Role of Ultrasonography in the Diagnosis of Carpal Tunnel Syndrome and Comparison With Electromyography

Abdullah Doğdaş; Oktay Işık; Cesur Gümüş; Sema Bulut; Bilge Öztoprak; Suat Topaktaş

Abdullah Doğdaş¹, Oktay Işık¹, Cesur Gümüş¹, Sema Bulut¹, Bilge Öztoprak¹, Suat Topaktaş²

¹Department Of Radiology, Cumhuriyet University, Faculty Of Medicine, Sivas, Turkey
²Department Of Neurology, Cumhuriyet University, Faculty Of Medicine, Sivas, Turkey

Keywords: Median nerve, entrapment neuropathy, diagnosis, ultrasonography

Abstract

OBJECTIVE: Carpal tunnel syndrome (CTS) is the impairment of median nerve function due to its entrapment or injury in the carpal tunnel. In this study, we aimed to determine the role and significance of sonography in the diagnosis of CTS.

METHODS: Patients with idiopathic CTS are included in this study. 60 patients who were sent to the electromyography (EMG) laboratory with a provisional diagnosis of CTS underwent median and ulnar nerve conduction studies. Sonographic examinations were performed with 7.5-12MHz linear transducers after the forearm was positioned neutrally, with the palm facing upwards. The cross-sectional area of the median nerve was calculated at the level of the psiform bone and at the level of the distal radius.

RESULTS: The cross-sectional area of the median nerve at the level of the psiform bone was found to be increased, with an average of 13.1mm², compared to the area at the level of the distal forearm in patients with EMG results consistent with CTS. The results of sonographic examination were compared with the EMG findings. The specificity, sensitivity, positive predictive value and negative predictive value of sonography were found to be 78.5%, 90.2%, 83.6% and 86.8%, respectively.

CONCLUSION: We suggest sonography can be effectively used in the diagnosis of CTS, since it has high sensitivity, specificity, and positive and negative predictive values.