HAI Book 2025 - Flipbook - Page 489
Results: Baseline comparisons revealed large effect-size, significant differences in 18F-Flortaucipir binding
between EOAD and LOAD (Fig. 1). EOAD participants had higher 18F-Flortaucipir levels in widespread neocortical
regions compared to LOAD, after adjusting for covariates. In both groups, tau load was negatively associated with
age. In EOAD, a significantly steeper slope was found in the association between amyloid-beta and 18F-Flortaucipir
load, as well as between cognitive scores and 18F-Flortaucipir load. Longitudinally, EOAD participants exhibited a
faster increase in 18F-Flortaucipir binding than LOAD, predominantly in frontal and occipital areas (Fig. 2), with
both groups showing an inverse linear relationship between 18F-Flortaucipir accumulation rates and age.
Conclusion: EOAD patients demonstrate significantly higher tau loads, broader neuroanatomical involvement and
faster tau accumulation over time compared to LOAD, independent of disease stage. These findings suggest that
earlier age-of-onset in AD is linked to a more aggressive tauopathy. The early, extensive tau spread in
symptomatic EOAD, even at an early clinical stage, may also limit the efficacy of anti-amyloid-beta therapies in
this population.
HAI2025 - 489
