Abstract

A VARIATION OF MUSCULOCUTANEOUS NERVE- A CASE REPORT

Chaitra S.*, Shelly Divyadarshan and Alka Jayavanthkumar

ABSTRACT

The brachial plexus is derived from the ventral rami of spinal nerves C5, C6, C7, C8, and T1 with variable contributions from C4 and T2. It has three cords, lateral cord, medial cord and posterior cord. The musculocutaneous nerve (C5, C6, C7) arises from the lateral cord. The medial nerve (C6, C7, C8, T1, sometimes also from C5) is usually formed by two roots: The lateral one ([C5], C6, C7) given from the lateral cord and the medial one (C8, T1) given from the medial cord. It has been reported that the brachial plexus is the most variable portion of the peripheral nervous system. On the other hand, variations of the Musculocutaneous nerve may occur in 6.25% cases. In our case report, there was a variation of the Musculocutaneous nerve which not pierce the coracobrachialis and the musculocutaneous and median nerves were fused. A branch to the biceps brachii originated from the common trunk itself. One communicating branch was present between medial and lateral cord. A good knowledge of nerve pathways and their variations is very important in order to an exploratory intervention of the arms for repairing peripheral nerves and surgical therapies during post-traumatic conditions of an upper limb.

Keywords: Musculocutaneous nerve, cords, Variations.