title: Mild traumatic brain injury induces prolonged visual processing deficits in children.
abstract: OBJECTIVE
  To compare the sensitivity to simple and complex visual stimuli of children who have sustained a mild traumatic brain injury (mTBI) to that of matched non-injured children and to determine the evolution of visuo-perceptual performance over time.
  
  
  METHODS
  A prospective design was used to assess 18 children with mTBI and 18 matched healthy controls (8-16 years of age).
  
  
  METHODS
  Sensitivity to static and dynamic forms of simple (first-order) and complex (second-order) stimuli were assessed at 1, 4 and 12 weeks post-injury and at equivalent times for controls. Orientation and direction identification thresholds were measured for all participants for static and dynamic conditions, respectively. In addition, sensitivity to radial optic flow (inward vs outward), a complex motion stimulus, was assessed.
  
  
  RESULTS
  Thresholds measured from all complex stimuli were significantly affected for the mTBI children over time whereas no difference in threshold between groups across all testing conditions was found for simple, first-order information. Sensitivity to all complex stimuli was still affected 12 weeks after the injury.
  
  
  CONCLUSIONS
  These findings suggest that injured children present selective processing deficits for higher-order information and that this deficit persists over relatively long periods. Such measures could be useful to assess children who have sustained mTBI and possibly contribute to identifying potential risks of returning these children to demanding physical activities.
authors.affiliation: Ecole d'Optometrie, Universite de Montreal, Montreal, Quebec, Canada.
authors.forename: Odile
authors.initials: O
authors.lastname: Brosseau-Lachaine
authors.forename: Isabelle
authors.initials: I
authors.lastname: Gagnon
authors.forename: Robert
authors.initials: R
authors.lastname: Forget
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Faubert
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D001924:Brain Concussion / Q000503:physiopathology*; D016022:Case-Control Studies; D002648:Child; D005074:Evoked Potentials, Visual / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010468:Perceptual Disorders / Q000503:physiopathology*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011597:Psychomotor Performance; D012684:Sensory Thresholds / Q000502:physiology; D013028:Space Perception / Q000502:physiology; D013647:Task Performance and Analysis; D014796:Visual Perception / Q000502:physiology*