Frontal Variant of Alzheimer Disease Differentiated From Frontotemporal Dementia Using in Vivo Amyloid and Tau Imaging.

TitleFrontal Variant of Alzheimer Disease Differentiated From Frontotemporal Dementia Using in Vivo Amyloid and Tau Imaging.
Publication TypeJournal Article
Year of Publication2020
AuthorsPaquin V, Therriault J, Pascoal TAli, Rosa-Neto P, Gauthier S
JournalCogn Behav Neurol
Volume33
Issue4
Pagination288-293
Date Published2020 12
ISSN1543-3641
KeywordsAlzheimer Disease, Diagnosis, Differential, Female, Frontotemporal Dementia, Humans, Middle Aged, Neurofibrillary Tangles, Plaque, Amyloid, tau Proteins
Abstract

The frontal variant of Alzheimer disease (fvAD) is characterized by behavioral and/or dysexecutive impairments that can resemble those of behavioral-variant frontotemporal dementia (bvFTD). This overlap, in addition to the lack of consensus clinical criteria for fvAD, complicates its identification. We provide the first case report of fvAD differentiated in vivo from bvFTD using amyloid-beta and tau PET imaging. The patient, a right-handed woman, presented with forgetfulness at age 60. Cognitive testing at that time revealed mild impairments in memory, attention, and executive functions. Three years later, her family reported that she was displaying socially inappropriate behaviors, inertia, diminished social interest, and altered food preferences-the sum of which met the criteria for possible bvFTD. PET using an amyloid-beta tracer (F-AZD4694) identified diffuse amyloid plaques across the cerebral cortex. PET using a tau tracer specific for neurofibrillary tangles (F-MK6240) identified substantial tau pathology in the brain's frontal lobes. Together with the clinical findings, these images supported the diagnosis of fvAD rather than bvFTD. Considering past and emerging evidence that tau topography in Alzheimer disease (AD) matches the clinical features of AD, we discuss the potential utility of in vivo tau imaging using F-MK6240 for identifying fvAD.

DOI10.1097/WNN.0000000000000251
Alternate JournalCogn Behav Neurol
PubMed ID33264158
Grant List / / CIHR / Canada