Resultados de um Protocolo QST em voluntários saudáveis e em pacientes com dor crónica: um ensaio clínico controlado

Abstract

Chronic pain is an important cause of disability with a high burden to society. Quantitative sensory testing (QST) is a non-invasive multimodal method used to discriminate function of nerve fibers. The aims of this study were to propose a new, reproducible and less time consuming thermal QST protocol to help characterize and monitor pain. Additionally, this study also compared QST outcomes between healthy and chronic pain subjects. 40 healthy young/adult medical students and 50 adult/elderly chronic pain patients were evaluated in individual sessions comprising pain history, followed by QST assessments divided in three proposed tests: pain threshold, suprathreshold, and tonic pain. In the chronic pain group, a significantly higher pain threshold (hypoesthesia) and a higher pain sensibility (hyperalgesia) were demonstrated at threshold temperature when compared to healthy participants. The sensitivity to the suprathreshold and tonic stimulus did not prove to be significantly different between both groups. The main results demonstrated that the heat threshold QST tests can be helpful in evaluating hypoesthesia and that the sensitivity threshold temperature test can demonstrate hyperalgesia in individuals with chronic pain. In conclusion, this study demonstrates the importance of using tools such as QST as a complement to detect changes in several pain dimensions.