Role of Ultrasonography and Color Doppler versus Nerve Conduction Test Results in Evaluation of Cases of Carpal Tunnel Syndrome

Abstract Background Carpal tunnel syndrome (CTS) is a common entrapment neuropathy with incidence rate of 2.7 to 5.8% of the general population. Nerve conduction studies (NCS) were considered gold standard for diagnosis. Due to false negative rate, Ultrasonography (US) evaluation of median nerve (MN) was suggested as a diagnostic test for CTS. Aim of the Work Our aim was to investigate the diagnostic accuracy of US derived measurements compared to NCS for the diagnosis of CTS and comparing different US derived measurements and ratios to know which could be used efficiently for the diagnosis of CTS. Patients and Methods This case control study included 52 participants; 26 cases and 26 healthy controls. Our results showed comparable sensitivity between US and NCS results which was 88% and 96.2, respectively. On the other hand, specificity with US measurements was 92% compared to 88% in case of NCS. Results Many US derived measurements as inlet MN CSA, outlet CSA, largest CSA between inlet and outlet, WFR and IOR showed statistically highly significant correlation with clinical diagnosis of CTS. Other measurements like CSA at proximal border and proximal third of pronator quadratus muscle failed to show statistically significant correlation. Conclusion US results are comparable to NCS results in cases of CTS. US derived measurements as MN CSA at carpal tunnel inlet and largest CSA between inlet and outlet were best to be used for correlation with clinical diagnosis with cut-off value = 9.35 and 9.3 cm2, respectively. WFR and IOR have also high correlation with clinical diagnosis with cut-off value = 1.1 and 1.02, respectively.