FDG-PET mapping the brain substrates of visuo-constructive processing in Alzheimer's disease.
The anatomical basis of visuo-constructive impairment in AD is widely unexplored. FDG-PET can be used to determine functional neuronal networks underlying specific cognitive performance in the human brain. In the present study, we determined the pattern of cortical metabolism that was associated with visuo-constructive performance in AD. We employed two widely used visuo-constructive tests that differ in their demand on visual perception and processing capacity. Resting state FDG-PET scans were obtained in 29 probable AD patients, and cognitive tests were administered. We made a voxel-based regression analysis of FDG uptake to scores in visual test performance, using the SPM5 software. Performance in the CERAD Drawing test correlated with FDG uptake in the bilateral inferior temporal gyri, bilateral precuneus, right cuneus, right supramarginal gyrus and right middle temporal gyrus covering areas of dorsal and ventral visual streams. In contrast, performance in the more complex RBANS Figure Copy test correlated with FDG uptake in the bilateral fusiform gyri, right inferior temporal gyrus, left anterior cingulate gyrus, left parahippocampal gyrus, right middle temporal gyrus and right insula, encompassing the ventral visual stream and areas of higher-level visual processing. The study revealed neuronal networks underlying impaired visual test performance in AD. The extent of involvement of visual and higher order association cortex increased with greater test complexity. From a clinical point of view, both of these widely used visual tests evaluate the integrity of complementary cortical networks and may contribute complementary information on the integrity of visual processing in AD.
Förster
Stefan
S
Department of Nuclear Medicine, Ludwig-Maximilian University, Munich, Germany. stefan.foerster@med.uni-muenchen.de
Teipel
Stefan
S
Zach
Christian
C
Rominger
Axel
A
Cumming
Paul
P
Fougere
Christian la
Cl
Yakushev
Igor
I
Haslbeck
Marianne
M
Hampel
Harald
H
Bartenstein
Peter
P
Bürger
Katharina
K
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D001921:Brain / Q000000981:diagnostic imaging*; D001931:Brain Mapping; D005260:Female; D019788:Fluorodeoxyglucose F18; D005492:Folic Acid / Q000097:blood; D006801:Humans; D016014:Linear Models; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009483:Neuropsychological Tests; D010775:Photic Stimulation / Q000379:methods; D049268:Positron-Emission Tomography; D014796:Visual Perception / Q000502:physiology*; D014805:Vitamin B 12 / Q000097:blood
D019788:Fluorodeoxyglucose F18; D005492:Folic Acid; D014805:Vitamin B 12