Neural underpinnings of nocebo hyperalgesia in XXXX : A fMRI study in healthy volunteers.

@entity3825 @entity148 @entity158 @entity490 @entity2701
UNASSIGNED: Despite the clinical relevance of nocebo effects, few studies have addressed their underlying neural mechanisms in clinically-relevant @entity158 models. We aimed to address the contribution of nocebo effects and their underlying neural circuitry to central @entity158 , as it may develop over repeated @entity158 experiences due to negative @entity158 -related expectations. Healthy volunteers received verbal suggestions of @entity158 sensitization (nocebo group, N=28) or neutral instructions (control group, N=16). fMRI was used to investigate changes in neural responses during cued @entity158 anticipation and @entity158 delivered in successive fMRI sessions. @entity158 intensity was rated trial-by-trial, and expected @entity158 intensity, state @entity148 and @entity2701 were assessed prior to each session. Behavioral analyses demonstrated significantly greater increases in both expected and perceived @entity158 in the nocebo group. The fMRI analysis performed on nocebo-responders only (N=14) revealed that these behavioral changes were associated with increased activation within the secondary somatosensory cortex and amygdala during @entity158 and amygdala during @entity158 stimulation when compared to controls. A subsequent psycho-physiological interaction analysis of the @entity158 phase showed increased functional connectivity between the anterior insula, which was set-up as seed region based on group results, and midcingulate cortex as a function of negative expectations. These findings support that negative @entity158 -related expectations can play a crucial role in @entity158 amplification of @entity3825 , which is mediated, at least in part, by a neural up-regulation of @entity158 and their connectivity. These findings may have implications for the pathophysiology and treatment of chronic @entity490 .
