Exploring discordant low amyloid beta and high neocortical tau positron emission tomography cases.

ABSTRACT:

Introduction

Neocortical 3R4R (3-repeat/4-repeat) tau aggregates are rarely observed in the absence of amyloid beta (Aβ). ¹⁸F-MK6240 binds specifically to the 3R4R form of tau that is characteristic of Alzheimer's disease (AD). We report four cases with negative Aβ, but positive tau positron emission tomography (PET) findings.

Methods

All Australian Imaging, Biomarkers and Lifestyle study of aging (AIBL) study participants with Aβ (¹⁸F-NAV4694) and tau (¹⁸F-MK6240) PET scans were included. Centiloid <25 defined negative Aβ PET (Aβ-). The presence of neocortical tau was defined quantitatively and visually.

Results

Aβ- PET was observed in 276 participants. Four of these participants (one cognitively unimpaired [CU], two mild cognitive im

SUBMITTER: Krishnadas N 

PROVIDER: S-EPMC9413469 | biostudies-literature | 2022

REPOSITORIES: biostudies-literature