Chief complaint: Intense left shoulder pain

Parsonage–Turner syndrome (PTS), or neuralgia amyotrophy, is a rare condition that affects mainly the lower motor neurons of the brachial plexus or individual nerves or nerve branches. The cause is unknown. The typical presentation is sudden, often excruciating neck and arm pain followed by marked muscle weakness and wasting of the shoulder girdle and upper arm. In this article, the authors describe the case of a 38–year–old white woman who presented with a complaint of acute left shoulder and neck pain.