Scale-free functional connectivity of the brain is maintained in anesthetized healthy participants but not in patients with unresponsive wakefulness syndrome. PLoS One 2014;9(3):e92182
Date
03/22/2014Pubmed ID
24647227Pubmed Central ID
PMC3960221DOI
10.1371/journal.pone.0092182Scopus ID
2-s2.0-84898623268 (requires institutional sign-in at Scopus site) 34 CitationsAbstract
Loss of consciousness in anesthetized healthy participants and in patients with unresponsive wakefulness syndrome (UWS) is associated with substantial alterations of functional connectivity across large-scale brain networks. Yet, a prominent distinction between the two cases is that after anesthesia, brain connectivity and consciousness are spontaneously restored, whereas in patients with UWS this restoration fails to occur, but why? A possible explanation is that the self-organizing capability of the brain is compromised in patients with UWS but not in healthy participants undergoing anesthesia. According to the theory of self-organized criticality, many natural complex systems, including the brain, evolve spontaneously to a critical state wherein system behaviors display spatial and/or temporal scale-invariant characteristics. Here we tested the hypothesis that the scale-free property of brain network organization is in fact fundamentally different between anesthetized healthy participants and UWS patients. We introduced a novel, computationally efficient approach to determine anatomical-functional parcellation of the whole-brain network at increasingly finer spatial scales. We found that in healthy participants, scale-free distributions of node size and node degree were present across wakefulness, propofol sedation, and recovery, despite significant propofol-induced functional connectivity changes. In patients with UWS, the scale-free distribution of node degree was absent, reflecting a fundamental difference between the two groups in adaptive reconfiguration of functional interaction between network components. The maintenance of scale-invariance across propofol sedation in healthy participants suggests the presence of persistent, on-going self-organizing processes to a critical state--a capacity that is compromised in patients with UWS.
Author List
Liu X, Ward BD, Binder JR, Li SJ, Hudetz AGAuthor
Jeffrey R. Binder MD Professor in the Neurology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AdultAlgorithms
Anesthesia
Brain
Consciousness
Deep Sedation
Female
Healthy Volunteers
Humans
Male
Middle Aged
Nerve Net
Wakefulness
Young Adult
