title: Changes in Pain Modulation Occur Soon After Whiplash Trauma but are not Related to Altered Perception of Distorted Visual Feedback.
abstract: OBJECTIVE
  Widespread sensory hypersensitivity has been observed in acute whiplash associated disorders (WAD). Changes in descending pain modulation take part in central sensitization. However, endogenous pain modulation has never been investigated in acute WAD. Altered perception of distorted visual feedback has been observed in WAD. Both mechanisms (ie, pain modulation and perception of distorted visual feedback) may be different components of one integrated system orchestrated by the brain. This study evaluated conditioned pain modulation (CPM) in acute WAD. Secondly, we investigated whether changes in CPM are associated with altered perception of distorted visual feedback.
  
  
  METHODS
  Thirty patients with acute WAD, 35 patients with chronic WAD and 31 controls were subjected to an experiment evaluating CPM and a coordination task inducing visual mediated changes between sensory feedback and motor output.
  
  
  RESULTS
  A significant CPM effect was observed in acute WAD (P = 0.012 and P = 0.006), which was significantly lower compared to controls (P = 0.004 and P = 0.020). No obvious differences in CPM were found between acute and chronic WAD (P = 0.098 and P = 0.041). Changes in CPM were unrelated to altered perception of distorted visual feedback (P > 0.01).
  
  
  CONCLUSIONS
  Changes in CPM were observed in acute WAD, suggesting less efficient pain modulation. The results suggest that central pain and sensorimotor processing underlie distinctive mechanisms.
authors.affiliation: Department of Neurology, Faculty of Medicine, University of Antwerp (UA), Antwerp, Belgium.|Department of Neurology, Born-Bunge Institute and Antwerp University Hospital, Antwerp, Belgium.|Department of Human Physiology, Faculty of Physical Education and Physiotherapy, Chronic Pain and Chronic Fatigue Research Group (CHROPIVER), Vrije Universiteit Brussel (VUB), Brussel, Belgium.
authors.forename: Liesbeth
authors.initials: L
authors.lastname: Daenen
authors.affiliation: Department of Human Physiology, Faculty of Physical Education and Physiotherapy, Chronic Pain and Chronic Fatigue Research Group (CHROPIVER), Vrije Universiteit Brussel (VUB), Brussel, Belgium.|Division of Musculoskeletal Physiotherapy, Department of Health Sciences, University College Antwerp (Artesis), Antwerp, Belgium.
authors.forename: Jo
authors.initials: J
authors.lastname: Nijs
authors.affiliation: Department of Neurology, Faculty of Medicine, University of Antwerp (UA), Antwerp, Belgium.|Department of Neurology, Born-Bunge Institute and Antwerp University Hospital, Antwerp, Belgium.
authors.forename: Patrick
authors.initials: P
authors.lastname: Cras
authors.affiliation: Department of Scientific Coordination and Biostatistics, University Hospital Antwerp (UZA), Antwerp, Belgium.
authors.forename: Kristien
authors.initials: K
authors.lastname: Wouters
authors.affiliation: Department of Human Physiology, Faculty of Physical Education and Physiotherapy, Chronic Pain and Chronic Fatigue Research Group (CHROPIVER), Vrije Universiteit Brussel (VUB), Brussel, Belgium.|Division of Musculoskeletal Physiotherapy, Department of Health Sciences, University College Antwerp (Artesis), Antwerp, Belgium.|Faculty of Medicine, University of Antwerp (UA), Antwerp, Belgium.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Roussel
mesh_terms: D000328:Adult; D059333:Central Nervous System Sensitization / Q000502:physiology; D056228:Feedback, Sensory / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D010147:Pain Measurement / Q000379:methods / Q000523:psychology; D058748:Pain Perception / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D014796:Visual Perception / Q000502:physiology; D014911:Whiplash Injuries / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology
keywords: altered perception; central nervous system; conditioned pain modulation; distorted visual feedback; neck pain; pain; pain assessment; pain modulation; whiplash; whiplash-associated disorders