Neurologic deficit and recovery in the donor limb following cross-C7 transfer in brachial-plexus injury.

Two adult patients with post-traumatic complete brachial plexus injury were treated with cross-C7 nerve-root transfer from the contralateral side. A detailed documentation of the motor and sensory functional status of the donor upper limb was carried out before and after division of the C7 nerve root. Gross motor deficits were observed immediately after surgery in shoulder extension and adduction, elbow extension, forearm pronation, wrist flexion, and hand movement. Sensory deficit involving the hand was maximal immediately after division of the C7 root. Functional recovery was rapid starting within 10 days following the root division. In both patients, the motor and sensory deficits were temporary. Full functional recovery was documented at 6 months. However, objective qualitative and quantitative differences in the motor and sensory deficits in the donor limbs were still present by 1.5 to 2 years, although these did not affect the functional status of the donor limbs. The presence of multiple segmental root innervation of the muscles and skin, other than the C7 root in the upper limb, provides for a compensatory mechanism that allows for this rapid and full functional recovery following the single nerve-root loss. The absence of any long-term functional deficit makes cross C7 transfer a viable option in the surgical management of complete unilateral brachial-plexus injury.