Resting State FMRI Study Of Regional Homogeneity And Amplitude Of Low-frequency Fluctuation In First-episode Schizophrenia

Objective To study the characteristics of spontaneous neural activity of schizophrenia patients under basic condition,and to explore the neuropathological mechanism of brain dysfunction in first-episde schizophrenia,as well as to further understand the relationship between intrinsic brain function and external manifestation of schizophrenia,based on the mathods of the regional homogeneity(ReHo)and the amplitude of low frequency fluctuation(ALFF),using resting state functional magnetic resonance imaging(rs-fMRI).Methods Sixty patients with schizophrenia(case group)and 32 healthy controls(control group)were included in the study.Positive and negative symptom scale(PANSS)was used to assess the severity of clinical symptoms.The static fMRI data of all participants were collected though the GE 750 Discovery MRI scanner.The DPARSFA software was run on Matlab7.8 platform,the resting state datas were preprocessed and were analyzed by mathods of ReHo and ALFF.Two-sample t-test with REST software was used to compare the differences between the two groups,The statistic threshold was set at P <0.05(k>10,after the Alphaism correction).The correlation analysis of ReHo and ALFF among the different brain regions was carried out and PANSS.Results 1 Compared with normal control group,the ReHo values increased in the right dorsolateral prefrontal cortex,bilateral putumns,the left medial prefrontal cortex,and orbital frontal gyrus(P<0.05,AlphaSim revised),but decreased in the bilateral medial occipital gyrus,fusiform gyrus,angular gyrus(P<0.05,AlphaSim revised).2 Compared with normal control group,the ALFF values increased in the right dorsolateral prefrontal cortex,bilateral putumns,right temporal medial gyrus(P<0.05,AlphaSim revised),but decreased in the left fusiform gyrus,angular gyrus,bilateral posterior cingulate gyrus,precuneus(P<0.05,AlphaSim revised).3 The ALFF values of right middle temporal gyrus are positively correlated with PANSS auditory hallucination scores.Conclusion 1 The ReHo abnormalities of early onset schizophrenic patients show in multiple brain regions,which suggesting that spontaneous activities of adjacent voxels in the space deviate from the normal,and may be associated with coordination disorders of autonomic nervous activities.2 In patients with schizophrenia,the ALFF abnormalities were found inmany brain regions,which illustrates schizophrenic patients possess abnormal spontaneous neural activity in several brain regions from the perspective of energy.3 The activities of right middle temporal gyrus may be involved in auditory hallucinations of the neuropathological process.Symptom grades should be taken into account in future studies.4 By the mathods of ALFF and ReHo,detecting spontaneous fluctuations of the brain in the resting state,contributing to observe the changes in brain function and speculate the pathomechanism of disease.