Correlation of Carpal Tunnel Syndrome 6 Score and Physical Exam Maneuvers With Electrodiagnostic Test Severity in Carpal Tunnel Syndrome: A Blinded Prospective Cohort Study

Abstract

Although carpal tunnel syndrome (CTS) can be diagnosed clinically with the Carpal Tunnel Syndrome 6 (CTS-6) evaluation tool, the relationship between disease severity and CTS-6 score has not been elucidated. The purpose of our study was to determine the correlation of the CTS-6 score and other physical examination maneuvers with the carpal tunnel severity grade by electrodiagnostic testing (EDT). We hypothesized that the CTS-6 score, Durkan test, and Semmes Weinstein Monofilament Testing (SWMT) positively correlate with EDT severity. We prospectively enrolled 105 consecutive patients who presented to the office with suspected CTS, excluding those with previous surgery, previous EDT from an outside facility, or concomitant neuropathy. Four fellowship-trained hand surgeons obtained the CTS-6 score, time to obtain a positive Durkan compression test, and SWMT of the thumb, index, and middle fingers. All patients were sent for EDT. Hand surgeons were blinded to the results of the EDT, and the electrodiagnosticians were blinded to the clinical data. We used the Bland criteria (0-6) to grade CTS severity on EDT. This grade was compared with the CTS-6 score, Durkan time, and SWMT results. Using Spearman correlation coefficients, we found a weakly positive correlation between a higher CTS-6 score and a higher severity grade on EDT. The mean CTS-6 score based on EDT grading were the following: (1) 14.8 (grade 0), (2) 16.0 (grade 1), (3) 14.8 (grade 2), (4) 16.7 (grade 3), (5) 18.7 (grade 4), (6) 18.3 (grade 5), and (7) 22.4 (grade 6). We also found a statistically significant association between the SWMT and a higher CTS-6 score as well as a higher severity grade on EDT. Durkan compression test did not appear to correlate with the EDT grade. The CTS-6 and SWMT show a positive correlation with EDT severity in CTS on the basis of the Bland criteria. The time to a positive Durkan test did not show any correlation. Diagnostic II.