and laterally, and then pierces through the coracobrachialis .After supplying it descends between the biceps and the brachialis, giving branches to both the muscles and continues as the lateral cutaneous nerve of the forearm. Variations in the origin, course, branching pattern, termination and connections of the musculocutaneous nerve (MCN) are not uncommon. Though its absence has been described previously but its real prevalence is unknown. A case of absence of the musculocutaneous nerve was observed during the dissection of the left arm of a male cadaver. The medial root of median nerve was found to be bifurcated and the area of innervation was supplied by lateral root of median nerve. From this, three branches emerged: one to the coracobrachialis muscle, another to the biceps brachii muscle and the third to the brachialis muscle. The knowledge of such Anatomical variations would be of value to the practicing neurosurgeons, orthopaedic surgeons, anaesthetist and interventional radiologists, during surgical procedures, including brachial plexus block and in diagnostic clinical neurophysiology to avoid unexpected complication.