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P4‐290: IMAGING BIOMARKER TRAJECTORIES OF THE MILD AD DEMENTIA POPULATION IN THE EXPEDITION3 TRIAL
Author(s) -
Shcherbinin Sergey,
Jaeger Ralf,
Charil Arnaud,
Holdridge Karen C.,
Longley Harriet,
Yaari Roy,
Sims John R.,
Mintun Mark A.
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.2019.06.3959
Subject(s) - biomarker , medicine , cohort , population , nuclear medicine , dementia , cardiology , disease , biology , biochemistry , environmental health
exists, we repeated analyses using two commonly used pre-processing approaches: global signal regression (GSR) and independent component analysis (ICA). We also explored the associations of variability changes with baseline cognitive performance and cognitive decline, as well as hippocampal atrophy. Results: Both overlapping and distinct patterns were found between frequency bands and data pre-processing methods (Figure 1). Specifically, using GSR, aMCI had higher variability in the posterior DMN but lower salience network (SN) variability compared with AD and HC for both frequency bands. Using ICA, we replicated this divergent DMN-SN variability changes in aMCI at slow5, and similar greater DMN variability in aMCI compared with AD at slow4. However, the slow4 DMN-SN differences between aMCI and HC were missing or even reversed. Furthermore, ICA-based denoising revealed lower posterior DMN variability in AD compared with HC for both frequency bands. Importantly, lower slow4 posterior DMN variability was related to poorer cognition at baseline and smaller hippocampal volume, and correlated with faster cognitive decline over time using both data denoising approaches. Conclusions: The present findings support the reciprocal DMN-SN balance at aMCI stage, possibly representing compensatory function before developing dementia. These frequency-based variability alterations may contribute differentially to cognitive impairment along the AD spectrum.