Functional Magnetic Resonance Imaging Evidence of Augmented Pain Processing in Fibromyalgia

Objective. To use functional magnetic resonance imaging (fMRI) to evaluate the pattern of cerebral activation during the application of painful pressure and determine whether this pattern is augmented in patients with fibromyalgia (FM) compared with con-trols. Methods. Pressure was applied to the left thumb-nail beds of 16 right-handed patients with FM and 16 right-handed matched controls. Each FM patient un-derwent fMRI while moderately painful pressure was being applied. The functional activation patterns in FM patients were compared with those in controls, who were tested under 2 conditions: the “stimulus pressure con-trol ” condition, during which they received an amount of pressure similar to that delivered to patients, and th