Abnormalities Of Topological Properties In Resting State Brain Network In First-episode Paranoid Schizophrenia

BackgroundSchizophrenia is a common mental disease whose etiology has not been fully elucidated,characterized by hallucinations,delusions,cognitive dysfunction and decline in social function.The clinical recovery is poor,which seriously affects the quality of life of patients.Paranoid schizophrenia is common in clinical practice,and its organic abnormalities is not obvious,but the brain functional activity has been changed.Recently,the development of functional magnetic resonance imaging(fMRI)technology has provided more possibilities for non-invasive exploration of brain functions.The topological properties of brain functional networks based on fMRI analysis technology reflect the information integration and regulation efficiency of brain network to a certain extent.Patients with paranoid schizophrenia show sensory perception and cognitive dysfunction,and show impaired brain functional information integration phenotype.ObjectivesTo explore the abnormalities of topological properties in resting state brain functional network in patients with first-episode paranoid schizophrenia and the correlations between topological properties and clinical symptoms.Methods73 patients with schizophrenia(SZ)meet with the Diagnostic and Statistical Manual of Mental Disorders,Fourth Edition(DSM-IV)criteria for schizophrenia and 70 subjects with healthy control(HC)were included.All subjects were checked by using functional magnetic resonance imaging(fMRI)and positive and negative symptom scales(PANSS)were used to assess the symptoms.Abnormalities of topological properties(global efficiency,local efficiency,clustering coefficient,shortest path length,degree centrality,betweenness centrality)of brain regions in brain functional network was analyzed by graph theory.Pearson correlation was used to analyze the correlation between the abnormal topological properties of brain regions in SZ and PANSS.Results1.Compared with the HC,SZ showed increased global efficiency in cerebellar vermisⅢ(t=3.27,P=0.039),decreased global efficiency in bilateral parahippocampal gyru(t_L=-3.34,P_L=0.039;t_R=-4.96,P_R<0.001)(P<0.05).2.Compared with the HC,SZ showed increased shortest path length in bilateral parahippocampal gyrus(t_L=4.62,P_L<0.001;t_R=3.88,P_R<0.001)and left hippocampus(t=3.29,P=0.033),decreased shortest path length in bilateral cerebellar lobuleⅩ(t_L=-4.28,P_L<0.001;t_R=-3.74,P_R<0.001),vermisⅧ(t=-4.16,P<0.001)andⅨ(t=-5.11,P<0.001)(P<0.05).3.Compared with the HC,SZ showed decreased shortest path length in bilateral parahippocampal gyrus(t_L=-4.03,P_L<0.001;t_R=-4.77,P_R<0.001)(P<0.05).4.Compared with the HC,SZ showed increased betweenness centrality in medial part of superior frontal gyrus(t=2.20,P=0.046),decreased betweenness centrality in left middle occipital gyrus(t=-3.30,P=0.046),middle temporal gyrus(t=-4.03,P<0.001),right parahippocampal gyrus(t=-3.17,P=0.046)and cerebellar vermisⅩ(t=-3.17,P=0.046)(P<0.05).5.There was no significant difference in the local efficiency and clustering coefficient between the SZ and the HC.6.Betweenness centrality of cerebellar vermisⅩwas negatively correlated with general psychopathology scale scores(r=-0.33,P=0.005).Conclusions1.Abnormalities of topological properties in limbic system,cerebellum,temporal lobe,occipital lobe and prefrontal lobe suggested that they played a role in the pathological mechanism of schizophrenia.2.Abnormalities of topological properties in cerebellar vermis were negatively correlated with general psychopathology scale scores,suggesting that vermis was associated with the severity of clinical symptoms in paranoid schizophrenia.