Retrosplenial cortical activation in the fibromyalgia syndrome

To study the CNS in chronic muscular pain typical of fibromyalgia we compared PET measures of regional cerebral blood flow (rCBF) in eight fibromyalgic patients and controls at rest. Higher rCBF for patients than controls was found bilaterally in the retrosplenial cortex. Lower rCBF for patients than controls were seen in the left frontal, temporal, parietal, and occipital cortices. The higher retroplenial rCBF in patients than controls may reflect increased attention towards sub-noxious somatosensory signaling, and agrees with the notion that fibromyalgic pain reflects secondary hyperalgesia. The brain regions with lower rCBF in fibromyalgic patients than controls participate in the normal cognitive processing of pain, which may be dysfunctional in fibromyalgia.