Variations in Commencement of Median Nerve

Abstract

Background: The median nerve, normally formed by two roots from the medial and lateral cords in relation to the axillary artery, but variations in its roots and unusual communications with other nerves are common. These anatomical differences can compromise anesthesia and are vulnerable to iatrogenic injury during surgical procedures of the upper limb. This study was conducted to determine the prevalence of such anatomical variations in axillary and arm regions.
Methods: A descriptive cross sectional study was conducted on 66 upper limbs from embalmed adult human cadavers, selected using a convenience sampling method. The median nerve was observed after dissections in the axillary and arm regions for variations in formations and nerve communications. Variations were photographed, and the data were recorded and analyzed using SPSSTM version 20.
Results: The median nerve was most commonly formed in the axilla (78.78%), with one case showing a high formation at the apex. A third root was present in 7.58% of cases, and one rare case involved four roots. Communication with the musculocutaneous nerve occurred in 13.63% of limbs, including a case with two separate communicating roots. Communication with the ulnar nerve was observed in 3.03% of cases.
Conclusions: Anomalous origin, aberrant branching patterns, and unusual communications of the median nerve are possible and clinically significant. Awareness of such variations is essential for accurate diagnosis, effective anesthesia, and safe surgical interventions involving the upper limb.
Keywords: Brachial plexus; cadaveric study; communication; dissection; median nerve.