THE PREDICTIVE VALUE OF ELECTRODIAGNOSTIC STUDIES IN CARPAL-TUNNEL SYNDROME

In recent years, electrodiagnostic studies have become an expected com ponent in tile work up and evaluation of carpal tunnel syndrome. We co nducted a retrospective review of 460 car-pal tunnel decompressions to determine whether the accuracy of diagnosis and the prediction of the rapeutic outcome could be related to the positivity and severity of fi ndings on preoperative electrical studies. The 349 patients (460 hands ) were divided into two groups: group 1 consisted of hands with the cl inical diagnosis of carpal tunnel syndrome but with normal electrodiag nostic studies (n = 62); in group 2 the hands had a clinical diagnosis of carpal tunnel syndrome with confirmatory electrodiagnostic studies (n = 398). The number and distribution of signs and symptoms of carpa l tunnel syndrome were not statistically different between these two g roups. There was nut a statistically significant difference in the suc cess rate of surgery or the incidence of complications. The similariti es between these two groups suggests that the distinction between them (the positivity of electrodiagnostic studies) is an artificial one an d that the clinical diagnosis of carpal tunnel syndrome is sufficient to predict the presence of the disease, as well as outcome of surgery. On tile basis of these data, strict adherence to electrodiagnostic st udies to confirm the diagnosis will exclude 13 percent of title patien ts with legitimate carpal tunnel syndrome from receiving appropriate t herapy.