Both amyloid‐beta (Aβ) and tau are necessary for memory decline in the preclinical stages of Alzheimer disease (AD), according to a recent study. These findings may be relevant for disambiguating aging and early cognitive manifestations of AD, and to inform secondary prevention trials in preclinical AD. 137 older individuals (age=76.3±6.22 years) participating in the Harvard Aging Brain Study underwent Aβ (11C‐Pittsburgh Compound B) and tau (18F‐Flortaucipir) positron emission tomography (PET) with prospective neuropsychological assessments following PET imaging. Tau and Aβ PET measures were assessed in regions of interest (ROI) as well as vertex‐wise map analyses. Cognitive change was evaluated with Memory and Executive Function composites. Researchers found:
- Higher levels of Aβ and tau were both associated with greater memory decline, but not with change in executive function.
- A significant interaction between tau and Aβ was observed in both ROI and map level analyses, such that rapid prospective memory decline was observed in participants who had high levels of both pathologies.
Sperling RA, Mormino EC, Schultz AP, et al. The impact of Aβ and tau on prospective cognitive decline in older individuals. [Published online ahead of print December 14, 2018]. Ann Neurol. doi:10.1002/ana.25395.