Research On Amplitude Of Low-frequency Fluctuation And Functional Connectivity Of Rs-fMRI In Adolescents With Non-suicidal Self-injury

Objective:This study aims to explore the brain function characteristics of adolescents with non-suicidal self-injury（NSSI）based on amplitude of low frequency fluctuation（ALFF）and functional connectivity（FC）of resting-state functional magnetic resonance imaging（rs-f MRI）,analyze the correlation between abnormal brain areas and clinical fea-tures,and explore the neuroimaging mechanism of NSSI,so as to provide scientific basis for clinical prevention and treatment of NSSI.Methods:23 adolescent（13-18 years old）patients（NSSI group）who met the DSM-5（diagnostic and statistical manual of mental disorders,5th edition）diagnostic criteria for NSSI from October 2019 to December 2020 in the Affiliated Psychological Clinic of Zunyi Medical University were collected,and 18 healthy control subjects（HC group）with the same age,sex and education level were recruited through advertisements.After com-pleting general data collection,evaluation questionnaire of adolescent with NSSI and24-item hamilton depression rating scale(HAMD₂₄)assessment,GE Signa HDxt 3.0T magnetic resonance was used for brain f MRI scanning.The DPARSF software and SPM12running on the MATLAB 2018b platform was used to preprocess the original images of all subjects,and then analyze the brain regions with statistically significant differences in ALFF between the NSSI group and the HC group by DPABI software.Differential brain areas were taken as the seed points to analyze FC of the whole brain,and Pearson correla-tion analysis were carried out for the differential brain areas and clinical symptom scales in ALFF and FC analysis.Results:There were no statistically significant differences in gender,age,education level,and growth environment between the two groups（P>0.05）;compared with the HC group,the brain areas with increased ALFF values in the NSSI group included bilateral amygdala and right dorsolateral superior frontal gyrus,and the difference was statistically significant（P<0.05,FDR correction）;after comparison between groups,the bilateral amygdala was used as the seed point for the whole brain functional connection analysis,FC intensity of left amygdala,right anterior cingulate cortex,left anterior cingulate cortex,right thalamus and left thalamus in the NSSI group increased,and the FC intensity of left amygdala,left orbital superior frontal gyrus and left orbital middle frontal gyrus decreased in the NSSI group.Through Pearson correlation analysis,it was found that the ALFF value of the left amygdala in the NSSI group was positively correlated with the HAMD₂₄ score（r=0.627,P=0.004）.Conclusion:Abnormal neuronal activity was found in many brain regions of NSSI ado-lescents under resting state,mainly involving the amygdala and dorsolateral superior frontal gyrus;and the FC between left amygdala and multiple brain regions are abnormal;the abnormal activity of the left amygdala is positively correlated with the severity of the disease,which may be of great significance to the evaluation of the disease.