McLachlan, MaxBettcher, BreccaMcVea, AndrewDiFillipo, AlexandraZammit, MatthewLeMerise, LisetteRouanet, JeremyPrice, JulieTudorascu, DanaLaymon, CharlesKeator, DavidLao, PatrickBrickman, Adam MFryer, TimHartley, SiganAnces, Beau MJohnson, SterlingBetthauser, TobeyStone, Charles KZaman, ShahidHanden, BenjaminHead, ElizabethMapstone, MarkChristian, Bradley T
Abstract
Adults with Down syndrome demonstrate striatum-first amyloid accumulation with [11C]PiB PET imaging, which has not been replicated with [18F]florbetapir (FBP). Early striatal accumulation has not been temporally quantified with respect to global cortical measures. Longitudinal PiB (n=175 participants) and FBP (n=92 participants) data from the Alzheimer Biomarkers Consortium-Down Syndrome were used to measure cortical and striatal binding. Generalized temporal models for cortical and striatal amyloid accumulation were created using the sampled iterative local approximation (SILA) method. PiB demonstrated greater striatal-to-cortical ratios than FBP. SILA analysis revealed striatal amyloid burden occurs 3.40 (2.39) years earlier than the cortex in PiB. There was no difference between the cortex and striatum in FBP. Among adults with Down syndrome, the striatum consistently accumulates amyloid earlier than the cortex when measured with PiB. This suggests the striatum is more sensitive to the onset of PiB PET-detectable amyloid in Down syndrome.