Can we accurately predict nerve conduction study outcome using a carpal tunnel syndrome questionnaire?

NCS are often routinely performed for CTS despite recommendations from the BOA, BSSH and NICE that they are associated with increased costs and prolonged waiting times. This prospective study aimed to assess if the Kamath and Stothard clinical questionnaire could accurately predict nerve conduction study (NCS) results when diagnosing carpal tunnel syndrome (CTS). Eighty-eight patients referred with signs and symptoms of CTS from September 2016 to February 2017 were included. All patients were assessed by specialist hand therapists using the Kamath and Stothard carpal tunnel questionnaire (CTQ) and all patients independently underwent NCS by neurophysiologists. We compared results of CTQ score versus NCS findings. Results showed that a CTQ score of less than 3 correlated 100% to negative NCS. When the CTQ score was more than or equal to 5, 90% of patients had a positive NCS result. For patients with a CTQ score of 3 or 4, the NCS could not be reliably predicted. These findings suggest that the Kamath and Stothard CTQ is a useful tool in determining which patients may require NCS. We suggest that only patients with a CTQ score of 3 or 4 and with equivocal signs and symptoms should undergo NCS. The questionnaire has the potential to be used as a primary tool for diagnosing CTS, with significant cost savings and reduction in waiting times for NCS.