Resting state functional magnetic resonance imaging study of amplitude of low-frequency fluctuation and fractional amplitude of low-frequency fluctuation in schizophrenia with violent behaviors

Objective To study the characteristics of spontaneous neural activity of schizophrenia patients under resting state, and to explore the neuropathological mechanism of brain dysfunction in schizophrenia with violent behaviors based on the methods of the amplitude of low frequency fluctuation (ALFF) and the fractional amplitude of low frequency fluctuation (fALFF), using resting state functional magnetic resonance imaging (rs-fMRI). Methods Thirty-five patients diagnosed with schizophrenia by ICD-10 were included in the study, and divided into the violent and non-violent group by the Modified Overt Aggression Scale (MOAS) score. The Positive and Negative Symptom Scale (PANSS) was used to assess the severity of clinical symptoms. The DPABI V2.3 (Data Processing & Analysis of Brain Imaging, DPABI) software was run on MATLAB2017b platform, the MRI data were preprocessed and were analyzed by ALFF and fALFF. Two-sample t-test was compared by DPABI software to recognize the differences between the two groups. The Pearson correlation analysis of ALFF/fALFF and PANSS scores were carried out. Results Compared with non-violent group (n=17), the ALFF values decreased in the Parietal_Sup_R and Parietal_Inf_R (AAL), and the fALFF increased in the bilateral inferior cerebellum lobe and Thalamus_L(AAL) in violent group (n=18). All the results were corrected by GRF (voxel level P<0.01, cluster level P<0.05). Pearson correlation analysis shows that the ALFF values of all schizophrenia (n=35) were positively correlated with PANSS-NS in the right inferior cerebellum lobe, Vermis, and Temporal_Mid_R (AAL, r=0.437, 0.610, 0.656 respectively). And the fALFF values of all schizophrenia (n=35) were negatively correlated with PANSS-NS in the Angular_R (AAL, r=-0.723) and positively correlated with PANSS-P7 scores in the Frontal_Sup_Medial_L (AAL, r=0.647) respectively. All the results were corrected by GRF (voxel level P<0.01, cluster level P<0.05). Conclusions The ALFF/fALFF abnormalities of schizophrenia patients with violent behaviors are in multiple brain regions, suggesting that violent schizophrenia patients may have abnormal spontaneous neural activity in several brain regions. Key words: Schizophrenia; Violence; Magnetic resonance imaging; Amplitude of low-frequency fluctuation; Fractional amplitude of low-frequency fluctuation