The Ultrasonographic Findings of the Median Nerve in the CarpalTunnel According to Age and Sex of Normal Korean Adults

Park, Ji Young; Park, Song Rae; Lee, Sang Hoon; Choi, Kyoung Hyo

Abstract

OBJECTIVE
To define the ultrasonographic findings of the median nerve within the carpal tunnel and to verify the differences of the median nerve according to age, sex and the wrist in the normal Korean adults. METHOD: We studied 152 hands of 76 normal Korean adults who had no symptoms of carpal tunnel syndrome such as hand numbness, pain, dysesthesia or hand weakness. All subjects were examined with a real-time ultrasonography. We evaluated the flattening ratio (FR) and cross-sectional area (CSA) of the median nerve within the carpal tunnel. RESULTS: The CSA of the median nerve was 6.44+/-0.02 mm2 (at distal radioulnar joint), 6.34+/-0.02 mm2 (at pisiform) and 6.31+/-0.02 mm2 (at hamate). The FR at distal radioulnar joint is 2.36+/-0.02, at pisiform is 2.33+/-0.01 and at hamate is 2.33+/-0.01. Men have a larger cross-sectional area and flattening ratio of the median nerve than women. The older group over age 50 years has a smaller cross-sectional area and flattening ratio than the younger group. There were differences between men and women in body mass index (BMI) as well as between the older and the younger. There was also a linear relationship with CSA and FR in weight and height. CONCLUSION: The ultrasonographic finding of the normal Korean adult's median nerve in the carpal tunnel were different according to age and sex. Weight, height and BMI might be important factors to bring different results according to race, sex and age.