Attenuated Task-Related Changes of Heart-Brain Coupling During Cognitive Load in Post-Stroke Cognitive Impairment: An EEG–ECG Maximal Information Coefficient Study

Evidence linking cardiovascular health to cognitive function suggests that interactions within the central autonomic network (CAN) may contribute to the development and progression of post-stroke cognitive impairment (PSCI). Heart-brain coupling (HBC) can serve as a readout of coordinated CAN function and offers a novel perspective for understanding PSCI. In this cross-sectional case-control study, we enrolled 16 patients with PSCI and 19 age-matched healthy controls and acquired simultaneous electroencephalography (EEG) and electrocardiography (ECG) recordings during resting state and a cognitive load condition. At both the sensor and source levels, we used the maximal information coefficient to quantify nonlinear coupling between cortical rhythms and heart rate variability (HRV) indices derived from Poincaré plots, and examined associations between these coupling metrics and the severity of cognitive impairment. Compared with healthy controls, HBC in PSCI is characterized by altered task-related modulation patterns, with a potential reduction in the flexibility of coordination between cortical activity and autonomic regulation under cognitive load. Some coupling features partially reflect the severity of cognitive impairment. Spatially, coupling patterns tend to involve widely distributed cortical regions rather than being confined to focal alterations. This study characterizes the nonlinear coupling between cortical rhythms and HRV under both resting and cognitive load conditions in PSCI, which may support a role of CAN dysfunction in the pathophysiology of PSCI and proposes testable potential regulatory targets for PSCI risk stratification and rehabilitation monitoring.