Comparative Study Of Regional Homogeneity In First-episode Schizophrenia And Individuals With A Genetic High Risk Of Schizophrenia:A Resting-state Functional Magnetic Resonance Imaging Study

Objective:In this study,resting-state functional magnetic resonance imaging was used to understand the aberrant homogeneity of regional spontaneous neuronal activity in the initial stage of schizophrenia(SZ)and vulnerable individuals at genetic high risk for SZ(GHR-SZ),which may find regions related to genetic vulnerability for SZ or the state of the disease itself and explore the susceptibility or protectiveness factors of SZ.Methods:Seventy first-episode SZ(FE-SZ)individuals,70 GHR-SZ individuals,and 84 healthy controls(HC)were recruited to undergo a functional magnetic resonance imaging(fMRI)scan.Regional homogeneity(ReHo)was utilized to explore regional spontaneous neuronal activity changes among the three groups at resting state.ANOVA test was used to compare the difference of ReHo values among FE-SZ,GHR-SZ and HC across the whole brain.Then post-hoc T-test was used to compare the difference between each two groups.Results:1)Significant differences were found in several regions,including the putamen,caudate,insula cortex,prefrontal cortex,parietal lobe,temporal lobe,and occipital lobe,among the three groups(p < 0.005,corrected).2)Markedly increased ReHo was observed in both the FE-SZ and GHR-SZ groups in the left putamen,left caudate,left insula,and bilateral orbitofrontal cortex when compared to HC(p < 0.05).3)The FE-SZ group peculiarly presented significantly decreased ReHo in the right middle temporal gyrus,inferior temporal gyrus,bilateral middle occipital gyrus,inferior occipital gyrus,right superior occipital gyrus,lingual gyrus,bilateral cuneus,calcarine cortex,and a significantly increased ReHo in the left angular gyrus when compared to GHR-SZ individuals and HC(p < 0.05)Conclusions:1)Our results showed that FE-SZ individuals had similar and specific changes in ReHo compared to GHR-SZ individuals.2)The current study found markedly increased ReHo in the left putamen,left caudate,left insula,and bilateral orbitofrontal cortex in FE-SZ and GHR-SZ individuals,indicating that these regions may be potential susceptibility markers of the disease.Altered ReHo peculiarly presented in the right middle temporal gyrus,right inferior temporal gyrus,bilateral middle occipital gyrus,bilateral inferior occipital gyrus,right superior occipital gyrus,right lingual gyrus,bilateral cuneus,bilateral calcarine cortex,and left angular gyrus in FE-SZ individuals,suggesting that these changes may be related to the pathophysiological mechanisms of psychotic symptoms in SZ.3)These affected regions may play a significant role in the occurrence and development of SZ.