Axillary nerve injury caused by intradeltoid muscular injection: a case report.

CASE REPORT A 25-year-old man got an intradeltoid muscular injection of 1 mL (0.5 mg) of atropine and 1 mL (50 mg) of hydroxyzine hydrochloride in his right shoulder as a premedication for operation on his right ear. A 25-gauge needle was used for the injection at 3-finger width below the acromion. Two days after the injection, he complained of dull pain and weakness of his shoulder. Four days after the injection, he was referred to the orthopaedic department. At the time of injection, he had neither pain nor numbness on his shoulder and arm. He was a professional dancer but could not dance well because of the weakness of his shoulder. There was no other specific trauma nor injection history to his shoulder. On physical examination, his right shoulder looked normal in the resting position but, because of the contraction of the anterior and posterior fibers, only the middle portion of the deltoid bulged out like a balloon (Figure 1, A and B) with activity. A slight decrease in abduction power was found, but there was neither tenderness nor sensory change. The affected shoulder had a normal range of motion with a stable glenohumeral joint. The radiographic examination was within normal limits. Two weeks after the injection, magnetic resonance imaging showed no pathologic changes. The electromyography and nerve conduction velocity (NCV) were checked 4 weeks after the injury. The electromyography showed positive sharp wave at rest. During voluntary contraction, polyphasic potentials and lower