Visual perceptual functions predict instrumental activities of daily living in patients with dementia.
OBJECTIVE
To assess relations between discrete visual perceptual functions commonly affected in patients with neurodegenerative dementia and the performance of instrumental activities of daily living (IADL).


BACKGROUND
Neuropsychologic measures are often used to predict IADL performances in dementia patients. Prior studies have focused on the contribution of higher-level memory and executive deficits to IADL. The relation between visuoperceptual dysfunction and IADL has not been studied systematically.


METHODS
Thirty-five elderly patients with neurodegenerative disorders, most diagnosed with probable Alzheimer disease, participated. Patients completed tasks tapping visual perceptual functions believed to be mediated by occipital lobe structures (shape discrimination), posterior inferotemporal regions (face, object form, and written word discrimination), and the dorsolateral parietal lobe (spatial localization). A knowledgeable caregiver rated IADL performance.


RESULTS
Object form discrimination, but not other visual perceptual functions, correlated significantly ( = 0.60) with performances of visually based IADL (e.g., misjudging distances, driving, and recognizing familiar people), but not with other IADL, when the variance attributable to dementia severity, language disturbance, and other visual perceptual abilities was controlled.


CONCLUSIONS
In contrast to prior investigations that have focused primarily on relations of memory and executive control deficits with IADL in neurologically impaired patients, the results of this study highlight the important contribution of bilateral inferotemporal visual perceptual systems for the performance of IADL in elderly patients with neurodegenerative dementia.
Glosser
Guila
G
Department of Neurology, University of Pennsylvannia School of Medicine, Philadelphia 19104-4283, USA. glosser@mail.med.upenn.edu
Gallo
Jennifer
J
Duda
Nanci
N
de Vries
Jeroen J
JJ
Clark
Christopher M
CM
Grossman
Murray
M
D000203:Activities of Daily Living; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000503:physiopathology / Q000523:psychology; D003704:Dementia / Q000503:physiopathology / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D013647:Task Performance and Analysis; D014796:Visual Perception