Abstract
Carpal tunnel syndrome is the most frequent form of median nerve entrapment, accounting for 90% of all entrapment neuropathies. Routinely nerve conduction study (NCS) tests are ordered to confirm the diagnosis however; there are issues of long waiting periods and costs with it. We aimed to compare carpal tunnel questionnaire score (CTQS) by Kamath and Stothard (2003) to nerve conduction study result in the diagnosis of carpal tunnel syndrome.
This prospective study involved analysis of data from all the patients referred to NHS Tayside (Dundee) hand clinic with signs and symptoms of Carpal tunnel syndrome (CTS) from September 2016 to February 2017. Statistical analysis was done using SPSS and sensitivity and specificity was calculated. The questionnaires were filled in by a team of specialist physiotherapists. Nerve conduction study tests were done by a team of consultant neurophysiologists. Both the groups were blinded to each other's assessment.
We analysed 88 patients who filled in CTQS and also underwent NCS. We noted that CTQS of less than 3 correlated 100% to negative nerve conduction result. When the carpal tunnel questionnaire score was more than or equal to 5, 54 patients had positive NCS result and 6 patients had negative NCS result, giving a 90% predictability of a positive NCS result. Mean waiting period of carpal tunnel patients for NCS was 141 days.
We noted from this prospective study that CTQS was sensitive enough to exclude carpal tunnel syndrome when the questionnaire score was less than 3. In addition, the questionnaire revealed a 90% probability of having carpal tunnel syndrome when CTQS was more than or equal to 5. Based on the present study, we would recommend that patients in grey zone of 3 to 4 on questionnaire should undergo NCS, resulting in only 20% of patients (based on the figures from the current study) being referred for NCS. The questionnaire can be used in primary health care or specialist physiotherapy screening clinic as a tool for diagnosing CTS with implications of cost saving and avoiding long waiting periods.
