Case ReportsPainful Myoclonus Triggered by Lateral Antebrachial Cutaneous Nerve Entrapment at the Brachioradialis MuscleAktas, Adem DO; Prather, Heidi DO; Brogan, David MD; Colorado, Dale DOAuthor Information From the Department of Neurology, Washington University School of Medicine, St. Louis, Missouri (AA); Division of Physical Medicine and Rehabilitation, Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri (HP, DC); and Division of Hand Surgery, Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri (DB). All correspondence should be addressed to: Heidi Prather, DO, Department of Orthopaedic Surgery, 14532 S Outer Forty Rd, Chesterfield, MO 63017. Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Web site (www.ajpmr.com). American Journal of Physical Medicine & Rehabilitation: August 2020 - Volume 99 - Issue 8 - p e94-e96 doi: 10.1097/PHM.0000000000001285 Buy SDC Metrics Abstract Compression of the lateral antebrachial cutaneous nerve is a rare clinical entrapment syndrome often overlooked as an initial etiology of pain. We present a case of an episodic upper limb painful movement disorder (myoclonus) in a 16-yr-old adolescent girl with a remote history of a surgically stabilized supracondylar humeral fracture who was later found to have entrapment of the lateral antebrachial cutaneous nerve. The incidence of a painful myoclonus triggered by a peripheral nerve entrapment is unknown. Combining a history and physical examination, electromyography, nerve conduction studies, and ultrasound enabled us to make an accurate diagnosis that was confirmed by resolution of symptoms after surgical release. This study conforms to all CARE guidelines and reports the required information accordingly (see Supplemental Check list, Supplemental Digital Content 1, http://links.lww.com/PHM/A855). Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.