A NEW study suggests that baseline amyloid PET scans may help identify individuals at increased risk of Alzheimer’s disease, even before conventional thresholds are reached.
The research, part of the FACEHBI study, analysed 197 people with subjective cognitive decline (SCD), a condition where individuals notice memory issues despite normal results on standard cognitive tests. Over a five-year period, participants underwent between two and three [18F]florbetaben PET scans to measure amyloid beta (Aβ) in the brain, a hallmark of Alzheimer’s disease.
Findings showed that even people with sub-threshold amyloid levels, those not traditionally considered at risk, could still accumulate Aβ over time and go on to develop mild cognitive impairment (MCI). In fact, 19% of individuals with very low Aβ at baseline showed significant amyloid accumulation during follow-up. Nearly nine in ten individuals in the “near-threshold” group and all participants in the grey zone (those just below the positivity cut-off) demonstrated Aβ build-up.
Risk of cognitive decline was found to be higher among those with greater baseline amyloid, as well as older and less educated participants. Brain imaging pinpointed the precuneus, a region often affected early in Alzheimer’s, as a key area of Aβ increase.
“These findings support the use of amyloid PET not just for diagnosis but for early identification of preclinical Alzheimer’s, even in people with seemingly normal results,” said Dr Marta Marquié, co-lead author of the study.
The results could help refine screening and prevention strategies by identifying at-risk individuals earlier and more accurately, before symptoms of dementia set in.
Aleksandra Zurowska, EMJ
Reference
Kolinger et al. Quantification of baseline amyloid PET in individuals with subjective cognitive decline can identify risk of amyloid accumulation and cognitive worsening: the FACEHBI study. Eur J Nucl Med Mol Imaging. 2025;DOI: 10.1007/s00259-025-07270-7.
