Increased plasma DOPA decarboxylase levels in Lewy body disorders are driven by dopaminergic treatment.

DOPA Decarboxylase (DDC) has been proposed as a cerebrospinal fluid (CSF) biomarker with increased concentrations in Lewy body disorders (LBDs) and highest levels in patients receiving dopaminergic treatment. Here we evaluate plasma DDC, measured by proximity extension assay, and the effect of dopaminergic treatment in three independent LBD (with a focus on dementia with Lewy bodies (DLB) and Parkinson's disease (PD)) cohorts: an autopsy-confirmed cohort (n = 71), a large multicenter, cross-dementia cohort (n = 1498) and a longitudinal cohort with detailed treatment information (n = 66, median follow-up time[IQR] = 4[4, 4] years). Plasma DDC was not altered between different LBDs and other disease groups or controls in absence of treatment.

Development and Validation of a Tool to Predict Onset of Mild Cognitive Impairment and Alzheimer Dementia.

Importance: The ability to predict the onset of mild cognitive impairment (MCI) and Alzheimer dementia (AD) could allow older adults and clinicians to make informed decisions about dementia care.

Objective: To assess whether the age at onset of MCI and AD can be predicted using a statistical modeling approach.

Design, Setting, And Participants: This prognostic study used data from 2 aging and dementia cohort studies-the Australian Imaging, Biomarker and Lifestyle (AIBL) study and the Alzheimer's Disease Neuroimaging Initiative (ADNI)-for model development and validation of the Florey Dementia Index (FDI), a tool used to predict the age at onset of MCI and AD in older adults.

Sleep discrepancy and brain glucose metabolism in community-dwelling older adults.

Sleep discrepancy (negative discrepancy reflects worse self-reported sleep than objective measures, such as actigraphy, and positive discrepancy the opposite) has been linked to adverse health outcomes. This study is first to investigate the relationship between sleep discrepancy and brain glucose metabolism (assessed globally and regionally via positron emission tomography), and to evaluate the contribution of insomnia severity and depressive symptoms to any associations. Using data from cognitively unimpaired community-dwelling older adults ( = 68), cluster analysis was used to characterise sleep discrepancy (for total sleep time (TST), wake after sleep onset (WASO), and sleep efficiency (SE)), and logistic regression was used to explore sleep discrepancy's associations with brain glucose metabolism, while controlling for insomnia severity and depressive symptoms.

Autoantibodies to BACE1 promote Aβ accumulation and neurodegeneration in Alzheimer's disease.

The profile of autoantibodies is dysregulated in patients with Alzheimer's disease (AD). Autoantibodies to beta-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1) are present in human blood. This study aims to investigate the clinical relevance and pathophysiological roles of autoantibodies to BACE1 in AD.