Differential Functional Connectivity Correlates of Cerebrospinal Fluid Biomarkers in Dementia of the Alzheimer's Type

Background: Alzheimer's disease (AD) is characterized by two cardinal pathologies, which have different topological distributions. The differential anatomical distributions of these pathologies raise the possibility that they exert differential effects on brain networks. Objectives: To investigate whether cerebrospinal fluid (CSF) biomarkers of the cardinal pathologies have differential relationships with functional connectivity networks in patients with dementia of the Alzheimer's type (DAT). Methods: Thirty-nine participants underwent CSF sampling and resting-state functional magnetic resonance imaging. Functional connectivity networks were computed for each participant. CSF biomarker levels of p-tau and amyloid-beta (A beta) were regressed onto these networks to identify subnetworks associated with each biomarker. Results: A subnetwork associated with tau-related pathology was identified with its hub in the right anterior entorhinal cortex. A separate subnetwork associated with A beta with its hub in the right dorsal anterior cingulate cortex was identified. Conclusion: These results demonstrate the differential effects of AD biomarkers on functional connectivity networks, supporting a possible division of labour between the cardinal pathologies. (C) 2015 S. Karger AG, Basel