title: Visual processing during recovery from vegetative state to consciousness: comparing behavioral indices to brain responses.
abstract: BACKGROUND
  Auditory stimulation is often used to evoke responses in unresponsive patients who have suffered severe brain injury. In order to investigate visual responses, we examined visual evoked potentials (VEPs) and behavioral responses to visual stimuli in vegetative patients during recovery to consciousness.
  
  
  METHODS
  Behavioral responses to visual stimuli (visual localization, comprehension of written commands, and object manipulation) and flash VEPs were repeatedly examined in eleven vegetative patients every two weeks for an average period of 2.6months, and patients' VEPs were compared to a healthy control group. Long-term outcome of the patients was assessed 2-3years later.
  
  
  RESULTS
  Visual response scores increased during recovery to consciousness for all scales: visual localization, comprehension of written commands, and object manipulation. VEP amplitudes were smaller, and latencies were longer in the patient group relative to the controls. VEPs characteristics at first measurement were related to long-term outcome up to three years after injury.
  
  
  CONCLUSIONS
  Our findings show the improvement of visual responding with recovery from the vegetative state to consciousness. Elementary visual processing is present, yet according to VEP responses, poorer in vegetative and minimally conscious state than in healthy controls, and remains poorer when patients recovered to consciousness. However, initial VEPs are related to long-term outcome.
authors.affiliation: Rehabilitation Centre Leijpark, Tilburg, The Netherlands; Tilburg University, Department of Psychology, Tilburg, The Netherlands. Electronic address: viona.wijnen@radboudumc.nl.
authors.forename: V J M
authors.initials: VJ
authors.lastname: Wijnen
authors.affiliation: Rehabilitation Centre Leijpark, Tilburg, The Netherlands.
authors.forename: H J
authors.initials: HJ
authors.lastname: Eilander
authors.affiliation: Tilburg University, Department of Psychology, Tilburg, The Netherlands; Brain and Emotion Laboratory, Maastricht University, Maastricht, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: de Gelder
authors.affiliation: Tilburg University, Department of Psychology, Tilburg, The Netherlands.
authors.forename: G J M
authors.initials: GJ
authors.lastname: van Boxtel
mesh_terms: D000293:Adolescent; D000328:Adult; D001072:Apraxias / Q000503:physiopathology / Q000523:psychology; D001519:Behavior / Q000502:physiology*; D001930:Brain Injuries / Q000503:physiopathology* / Q000523:psychology; D002648:Child; D003243:Consciousness / Q000502:physiology*; D003289:Convalescence / Q000523:psychology; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology; D009048:Motor Skills / Q000502:physiology; D018458:Persistent Vegetative State / Q000503:physiopathology* / Q000523:psychology; D010775:Photic Stimulation; D011379:Prognosis; D016896:Treatment Outcome; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: Brain injury; Conscience; Consciousness; Minimally conscious state; Potentiels évoqués visuels; Traumatisme crânien; Unresponsive wakefulness syndrome; Vegetative state; Visual evoked potentials; État de conscience minimale; État végétatif