Anat Cell Biol.  2012 Sep;45(3):207-210. 10.5115/acb.2012.45.3.207.

Bilateral absence of musculocutaneous nerve with unusual branching pattern of lateral cord and median nerve of brachial plexus

• Bhanu PS
• Sankar KD

• KMID: 2046749
• DOI: http://doi.org/10.5115/acb.2012.45.3.207

Abstract

A 43-year-old female cadaver showed a complete bilateral absence of the musculocutaneous nerve. The anterior compartment muscles of both arms were supplied by median nerve excepting the coracobrachialis which was innervated by a direct branch from the lateral cord of brachial plexus. The median nerve, after supplying the biceps and brachialis muscles, gave onto the lateral cutaneous nerve of the forearm. The median nerve also showed variation on the left side where it was formed by two lateral roots and one medial root. Variations of the brachial plexus are of great interest to anatomists, clinicians and surgeons, in that they may be incorporated in their day to day practice. Our present case may be noted for its clinical and surgical significance in the variations of brachial plexus which can be useful for diagnostic purposes.

Keyword

Musculocutaneous nerve; Median nerve; Nerve to coracobrachialis; Variations

MeSH Terms

Adult
Anatomists
Arm
Brachial Plexus
Cadaver
Female
Forearm
Humans
Median Nerve
Muscles
Musculocutaneous Nerve

Figure

• 

  Fig. 1 Photograph of the right axilla showing the absence of musculocutaneous nerve. BA, brachial artery; BBr, biceps brachii muscle; CB, coracobrachialis muscle; CTMCAF, common trunk for medial cutaneous nerve of arm and forearm; LPN, lateral pectoral nerve; MN, median nerve; MPN, medial pectoral nerve; NCB, nerve to coracobrachialis; UN, ulnar nerve; arrow, communication between lateral and medial pectoral nerves; 1, nerve to biceps brachii from MN.

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  Fig. 2 Photograph showing the variant branches of median nerve on the right side. BA, brachial artery; BBr, biceps brachii; Br, brachialis; CTMCAF, common trunk for medial cutaneous nerve of arm and forearm from medial cord; MCNA, medial cutaneous nerve of arm; MCNF, medial cutaneous nerve of forearm; MN, median nerve; 1, nerve to biceps brachii from MN; 2, branch to brachialis from common trunk of MN; 3, lateral cutaneous nerve of forearm from common trunk of MN.

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  Fig. 3 Photograph of the left axilla showing the absence of musculocutaneous nerve. BA, brachial artery; BBr, biceps brachii muscle; CB, coracobrachialis; CTMCAF, common trunk for medial cutaneous nerve of arm and forearm; MN, median nerve; NCB, nerve to coracobrachialis; UN, ulnar nerve; arrow, single long trunk from MN; arrowhead, additional lateral root of MN from lateral cord; 1, nerve to biceps brachii from the single long trunk of MN.

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  Fig. 4 Photograph showing the variant branches of median nerve on the left side. BBr, biceps brachii; CTMCAF, common trunk for medial cutaneous nerve of arm and forearm from medial cord; MCNA, medial cutaneous nerve of arm; MCNF, medial cutaneous nerve of forearm; MN, median nerve; UN, ulnar nerve; arrow, single long trunk from MN; 1, nerve to biceps brachii; 2, branch to brachialis; 3, lateral cutaneous nerve of forearm.

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