NORMAL VALUES OF MEDIAN NERVE CROSS-SECTIONAL AREA OBTAINED BY ULTRASOUND ALONG ITS COURSE IN THE ARM WITH ELECTROPHYSIOLOGICAL CORRELATIONS, IN 100 ASIAN SUBJECTS

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 mm(2); mid-forearm 4.8 +/- 0.9 mm(2); mid-arm 6.1 +/- 1 mm(2); axilla 5.9 +/- 0.9 mm(2). The CSA at the wrist was the largest compared with other levels (P < 0.001), and it increased with advancing age (P < 0.002). 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. Muscle Nerve 49: 284-286, 2014