Effectiveness of Cold Stress Thermography in the Diagnosis of Complex Regional Pain Syndrome Type 1

Park, Eun Jung; Han, Kyung Ream; Chae, Yun Jeong; Jeong, Won Ho; Kim, Chan

Abstract

BACKGROUND
Despite the enormous amount of basic research on neuropathic pain, there is the lack of an objective diagnostic test for complex regional pain syndrome (CRPS). The aim of this study was to evaluate the usefulness of cold stress thermography in the diagnosis of CRPS. METHODS: The study involved 12 patients with CRPS type 1, according to the IASP criteria, who were compared with 15 normal healthy volunteers. All subjects underwent thermographic examination under baseline conditions at 21degrees C. A cold stress test (CST; 10degrees C water for 1 minute) was then applied to both hands below the wrists, immediate, and after 10 and 20 minutes. RESULTS: The temperature asymmetry between the patients with CRPS and the volunteers showed significant discrimination at the baseline and after a 20 minute recovery period from the CST. Among the study subjects having temperature asymmetry of both hands of less than 1degrees C (8 out of 12 CRPS patients and 14 out of 15 volunteer), 7 (87.5%) of the 8 CRPS patients and 3 (21%) of the 14 volunteers showed a temperature difference of more than 1degrees C after the 20 minute recovery period. The actual temperature values during the four periods did not discriminate between the patients with CRPS and the volunteers. CONCLUSIONS: Thermography, under the CST, could be a more objective test for the diagnosis of CRPS. A temperature asymmetry greater than 1degrees C during the 20 minute recovery period following CST provides strong diagnostic information about CRPS, with both high sensitivity and specificity.