OBJECTIVES: To test the hypothesis that @entity1 with chronic @entity158 develop adaptive cortical responses to noxious stimulation characterised by reduced anterior cingulate responses. METHODS: Positron emission tomography was used to measure changes in regional cerebral blood flow (rCBF) in response to an acute experimental @entity158 stimulus in six @entity1 with @entity309 ( @entity309 ) in comparison to six age and sex matched controls. A standardised and reproducible non- @entity158 and @entity158 phasic heat stimulus was delivered by a thermal probe to the back of the right hand during six two minute periods during which time rCBF measurements were made. The effects of @entity158 were subtracted from those of @entity158 to weight the analysis towards the non-discriminatory or 'suffering' components of @entity158 processing. Significance maps of @entity158 processing were generated and compared in each group and contrasted with results obtained in a group of @entity1 with atypical @entity158 (AFP) that have been previously published. RESULTS: The @entity309 @entity1 showed remarkably damped cortical and subcortical responses to @entity158 compared with the control group. Significant differences between the two groups were observed in the prefrontal (BA 10) and anterior cingulate (BA 24) and cingulofrontal transition cortical (BA 32) areas. The reduced anterior cingulate responses to standardised @entity158 were compared with the increased cingulate responses seen in @entity1 with psychogenically maintained @entity158 (AFP) who had both lower @entity158 tolerance and mood than the @entity309 group. CONCLUSIONS: Major cortical adaptive responses to standardised noxious heat can be measured and contrasted in @entity1 with different types of @entity1118 . The different pattern of cingulate and frontal cortical responses in the @entity1 with inflammatory and non-nociceptive @entity158 suggest that different mechanisms are operating, possibly at a thalamocortical level. Implications for treatment strategies for @entity1118 are discussed.

Reduced cortical responses to noxious heat in XXXX with @entity309 .

@entity1 :: ('9606', 'Species') :: ['patients'] @entity1118 :: ('MESH:D059350', 'Disease') :: ['chronic pain'] @entity309 :: ('MESH:D001172', 'Disease') :: ['rheumatoid arthritis', 'RA'] @entity158 :: ('MESH:D010146', 'Disease') :: ['inflammatory pain', 'non-painful heat', 'facial pain', 'pain', 'heat pain', 'painful heat', 'painful']
@entity1 :: (9606,Species) :: ['patients']
