Tau pathology and neurodegeneration contribute to cognitive impairment in Alzheimer ’s disease

AbstractNeuropathological andin vivo studies have revealed a tight relationship between tau pathology and cognitive impairment across the Alzheimer ’s disease spectrum. However, tau pathology is also intimately associated with neurodegeneration and amyloid pathology. The aim of the present study was therefore to assess whether grey matter atrophy and amyloid pathology contribute to the relationship between tau pathology, as measured with18F-AV-1451-PET imaging, and cognitive deficits in Alzheimer ’s disease. We included 40 amyloid-positive patients meeting criteria for mild cognitive impairment due to Alzheimer’s disease (n = 5) or probable Alzheimer ’s disease dementia (n = 35). Twelve patients additionally fulfilled the diagnostic criteria for posterior cortical atrophy and eight for logopenic variant primary progressive aphasia. All participants underwent 3 T magnetic resonance imaging, amyloid (11C-PiB) positron emission tomography and tau (18F-AV-1451) positron emission tomography, and episodic and semantic memory, language, executive and visuospatial functions assessment. Raw cognitive scores were converted to age-adjusted Z-scores (W-scores) and averaged to compute composite scores for each cognitive domain. Independent regressions were performed between18F-AV-1451 binding and each cognitive domain, and we used the Biological Parametric Mapping toolbox to further control for local grey matter volumes,11C-PiB uptake, or both. Partial correlations and causal medi...

Source: Brain - October 7, 2017 Category: Neurology Source Type: research