Visuoperceptual impairment in dementia with Lewy bodies.
BACKGROUND
In dementia with Lewy bodies (DLB), vision-related cognitive and behavioral symptoms are common, and involvement of the occipital visual cortices has been demonstrated in functional neuroimaging studies.


OBJECTIVE
To delineate visuoperceptual disturbance in patients with DLB in comparison with that in patients with Alzheimer disease and to explore the relationship between visuoperceptual disturbance and the vision-related cognitive and behavioral symptoms.


METHODS
Case-control study.


METHODS
Research-oriented hospital.


METHODS
Twenty-four patients with probable DLB (based on criteria of the Consortium on DLB International Workshop) and 48 patients with probable Alzheimer disease (based on criteria of the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association) who were matched to those with DLB 2:1 by age, sex, education, and Mini-Mental State Examination score.


METHODS
Four test items to examine visuoperceptual functions, including the object size discrimination, form discrimination, overlapping figure identification, and visual counting tasks.


RESULTS
Compared with patients with probable Alzheimer disease, patients with probable DLB scored significantly lower on all the visuoperceptive tasks (P<.04 to P<.001). In the DLB group, patients with visual hallucinations (n = 18) scored significantly lower on the overlapping figure identification (P = .01) than those without them (n = 6), and patients with television misidentifications (n = 5) scored significantly lower on the size discrimination (P<.001), form discrimination (P = .01), and visual counting (P = .007) than those without them (n = 19).


CONCLUSIONS
Visual perception is defective in probable DLB. The defective visual perception plays a role in development of visual hallucinations, delusional misidentifications, visual agnosias, and visuoconstructive disability charcteristic of DLB.
Mori
E
E
Department of Clinical Neurosciences, Hyogo Institute for Aging Brain and Cognitive Disorders, Himeji, Japan. mori@hiabcd.go.jp
Shimomura
T
T
Fujimori
M
M
Hirono
N
N
Imamura
T
T
Hashimoto
M
M
Tanimukai
S
S
Kazui
H
H
Hanihara
T
T
D000368:Aged; D000377:Agnosia / Q000175:diagnosis; D000544:Alzheimer Disease / Q000175:diagnosis / Q000503:physiopathology; D016022:Case-Control Studies; D003937:Diagnosis, Differential; D004522:Educational Status; D005260:Female; D006212:Hallucinations / Q000175:diagnosis; D006801:Humans; D020961:Lewy Body Disease / Q000175:diagnosis / Q000503:physiopathology*; D008297:Male; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology; D011237:Predictive Value of Tests; D014793:Visual Cortex / Q000503:physiopathology; D014796:Visual Perception / Q000502:physiology