Correlation of clinical signs with nerve conduction tests in the diagnosis of carpal tunnel syndrome.

In order to establish the need for nerve conduction studies, a prospective study has been performed on 112 patients with symptoms of carpal tunnel syndrome (172 symptomatic hands), seeking correlation with 11 clinical criteria taken either singly or in combination. Even when the patient presents with a typical clinical presentation of carpal tunnel syndrome the diagnosis is only confirmed electrophysiologically in 61% of cases. Analysis of the sensitivity and specificity of various clinical tests and diagnostic manoeuvres has shown their mediocre reliability in establishing the diagnosis with a sensitivity of 58% and a specificity of 54% for Phalen's test.