Background and Purpose: Widespread pain sensitivity in patients with FM suggests a CNS [central nervous system/brain] processing problem. The purpose of this study was to assess alterations in perfusion [blood flow] as measured by DSC in a number of brain regions implicated in pain processing between patients with FM and healthy controls.
Materials and Methods: 21 patients with FM and 27 healthy controls underwent conventional MR imaging and DSC.
[Note: DSC stands for “dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging” – an imaging technique that is sensitive to microscopic levels of blood flow (perfusion), which are measured as rCBF (relative cerebral blood flow) values.]
For DSC, 12 regions of interest were placed in brain regions previously implicated in pain processing. rCBF values were calculated for each region of interest.
Subjects answered mood/pain coping questionnaires and underwent clinical/experimental pain assessment.
• There were significant correlations between the thalamic rCBF values and the pain-control beliefs of FM subjects. [Note: the thalamus is located in the center of the brain, and is made up of two thalami, one beneath each cerebral hemisphere. The thalami are ‘relay stations’ for sensory nerve impulses from the spinal cord to the brain, and essentially ‘decide’ which signals to pass on.
• The strength of the relationship between clinical pain measures and thalamic rCBF values increased after adjusting for pain-control beliefs.
• There was a significantly different distribution pattern of rCBF values across various brain regions between the FM group and the healthy controls.
• There was a lower degree of correlation in the FM group between the thalamic rCBF values and the other brain regions relative to the healthy controls.
Significant correlations were found between thalamic rCBF values and pain belief values.
These data suggest that there are baseline alterations of brain perfusion in patients with FM.
rCBF values of the thalami exhibited lower correlations with respect to other brain regions thought to be involved in pain processing compared with those in healthy controls.
Source: American Journal of Neuroradiology, Aug 25, 2011. Foerster BR, Petrou M, Harris RE, Barker PB, Hoeffner EG, Clauw DJ, Sundgren PC. Division of Neuroradiology, Department of Radiology, and Departments of Anesthesiology, Psychiatry, and Internal Medicine, Division of Rheumatology, University of Michigan, Ann Arbor; Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland; VA Ann Arbor Healthcare System, Ann Arbor, Michigan; Department of Diagnostic Radiology, Clinical Sciences Lund, Lund University, Sweden. [Email: Bradley Foerster, MD, firstname.lastname@example.org]