A multi-cohort study of longitudinal and cross-sectional Alzheimer's disease biomarkers in cognitively unimpaired older adults.

Introduction: The generalizability of neuroimaging and cognitive biomarkers in their sensitivity to detect preclinical Alzheimer's disease (AD) and power to predict progression in large, multisite cohorts remains unclear.

Method: Longitudinal demographics, T1-weighted magnetic resonance imaging (MRI), and cognitive scores of 3036 cognitively unimpaired (CU) older adults (amyloid beta [Aβ]-negative/positive [A-/A+]: 1270/1558) were included. Cross-sectional and longitudinal cognition and medial temporal lobe (MTL) structural measures were extracted.

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.

Clinical criteria for limbic-predominant age-related TDP-43 encephalopathy.

Limbic predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC) is highly prevalent in late life and a common co-pathology with Alzheimer's disease neuropathologic change (ADNC). LATE-NC is a slowly progressive, amnestic clinical syndrome. Alternatively, when present with ADNC, LATE-NC is associated with a more rapid course.

Convolutional Neural Networks for the segmentation of hippocampal structures in postmortem MRI scans.

Background: The hippocampus plays a crucial role in memory and is one of the first structures affected by Alzheimer's disease. Postmortem MRI offers a way to quantify the alterations by measuring the atrophy of the inner structures of the hippocampus. Unfortunately, the manual segmentation of hippocampal subregions required to carry out these measures is very time-consuming.

Feasibility, validity, and normative data for the remote Uniform Data Set neuropsychological battery at the University of Pennsylvania Alzheimer's Disease Research Center.

Introduction: We investigated the feasibility and validity of the remotely-administered neuropsychological battery from the National Alzheimer's Coordinating Center Uniform Data Set (UDS T-Cog).

Methods: Two hundred twenty Penn Alzheimer's Disease Research Center participants with unimpaired cognition, mild cognitive impairment, and dementia completed the T-Cog during their annual UDS evaluation. We assessed administration feasibility and diagnostic group differences cross-sectionally across telephone versus videoconference modalities, and compared T-Cog to prior in-person UDS scores longitudinally.