Evaluation of current perception threshold testing as a screening procedure for carpal tunnel syndrome among industrial workers

Abstract

Eighty-four workers participated in a work-site screening program designed, in part, to estimate the prevalence of carpal tunnel syndrome (CTS). Each worker completed a discomfort survey, limited electrodiagnostic testing of the median and ulnar sensory nerves in each wrist, and current perception threshold (CPT) testing in the right 2nd digit using the NEUROMETER CPT device. A subset of study participants also completed CPT testing in digit 5 on the right (n = 33). Comparisons were made among the CPT results, symptoms consistent with CTS, and electrophysiologic findings. The CPT results correlated poorly with electrophysiologic parameters from the same nerve distribution, and CPT results were statistically unrelated to self-reported symptoms that may be suggestive of CTS. The test performance characteristics of CPT testing (sensitivity, specificity, positive predictive value, and negative predictive value) were low in comparison with electrodiagnostic measurements and self-reported symptoms consistent with CTS. The electrophysiologic results were significantly associated with the constellation of symptoms that are consistent with CTS. On the basis of these results, CPT testing cannot be recommended as a screening procedure for identification of possible cases of CTS among active industrial workers.