Neuromuscular Ultrasound of the Median Nerve at the Carpal Tunnel

The use of neuromuscular ultrasound greatly enhances the evaluation of carpal tunnel syndrome as an adjunct diagnostic tool as it provides dynamic and structural information about the median nerve and its surrounding anatomy. Neuromuscular ultrasound aids in diagnostic accuracy (when used with electrodiagnostic testing) and offers etiologic information as a non-invasive, painless, cost-effective, and radiation-free imaging technology that can be easily carried out at the bedside for immediate interpretation. Neuromuscular ultrasound has the limitation of subjectivity, and the need for training and experience will affect the interpretation of results. This article describes a basic practical guide to visualizing the median nerve using neuromuscular ultrasound in a step-by-step manner to aid in the evaluation of carpal tunnel syndrome. Even though the use of ultrasound in the assessment of median nerve entrapment has been long established, there has been no recognized standard protocol. The present protocol aims to provide clear and concise instructions to describe a standard technique to visualize the median nerve through diagnostic ultrasound.