Median nerve’s loop in the arm penetrated by a superficial brachial artery: case report and neurosurgical considerations

George K. Paraskevas, Ioannis Varnalidis, Konstantinos Koutsouflianiotis


Median nerve is commonly formed by the union of the lateral and medial cord of the brachial plexus, which embrace the third part of the axillary artery. Formation of a median nerve’s loop is a very rare condition. We present a cadaveric case, in which the right median nerve was found at the upper arm forming a fusiform neural loop penetrated by a superficial brachial artery, which continued over the forearm as the radial artery. The literature concerning nerve loops and traversing arteries is discussed, as well as the relevant embryology. We consider that such nerve loops constitute vulnerable sites of the nerve trunk since it is compressed by the pulsation of the abnormal traversing artery. Moreover, neurosurgeons should keep in mind that in case of existing arterial variation, variation of the associated neural structures may co-exist.


Median nerve, Superficial brachial artery, Loop

Full Text:



Williams PL (Ed). Gray’s Anatomy. Edinburgh: Churchill Livingstone;1995.

Natsis K, Papadopoulos AL, Paraskevas G, Totlis T, Tsikaras P. High origin of a superficial ulnar artery arising from the axillary artery : anatomy , embryology , clinical significance and review of the literature. Folia Morphol. 2006;65(4):189-94.

Satyanaraya N, Vishvakarma N, Kumar GP, Guha R, Datta AK, Sunitha P. Rare variations in the formation of median nerve-embryological basis. Nepal Med Col J. 2009;11(4):287-90.

Uzun A, Selling LL. A variation in the formation of median nerve and communicating branches between musculocutaneous and median nerve. Folia Morphol. 2001;60(2):99-101.

Bhat KMR, Gowda S, Potu BK. Nerve loop around the axillary vessels by the roots of the median nerve, a rare variation in a south Indian male cadaver: a case report. Cases Journal. 2009;2:179.

Srivastava SK, Pande BS. Anomalous pattern of median artery in the forearm of Indians. Acta Anat. 1990;138:193-4.

Kolagi SI, Rairam GB, Herur A. Multiple variations of median nerve with persistent median artery- a case report and review of literature. Anatomica Karnataka. 2010;4(1):44-6.

Chou HC, Jeng H, Ko TL, Pai MH, Chang CY, Wu CH. Variant palmaris profundus enclosed by an unusual loop of the median nerve. J Anat. 2001;199:499-500.

Hartmann H. Note sur l’anatomie des nerfs de la paume de la main. Bull Mem Soc Anat Paris. 1887;62:860-64.

Lee JY, Kim YR, Kim JN, Choi HG, Song WC, Koh KC. Penetration of the digital nerves by the common palmar digital arteries in human cadavers. J Hand Surg. 2010;35(A):2022-26.

Miller RA. Observations upon the arrangement of the axillary artery and brachial plexus. Am J Anat. 1939;64:143-63.

Roy TS. Median nerve penetration by a muscular branch of the brachial artery. Clin Anat. 2003;16:335-9.

Lippert H, Pabst R. Arterial variations in man. Classification and frequency. Munchen: JF Bergmann Verlag; 1985.

Beheiry EE. Anatomical variations of the median nerve distribution and communication in the arm. Folia Morphol. 2004;63:313-18.

Gross PT, Tolomeo EA. Proximal median neuropathies. Neurol Clin. 1999;17:425-45.

Hofmann KJ, Ruchelsman DE. Symptomatic neural loop causing hemigital anaesthesia: case report. J Hand Surg. 2012;37A:1994-96.

Delfiner JS. Dynamics and pathophysiology of nerve compression in the upper extremity. Orthop Clin North Am. 1996;27:219-26.