Investigation of a method of thermal imaging with the potential to assist in the diagnosis of carpal tunnel syndrome

Abstract

BACKGROUND AND AIMS.: It has been suggested that thermal imaging may provide alternative appropriate diagnostic information for Carpal Tunnel Syndrome (CTS). The aims of this study are to investigate the optimum method of data collection from thermal images of subjects with CTS, establish base line thermographic reference data in subjects with CTS, measure the effect of a thermal washout on these patients and compare pre/post surgery baseline thermographic data to assess the effects of surgery. METHODS: Patients who had a diagnosis of CTS and were waiting for decompression surgery were recruited. The study involved two data collection sessions, the first immediately before decompression surgery, the second 6 weeks after the operation. A baseline image was taken, cooling using a Cryo/Cuff took place, following removal of the Cryo/Cuff temperature data were sampled during rewarming. Data from pre and post operative images were extracted by mapping three areas defined on screen by using thermally inert markers. RESULTS: The most clinically significant results were seen in the temperature change in the distal portion of the 2nd and 5th digits of the symptomatic hand. The same difference was not seen in the proximal portion of the same digits or in the asymptomatic hand. The greatest increase in post operative temperature of the distal portion of the digits occurred in the 2nd digit which is supplied by the median nerve compared to the smaller increase in temperature in the 5th digit which is supplied by the ulnar nerve. DISCUSSION: Considering the underlying pathology where the median nerve is primarily affected in CTS this could have significant diagnostic implications. There would appear to be clinical implications in these findings with potential for this method to be developed further as a diagnostic thermal imaging test which would be better tolerated and more readily available than nerve conduction studies thus reducing waiting times for diagnostic testing to confirm CTS.