Ultrasonographic cross-sectional area normal values of the ulnar nerve along its course in the arm with electrophysiological correlations in 100 Asian subjects.

ABSTRACT

INTRODUCTION: Normative cross-sectional areas (CSAs) have been obtained for the Western population. We obtained CSAs of normal ulnar nerves at predetermined sites and correlate them with electrophysiological variables in Asian subjects. METHODS: One hundred healthy volunteers, mean age 39 ± 14 years (range, 18-75 years), were recruited for the study after obtaining informed consent. The ulnar nerve was examined ultrasonographically from wrist to axilla, and CSA was measured at predetermined sites. All subjects underwent a simultaneous standardized nerve conduction study. RESULTS: Men had larger CSAs, and CSAs increased with advancing age. There was a statistically significant correlation between CSA at the wrist and distal ulnar motor latency (P = 0.005). CONCLUSIONS: Ulnar CSA correlated with age, gender, and distal motor latency. No correlations were observed with height, weight, or body mass index.