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

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.