Tau deposition assessed by [18F]MK6240 PET is associated with longitudinal decrease in grey matter density across the spectrum of Alzheimer's disease: Neuroimaging / multi‐modal comparisons. (7th December 2020)

• Record Type: Journal Article
• Authors: Lussier, Firoza Z.; Pascoal, Tharick A.; Therriault, Joseph; Tissot, Cécile; Savard, Mélissa; Benedet, Andréa Lessa; Kang, Min Su; Arias, Jaime Fernandez; Wang, Yi‐Ting; Mathotaarachchi, Sulantha; Stevenson, Jenna; Gauthier, Serge; Rosa‐Neto, Pedro
• Is Part Of: Alzheimer's & dementia. Volume 16(2020)Supplement 4
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-12-07
• Subjects: Alzheimer's disease -- Periodicals; Alzheimer Disease -- Periodicals; Dementia -- Periodicals; Démence; Maladie d'Alzheimer; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 616.83
• DOI: 10.1002/alz.046670
• Languages: English
• ISSNs: 1552-5260

Abstract

Abstract: Background: Reduction in grey matter (GM) is a well‐established neuroimaging finding in Alzheimer's disease (AD). Here, we sought to determine whether baseline tau‐PET using the high‐affinity tracer [ 18 F]MK6240 is predictive of longitudinal changes in GM across the AD spectrum. Method: Baseline [ 18 F]MK6240 PET data and longitudinal structural MRI was acquired for 79 participants in the TRIAD cohort (47 CN, 20 MCI, 12 AD). [ 18 F]MK6240 standardized uptake value ratio (SUVR) were calculated 90‐110 minutes post‐injection using cerebellar GM as the reference region. T1‐weighted MR images were segmented into probabilistic GM and WM maps, which were non‐linearly registered to the ADNI template using DARTEL and smoothed with an 8mm FWHM Gaussian kernel. Voxel‐based morphometry (VBM) was run on GM and WM maps. Longitudinal changes in GM density were indexed by voxel‐wise percentage change in VBM‐derived GM. Voxel‐based regression analyses were conducted to examine associations between baseline [ 18 F]MK6240 SUVR and change in GM density, with age, gender, years of education, diagnosis, and time interval between MRI acquisitions employed as covariates. Result: Baseline [ 18 F]MK6240 SUVRs in Braak I/II, III/IV, and V/VI were significantly correlated with longitudinal decrease in GM density in the lateral and medial temporal lobe, including hippocampal regions. All results survived correction for multiple comparisons using random field theory at p < 0.001. Conclusion: Our results suggest that tau pathology at baseline is associated with the progression of GM atrophy over time in brain regions vulnerable to AD pathological changes, providing evidence that tau‐PET may identify individuals who are more susceptible to atrophy.