Identifying the Diffusion Source of Dementia Spreading in Structural Brain Networks

摘要

Normal and aberrant cognitive functions arc the result of the dynamic interplay between large-scale neural circuits. Describing the nature of these interactions has been a challenging task yet important for neurodegenerative disease evolution. The origin of Alzheimer's disease lies in the hippocampus and subsequently diffuses to the temporal, parietal and prcfrontal cortices. Determining the sources of dementia is crucial to the prediction of the disease evolution and choice of treatment. State-of-the-art method for determining dementia progression are network diffusion models derived from the heat equation without diffusion sources. We propose a different research avenue based on epidemic modeling to localize the disease sources. These models may better characterize the empirical spread of dementia through brain regions. We explore an estimation algorithm based on a susceptible-infected (SI) epidemic algorithm and a network diffusion model for comparison purposes emulating the disease evolution from sources (susceptible) to non-recovered (atrophy, infected) areas. The goal is to identify the probable disease diffusion sources, which we accomplish via a ranking heuristic based upon steady-state convergence times. Graph centrality measures arc employed to provide a baseline for further comparison. Our results applied on structural brain networks in dementia suggest that epidemic models arc able to accurately describe the different node roles in controlling trajectories of brain networks comparably to the existing diffusion approach.