Biomarkers.

Background: There is a strong link between tau and progression of Alzheimer's disease (AD), necessitating an understanding of tau spreading mechanisms. Prior research, predominantly in typical AD, suggested that tau propagates from epicenters (regions with earliest tau) to functionally connected regions. However, given the constrained spatial heterogeneity of tau in typical AD, validating this connectivity-based tau spreading model in AD variants with distinct tau deposition patterns is crucial.

Biomarkers.

Background: Dementia with Lewy bodies (DLB) is a an α-synucleinopathy characterized by dementia and a combination of parkinsonism, visual hallucinations, fluctuating cognition or REM sleep behaviour disorder. Specific biomarkers for DLB are lacking. DLB-related pattern (DLBRP) is a metabolic network imaging biomarker which expression can be quantified on a single patient basis.

Biomarkers.

Background: Alzheimer's Disease (AD) is often accompanied by neuroinflammation, which manifests prior to significant cognitive decline. Reactive astrocytosis is a hallmark of such inflammation, potentially serving as an early biomarker for AD pathology. Our study employs [18F]fluorodeprenyl-D2 ([18F]F-DED) positron emission tomography (PET) imaging to in vivo quantify astrocytosis comparing AD with healthy controls and examines its assocciation with cognitive deterioration in AD.

Biomarkers.

Background: In Alzheimer's disease (AD), cortical tau aggregation is a strong predictor of cortical brain atrophy as shown by MRI and PET studies, particularly driving the degeneration of neuronal somata in the grey matter. However, tau's physiological role is to stabilize microtubules within axons in the brain's white matter (WM) pathways. Therefore, tau's white-to-grey-matter translocation and aggregation in neurofibrillary tangles close to neuronal somata may induce WM degeneration through destabilization of axonal microtubule integrity.

Biomarkers.

Background: Patterns of regional atrophy and hypometabolism have been observed in dementia with Lewy bodies (DLB). However, determinants of regional vulnerability to structural and functional neurodegeneration remain largely unexplored. First, we investigated the association between regional gene expression and grey matter volumes in probable DLB patients.