Clinical Diagnosis of Carpal Tunnel Syndrome

Abstract

Background: Carpal Tunnel Syndrome (CTS) is a condition affecting wrists and hands, causing pain, tingling, and numbness. Despite the high prevalence of CTS and the existence of several diagnostic tools, there is no consensus over a diagnostic gold standard test. Thesis Objectives: To conduct a systematic review of diagnostic test accuracy of clinical scales, questionnaires and hand symptom diagrams/maps for the diagnosis of CTS in people suspected with this condition; and to do a cognitive interviewing qualitative study of the Kamath and Stothard questionnaire, a diagnostic tool for CTS, to identify and resolve potential sources of error. Methods: In the first study, we searched MEDLINE, CINAHL, and Embase databases keywords related to diagnostic accuracy and clinical tests of CTS. In the second study, we interviewed clinicians and people diagnosed with CTS and other upper extremity conditions. We recorded, and content analyzed their opinion on comprehensiveness and comprehensibility of Kamath and Stothard questionnaire. Results: Twenty-one articles met the eligibility criteria of the systematic review, of which nine were on the diagnostic accuracy of hand symptom diagrams and twelve assessed the diagnostic accuracy of clinical scales and questionnaires for the diagnosis of CTS. Positive likelihood ratios (LRs) to diagnose or rule in CTS ranged from 0.94 for Boston carpal tunnel questionnaire to 10.5 for CTS-6 scale, and negative LRs to rule out CTS ranged from 1.05 to 0.05 for the same diagnostic tools. In the cognitive interviewing study, we categorized the areas of uncertainty in the participants’ responses into five themes: clarity and comprehension (51%), relativeness (38%), inadequate response definition (3.75%), perspective modifiers (3.75%), and a reference point (2.5%). Conclusions: Very few high-quality studies exist on the diagnostic accuracy of CTS-6, Kamath and Stothard questionnaire, Bland questionnaire, and Katz and Stirrat’s hand symptom diagram. By doing cognitive interviews, we identified options for potential improvement in the wording of the Kamath and Stothard questionnaire. Future studies should assess the diagnostic properties of the proposed modified questionnaire, and high-quality studies are warranted to assist in deciding on ruling in or out CTS.