title: Visual cortex in dementia with Lewy bodies: magnetic resonance imaging study.
abstract: BACKGROUND
  Visual hallucinations and visuoperceptual deficits are common in dementia with Lewy bodies, suggesting that cortical visual function may be abnormal.
  
  
  OBJECTIVE
  To investigate: (1) cortical visual function using functional magnetic resonance imaging (fMRI); and (2) the nature and severity of perfusion deficits in visual areas using arterial spin labelling (ASL)-MRI.
  
  
  METHODS
  In total, 17 participants with dementia with Lewy bodies (DLB group) and 19 similarly aged controls were presented with simple visual stimuli (checkerboard, moving dots, and objects) during fMRI and subsequently underwent ASL-MRI (DLB group n = 15, control group n = 19).
  
  
  RESULTS
  Functional activations were evident in visual areas in both the DLB and control groups in response to checkerboard and objects stimuli but reduced visual area V5/MT (middle temporal) activation occurred in the DLB group in response to motion stimuli. Posterior cortical perfusion deficits occurred in the DLB group, particularly in higher visual areas.
  
  
  CONCLUSIONS
  Higher visual areas, particularly occipito-parietal, appear abnormal in dementia with Lewy bodies, while there is a preservation of function in lower visual areas (V1 and V2/3).
authors.affiliation: Institute for Ageing and Health, Newcastle University, Wolfson Research Centre, Campus for Ageing and Vitality, UK. john-paul.taylor@ncl.ac.uk
authors.forename: John-Paul
authors.initials: JP
authors.lastname: Taylor
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Firbank
authors.forename: Jiabao
authors.initials: J
authors.lastname: He
authors.forename: Nicola
authors.initials: N
authors.lastname: Barnett
authors.forename: Sarah
authors.initials: S
authors.lastname: Pearce
authors.forename: Anthea
authors.initials: A
authors.lastname: Livingstone
authors.forename: Quoc
authors.initials: Q
authors.lastname: Vuong
authors.forename: Ian G
authors.initials: IG
authors.lastname: McKeith
authors.forename: John T
authors.initials: JT
authors.lastname: O'Brien
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001931:Brain Mapping / Q000379:methods; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D006801:Humans; D016631:Lewy Bodies / Q000473:pathology / Q000502:physiology*; D020961:Lewy Body Disease / Q000473:pathology / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D009039:Motion Perception / Q000502:physiology; D010775:Photic Stimulation; D014792:Visual Acuity / Q000502:physiology; D014793:Visual Cortex / Q000473:pathology / Q000503:physiopathology*