Recovery of activation propagation and self-sustained oscillation abilities in stroke brain networks

TL;DR

This study investigates how stroke impacts brain network dynamics, revealing that structural and functional recovery of activation propagation and oscillation abilities occurs over time, with significant improvements observed one year post-stroke.

Contribution

The paper introduces a reaction-diffusion model to analyze stroke-related changes in brain activation and oscillation patterns, linking structural repair to functional recovery.

Findings

Stroke slows activation propagation across brain scales.

Self-sustained oscillation patterns are significantly altered three months post-stroke.

Recovery of these patterns correlates with structural connection repair over one year.

Abstract

Healthy brain networks usually show highly efficient information communication and self-sustained oscillation abilities. However, how the brain network structure affects these dynamics after an injury (stroke) is not very clear. The recovery of structure and dynamics of stroke brain networks over time is still not known precisely. Based on the analysis of a large number of strokes' brain network data, we show that stroke changes the network properties in connection weights, average degree, clustering, community, etc. Yet, they will recover gradually over time to some extent. We then adopt a simplified reaction-diffusion model to investigate stroke patients' activation propagation and self-sustained oscillation abilities. Our results reveal that the stroke slows the adoption time across different brain scales, indicating a weakened brain's activation propagation ability. In addition, we show that the lifetime of self-sustained oscillatory patterns at three months post-stroke patients' brains significantly departs from the healthy one. Finally, we examine the properties of core networks of self-sustained oscillatory patterns, in which the directed edges denote the main pathways of activation propagation. Our results demonstrate that the lifetime and recovery of self-sustaining patterns are related to the properties of core networks, and the properties in the post-stroke greatly vary from those in the healthy group. Most importantly, the strokes' activation propagation and self-sustained oscillation abilities significantly improve at one year post-stroke, driven by structural connection repair. This work may help us to understand the relationship between structure and function in brain disorders.