Loss of consciousness reduces the stability of brain hubs and the heterogeneity of brain dynamics

• Published in: Communications biology Vol. 4; no. 1; p. 1037
• Main Authors: López-González, Ane, Panda, Rajanikant, Ponce-Alvarez, Adrián, Zamora-López, Gorka, Escrichs, Anira, Martial, Charlotte, Thibaut, Aurore, Gosseries, Olivia, Kringelbach, Morten L., Annen, Jitka, Laureys, Steven, Deco, Gustavo
• Format: Journal Article Web Resource
• Language: English
• Published: London Nature Publishing Group UK 06-09-2021; Nature Publishing Group; Nature; Nature Portfolio
• Subjects: 59/36; 59/57; 631/378/116/2393; 631/378/2649/1398; Adult; Aged; Aged, 80 and over; Anesthesia; Arousal; Biology; Biomedical and Life Sciences; Brain - physiopathology; Brain injury; Brain mapping; Consciousness; Female; Functional magnetic resonance imaging; Human health sciences; Humans; Life Sciences; Male; Middle Aged; Models, Neurological; Neural networks; Neural Pathways; Neurologie; Neurology; Propofol; Sciences de la santé humaine; Synchronization; Traumatic brain injury; Unconsciousness - physiopathology; Young Adult
• ISSN: 2399-3642; 2399-3642
• DOI: 10.1038/s42003-021-02537-9

Low-level states of consciousness are characterized by disruptions of brain activity that sustain arousal and awareness. Yet, how structural, dynamical, local and network brain properties interplay in the different levels of consciousness is unknown. Here, we study fMRI brain dynamics from patients that suffered brain injuries leading to a disorder of consciousness and from healthy subjects undergoing propofol-induced sedation. We show that pathological and pharmacological low-level states of consciousness display less recurrent, less connected and more segregated synchronization patterns than conscious state. We use whole-brain models built upon healthy and injured structural connectivity to interpret these dynamical effects. We found that low-level states of consciousness were associated with reduced network interactions, together with more homogeneous and more structurally constrained local dynamics. Notably, these changes lead the structural hub regions to lose their stability during low-level states of consciousness, thus attenuating the differences between hubs and non-hubs brain dynamics.
López-González et al study the fMRI brain dynamics and their underlying mechanism from patients that suffered brain injuries leading to a disorder of consciousness as well as from healthy subjects undergoing propofol-induced sedation. They show that pathological and pharmacological low-level states of consciousness display disrupted synchronization patterns, higher constraint to the anatomy and a loss of heterogeneity and stability in the structural hubs compared to conscious states.