Functional connectivity associated with tau levels in ageing, Alzheimer’s, and small vessel disease
Abstract
In Alzheimer’s disease, tau pathology spreads hierarchically from the inferior temporal lobe throughout the cortex, ensuing cognitive decline and dementia. Similarly, circumscribed patterns of pathological tau have been observed in normal ageing and small vessel disease, suggesting a spatially ordered distribution of tau pathology across normal ageing and different diseases. In vitro findings suggest that pathological tau may spread ‘prion-like’ across neuronal connections in an activity-dependent manner. Supporting this notion, functional brain networks show a spatial correspondence to tau deposition patterns. However, it remains unclear whether higher network-connectivity facilitates tau propagation. To address this, we included 55 normal aged elderly (i.e. cognitively normal, amyloid-negative), 50 Alzheimer’s disease patients (i.e. amyloid-positive) covering the preclinical to dementia spectrum, as well as 36 patients with pure (i.e. amyloid-negative) vascular cognitive impairment due to small vessel disease. All subjects were assessed with AV1451 tau-PET and resting-state functional MRI. Within each group, we computed atlas-based resting-state functional MRI functional connectivity across 400 regions of interest covering the entire neocortex. Using the same atlas, we also assessed within each group the covariance of tau-PET levels among the 400 regions of interest. We found that higher resting-state functional MRI assessed functional connectivity between any given region of interest pair was associated with higher covariance in tau-PET binding in corresponding regions of interest. This result was consistently found in normal ageing, Alzheimer’s disease and vascular cognitive impairment. In particular, inferior temporal tau-hotspots, as defined by highest tau-PET uptake, showed high predictive value of tau-PET levels in functionally closely connected regions of interest. These associations between functional connectivity and tau-PET uptake were detected regardless of presence of dementia symptoms (mild cognitive impairment or dementia), amyloid deposition (as assessed by amyloid-PET) or small vessel disease. Our findings suggest that higher functional connectivity between brain regions is associated with shared tau-levels, supporting the view of prion-like tau spreading facilitated by neural activity.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 15, 2019
- Source ID
- 10.1093/brain/awz026
Entities
People
- Alexander Damm
- Anna Rubinski
- Chul Hyoung Lyoo
- Duk L. Na
- For The Alzheimer’s Disease Neuroimaging Initiative*
- Hana Cho
- Hee Jin Kim
- Julia Neitzel
- Marco Duering
- Michael Ewers
- Nicolai Franzmeier
- Sang Won Seo
- Sofia Finsterwalder
- Yeshin Kim
Organizations
- AbbVie
- Alzheimer Forschung Initiative
- BioClinica
- Bristol-Myers Squibb
- European Commission
- Kangwon National University
- Ludwig-Maximilians-Universität München
- National Institute of Biomedical Imaging and Bioengineering
- National Institute on Aging
- National Institutes of Health
- Samsung Medical Center
- Sungkyunkwan University
- United States Department of Defense
- University of California
- Yonsei University