NEONATAL BRACHIAL PLEXUS INJURIES
The brachial plexus refers to the grouping of the nerves that exit the spinal cord to recollect as peripheral nerves to the arm. In neonatal brachial plexus injuries, the nerves are stretched during an obstructive labour process. This presents as a flail or weak upper limb with minimal shoulder and elbow movements. The classic Erb’s Palsy affects the upper two nerve roots (C5 & C6), presenting with no shoulder abduction (lifting the arm to the side) and no elbow flexion (bending), with or without the ability to lift the wrist. The arm usually hangs and is not used. Risk factors include a large foetus, small or obese mothers, gestational diabetes, shoulder dystocia and instrumented deliveries.
The injury is usually a stretch of the nerve, and has the potential to heal over time. The challenge, is that it is difficult to predict whether a child will regain the limb’s function. Internationally, there is consensus that it is unlikely that there will be any recovery if elbow flexion is not recovered by 4-6 months. In these cases, surgical reconstruction earlier rather than later, is recommended. Surgical reconstruction in the past focused on brachial plexus exploration and nerve grafting. There is a fresh interest in nerve transfers (popularised in adult reconstruction) for reconstruction (away from brachial plexus), which yields quicker and more predictable results.
There is very little to do to enhance recovery, but parents must be taught to keep the infant’s limb mobile (especially shoulder) to prevent contractures. A physiotherapist can assist with providing developmental input, and teach parents correct handling of the infant. Regular evaluations by the specialist are very important to correlate trends and to ensure that surgical intervention (if needed) is performed at the right time.