In vivo measures of tau burden are associated with atrophy in early Braak stage medial temporal lobe regions in amyloid-negative individuals

Abstract

Introduction: It is unclear the degree to which tau pathology in the medial temporal lobe (MTL) measured by ¹⁸F-flortaucipir positron emission tomography relates to MTL subregional atrophy and whether this relationship differs between amyloid-β-positive and amyloid-β-negative individuals.

Methods: We analyzed correlation of MTL ¹⁸F-flortaucipir uptake with MTL subregional atrophy measured with high-resolution magnetic resonance imaging in a region of interest and regional thickness analysis and determined the relationship between memory performance and positron emission tomography and magnetic resonance imaging measures.

Results: Both groups showed strong correlations between ¹⁸F-flortaucipir uptake and atrophy, with similar spatial patterns. Effects in the rhinal cortex recapitulated Braak staging. Correlations of memory recall with atrophy and tracer uptake were observed.

Discussion: Correlation patterns between tau burden and atrophy in the amyloid-β-negative group mimicking early Braak stages suggests that ¹⁸F-flortaucipir is sensitive to tau pathology in primary age-related tauopathy. Correlations of imaging measures with memory performance indicate that this pathology is associated with poorer cognition.

Keywords: (18)F-flortaucipir; AV1451; Amyloid negative; Amyloid positive; Atrophy; Braak stages; Logical memory; Medial temporal lobe; Subfield; Subregion; Tau PET; Volume.