F-PI-2620 Tau PET is associated with cognitive and motor impairment in Lewy body disease.

Co-pathology is frequent in Lewy body disease, which includes clinical diagnoses of both Parkinson's disease and dementia with Lewy bodies. Measuring concomitant pathology can improve clinical and research diagnoses and prediction of cognitive trajectories. Tau PET imaging may serve a dual role in Lewy body disease by measuring cortical tau aggregation as well as assessing dopaminergic loss attributed to binding to neuromelanin within substantia nigra.

Longitudinal network changes and phenoconversion risk in isolated REM sleep behavior disorder.

Isolated rapid eye movement sleep behavior disorder is a prodrome of α-synucleinopathies. Using positron emission tomography, we assessed changes in Parkinson's disease-related motor and cognitive metabolic networks and caudate/putamen dopaminergic input in a 4-year longitudinal imaging study of 13 male subjects with this disorder. We also correlated times to phenoconversion with baseline network expression in an independent validation sample.

Plasma Aβ/Aβ is sensitive to early cerebral amyloid accumulation and predicts risk of cognitive decline across the Alzheimer's disease spectrum.

Introduction: The availability of amyloid beta (Aβ) targeting therapies for Alzheimer's disease (AD) is increasing the demand for scalable biomarkers that are sensitive to early cerebral Aβ accumulation.

Methods: We evaluated fully-automated Lumipulse plasma Aβ/Aβ immunoassays for detecting cerebral Aβ in 457 clinically unimpaired (CU) and clinically impaired (CI) Stanford Alzheimer's Disease Research Center (Stanford ADRC) participants and 186 CU in the Stanford Aging and Memory Study (SAMS). Longitudinal change in ADRC plasma Aβ/Aβ and cognition and cross-sectional associations with SAMS memory and tau positron emission tomography (PET) were examined.

Impact of dopamine deficiency and REM sleep behavior disorder on cognition in early neuronal synuclein disease with hyposmia.

Objectives: To determine the impact of dopamine deficiency and isolated REM sleep behavior disorder (iRBD) on cognitive performance in early neuronal alpha-synuclein disease (NSD) with hyposmia.

Methods: Using Parkinson's Progression Markers Initiative baseline data, cognitive performance was assessed with a cognitive summary score (CSS) developed by applying regression-based internal norms derived from a robust healthy control (HC) group. Performance was examined for participants with hyposmia classified as NSD-Integrated Staging System (NSD-ISS) Stage 2, either Stage 2A (CSF alpha-synuclein seed amplification assay [SAA]+, SPECT dopamine transporter scan [DaTscan]-) or 2B (SAA+, DaTscan+).