title: Altered cortical processing of observed pain in patients with fibromyalgia syndrome.
abstract: 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.
  
  
  CONCLUSIONS
  Patients with FMS demonstrate increased activations associated with pain and nonpain pictures. The findings suggest that even innocuous, everyday visual stimuli with somatic connotations may challenge the emotional state of patients with FMS. Our study points toward the importance of cognitive-emotional therapeutic approaches for the treatment of FMS.
authors.affiliation: Department Psychological Sciences, Institute of Psychology, Health, and Society, University of Liverpool, Liverpool, United Kingdom. Electronic address: nickfal@liverpool.ac.uk.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Fallon
authors.affiliation: Department Psychological Sciences, Institute of Psychology, Health, and Society, University of Liverpool, Liverpool, United Kingdom.
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Li
authors.affiliation: Wirral University Teaching Hospital NHS Foundation Trust, Wirral, United Kingdom.
authors.forename: Yee
authors.initials: Y
authors.lastname: Chiu
authors.affiliation: Pain Research Institute, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom; The Walton Centre NHS Foundation Trust, Liverpool, United Kingdom.
authors.forename: Turo
authors.initials: T
authors.lastname: Nurmikko
authors.affiliation: Department Psychological Sciences, Institute of Psychology, Health, and Society, University of Liverpool, Liverpool, United Kingdom.
authors.forename: Andrej
authors.initials: A
authors.lastname: Stancak
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000503:physiopathology*; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D005356:Fibromyalgia / Q000473:pathology* / Q000523:psychology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D057566:Self Report
keywords: Electroencephalography; chronic pain; event-related potential; hypervigilance