Multimodal neuroimaging biomarkers and subtle cognitive decline in a population-based cohort without dementia.

Background: The relationship between subtle cognitive decline and Alzheimer's disease (AD) pathology as measured by biomarkers in settings outside of specialty memory clinics is not well characterized.

Objective: To investigate how subtle longitudinal cognitive decline relates to neuroimaging biomarkers in individuals drawn from a population-based study in an economically depressed, small-town area in southwestern Pennsylvania, USA.

Methods: A subset of participants without dementia (N = 115, age 76.

Where Do Plasma Biomarkers fit in With Current Alzheimer's Disease Detection?

Objectives: We examine the clinical utility of plasma-based detection for Alzheimer's disease (AD) pathophysiology in older adults with mild cognitive impairment (MCI) and whether cognitive screening can inform when to use plasma-based AD tests.

Methods: Seventy-four community-dwelling older adults with MCI had testing with plasma phosphorylated tau (p-tau) 217 and 181, positron emission tomography (PET) imaging for amyloid beta (Aβ), and cognitive assessment. Receiver operating characteristic (ROC) analysis was used to assess the diagnostic value of plasma p-tau.

Higher Striatal Dopamine is Related With Lower Physical Performance Fatigability in Community-Dwelling Older Adults.

Background: Fatigability in community-dwelling older adults is highly prevalent and disabling, but lacks a treatment. Greater nigrostriatal dopaminergic signaling can ameliorate performance fatigability in healthy young adults, but its role in community-dwelling older adults is not known. We hypothesized that higher nigrostriatal dopaminergic integrity would be associated with lower performance fatigability, independent of cardiopulmonary and musculoskeletal energetics and other health conditions.

A preliminary investigation of worry, cortical amyloid burden, and stressor-evoked brain and cardiovascular reactivity in older adults.

Worry is a transdiagnostic symptom common to many neurocognitive disorders of aging, including early stages of Alzheimer's disease and related dementias (ADRD). Severe worry is associated with amyloid burden in cognitively intact older adults, yet the mechanisms underlying this association are not well understood. We hypothesize that this relationship involves altered brain and cardiovascular reactivity to acute stressors, a brain-body phenotype that also increases risk for cardiovascular disease.

Implementation and Assessment of Tau Thresholds in Non-Demented Individuals as Predictors of Cognitive Decline in Tau Imaging Studies.

Background: Tau accumulation in Alzheimer's disease is associated with short term clinical progression and faster rates of cognitive decline in individuals with high amyloid-β deposition. Defining an optimal threshold of tau accumulation predictive of cognitive decline remains a challenge.

Objective: We tested the ability of regional tau PET sensitivity and specificity thresholds to predict longitudinal cognitive decline.