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Updated: Oct 12, 2025

Screening of Axonal Degeneration in Carpal Tunnel Syndrome Using Ultrasonography and Nerve Conduction Studies
Published on: January 11, 2019
Preoperative Evaluation of Thenar Muscles in Carpal Tunnel Syndrome by Ultrasonography
Issei Nagura1, Takako Kanatani2, Yoshifumi Harada2
1Department of Orthopedic Surgery, Ako City Hospital, 1090 Nakahiro, Ako 678-0232, Japan.
Abstract:
This article aims to evaluate the usefulness of ultrasonography for the measurement of thenar muscles in carpal tunnel syndrome (CTS). A total of 85 patients with CTS who had a carpal tunnel release procedure were included in this study. The transducer was applied onto the palmar surface of the hand perpendicularly to the longitudinal axis of the first metacarpal bone. Thenar atrophy was evaluated visually and classified using the visual grading scale. A nerve conduction test was performed and classified according to the electrophysiological severity scale. This technique is more precise than visual evaluation because it is a quantitative assessment.
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