Altered Cortical Processing of Observed Pain in Patients With Fibromyalgia Syndrome

摘要

Fibromyalgia syndrome (FMS) is characterized by widespread chronic pain, fatigue, sleep disorders, and cognitive-emotional disturbance. Patients with FMS exhibit increased sensitivity to experimental pain and pain-related cues, as well as deficits in emotional regulation. The present study investigated the spatiotemporal patterns of brain activations for observed pain in 19 patients with FMS and 18 age-matched, healthy control individuals using event-related potential analysis. Patients with FMS attributed greater pain and unpleasantness to pain pictures, relative to healthy control participants. An augmented late positive potential (LPP) component (>500 milliseconds) was found in patients viewing both pain and nonpain pictures, and this amplitude difference in the LPP covaried with perceived unpleasantness of pictures. Mid-latency potentials (250-450 milliseconds) demonstrated similar amplitude increases of positive potentials in the FMS patient group. By contrast, the short-latency positive potential (140 milliseconds) was reduced in patients with FMS relative to healthy control participants. Results suggest amplitude increases to mid- to long-latency cortical activations in patients with FMS, which are known to reflect emotional control and motivational salience of stimuli.