LETTER TO EDITOR Comparison of High Resolution Ultrasonography and Nerve Conduction Study in the Diagnosis of Carpal Tunnel Syndrome: Diagnostic Value of Median Nerve Cross-Sectional Area

I read the recent publication by Mohammadi et al. on ultrasonographic diagnosis of carpal tunnel syn-drome (CTS) with great interest.1 Mohammadi et al. concluded that “In patients with the clinical diagnosis of CTS, we confirm that the diagnostic value of ultra-sonography is similar to NCS, and sonography may be used in the primary evaluation of CTS”.1 The results of this study are similar to a recent report by Moran et al.2 Confirmation of the feasibility of using ultraso-nography for diagnosis of CTS can be reached. How-ever, there are some points to be concerned on this report. First, very few number of subjects and non-matched controls in this work lead to the limitation for generalization of the result. The variability of the anatomy between sex, age and race should be dis-cussed. Second, although ultrasonography might show the narrowing, it cannot show the pathophysio-logical change in nerve electrical conduction in CTS,2 which is an important data for assessment of the se-verity.3 Third, to judge the diagnostic value, the com-plete set of evaluation for sensitivity and specificity as well as cost effectiveness should be given