Disrupted small-world networks in schizophrenia

Yong Liu, Meng Liang, Yuan Zhou, Yong He, Yihui Hao, Ming Song, Chunshui Yu, Haihong Liu, Zhening Liu, Tianzi Jiang
2008 Brain  
The human brain has been described as a large, sparse, complex network characterized by efficient small-world properties, which assure that the brain generates and integrates information with high efficiency. Many previous neuroimaging studies have provided consistent evidence of 'dysfunctional connectivity' among the brain regions in schizophrenia; however, little is known about whether or not this dysfunctional connectivity causes disruption of the topological properties of brain functional
more » ... tworks.To this end, we investigated the topological properties of human brain functional networks derived from resting-state functional magnetic resonance imaging (fMRI). Data was obtained from 31 schizophrenia patients and 31 healthy subjects; then functional connectivity between 90 cortical and sub-cortical regions was estimated by partial correlation analysis and thresholded to construct a set of undirected graphs. Our findings demonstrated that the brain functional networks had efficient smallworld properties in the healthy subjects; whereas these properties were disrupted in the patients with schizophrenia. Brain functional networks have efficient small-world properties which support efficient parallel information transfer at a relatively low cost. More importantly, in patients with schizophrenia the small-world topological properties are significantly altered in many brain regions in the prefrontal, parietal and temporal lobes. These findings are consistent with a hypothesis of dysfunctional integration of the brain in this illness. Specifically, we found that these altered topological measurements correlate with illness duration in schizophrenia. Detection and estimation of these alterations could prove helpful for understanding the pathophysiological mechanism as well as for evaluation of the severity of schizophrenia. Abbreviations: BOLD = blood oxygenation level dependent; EPI = echo planar imaging; fMRI = functional magnetic resonance imaging; PANSS = Positive and Negative Syndrome Scale by guest on June 15, 2016 http://brain.oxfordjournals.org/ Downloaded from 946 Brain (2008), 131, 945^961 Y. Liu et al. by guest on June 15, 2016 http://brain.oxfordjournals.org/ Downloaded from Disrupted small-world networks Brain (2008), 131, 945^961 947 by guest on June 15, 2016 http://brain.oxfordjournals.org/ Downloaded from Disrupted small-world networks Brain (2008), 131, 945^961 951 by guest on June 15, 2016 http://brain.oxfordjournals.org/ Downloaded from Disrupted small-world networks Brain (2008), 131, 945^961 Disrupted small-world networks Brain (2008), 131, 945^961 Disrupted small-world networks Brain (2008), 131, 945^961
doi:10.1093/brain/awn018 pmid:18299296 fatcat:iptnbzznozge7efy3s6um65i2a