Nerve Transfers in Severe Obstetrical Brachial Plexus Palsy

Abstract

Nerve transfers are increasingly utilized for repair of servere brachial plexus injuries and, indeed, are the only option when the proximal spine nerve roots have been avulsed from the spinal cord. The procedure essentially involves the coaption of a proximal foreign nerve to the distal denervated nerve, so that the latter will be reinnervated by the donated axons. The primary goal of surgery in the severe obstetrical brachial plexus palsy case is to return proximal arm function, particularly elbow flexion and a stable, dynamic shoulder that can abduct and externally rotate. Neural input should thus be directed first to the biceps via the musculocutaneous nerve or its branches, and next to reconstructing the suprascapular nerve. Unlike an adult with a complete palsy, where the return of distal hand function is virtually impossible, the infant has better odds of successful reinnervation of the hand. If donor nerve sources are available following repair of the musculocutaneous and suprascapular nerves, grafts can be directed to the radial (for wrist and finger extention) and median (for elbow and finger flexion and critical hand sensibility) nerves. Recovery of intrinsic hand muscle function from plexus reconstruction in the global severe palsy case is not a realistic possibility at present. Cortical plasticity, which is likely more prevelent in the baby than the adult, appears to play an important physiological role in the functional recovery of the reinnervated muscles following nerve transfers.