RT Journal Article
SR Electronic
T1 Between SNAP and a hard Aβ rock: Characterizing the fate of preclinical Alzheimer's disease
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 610
OP 610
VO 56
IS supplement 3
A1 Burnham, Samantha
A1 Rowe, Christopher
A1 Bourgeat, Pierrick
A1 Doré, Vincent
A1 Brown, Belinda
A1 Salvado, Olivier
A1 Martins, Ralph
A1 Ames, David
A1 Masters, Colin
A1 Villemagne, Victor
YR 2015
UL http://jnm.snmjournals.org/content/56/supplement_3/610.abstract
AB 610 Objectives The objective of the study was to characterize a two-imaging marker construct in the preclinical stages of Alzheimer diseaseMethods 497 cognitively unimpaired individuals (HC, 73.0±6.2years; 56%female) were included in the study. Aβ status (A) was determined with either PiB, flutemetamol or florbetapir, while neurodegeneration (N) was established using hippocampal volume. Following Jack et al (2012) individuals were categorized as either A-N-, A+N-, A+N+, or suspected non-Alzheimer disease pathophysiology (SNAP, A-N+). Clinical progression, cognitive domain-specific trajectories, global composite scores, and brain volumetrics were assessedResults 64% of HC were classified as A-N-, 18% as A+N-, 6% as A+N+, and 12% as A-N+. Participants in the A-N- group were significantly younger, and while males were more prevalent among A+N+ and A-N+, females were more prevalent among A+N- and A-N-. ApoE4 carriage was more frequent in A+N-(46%) and A+N+(58%) than in A-N-(19%) and A-N+(24%). While no Significant differences were observed in baseline scores significantly faster cognitive decline was observed in A+N+(-0.30SD/yr) and A+N-(-0.08SD/yr) when compared to A-N-(+0.02SD/yr). The A-N- and A-N+ groups did not show significant decline over time, although A-N+ was associated with a lower baseline cognitive performance. Within 1.5-4.5 years, 22.2% of A+N+ progressed to amnestic MCI/AD, compared to only 7.3% of A-N+(2MCI, 1AD, 1VaD)Conclusions Increasing marker abnormality was reflected in faster cognitive decline. Compared to A+N+, the different cognitive trajectories of subjects with neurodegeneration but no AD pathology suggest distinct underlying pathophysiological mechanismsResearch Support Supported in part by NHMRC Project Grants 1011689 & 1071430