Value of Ultrasonography in the Diagnosis of Carpal Tunnel Syndrome: Correlation with Electrophysiological Abnormalities and Clinical Severity

Abstract

ObjectiveTo investigate a diagnostic value of ultrasonography in carpal tunnel syndrome (CTS) patients and to evaluate a correlation of sonographic measurements with the degree of electrodiagnostic abnormalities and clinical severity.MethodsTwo-hundred-forty-six symptomatic hands in 135 patients and 30 asymptomatic hands in 19 healthy individuals as control group were included. In ultrasonographic study, we measured the cross-sectional area (CSA) and flattening ratio (FR) of the median nerve at the pisiform as well as palmar bowing (PB) of the flexor retinaculum. Sensitivity and specificity of ultrasonographic measurements were evaluated and ultrasonographic data from the symptomatic and control hands were compared to the grade of electrodiagnostic and clinical severity.ResultsThe mean CSA was 13.7±4.2 mm2 in symptomatic hands and 7.9±1.3 mm2 in asymptomatic hands. The mean FR was 4.2±1.0 in symptomatic hands and 3.4±0.4 in asymptomatic hands. The mean PB was 3.5±0.5 mm in symptomatic hands and 2.6±0.3 mm in asymptomatic hands. Statistical analysis showed differences of the mean CSA, FR and PB between groups were significant. A cut-off value of 10 mm2 for the mean CSA was found to be the upper limit for normal value. Both the mean CSA and PB are correlated with the grade of electrophysiological abnormalities and clinical severity, respectively.ConclusionUltrasographic measurement of the CSA and PB is helpful to diagnose CTS as a non-invasive and an alternative modality for the evaluation of CTS. In addition, ultrasonography also provides a reliable correlation with the grade of electrodiagnostic abnormalities and clinical severity.

Idiopathic Carpal Tunnel Syndrome: Evaluation of the Depth of the Carpal Tunnel by Ultrasonography

“…Flattening ratio sensitivity ranged from 37% to 100% in previous studies (Buchberger et al 1991;Yesildag et al;, FR specificity was between 50% and 75%; cutoff values ranged from 3.0 to 4.2 cm (Ahmad 2011;Kim et al 2014). In our study, sensitivity was 75% and specificity was 60% at a cutoff value of 3.2 cm.…”

Carpal tunnel syndrome severity staging using sonographic and clinical measures

“…18,19 Once physiological changes progress beyond electrodiagnostic thresholds, the continued increase in CSA has been correlated positively with severity classification. 8,20 Similarly, intraneural vascularity may be useful for identifying stages and severity of CTS. Increased vascularity is often noted in acute, pre-clinical, and mild stages of CTS as compared to decreased perfusion in more advanced and chronic stages of the disorder.…”

Diagnostic Accuracy of Ultrasound Parameters in Carpal Tunnel Syndrome: Additional Criteria for Diagnosis

“…Studies on the diagnostic accuracy of US in detecting CTS have centered mainly on the CSA of the median nerve, measured either at the CTI or CTO. There are studies that have examined different US parameters but did not conduct a regression analysis to determine whether combined measurements are more diagnostically discriminatory . Using stepwise multiple logistic regression models, this study demonstrated that the wrist‐forearm difference coupled with evidence of hypervascularity at the CTO were predictive parameters for CTS with high sensitivity (98.1%).…”