HAI Book 2025 - Flipbook - Page 417
Millar, Peter
104
Tau PET subgroups differ in network patterns of functional
connectivity and amyloid PET
Peter Millar1, Stephanie Doering1, Babatunde Adeyemo1, Nicole McKay1, Nicholas Metcalf1,
June Roman1, Pete Canfield1, Saurabh Jindal1, Shaney Flores1, Jeremy Strain1, Julie Wisch1,
Jason Hassenstab1, Suzanne Schindler1, John Morris1, Brian Gordon1, Beau Ances1, Tammie
Benzinger1
1
Washington University in St. Louis, St. Louis, MO, US
Background: Spatiotemporal patterns of tau accumulation differ between distinct presentations of Alzheimer
disease (AD) and can be identified with PET. Tau accumulation may be driven in part by trans-neuronal spreading
through network connections, which can be estimated using resting-state-functional-connectivity MRI (RSFC),
and by amyloid-´ (A´) deposition. We aimed to replicate tau-PET subtypes and tested subtype-specific
differences in RSFC and A´-PET.
Method: We used the Subtype-and-Stage-Inference (SuStaIn) model to identify spatiotemporal patterns in 820
tau-PET scans (18F-flortaucipir) from 629 Knight-ADRC participants (mean age=70.3, SD=8.6, N=690 CDR®-0, N=130
CDR>0). RSFC correlations were analyzed using seeds in primary-visual-cortex (V1) and precuneus/posteriorcingulate-cortex (PCC). A´-PET SUVRs using 11C-Pittsburgh-compound-B (N=365) or 18F-florbetapir (N=423) were
harmonized using a Centiloid transformation.
Result: We identified three tau-PET subtypes, resembling previously-reported patterns: limbic-predominant
(N=157), posterior-predominant (N=27), and medial-temporal-lobe (MTL)-sparing (N=52), Figure 1. The remaining
scans were tau-negative (N=570) or had unstable classifications (N=14). MTL-sparing participants were younger,
more severely impaired, and had greater levels of A´-PET than other groups (p9s
