ABSTRACT
Background: The brachial plexus is a major and complicated plexus that gives rise to a number of nerves to themuscles of the back and the upper limb .Median nerve (MN) is one of the terminal branches of the brachial plexus(BP). It is normally formed in the axilla by union of lateral and medial spinal roots, which arise from lateral andmedial cords of brachial plexus. The purpose of this study is to provide additional information about variationsin the formation of median nerve as its abnormal branching pattern constitutes a major importance in anatomical,clinical and surgical fields.Methods: Observational based descriptive study was made on sixteen cadavers comprising of 32 upper limbs,of which one specimen was female cadaver. The dissection was performed bilaterally on both upper limbs andthe axillary regions of the cadavers. Careful observation for the variation in the formation of median nerve hasbeen carried out. The finding was properly photographed for proper documentation.Results: It was observed that out of 32 upper limbs 5 (15.63%) showed anatomical variations in the formation ofmedian nerve, with its course, branching pattern and communication with musculocutaneous nerve. Among thevariations in 1(3.13%) median nerve was formed by the fusion of three roots, two from the lateral and one fromthe medial cord of the brachial plexus (BP). Further in 2(6.25%) medial root of medial cord receive additionalunusual small lateral root from lateral cord forms median nerve. In other 2(6.25%) median nerve also receivecommunication rami from musculocutaneous nerve at the lower third of the arm just below coracobrachialismuscle.Conclusion: The anatomical variations were not bilateral in any cadaver, hence 4 (12.50%) of the variationsoccurred more often on the left side, and 1(3.13%) occurred in right side. Therefore knowledge of such variationsis important for anatomists, radiologists, neurologists, anesthesiologists, and surgeons for proper clinicaldiagnosis. So, these variations should be well kept in mind.