Visuoconstructive performance and regional cerebral glucose metabolism in Alzheimer's disease

The drawings of Alzheimer's disease (AD) patients and elderly control subjects were rated on a number of specific performance scales, such as attention to configuration, attention to detail, and stimulus boundedness. AD patients showed significantly poorer performance than controls on most drawing scales, and the drawing measures were differentially affected by disease severity. Regional cerebral glucose metabolism (rCMRglc) was assessed via positron emission tomography (PET, with 18FDG) in a subgroup of the AD patients. Partial correlations of rCMRglc with drawing measures (age, sex, and education served as control variables) were conducted. Five out of eight of the drawing measures were significantly correlated (p less than .005) with rCMRglc in occipital and/or temporal-parietal regions, for both left and right hemispheres. Only one of the eight drawing measures, attention to detail, was significantly correlated with rCMRglc in both frontal and posterior regions of interest, again for both hemispheres. Overall dementia severity showed no significant correlations with rCMRglc in any of the regions. These findings are suggestive of a posterior-anterior differentiation, but no left-right hemisphere differentiation, in the relationship between drawing performance and cerebral metabolism in AD, which cannot be accounted for by overall dementia severity. Differences between the drawing performance of AD and unilateral brain damaged patients are discussed, and further applications of the rating scales (provided in the Appendix) are suggested.