Role of tau deposition in early cognitive decline in Down syndrome
Sigan L. Hartley, Benjamin L. Handen, Dana Tudorascu, Laise Lee, Annie Cohen, Brianna Piro‐Gambetti, Matthew Zammit, William E. Klunk, Charles M. Laymon, Shahid Zaman, Beau M. Ances, Marwan N. Sabbagh, Bradley T. Christian
Abstract
Abstract Introduction Drawing on the amyloid/tau/neurodegeneration (AT[N]) model, the study examined whether the tau positron emission tomography (PET) biomarker [ 18 F]AV‐1451 was associated with episodic memory problems beyond what was predicted by the amyloid beta (Aβ) PET in Down syndrome (DS). Methods Data from 123 non‐demented adults with DS ( M = 47 years, standard deviation = 6.34) were analyzed. The Cued Recall Test assessed episodic memory. Tau PET standardized update value ratio (SUVR) was assessed across Braak regions as continuous and binary (high tau [T H ] vs. low tau [T L ]) variable. Global PET Aβ SUVR was assessed as binary variable (Aβ– vs. Aβ+). Results In models adjusting for controls, tau SUVR was negatively associated with episodic memory performance in the Aβ+ but not Aβ– group. The Aβ+/T H group evidenced significantly worse episodic memory than the Aβ+/T L group. Discussion Similar to late‐onset and autosomal dominant Alzheimer's disease (AD), high tau was an indicator of early prodromal AD in DS.