Topographical distribution of amyloid-β, tau and atrophy in behavioral / dysexecutive AD patients.

TitleTopographical distribution of amyloid-β, tau and atrophy in behavioral / dysexecutive AD patients.
Publication TypeJournal Article
Year of Publication2020
AuthorsTherriault J, Pascoal TA, Savard M, Benedet AL, Chamoun M, Tissot C, Lussier F, Kang MSu, Thomas É, Terada T, Rej S, Massarweh G, Nasreddine Z, Vitali P, Soucy J-P, Saha-Chaudhuri P, Gauthier S, Rosa-Neto P
JournalNeurology
Date Published2020 Oct 22
ISSN1526-632X
Abstract

OBJECTIVE: To determine the associations between amyloid-PET, tau-PET and atrophy with the behavioural/dysexecutive presentation of Alzheimer's disease (AD), how these differ from amnestic AD, and how they correlate to clinical symptoms.METHODS: We assessed 15 cases of behavioural/dysexecutive AD recruited from a tertiary care memory clinic, all of whom had biologically defined AD. They were compared with 25 disease severity- and age-matched amnestic AD patients and a group of 131 cognitively unimpaired (CU) elderly individuals. All subjects were evaluated with amyloid-PET with [F]AZD4694, tau-PET with [F]MK6240, MRI and neuropsychological testing.RESULTS: Voxelwise contrasts identified patterns of frontal cortical tau aggregation in behavioural/dysexecutive AD, with peaks in medial prefrontal, anterior cingulate and frontal insular cortices in contrast to amnestic AD. No differences were observed in the distribution of amyloid-PET or atrophy as determined by voxel-based morphometry. Voxelwise area under the ROC curve analyses revealed that tau-PET uptake in the medial prefrontal, anterior cingulate and frontal insular cortices were best able to differentiate between behavioural/dysexecutive and amnestic AD (AUC = 0.87). Voxelwise regressions demonstrated relationships between frontal cortical tau load and degree of executive dysfunction.CONCLUSIONS: Our results provide evidence of frontal cortical involvement of tau pathology in behavioural/dysexecutive AD and highlight the need for consensus clinical criteria in this syndrome.

DOI10.1212/WNL.0000000000011081
Alternate JournalNeurology
PubMed ID33093220