Sonography versus nerve conduction studies in patients referred with a clinical diagnosis of carpal tunnel syndrome.
OBJECTIVE
To compare the diagnostic value of high-resolution ultrasound (US) with nerve conduction studies (NCS) in patients with clinically defined carpal tunnel syndrome (CTS).


METHODS
A prospective study was conducted on 66 consecutive patients investigated for sensory hand symptoms. The gold standard was the clinical diagnosis of CTS.


RESULTS
NCS showed greater diagnostic sensitivity (82%) than US (62%) in supporting a diagnosis of CTS. With increasing neurophysiologic severity of median neuropathy, there was increasing convergence of the two test methods. Abnormal US as the only diagnostic supportive evidence of CTS was rare. However, the positive predictive value of US for CTS was 100%.


CONCLUSIONS
NCS show better sensitivity than US in supporting a diagnosis of CTS. However, because of its high positive predictive value, one may consider using US as a screening test, eliminating the need for NCS in the majority of clinical suspicion of CTS and reserving NCS for cases in which US is negative.
Pastare
D
D
Neurology, National University Health Systems, 5 Lower Kent Ridge Road, 119074, Singapore.
Therimadasamy
A K
AK
Lee
E
E
Wilder-Smith
E P
EP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019412:Anatomy, Cross-Sectional; D002349:Carpal Tunnel Syndrome / Q000175:diagnosis* / Q000000981:diagnostic imaging* / Q000503:physiopathology; D016022:Case-Control Studies; D005260:Female; D006225:Hand / Q000000981:diagnostic imaging / Q000294:innervation; D006801:Humans; D008297:Male; D020423:Median Neuropathy / Q000000981:diagnostic imaging / Q000503:physiopathology; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014463:Ultrasonography; D055815:Young Adult