[Radial nerve palsy as a presenting feature of neuralgic amyotrophy]

A 28-year-old man noticed weakness in his left arm when he woke up. He was diagnosed as left radial nerve palsy and managed conservatively at a local hospital. A few days later, severe pain of the brachium appeared. Although severe pain improved in a year, dysesthesia and muscle atrophy remained. On admission, muscle weakness and atrophy were found in muscles innervated predominantly by the left radial nerve. In addition, needle-electromyography and computed tomography revealed the involvement of muscles innervated by the left suprascapular, long thoracic and axillary nerves, and we diagnosed the patient as neuralgic amyotrophy. Neuralgic amyotrophy should be kept in mind in diagnosing acute onset, painful radial palsy.