Effects of Multi-Sensory Stimulation on Brain Functional Connectivity in Patients with Disorders of Consciousness

Background/Objectives: This study investigates the effects of multi-sensory stimulation on brain functional connectivity in patients with disorders of consciousness (DOC). DOC patients experience prolonged loss of consciousness due to brain injury, posing significant challenges for rehabilitation. Methods: In the study, visual, olfactory, and visual-olfactory (V-O) combined stimulation were applied to DOC patients while their EEG signals were recorded. A brain functional network was constructed based on the conditional Granger causality (CGC) method to analyze its topological characteristics. Results: The results revealed that the strength of brain functional connectivity in Minimally Conscious State (MCS) patients was significantly higher than that in Vegetative State (VS) patients, indicating a strong correlation between the intensity of synergistic activity in brain functional connectivity and the level of consciousness. Furthermore, V-O combined stimulation significantly enhanced brain functional connectivity compared to single-modality stimulation. The selection of different stimulation also differentially affected brain functional connectivity, with olfactory stimulation exhibiting high pleasure, arousal, and dominance (Self-Assessment Manikin) values demonstrating unique advantages in reducing individual variability and improving global efficiency. Conclusions: The study provides a theoretical foundation for the application of multi-sensory stimulation in the rehabilitation of DOC patients. V-O stimulation not only enhances information transmission in brain regions corresponding to visual and olfactory processing under single-modality stimulation but also increases the intensity of information transfer to other brain regions; this may serve as a reference for understanding the effects of multi-sensory stimulation on brain networks.