Relationship between memory performance and β-amyloid deposition at different stages of Alzheimer's disease.
BACKGROUND
Postmortem studies have suggested that β-amyloid (Aβ) deposition was only weakly related to the degree of cognitive impairment in Alzheimer's disease (AD). The development of Aβ ligands for in vivo PET imaging has greatly facilitated the assessment of this question.


OBJECTIVE
The objective of the present study was to provide an overview of our current knowledge regarding the relationship between Aβ deposition and episodic memory deficits in nondemented elderly and in patients with mild cognitive impairment or AD.


METHODS
Information was obtained both from studies comparing memory performance in individuals with high Pittsburgh compound B (PiB) and those with low PiB and from studies performing correlation analyses between memory performance and PiB retention considered as a continuous variable.


RESULTS
Previous studies assessing the relationship between memory and global neocortical PiB reported conflicting findings, and overall suggest that this link is weak, probably indirect, and detectable only in early stages. Assessing the relationship with regional instead of global neocortical PiB, we found a specific relationship between episodic memory deficits and neocortical temporal PiB, independent from hippocampal atrophy, in the predementia stage of the disease.


CONCLUSIONS
There is a relationship between regional Aβ deposition and episodic memory deficits in the presymptomatic stage of AD.
Department of Nuclear Medicine and Centre for PET, Austin Health, Heidelberg, Vic, Australia. chetelat@cyceron.fr
Gaël
G
Chételat
Victor L
VL
Villemagne
Kerryn E
KE
Pike
Kathryn A
KA
Ellis
David
D
Ames
Colin L
CL
Masters
Christopher C
CC
Rowe
D000544:Alzheimer Disease / Q000150:complications* / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000814:Aniline Compounds; D001284:Atrophy / Q000000981:diagnostic imaging / Q000473:pathology; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008569:Memory Disorders / Q000000981:diagnostic imaging / Q000209:etiology*; D049268:Positron-Emission Tomography; D013844:Thiazoles
C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D016229:Amyloid beta-Peptides; D000814:Aniline Compounds; D013844:Thiazoles