Differential Diagnosis and Intervention of Proximal Median Nerve Entrapment: A Resident's Case Problem

Study Design Resident's case problem. Background Entrapment neuropathies represent a diagnostic challenge and require a comprehensive understanding of the nerve's path and the anatomical structures that may cause compression of the nerve. This resident's case problem details the evaluation and differential diagnosis process for median nerve entrapment resulting from forceful and repetitive pronation/supination motions. Diagnosis Median nerve compression syndromes include pronator syndrome, anterior interosseous nerve syndrome, and carpal tunnel syndrome. A cluster of clinical special tests were performed to determine the anatomical site of median nerve entrapment. Based on the patient's history and clinical test results, a diagnosis of pronator syndrome was determined. Provocation testing specific to pronator syndrome assisted with further localizing the site of entrapment to the pronator teres muscle, which guided effective management strategies. Discussion This resident's case problem illustrates the importance of detailed anatomical knowledge and a differential diagnostic process when evaluating a patient with signs and symptoms of an entrapment neuropathy of the median nerve. Electrodiagnostic studies are useful in ruling out carpal tunnel and anterior interosseous nerve syndromes, but are often inconclusive in cases of pronator syndrome. Therefore, a diagnosis of pronator syndrome in this case problem was based on a detailed understanding of median nerve anatomy, potential sites of compression, and unique clinical features associated with this condition. Level of Evidence Differential diagnosis, level 4. J Orthop Sports Phys Ther 2016;46(9):800-808. Epub 5 Aug 2016. doi:10.2519/jospt.2016.6723.