A unilateral variant of musculocutaneous nerve

Variations in the origin, course, branching pattern, termination and connections of the musculocutaneous nerve (MCN) are not uncommon. These variations have clinical significance during surgical procedures, in brachial plexus block and in diagnostic clinical neurophysiology. In the present case, we have reported unilateral variation of musculocutaneous and radial nerves on the right side in a male cadaver. The MCN trifurcated after piercing coracobrachialis and innervated biceps brachii and brachialis muscles and the third branch descended along lateral border of forearm terminating at the proximal phalanx of the right thumb. The superficial branch of radial nerve (RN) was found to be missing. The structures on the left limb were found to be normal. Knowledge of such variations helps in the management of shoulder and arm traumas, nerve grafting and diagnosing peripheral neuropathies.