Anatomical variations in morphology of right and left brachial plexus among black African population; a cadaveric study in western Kenya

Abstract

Background: Brachial plexus (Bp) is a network of bundles of nerves of spinal cord around neck and axilla in the body formed by union of anterior primary rami of C5 to C8, and T1. Technical expertise required for clinical and surgical procedures remains challenging for the beginners. Variations may be due to trauma, irradiation, neoplasm, infection, and autoimmune inflammatory disease. The purpose of this study was to determine the difference in variation of right and left Bp of the study population. Methods: Cross sectional descriptive study was used in Maseno, Uzima and Masinde Muliro Universities anatomy laboratory to get sample size of 35male and 35 female cadavers. Chi- square test was set at a p= 0.05. Ethical consideration was observed. Results: Statistically significant difference (p=0.009) between the right and the left upper limb in the branching of musculocutaneous nerve was recorded. A total of 17.8% variations in origin and segments of Bp, majority 9.9% were from left while 7.9% from right. Highest frequency of variation occurred at the prefixed root of Bp with 8.7% occurring on left upper limb and 12.13% on right upper limb. Right upper limbs had highest incidence of variations in branching patterns of Bp at 43% whilst left had incidence of 23.5%. Highest frequency of main terminal variation was of musculocutaneous nerve at 18.6% with 13.6% occurring on right side and 5% on left side. Conclusion: Knowledge of variations is essential in evaluation of unexplained sensory and motor loss after trauma and surgical interventions to the upper limb.