Longitudinal testing of visual perception in dementia with Lewy bodies and Alzheimer's disease.

OBJECTIVES

Visuo-perceptual abnormalities are a prominent feature in dementia with Lewy bodies (DLB) and also occur in Alzheimer's disease (AD) to a lesser extent. We studied the progression of visuo-perceptual abnormalities over a 12-month period in DLB and AD by using a novel computerised test battery.

METHODS

Following our previous work using the Newcastle Visual Perception (NEVIP) battery, we re-assessed 16 AD, 12 DLB and 28 similar-aged comparison participants 12 months after initial baseline assessment.

RESULTS

DLB visual perception at follow-up showed worse performance than AD (U = 43, p = 0.027); however, there were no significant changes in visuo-perceptual scores between baseline assessment and 12-month assessment within groups. A poor baseline score on the NEVIP predicted subsequent deterioration on the Bristol Activities of Daily Living Scale (rs  = -0.725, p = 0.014) in DLB participants but not in the AD group.

CONCLUSIONS

The NEVIP is a reliable test of visuo-perception, relatively independent of cognitive decline, with predictive value in identifying DLB participants at risk of functional decline. Visuo-perceptual dysfunction is a core feature of the disorder for some DLB patients and was stable over the 12-month period examined here.