Impact of mental stressor on conditioned pain modulation

Abstract

[6] Nilsen KB, Christiansen SE, Holmen LB, Sand T. The effect of a mental stressor on Conditioned pain modulation (CPM) is the phenomenon hrough which the conditioning stimulus affects the test stimuus [1]. Such phenomenon is previously termed “Diffuse noxious nhibitory controls (DNIC)” [2], which is known as “pain inhibits ain phenomenon (inhibitory CPM)”. It has been reported that the CPM effect is impaired in, e.g. usculoskeletal pain patients [3]. Moreover, there is an indication hat the attenuated CPM might be relevant to stress [4]. Although tresswould reduce pain [5], the effect ofmental stressor on CPM is nclear to date. The elucidation of the relationship betweenmental tressor and CPM may play a key role to reveal such a complicated ndogenous pain inhibitory phenomenon in chronic pain patients. The study of Kristian B. Nilsen and co-workers in theis issue f the Scandinavian Journal of Pain [6] investigated the effect of a ental stressor on CPM on young healthy human subjects. Conitioning stimulus was induced with tourniquet. The test stimuli ereheatpain threshold, supra-thresholdheatpain level, andpresure pain threshold. Stressful task was to subtract 7 from 1000 uccessively for five minutes. The applied methodology for test timuli and the conditioning stimulus is common to test CPM [7]. In ddition, a well-established stressful test was employed. Measureents of CPM effect were performed at baseline, after a stressful ask, and after a non-stressful task. The CPMeffectswere calculated s thedifferencebetween the threshold/level after the conditioning timulus and the baseline threshold/level. The results showed that the CPM effect was significantly higher fter the non-stressful task compared to the stressful task. This is he first study to systematically investigate the effect of mental tressor on CPM.