title: Testing visual perception in dementia with Lewy bodies and Alzheimer disease.
abstract: OBJECTIVE
  Visuoperceptual deficits are common in dementia with Lewy bodies (DLB) and Alzheimer disease (AD). Testing visuoperception in dementia is complicated by decline in other cognitive domains and extrapyramidal features. To overcome these issues, we developed a computerized test, the Newcastle visuoperception battery (NEVIP), which is independent of motor function and has minimal cognitive load.We aimed to test its utility to identify visuoperceptual deficits in people with dementia.
  
  
  METHODS
  We recruited 28 AD and 26 DLB participants with 35 comparison participants of similar age and education. The NEVIP was used to test angle, color, and form discrimination along with motion perception to obtain a composite visuoperception score.
  
  
  RESULTS
  Those with DLB performed significantly worse than AD participants on the composite visuoperception score (Mann-Whitney U = 142, p = 0.01). Visuoperceptual deficits (defined as 2 SD below the performance of comparisons) were present in 71% of the DLB group and 40% of the AD group. Performance was not significantly correlated with motor impairment, but was significantly related to global cognitive impairment in DLB (rs = -0.689, p <0.001), but not in AD.
  
  
  CONCLUSIONS
  Visuoperceptual deficits can be detected in both DLB and AD participants using the NEVIP, with the DLB group performing significantly worse than AD. Visuoperception scores obtained by the NEVIP are independent of participant motor deficits and participants are able to comprehend and perform the tasks.
authors.affiliation: Institute for Cellular Medicine, Newcastle Magnetic Resonance Centre, Campus for Ageing and Vitality, Newcastle University, Newcastle, United Kingdom. Electronic address: josh.wood@ncl.ac.uk.
authors.forename: Joshua S
authors.initials: JS
authors.lastname: Wood
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Firbank
authors.forename: Urs P
authors.initials: UP
authors.lastname: Mosimann
authors.forename: Rosie
authors.initials: R
authors.lastname: Watson
authors.forename: Robert
authors.initials: R
authors.lastname: Barber
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Blamire
authors.forename: John T
authors.initials: JT
authors.lastname: O'Brien
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000150:complications / Q000175:diagnosis / Q000523:psychology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D020961:Lewy Body Disease / Q000150:complications / Q000175:diagnosis / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010468:Perceptual Disorders / Q000150:complications / Q000175:diagnosis* / Q000523:psychology; D010775:Photic Stimulation; D011237:Predictive Value of Tests; D014796:Visual Perception