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IC‐P‐117: FMRI AND THE AGING BRAIN: COMMON AREAS OF SIGNAL DISRUPTION IN AN OLDER POPULATION
Author(s) -
Beason-Held Lori L.,
Shafer Andrea T.,
June Danielle,
Ziontz Jacob,
Resnick Susan M.
Publication year - 2018
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.2018.06.2183
Subject(s) - putamen , neuroscience , psychology , medicine , magnetic resonance imaging , globus pallidus , basal ganglia , frontal lobe , population , audiology , central nervous system , radiology , environmental health
Background:Older individuals (80 or over age group) are a growing segment of our population. Our goal was to identify predictors of cognitive performance among demographics and aging and dementia markers in a group of cognitively resilient 80+ individuals. We alsowanted to identify imaging based mechanisms for cognitive resilience using FDG and sMRI. Methods:We identified 442 participants aged 80+ cognitively unimpaired in the population-based Mayo Clinic Study of Aging who had at least one amyloid scan. We defined a cognitively resilient group of 207 participants with normal cognition for 2 or more visits (mean age: 83 years, 52% males, 21%APOE4+, mean education: 15 years; 47% amyloid positive, mean follow: 5 years). In the cognitively resilient group, we performed a first set of analyses using multivariate multiple linear regression models to test for associations between demographics and aging and dementia markers (amyloid burden, FDG and cortical thickness from AD signature regions, APOE4 status and cardiovascular and metabolic conditions (CMC)) and standardized global cognitive performance (average of attention, memory, visuospatial, and language). In the second set of analyses, we examined voxel-wise associations between imaging (sMRI and FDG-PET) and global cognition. Results: In the cognitive resilience group: i) APOE4 status, CMC, amyloid burden, FDGmetabolism or cortical thickness in AD signature regions did not predict global cognition; ii) higher education and lower agewas associated with better cognitive performance. Finally, iii) gray matter metabolism (but not volume), notably in the anterior and mid-cingulate gyrus and the medial prefrontal cortex, was significantly associated with greater cognitive performance (see Fig 1). These results remained consistent even when we looked at amyloid positive and amyloid negative cognitively resilient individuals separately. Conclusions: In 80+ individuals who are cognitively resilient, aging and dementia markers including amyloid levels and APOE4 status have minimal impact on cognitive performance. Greater gray matter metabolism (particularly in the frontal lobes) had a positive impact on cognitive performance. Development of imaging markers for cognitive resilience and applying them in conjunction with AD biomarkers will be important as we move towards AD dementia prevention in the 80+ populations.