The diagnosis of carpal tunnel syndrome. Sensitivity and specificity of some clinical and electrophysiological tests.

The study group consisted of 100 persons referred with suspected carpal tunnel syndrome. Clinical and neurophysiological examinations were performed blinded from each other. The gold standard for the carpal tunnel syndrome (CTS) diagnosis was based on the results of these examinations but relief of CTS symptoms after surgery was also required. The sensitivity and specificity for the combined results of the clinical examinations were 94% and 80% respectively, and for the neurophysiological examinations, 85% and 87%. Of the neurophysiological methods used, the quotient of sensory nerve conduction velocity between palm to wrist and wrist to elbow was best and the cut-off for this test was studied by means of an ROC-curve. According to our results clinical examination by an experienced doctor seems to be sufficient if there are typical symptoms of carpal tunnel syndrome, but if there is a history of pain, atypical symptoms or earlier fractures in the arm, wrist or hand, it is important to add a neurophysiological examination.