Amyloid- β and tau deposition influences cognitive and functional decline in Down syndrome
Monika Grigorova, Elijah Mak, Stephanie Brown, Jessica Beresford‐Webb, Young T. Hong, Tim D. Fryer, Jonathan Coles, Franklin I. Aigbirhio, Dana Tudorascu, Annie Cohen, Bradley T. Christian, Beau M. Ances, Benjamin L. Handen, Charles M. Laymon, William E. Klunk, I. C. H. Clare, Anthony Holland, Shahid Zaman
Abstract
This study investigates whether tau has (i) an independent effect from amyloid-β on changes in cognitive and functional performance and (ii) a synergistic relationship with amyloid-β in the exacerbation of decline in aging Down syndrome (DS). 105 participants with DS underwent baseline PET [18F]-AV1451 and PET [11C]PiB scans to quantify tau deposition in Braak regions II-VI and the Striatum and amyloid-β status respectively. Linear Mixed Effects models were implemented to assess how tau and amyloid-β deposition are related to change over three time points. Tau was a significant independent predictor of cognitive and functional change. The three-way interaction between time, [11C]PiB status and tau was significant in the models of episodic memory and visuospatial cognition. Baseline tau is a significant predictor of cognitive and functional decline, over and above the effect of amyloid-β status. Results suggest a synergistic relationship between amyloid-β status and tau as predictors of change in memory and visuospatial cognition.