title: Consciously postural sway and cervical vertigo after whiplash injury.
abstract: METHODS
  Cross-sectional study of whiplash injury patients with vertigo and healthy volunteers consciously pretending to have postural sway as in malingering.
  
  
  OBJECTIVE
  The aim of this study was to evaluate the postural sway in malingerers by posturography.
  
  
  BACKGROUND
  Malingering is not a problem in the majority of cases with whiplash injury and diagnosis should be made carefully. However, some patients with whiplash injury might exaggerate their symptoms or be malingerers because of the potential gain associated with insurance claims. We designed a diagnostic study to screen putative malingerers.
  
  
  METHODS
  Subjects were 20 healthy volunteers who were tested under standing condition (normal group), consciously swaying the body under standing condition like malingerers (pseudomalingering group) and 32 patients who complained of neck pain with vertigo or dizziness after whiplash injury with WAD (whiplash-associated disorders) grade I and II (WAD group). The movement of the center of pressure (COP) was measured using a force platform to quantify postural sway. Static posturography was performed under open and closed eyes. We analyzed (1) total envelop area per unit of time (EAREA), (2) shifting length per second (LNG/TIME), (3) sway pattern, and (4) Romberg rate representing total shifting length under eyes-closed/eyes-open.
  
  
  RESULTS
  In open eyes condition, the values of EAREA and LNG/TIME were significant higher under pseudomalingering than both of the control and WAD groups (P < 0.05). The Romberg rate was 1.30 +/- 0.17, 1.13 +/- 0.19, and 1.83 +/- 0.94 in control, pseudo-malingering, and WAD group, respectively, and was less than 1.0 in 45% of pseudomalingering. There were significant differences in the EAREA, LEN/TIME, and Romberg rate between pseudomalingering and the other 2 groups (P < 0.05).
  
  
  CONCLUSIONS
  Our results suggest that compared with normal subjects and WAD patients, malingerers are more likely to exhibit a wide EAREA, a long sway length per second, and a low Romberg rate. Malingering must be diagnosed carefully and posturography could be a helpful supplementary tool for differentiating whiplash-associated vertigo from malingering.
authors.affiliation: Department of Orthopedic Surgery, Tokyo Medical University, Tokyo, Japan. kendo@tokyo-med.ac.jp
authors.forename: Kenji
authors.initials: K
authors.lastname: Endo
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Suzuki
authors.forename: Kengo
authors.initials: K
authors.lastname: Yamamoto
mesh_terms: D000328:Adult; D002574:Cervical Vertebrae / Q000502:physiology; D003243:Consciousness / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008306:Malingering / Q000175:diagnosis / Q000503:physiopathology; D008875:Middle Aged; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D014717:Vertigo / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D014911:Whiplash Injuries / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology