Variations in brachial plexus and the relationship of median nerve with the axillary artery: a case report^[*]

Abstract

Background Brachial Plexus innervates the upper limb. As it is the point of formation of many nerves, variations are common. Knowledge of these is important to anatomists, radiologists, anesthesiologists and surgeons. The presence of anatomical variations of the peripheral nervous system is often used to explain unexpected clinical signs and symptoms.

Case Presentation On routine dissection of an embalmed 57 year old male cadaver, variations were found in the formation of divisions and cords of the Brachial Plexus of the right side. Some previously unreported findings observed were; direct branches to the muscles Pectoralis Minor and Latissimus dorsi from C6, innervation of deltoid by C6 and C7 roots and the origin of lateral pectoral nerve from the posterior division of upper trunk. The median nerve was present lateral to axillary artery. The left side brachial plexus was also inspected and found to have normal anatomy.

Conclusion The probable cause for such variations and their embryological basis is discussed in the paper. It is also concluded that although these variations may not have affected the functioning of upper limb in this individual, knowledge of such variations is essential in evaluation of unexplained sensory and motor loss after trauma and surgical interventions to the upper limb.

^*This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

• References

• 1 Williams PL, Bannister LH, Berry MM, Collins P, Dyson M, Dussek JE, Ferguson MWJ. Nervous system. In: Gray’s Anatomy. Churchill Livingstone; Edinburgh: 38th edition 1995: 1266-1272
• 2 Horwitz MT, Tocantins LM. An anatomical study of the role of the long thoracic artery and the related scapular bursae in the pathogenesis of local paralysis of the serratus anterior muscle. Anat Rec 1938; 31: 375-380 10.1002/ar.1090710402
• 3 Hollinshead WH. Anatomy for surgeons. In: General survey of the upper limb. – The Back and Limbs. A Hoeber Harper Book; New York: 1958. 3. 225-245
• 4 Kerr AT. The brachial plexus of nerves in man, the variations in its formation and branches. American Journal of Anatomy 1918; 23: 285-395 10.1002/aja.1000230205
• 5 Gupta M, Goyal N Harjeet Anomalous communications in the branches of brachial plexus. Journal of the Anatomical Society of India 2005; 54 (1) 22-25
• 6 Nakatani T, Tanaka S, Mizukami S. Absence of the musculocutaneous nerve with innervation of coracobrachialis, biceps brachii, brachialis and the lateral border of the forearm by branches from the lateral cord of the brachial plexus. Journal of Anatomy 1997; 191: 459-460 1467704 9419004 10.1046/j.1469-7580.1997.19130459.x
• 7 Gümüsburun E, Adigüzel E. A variation of the brachial plexus characterized by the absence of the musculocutaneous nerve: a case report. Surg Radiol Anat 2000; 22 (1) 63-65 10.1007/s00276-000-0063-x 10863751
• 8 Venieratos D, Anagnostopoulou S. Classification of communications between the musculocutaneous and median nerves. Clinical Anatomy 1998; 11: 327-331 10.1002/(SICI)1098-2353(1998)11:5<327::AID-CA6>3.0.CO;2-M 9725577
• 9 Loukas M, Aqueelah H. Musculocutaneous and median nerve connections within, proximal and distal to the coracobrachialis muscle. Folia Morphol (Warsz) 2005; 64 (2) 101-108 16121328
• 10 Fazan V, Amadeu A, Calaffi A, Felio C. Brachial Plexus variations in its formation and main branches. Acta Cirurgica Brasileisa 2001; 18 (5) 14-18
• 11 Aktan Z, Oztunk L, Bilge O, Ozer M, Pinar Y. A cadaveric study of the anatomical variations of the brachial plexus nerves in the axillary region and arm. Turk J Med Sci 2001; 31: 147-150
• 12 Das S, Paul S. Anomalous branching pattern of lateral cord of brachial plexus. Int J Morphol 2005; 23 (4) 289-292
• 13 Pandey SK, Shukla VK. Anatomical variations of the cords of brachial plexus and the median nerve. Clin Anat 2007; 20 (2) 150-156 10.1002/ca.20365 16795062