Carpal tunnel syndrome diagnosed using ultrasound as a first-line exam by the surgeon.

This study evaluates the diagnostic value of ultrasound as a first-line exam in carpal tunnel syndrome. In 16 patients with carpal tunnel syndrome and 32 matched controls, evaluation of the median nerve was performed by the cross-sectional area at wrist level and wrist-forearm ratio. This study found statistically significant differences between patients and controls by both methods, and both showed high specificity and positive predictive values. Optimal cut-off values were identified at a 14 mm(2) cross-sectional area and a 1.6 wrist-forearm ratio. This study implies that ultrasound evaluation of the median nerve is a valuable tool as a first-line diagnostic test used by the surgeon for examination of patients with presumed carpal tunnel syndrome. Owing to the high positive predictive value of ultrasound, the need for referral to nerve conduction study may be limited.