title: Effects of Stress and Relaxation on Central Pain Modulation in Chronic Whiplash and Fibromyalgia Patients Compared to Healthy Controls.
abstract: BACKGROUND
  Compelling evidence has demonstrated that impaired central pain modulation contributes to persistent pain in patients with chronic whiplash associated disorders (WAD) and fibromyalgia (FM). However, there is limited research concerning the influence of stress and relaxation on central pain modulation in patients with chronic WAD and FM.
  
  
  OBJECTIVE
  The present study aims to investigate the effects of acute cognitive stress and relaxation on central pain modulation in chronic WAD and FM patients compared to healthy individuals.
  
  
  METHODS
  A randomized crossover design was employed.
  
  
  METHODS
  The present study took place at the University of Brussels, the University Hospital Brussels, and the University of Antwerp.
  
  
  METHODS
  Fifty-nine participants (16 chronic WAD patients, 21 FM, 22 pain-free controls) were enrolled and subjected to various pain measurements. Temporal summation (TS) of pain and conditioned pain modulation (CPM) were evaluated. Subsequently, participants were randomly allocated to either a group that received progressive relaxation therapy or a group that performed a battery of cognitive tests (= cognitive stressor). Afterwards, all pain measurements were repeated. One week later participant groups were switched.
  
  
  RESULTS
  A significant difference was found between the groups in the change in TS in response to relaxation (P = 0.008) and cognitive stress (P = 0.003). TS decreased in response to relaxation and cognitive stress in chronic WAD patients and controls. In contrast, TS increased after both interventions in FM patients. CPM efficacy decreased in all 3 groups in response to relaxation (P = 0.002) and cognitive stress (P = 0.001).
  
  
  CONCLUSIONS
  The obtained results only apply for a single session of muscle relaxation therapy and cognitive stress, whereby no conclusions can be made for effects on pain perception and modulation of chronic cognitive stress and long-term relaxation therapies.
  
  
  CONCLUSIONS
  A single relaxation session as well as cognitive stress may have negative acute effects on pain modulation in patients with FM, while cognitive stress and relaxation did not worsen bottom-up sensitization in chronic WAD patients and healthy persons. However, endogenous pain inhibition, assessed using a CPM paradigm, worsened in chronic WAD and FM patients, as well as in healthy people following both interventions.
authors.forename: Iris
authors.initials: I
authors.lastname: Coppieters
authors.forename: Barbara
authors.initials: B
authors.lastname: Cagnie
authors.affiliation: Pain in Motion Research Group (www.paininmotion.be); Department of Human Physiology and Physiotherapy, Faculty of Physical Education & Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium; Department of Physical Medicine and Physiotherapy, University Hospital Brussels, Brussels, Belgium.
authors.forename: Jo
authors.initials: J
authors.lastname: Nijs
authors.forename: Jessica
authors.initials: J
authors.lastname: van Oosterwijck
authors.forename: Lieven
authors.initials: L
authors.lastname: Danneels
authors.forename: Robby
authors.initials: R
authors.lastname: De Pauw
authors.affiliation: Pain in Motion Research Group (www.paininmotion.be); Rehabilitation Sciences and Physiotherapy, Faculty of Medicine & Health Sciences, Ghent University, Ghent, Belgium; Department of Rehabilitation Sciences and Physiotherapy, Faculty of Medicine & Health Sciences, University of Antwerp, Antwerp, Belgium.
authors.forename: Mira
authors.initials: M
authors.lastname: Meeus
mesh_terms: D000328:Adult; D000368:Aged; D059350:Chronic Pain / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D018592:Cross-Over Studies; D005260:Female; D005356:Fibromyalgia / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009126:Muscle Relaxation; D059408:Pain Management / Q000379:methods*; D010147:Pain Measurement / Q000379:methods; D012064:Relaxation Therapy / Q000379:methods*; D013315:Stress, Psychological / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D014911:Whiplash Injuries / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*