Figure 3

Changes on cortical excitability and pain during the QST and CPM-TASK. (A) Motor-evoked potentials (MEP) expressed in mV, evoked by a stimulus of 130% of the rMT, before and during the heat pain threshold induced by the Quantitative Sensory Test (QST) in patients and healthy controls. Bars represent the standard error of the mean (S.E.M.). Asterisks positioned above the bars indicate a significant difference (P < 0.05) between the MEP amplitude before and after QST. (B) Reduction in pain intensity during the Conditioned Pain Modulation (CPM). The pain on the numeric rating scale (NRS) from 0 to 10 is presented during the test stimulus (QST) and during the conditioning stimulus (cold-pressor task, CPM-TASK). Bars express the standard error of the mean (S.E.M.) (n = 47). Asterisk positioned above the bars indicate a significant difference (P < 0.05) between the NRS during the CPM.