Abstract Details

Title FDG-PET Brain Metabolic Changes in A-/T-/N- Early- and Late-onset Cognitively Impaired Subjects

Topic Aging, Dementia, and Behavioral Neurology

Presentation(s) Aging and Dementia Posters (7:00 AM-5:00 PM)

Poster/Presentation
Number 045

Objective

To uncover underlying patterns of FDG-PET hypometabolism in early-onset (EO) and late-onset (LO) cognitively impaired amyloid and tau negative (A-/T-) ADNI subjects, without significant hippocampal atrophy (N_HIP-).

Background

Alzheimer’s disease (AD) is characterized by amyloid-beta and tau protein deposits, and neurodegeneration. Previous studies have reported that 15% of mild cognitively impaired and 11% of dementia subjects thought to have underlying AD pathology are A-T-N- (Burnham, 2019). The underlying etiology for the A-T-N- cognitively impaired population remains largely unknown.

Design/Methods

Data for 159 cognitively normal (CN), 74 EO, and 40 LO ADNI subjects classified as A-T-N_HIP- were selected based on their first FDG-PET visit. FDG-PET images were processed in SPM12 and normalized to mean pons uptake, generating SUVR images. Statistical maps of FDG-PET SUVR were created using voxel-wise regression in SPM12, where EO and LO A-T-N_HIP- were compared to young-CN and old-CN, correcting for age, sex, and education. Results were displayed at a cluster-level FWE correction of p<0.05. Subject demographics, global cognitive, Crane cognitive composite, and biomarker measures were compared between A-T-N_HIP- groups in SPSS.

Results Main demographic comparisons showed the expected differences in age and CDR-SB across groups. Relative to CN, both EO and LO A-T-N_HIP- showed significantly worse performance on CDR-SB (both p<0.001), memory function (EO, p=0.006; LO, p<0.001), and executive functioning (EO, p=0.02; LO, p=0.001). LO A-T-N_HIP- also showed worse performance in the language domain compared to CN (p<0.001). LO A-T-N_HIP- had significantly less total white matter volume (p<0.001) and significantly more total gray matter volume (p=0.035) when compared to CN. In the voxel-wise regression, LO A-T-N_HIP- showed a frontotemporal pattern of FDG-hypometabolism, while EO A-T-N_HIP- subjects did not show significant hypometabolism relative to CN.

Conclusions The observed frontotemporal hypometabolism in LO A-T-N_HIP- might be indicative of non-AD dementias such as late-onset frontotemporal dementia, limbic-predominant age-related TDP-43 encephalopathy (LATE), or vascular dementia.

Authors/Disclosures
Paige E. Logan PRESENTER	Ms. Logan has nothing to disclose.
Eddie Stage, Jr. (Indiana University School of Medicine)	Mr. Stage has nothing to disclose.
	No disclosure on file
	No disclosure on file
	No disclosure on file
Shannon Risacher	Shannon Risacher has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Springer. Shannon Risacher has stock in Eli Lilly. Shannon Risacher has received personal compensation in the range of $500-$4,999 for serving as a Reviewer with NIH.
Andrew J. Saykin, PsyD (Indiana University School of Medicine)	Dr. Saykin has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Bayer Oncology. Dr. Saykin has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Springer Nature Publishing. The institution of Dr. Saykin has received research support from Eli Lilly/Avid Radiopharmaceuticals.
Liana Apostolova, MD, F�鶹��ýӳ�� (Indiana University School of Medicine)	Dr. Apostolova has received personal compensation in the range of $500-$4,999 for serving as a Consultant for NIH. Dr. Apostolova has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Eli Lilly. Dr. Apostolova has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Roche. Dr. Apostolova has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for siemens. Dr. Apostolova has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Eisai. Dr. Apostolova has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Alnylam. Dr. Apostolova has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Alzheimer Association. The institution of Dr. Apostolova has received research support from Roche Diagnostics. The institution of Dr. Apostolova has received research support from NIA. The institution of Dr. Apostolova has received research support from Alzheimer Association. The institution of Dr. Apostolova has received research support from AVID radiopharmaceuticals. The institution of Dr. Apostolova has received research support from Life Molecular Imaging. Dr. Apostolova has a non-compensated relationship as a advisor with FDA that is relevant to �鶹��ýӳ�� interests or activities.

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