Anat Cell Biol.  2013 Sep;46(3):223-227. 10.5115/acb.2013.46.3.223.

Bilateral single cord of the brachial plexus in an adult female cadaver of South Indian origin

• Viswanathan U
• Madhivadhany V
• Shankar N

• KMID: 2263151
• DOI: http://doi.org/10.5115/acb.2013.46.3.223

Abstract

The occurrence of a brachial plexus united into a single cord is very rare. During routine dissection of an elderly female cadaver, the brachial plexus united into a single cord was observed bilaterally. On the left side, C4, C5, and C6 roots combined to form the upper trunk, the C7 root continued as the middle trunk, and C8 and T1 united to form the lower trunk. All three trunks almost immediately fused to form a single cord. On the right side, C5 and C6 roots joined to form the upper trunk, which divided into anterior and posterior divisions. C7, C8, and T1 roots combined to form the lower trunk. The anterior and posterior divisions united with the lower trunk to form a single cord. On both sides, the subclavian artery was superior to the single cord. Supraclavicular brachial plexus injuries in such individuals may have serious clinical manifestations.

Keyword

Brachial plexus; Single cord; Bilateral

MeSH Terms

Adult
Aged
Brachial Plexus
Cadaver
Female
Humans
Subclavian Artery

Figure

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  Fig. 1 Formation of the single cord on the left side. C4, C5, C6, C7, C8, T1, roots of the brachial plexus; I, inferior; L, lateral; LT, lower trunk; M, medial; MT, middle trunk; PN, phrenic nerve; S, superior; SA, subclavian artery; UT, upper trunk.

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  Fig. 2 The branches of the brachial plexus on the left side. AN, axillary nerve; CNA, medial cutaneous nerve of the arm; CNF, medial cutaneous nerve of the forearm; DM, deltoid muscle; I, inferior; L, lateral; M, medial; MN, median nerve; MPN, medial pectoral nerve; RN, radial nerve; S, superior; SC, single cord; ScA, displaced scalenus anterior; SN, suprascapular nerve; UN, ulnar nerve.

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  Fig. 3 Schematic representation of the major variations of the brachial plexus observed on the left side. B, major branches of the single cord; C4, C5, C6, C7, C8, T1, roots of the brachial plexus; LT, lower trunk; MN, median nerve; MT, middle trunk; R, roots; RN, radial nerve; SC, single cord; T, trunks; UN, ulnar nerve; UT, upper trunk.

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  Fig. 4 Formation of the single cord on the right side. AD, anterior division of upper trunk; AN, axillary nerve; C5, C6, C7, C8, T1, roots of the brachial plexus; I, inferior; L, lateral; M, medial; MN, median nerve; PD, posterior division of upper trunk; RN, radial nerve; S, superior; SA, subclavian artery; SC, single cord; UN, ulnar nerve.

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  Fig. 5 Branches of the brachial plexus on the right side. AA, subclavian artery; AN, axillary nerve; I, inferior; L, lateral; LSN, lower subscapular nerve; M, medial; MN, median nerve which splits and rejoins; RN, radial nerve; S, superior; SC, single cord; SN, suprascapular nerve; UN, ulnar nerve; USN, upper subscapular nerve.

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  Fig. 6 Schematic representation of the major variations of the brachial plexus observed on the right side. AD, anterior division; B, major branches of the single cord; C5, C6, C7, C8, T1, roots of the brachial plexus; D, divisions; LT, lower trunk; MN, median nerve; PD, posterior division; R, roots; RN, radial nerve; SC, single cord; T, trunks; UN, ulnar nerve; UT, upper trunk.

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