Normal values of median nerve cross-sectional area obtained by ultrasound along its course in the arm with electrophysiological correlations, in 100 Asian subjects

摘要

Introduction: The objective of this study is to obtain normative cross-sectional area (CSA) values for median nerve by ultrasound at predetermined sites and correlate them with electrophysiological variables in healthy Asian subjects. Methods: The median nerve was examined ultrasonographically in 100 healthy volunteers, mean age 39 years (range, 18-75 years). CSA of the median nerve was measured at wrist, mid-forearm, mid-arm, and axilla. All subjects underwent simultaneous standardized nerve conduction studies. Results: The mean median nerve CSAs±SD at the distal wrist crease was 7.2±1 mm2; mid-forearm 4.8±0.9 mm2; mid-arm 6.1±1 mm2; axilla 5.9±0.9 mm2. The CSA at the wrist was the largest compared with other levels (P0.001), and it increased with advancing age (P0.002). Conclusions: These normative data show that median nerve CSA is not uniform along its length. There are differences between gender, and values increase with advancing age.