title: Altered perception of distorted visual feedback occurs soon after whiplash injury: an experimental study of central nervous system processing.
abstract: BACKGROUND
  Sensory and motor system dysfunctions have been documented in a proportion of patients with acute whiplash associated disorders (WAD). Sensorimotor incongruence may occur and hence, may explain pain and other sensations in the acute stage after the trauma.
  
  
  OBJECTIVE
  The present study aimed at (1) evaluating whether a visually mediated incongruence between sensory feedback and motor output increases symptoms and triggers additional sensations in patients with acute WAD, (2) investigating whether the pattern of sensations in response to sensorimotor incongruence differs among patients suffering from acute and chronic WAD, and healthy controls.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Patients with acute WAD were recruited within one month after whiplash injury via the emergency department of a local Red Cross medical care unit, the Antwerp University Hospital, and through primary care practices. Patients with chronic WAD were recruited through an advertisement on the World Wide Web and from the medical database of a local Red Cross medical care unit. Healthy controls were recruited from among the university college staff, family members, and acquaintances of the researchers.
  
  
  METHODS
  Thirty patients with acute WAD, 35 patients with chronic WAD, and 31 healthy persons were subjected to a coordination test. They performed congruent and incongruent arm movements while viewing a whiteboard or mirror. RESULTS. Twenty-eight patients with acute WAD reported sensations such as pain, tightness, feeling of peculiarity, and tiredness at some stage of the test protocol. No significant differences in frequencies and intensities of sensations were found between the various test stages (P > .05). Significantly more sensations were reported during the incongruent mirror stage compared to the incongruent control stage (P < .05). The pattern in intensity of sensations across the congruent and incongruent stages was significantly different between the WAD groups and the control group.
  
  
  CONCLUSIONS
  The course and prognostic value of susceptibility to sensorimotor incongruence after an acute whiplash trauma are not yet clear from these results. A prospective longitudinal study with an expanded study population is needed to investigate if those with a lowered threshold to visually mediated sensorimotor incongruence in the acute stage are at risk to develop persistent pain and disability.
  
  
  CONCLUSIONS
  Patients with acute WAD present an exacerbation of symptoms and additional sensations in response to visually mediated changes during action. These results indicate an altered perception of distorted visual feedback and suggest altered central sensorimotor nervous system processing in patients with acute WAD.
authors.affiliation: Department of Neurology, Faculty of Medicine, University of Antwerp, Belgium.
authors.forename: Liesbeth
authors.initials: L
authors.lastname: Daenen
authors.forename: Jo
authors.initials: J
authors.lastname: Nijs
authors.forename: Nathalie
authors.initials: N
authors.lastname: Roussel
authors.forename: Kristien
authors.initials: K
authors.lastname: Wouters
authors.forename: Patrick
authors.initials: P
authors.lastname: Cras
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D002490:Central Nervous System / Q000503:physiopathology*; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D056228:Feedback, Sensory / Q000502:physiology*; D005260:Female; D006801:Humans; D007100:Imitative Behavior / Q000502:physiology; D008297:Male; D008875:Middle Aged; D010468:Perceptual Disorders / Q000209:etiology*; D011597:Psychomotor Performance / Q000502:physiology; D057566:Self Report; D012677:Sensation / Q000502:physiology*; D011795:Surveys and Questionnaires; D014911:Whiplash Injuries / Q000150:complications* / Q000473:pathology* / Q000523:psychology