Traumatic avulsion injury of the brachial plexus.

The case report of a motor vehicle accident victim with a right arm paralysis, Horner's pupil, and a widened mediastinum is presented. These findings were the result of a traction injury to the brachial plexus. The widened mediastinum and apical capping in this patient were the result of a hemorrhage at the base of the neck which extended into the mediastinum. The clinical manifestations and pathophysiology of traction injuries to the brachial plexus are discussed, and an approach to the diagnosis and emergency management of this problem is reviewed.