Difference in normal values of median nerve cross-sectional area between Dutch and Indian subjects.

INTRODUCTION

Ultrasound (US) measurement of the median nerve cross-sectional area (CSA) at the wrist is a useful diagnostic test for carpal tunnel syndrome (CTS). We compared median nerve normal values between samples of Indian and Dutch populations.

METHODS

The median nerve was examined by US at the wrist in 100 healthy volunteers in India and 137 volunteers in The Netherlands using the same protocol.

RESULTS

Median nerve CSA at the wrist (7.0 ± 1.1 mm(2)) in the Indian cohort was lower in comparison to the Dutch cohort (8.3 ± 1.9 mm(2) ; P < 0.05). This difference was still present after controlling for age, height, and weight (P = 0.001).

CONCLUSIONS

CSA normal values for the median nerve were different between the examined population samples even after correcting for age, height, and weight. This enforces the idea that laboratories around the world should obtain their own normative data.