Brachial neuritis: an under-recognized cause of upper extremity paresis after cervical decompression surgery

Case series. To identify an alternative etiology for the development of upper extremity weakness after cervical spine surgery. The development of proximal upper extremity paresis after cervical decompression surgery is commonly diagnosed as postoperative C5 palsy. Symptoms most commonly consist of weakness involving the deltoid and/or biceps brachii muscles, and in many patients there is also associated pain in the shoulder region with or without sensory deficits. Interestingly, the onset of symptoms is often delayed until days to weeks after surgery. The pathogenic mechanisms underlying postoperative C5 palsy remain unclear, although direct injury to the nerve root during surgery or a traction injury from a tethering phenomenon are frequently cited. These explanations seem unlikely, however, given the delayed onset of symptoms. Two patients who underwent cervical decompression surgery with subsequent development of shoulder pain associated with proximal upper extremity weakness are presented. Based on clinical presentation and nerve conduction/EMG studies, both patients were diagnosed with brachial neuritis. This article describes an alternative diagnosis for the constellation of symptoms typically attributed to postoperative C5 palsy. Specifically, brachial neuritis is a type of peripheral neuropathy that involves the sudden onset of pain in the shoulder girdle followed by weakness, most commonly of the deltoid and spinati muscles. Brachial neuritis appears to be an under-recognized cause of delayed-onset shoulder pain associated with upper extremity weakness that develops as a consequence of the stress of surgery rather than as a complication of surgical technique.