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O4‐12‐02: TAU PATHOLOGY AND COGNITION ARE RELATED TO BASAL FOREBRAIN DEGENERATION IN AGING
Author(s) -
Harrison Theresa M.,
Becerra Marisa,
Winer Joseph R.,
Baker Suzanne L.,
Grothe Michel J.,
Jagust William J.
Publication year - 2019
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2019.06.4807
Subject(s) - nucleus basalis , basal forebrain , neuroscience , psychology , entorhinal cortex , working memory , temporal lobe , neocortex , episodic memory , hippocampal formation , hippocampus , cognition , cholinergic , epilepsy
topography along the spectrum of normal aging to early AD. Methods: Autopsies were performed on 26 participants from the Mayo Clinic who had ante-mortem tau PET with Flortaucipir within 30 months. Autopsy diagnosis and Braak NFT Stage of the participants were compared to tau PET imaging findings. Tau PET standardized uptake value ratios (SUVr) were determined by a composite multi-region target comprised of regions of interest (ROI) (amygdala, entorhinal cortex, fusiform, parahippocampal, and inferior temporal and middle temporal gyri) normalized to the bilateral cerebellar crus gray matter (positivewhen SUVr values > 1.25). Correlation of% tau burden by immunohistochemistry and tau PET SUVr was performed in hippocampal, superior and mid temporal cortical regions. Results: Autopsy diagnoses included AD (N1⁄410), AD (early) (N1⁄41), pathologic aging (N1⁄41), PART (N1⁄43), LBD (N1⁄49), hippocampal sclerosis/TDP (N1⁄41), and probable globular glial tauopathy (N1⁄41). Tau PET categorized all participants in the AD and early AD groups as positive. Five LBD, one PART, and the hippocampal sclerosis/TDP and the probable globular glial tauopathy participants were also tau PET positive. (Figure 1) Those with Braak Stages of 4 or greater were all tau PET positive. (Figure 2) Correlation was seen between temporal regions (hippocampus, mid temporal and superior temporal) and quantitative tau burden measurements (p 0.002). Conclusions: Positive tau PET signal seen with Flortaucipir with an AD composite multi-region target reflects Braak stage 4 or greater neuropathology. Participants with LBD had positive tau signal in the AD-centric multi region ROI but the signal intensity was low (not greater than 1.5 in this group). A secondary pathologic diagnosis of AD or AD spectrum disease can be the cause of minimally positive Flortaucipir signal. Flortaucipir signal intensity in vivo is a good representation of quantitative tau signal found at autopsy.