Radial nerve palsy in the newborn: a case series.

BACKGROUND Peripheral nerve palsies of the upper extremities presenting at birth can be distressing for families and care providers. It is therefore important to be able to identify patients whose diagnosis is compatible with full recovery so that their families can be reassured. METHODS We conducted a retrospective review of all infants presenting with weakness of the upper extremity to our clinic between July 1995 and September 2009. We also conducted a review of the current literature. RESULTS During the study period, 953 infants presented to our clinic. Of these patients, 25 were identified as having isolated radial nerve palsy (i.e., a radial nerve palsy in isolation with good shoulder function and intact flexion of the elbow). Seventeen infants (68.0%) had a subcutaneous nodule representing fat necrosis in the inferior posterolateral portion of the affected arm. Full recovery occurred in all patients within a range of one week to six months, and 72.0% of the patients (18/25) had fully recovered by the time they were two months old. INTERPRETATION Although the outcome of obstetrical brachial plexus palsy is highly variable, isolated radial nerve palsy in the newborn carries a uniformly favourable prognosis.