AbstractMusculocutaneous nerve is the nerve of front of arm. It is one of the terminal branches of lateral cord of brachial plexus.This nerve is responsible for innervation of flexor compartment of arm and for cutaneous innervation on lateral surface of forearm. Median nerve is formed by the union of lateral and medial roots respectively arising from lateral and medial cords. Median nerve does not give any branch in the arm. Th aim of this study is to find out the prevalence of variations of the median nerve in the arm with respect to its branching pattern and distribution as well as its possible communication with the musculocutaneous nerve. 30 arms pertaining to 15 preserved human cadavers, ranging in age from 35 to 70 years, were dissected in anatomy dissection hall in a private medical college. In two limbs out of 30 (6.7%) the lateral root of median nerve gave off muscular branches to the coracobrachialis, brachialis as well as biceps brachii muscle. The trunk of median nerve gave lateral cutaneous nerve of forearm which is usually a continuation of musculocutaneous nerve. Concomitantly the musculocutaneous nerve was absent. Knowledge of such anatomical variations is of interest to the anatomists and clinicians. These observations should be considered when a high median nerve paralysis is shown to originate in the axilla or proximal arm in a patient presenting with weakness of forearm flexion and supination. Similarly, it can explain weakness of the arm flexor muscles in thoracic outlet syndrome with median nerve affection.
Keywords: Brachial Plexus; Lateral Cord; Median Nerve; Musculocutaneous Nerve; Variations.