An FMRI Study Of Brian Resting-State Functional Connectivity In First-episode Adolescent Schizophrenia

Objective:We aim to analysis the brain functional connectivity in first-episode medication-naive adolescent schizophrenia patients using resting state fMRI(rs-fMRI)and to explore the potential neural mechanism of adolescent schizophrenia.Methods:The first-episode adolescent patients with schizophrenia were diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders,the fifth edition(DSM-Ⅴ)in the third hospital of Mianyang from December 2016 to January 2018,and the severity of their clinical symptoms were estimated according to Positive Symptom and Negative Symptom Scale(PANSS)and Psychotic Symptom Rating Scales(PSYRAT).Twenty one healthy volunteers matched with age and gender were selected as normal control group.Each of the subjects was scanned by 3.0T MRI.The Posterior cingulate gyrus(PCC)was defined as a seed region of interest(ROI),and the functional connectivities between seed region and other brain regions were calculated.Subsequently,two sample t test was used to compare the differences of the resting-state functional connectivities(rs-FC)maps between the two groups,and the correlation between regions of FC maps with statistically significant differences and clinical symptom severity was analyzed with Pearson correlation.Results:Two patients were eliminated because of head motion after Realignment.Data of 19 remaining patients were included in statistical analysis,which included 7 males(37%)and 12(63%)females,whose mean age and average school age were 16.6±1.4 and 10.0±1.5 years respectively and course of disease were 5.4±4.7 months.There were 8 males(38%)and 13(62%)females in the control group whose average age and average school age were 16.8±1.1 and 10.4±1.2 years,respectively.There was no statistical difference between the two groups in sex,age and educational level,(p>0.05).Compared to the control group,the schizophrenia group exhibited increased PCC rs-FC in two brain regions in including the left orbital part of inferior frontal gyrus extended to the left superior temporal gyrus and the bilateral middle cingulate gyrus,and the weaker PCC rs-FC with the left postcentral gyrus and the right postcentral gyrus(P<0.05,AlphaSim-corrected for multiple comparisons,cluster size>40).The functional connectivities between the left orbital part of inferior frontal gyrus and the PCC was positively correlated with the PANSS negative symptom scores(r=0.487,P=0.032).Conclusion:The results of current study showed that resting-state brain functional dysconnectivities of the PCC in first-episode adolescent schizophrenia patients in the early stage of disease,which ulteriorly supported and confirmed the hypothesis of neurological dysconnectivity in schizophrenia.The increased functional connectivity between the orbitofrontal cortex and the posterior cingulate gyrus may be a potential neurological mechanism for the onset of negative symptoms in adolescent schizophrenia patients.