title: Quantitative sensory testing in fibromyalgia patients and in healthy subjects: identification of subgroups.
abstract: OBJECTIVE
  To determine perception and pain thresholds in patients with fibromyalgia syndrome and in healthy controls, and to investigate whether patients with fibromyalgia syndrome can be grouped with respect to thermal hyperalgesia and whether these subgroups differ from healthy controls and in clinical appearance.
  
  
  METHODS
  The authors conducted a quasi-experimental clinical study.
  
  
  METHODS
  Twenty-nine women patients with fibromyalgia syndrome and 21 healthy pain-free age-matched women participated in the study.
  
  
  METHODS
  Quantitative sensory testing using a Thermotest instrument was performed on the dorsum of the left hand. Sleep and pain intensity were rated using visual analog scales.
  
  
  RESULTS
  Cold and heat pain but not perception thresholds differed significantly between patients with fibromyalgia syndrome and healthy subjects. Based on thermal pain thresholds, two subgroups could be identified in fibromyalgia syndrome using cluster analysis.
  
  
  CONCLUSIONS
  Patients with fibromyalgia syndrome were subgrouped by quantitative sensory testing (i.e., thermal pain thresholds). Subgroups show clinical differences in pain intensities, number of tender points, and sleep quality. Cold pain threshold was especially linked to these clinical aspects.
authors.affiliation: Department of Medicine and Care, Pharmacology, Faculty of Health Sciences, Linköping, Sweden. ingrid@hurtig@far.liu.se
authors.forename: I M
authors.initials: IM
authors.lastname: Hurtig
authors.forename: R I
authors.initials: RI
authors.lastname: Raak
authors.forename: S A
authors.initials: SA
authors.lastname: Kendall
authors.forename: B
authors.initials: B
authors.lastname: Gerdle
authors.forename: L K
authors.initials: LK
authors.lastname: Wahren
mesh_terms: D000328:Adult; D000368:Aged; D016000:Cluster Analysis; D003080:Cold Temperature; D005260:Female; D005356:Fibromyalgia / Q000145:classification / Q000150:complications* / Q000503:physiopathology*; D006358:Hot Temperature; D006801:Humans; D006930:Hyperalgesia / Q000209:etiology* / Q000503:physiopathology; D008875:Middle Aged; D010146:Pain / Q000503:physiopathology; D010147:Pain Measurement; D017288:Pain Threshold; D012016:Reference Values; D012044:Regression Analysis; D012890:Sleep