Ultrasonography in carpal tunnel syndrome: Comparison with electrophysiological stage and motor unit number estimate

Abstract

The purpose of this study was to document the ultrasonographic measurement differences in median nerve size between patients with carpal tunnel syndrome (CTS) and controls, and to correlate these findings with electrophysiological stage and motor unit number estimation (MUNE), thereby allowing us to test the validity of ultrasound as a diagnostic modality for assessing the severity of CTS. High-resolution sonography and electrophysiological studies were performed on 41 wrists of 27 patients and compared with findings on 40 wrists of 20 healthy individuals. On ultrasonographic views, cross-sectional area and flattening ratio in proximal, middle, and distal tunnel segments of the median nerve were measured both by calculating ellipsoid area by large and small cross-sectional diameters and by automated ellipsoid area calculation. We compared electrophysiological stage and MUNE with proximal, middle, and distal cross-sectional area and other ultrasonographic findings. All correlations between electrophysiological stage and cross-sectional areas in these different segments of the median nerve were significant with both measurement methods. Negative correlations were seen between MUNE and cross-sectional area in the proximal and middle segments, whereas no significant correlation was detected in the distal segment. Our results indicate that there are close correlations between the ultrasonographic findings and electrophysiological stage. Ultrasound also reflects the reduction in the number of axons estimated by the MUNE method. Therefore, we suggest that the ultrasonographic findings reflect the severity of disease in patients with CTS.

Sonographic Follow-Up of Patients With Carpal Tunnel Syndrome Undergoing Surgical or Nonsurgical Treatment: Prospective Cohort Study

“…Several authors have studied the value of highfrequency ultrasonography for the diagnosis of CTS. [2][3][4][5][12][13][14][15][16][17][18][19] In addition to contributing to the diagnostic work-up of patients with suspected CTS, sonographic examination allows noninvasive detection of aberrations such as a bifid nerve or a neuroma, inspection of the surrounding soft tissue with a diagnosis of a synovitis or tenosynovitis, and detection of space-occupying masses. In our study, we found clinically relevant pathologies in 3 of 57 surgically treated wrists in the sonographic follow-up.…”

Ultrasonography of Median Nerve and Electrophysiologic Severity in Carpal Tunnel Syndrome

“…Lee et al26 reported that the swelling of the median nerve at the proximal carpal tunnel was related to the results of nerve conduction study. Bayrak et al27 reported that the motor unit number estimation of the abductor pollicis brevis muscle was negatively correlated with CSA of the median nerve at the proximal and middle segment of carpal tunnel. Padua et al28 reported that a positive correlation exists between CSA-W and the neurophysiological severity of CTS.…”

Comparison of the Diagnostic Utility of Electromyography, Ultrasonography, Computed Tomography, and Magnetic Resonance Imaging in Idiopathic Carpal Tunnel Syndrome Determined by Clinical Findings

“…Computed tomography (CT), magnetic resonance imaging (MRI), and ultrasonography (US) may also be used for the diagnosis. 8,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] There are numerous studies on each particular diagnostic test. Most of the studies accept EMG as the gold standard and attempt to determine the accuracy of other tests in comparison with EMG.…”