Tau Burden is Best Captured by Magnitude and Extent: Tau-MaX as a Measure of Global Tau.

Tau exhibits change in both spatial extent and density of pathology along the Alzheimer's disease (AD) spectrum with each aspect contributing to the overall burden of pathological tau. Nevertheless, studies using Tau PET have measured either magnitude using standardized uptake value ratios (SUVRs) or extent using number of Tau+ regions. We hypothesized that combining these two dimensions into a single measure of Magnitude and eXtent, Tau-MaX, would provide improved quantification of global tau burden as well as allowing for a region-agnostic measure of global tau burden that does not require a pre-specified region of interest (ROI) or meta-ROI.

Racial/Ethnic Differences in Neuropsychological Test Performance in Frontotemporal Degeneration.

Racial disparities in neuropsychological test performance are well documented in Alzheimer's Disease (AD) but have received little attention in frontotemporal degeneration (FTD). Identification of potential disparities in neuropsychological performance is critical to identify ways to improve inclusivity in clinical research and care of representative FTD populations. We evaluated disparities in neuropsychological performance among individuals with clinically diagnosed FTD (behavioral variant FTD [bvFTD] or primary progressive aphasia [PPA]) using data from the National Alzheimer's Coordinating Center (NACC) collected between September 2005 and November 2023.

Feline Diabetes Is Associated with Deficits in Markers of Insulin Signaling in Peripheral Tissues.

Like humans, cats have a strong relationship between decreasing insulin sensitivity and the development of diabetes with obesity. However, the underlying molecular mechanisms of impaired insulin secretion and signaling in cats remain largely unknown. A total of 54 client-owned nondiabetic lean ( = 15), overweight ( = 15), and diabetic ( = 24) cats were included in the study.

Posterior hippocampal sparing in Lewy body disorders with Alzheimer's copathology: An in vivo MRI study.

Background: Lewy body disorders (LBD), encompassing Parkinson disease (PD), PD dementia (PDD), and dementia with Lewy bodies (DLB), are characterized by alpha-synuclein pathology but often are accompanied by Alzheimer's disease (AD) neuropathological change (ADNC). The medial temporal lobe (MTL) is a primary locus of tau accumulation and associated neurodegeneration in AD. However, it is unclear the extent to which AD copathology in LBD (LBD/AD+) contributes to MTL-specific patterns of degeneration.