Objective:To investigate the changes of abnormal spontaneous brain activity and whole-brain effector connectivity in patients with obsessive-compulsive disorder (OCD) by combining low frequency amplitude (ALFF) and Granger causality analysis (GCA), and explore their relations with clinical symptoms.Methods:Forty-nine patients with OCD admitted to Department of Psychiatry, Second Affiliated Hospital of Xinxiang Medical College from January 2020 to September 2023 were selected as OCD group; 50 healthy volunteers matched with gender, age and years of education were enrolled as healthy control (HC) group. Obsessive-compulsive symptoms and severities in the OCD group were assessed by Yale Brown obsessive-compulsive scale (Y-BOCS). All subjects underwent whole-brain resting-state functional magnetic resonance imaging scanning (rs-fMRI). ALFF differences between the 2 groups were compared. Brain regions with ALFF differences were used as seed points, and effector connectivity changes in seed points were compared with those in whole-brain by GCA. Correlations of ALFF and effector connectivity in brain regions with ALFF differences with total scores, obsession scores and compulsion scores of Y-BOCS were analyzed by partial correlation analysis.Results:(1) Compared with that in the HC group, ALFF was significantly enhanced in the right supplementary motor area, right hippocampus, left caudate nucleus, and right fusiform gyrus, and statistically attenuated in the left suboccipital gyrus in the OCD group ( P<0.05). (2) Compared with that in the HC group, effector connectivity from the right dorsolateral superior frontal gyrus to right supplementary motor area was significantly attenuated, and effector connectivity from the left superior occipital gyrus to right supplementary motor area was significantly enhanced in the OCD group ( P<0.05); compared with that in the HC group, effector connectivity from the right fusiform gyrus to right precentral gyrus was significantly attenuated, and effector connectivity from the right hippocampus to left mesial temporal gyrus was significantly enhanced in the OCD group ( P<0.05). (3) In OCD patients, altered ALFF in the left caudate nucleus was positively correlated with obsession scores ( r=0.357, P=0.027), and altered effector connectivity from the right dorsolateral superior frontal gyrus to right supplementary motor area was negatively correlated with obsession scores ( r=-0.312, P=0.029). Conclusion:Abnormalities in sensorimotor network function are closely related to clinical symptoms in patients with OCD.

Objective:To analyze brain topological property data through machine learning methods and explore changes in brain network topological properties in patients with schizophrenia.Methods:From January 2022 to August 2023, functional magnetic resonance imaging data of 60 patients with schizophrenia and 56 healthy controls were collected , and the data were preprocessed to construct brain functional networks and extract global and nodal topological properties. All subjects were divided into a training group and a testing group.The data of training group were fitted based on support vector machine, and the predictive performance was evaluated through cross-validation.The model was optimized by recursive feature elimination algorithm, then the indicators that contributed the most to predictive performance were extrated.The classification performance of the testing group was calculated based on the trained model with optimal predictive performance.SPSS 20.0 software was used for data analysis, the independent t-test and χ2 test were used for comparing the differences between the two groups. Results:The support vector machine achieved an accuracy of 75.00% in predicting the test group of schizophrenia patients based on all indicators. After removing redundant features and combining with the recursive feature elimination algorithm, the accuracy of the SVM model in predicting the test group increased to 90.00%. The nodal global efficiency(Ne)of the left superior temporal gyrus, right dorsal agranular insula, bilateral dorsal granular insula, bilateral caudal cingulate gyrus, and left lateral orbitofrontal cortex in the model contributed the most to classification.Compared to the control group, patients with schizophrenia had abnormal Ne values in these brain regions.Conclusion:There are multiple brain regions with abnormal Ne values in patients with schizophrenia, indicating that the abnormalities in information integration and transmission functions may be related to the imbalance in the dynamic equilibrium of the patients' brain networks.

Objective:To explore the functional changes of brain network node information integration and separation in patients with obsessive-compulsive disorder (OCD) and its correlation with clinical symptoms.Methods:Fifty-six patients with obsessive-compulsive disorder (OCD group) and fifty-six healthy controls (control group) matched in gender, age and years of education were enrolled. All participants accepted resting-state functional magnetic resonance imaging scans of the whole brain. Yale-Brown Obsessive Compulsive Scale(Y-BOCS) was used to assess patients′ clinical symptoms. Based on graph theory and independent-sample t-test, the differences in functional network topological properties of nodes between the two groups were analyzed. Partial correlation analysis was used to discuss the relationship between the values of these properties and clinical symptoms. Results:Compared with the control group, the OCD group showed decreased global efficiency and increased shortest path length of the left superior temporal gyrus rostral area and right posterior central gyrus trunk region(both P<0.001, FDR corrected); decreased local efficiency( P=0.002, uncorrected) and clustering coefficient( P<0.001, FDR corrected) of the left inferior frontal gyrus dorsal region. Further analysis showed that the score of the global efficiency of the left superior temporal gyrus rostral area was positively correlated with the score of obsessive thoughts sub-scale ( r=0.390, P=0.005). The score of the shortest path length of the left superior temporal gyrus rostral area was negatively correlated with the obsessive thoughts sub-scale ( r=-0.359, P=0.010) in the OCD group. Conclusion:OCD patients have abnormal information integration and separation functions in the frontoparietal network(inferior frontal gyrus, posterior central gyrus) and abnormal information integration functions in the superior temporal gyrus rostral area. Higher global efficiency and shorter the shortest path length of the superior temporal gyrus rostral area suggest more obsessive thoughts in OCD patients.

Objective:To explore the functional changes of brain network node information integration and separation in patients with obsessive-compulsive disorder (OCD) and its correlation with clinical symptoms.Methods:Fifty-six patients with obsessive-compulsive disorder (OCD group) and fifty-six healthy controls (control group) matched in gender, age and years of education were enrolled. All participants accepted resting-state functional magnetic resonance imaging scans of the whole brain. Yale-Brown Obsessive Compulsive Scale(Y-BOCS) was used to assess patients′ clinical symptoms. Based on graph theory and independent-sample t-test, the differences in functional network topological properties of nodes between the two groups were analyzed. Partial correlation analysis was used to discuss the relationship between the values of these properties and clinical symptoms. Results:Compared with the control group, the OCD group showed decreased global efficiency and increased shortest path length of the left superior temporal gyrus rostral area and right posterior central gyrus trunk region(both P<0.001, FDR corrected); decreased local efficiency( P=0.002, uncorrected) and clustering coefficient( P<0.001, FDR corrected) of the left inferior frontal gyrus dorsal region. Further analysis showed that the score of the global efficiency of the left superior temporal gyrus rostral area was positively correlated with the score of obsessive thoughts sub-scale ( r=0.390, P=0.005). The score of the shortest path length of the left superior temporal gyrus rostral area was negatively correlated with the obsessive thoughts sub-scale ( r=-0.359, P=0.010) in the OCD group. Conclusion:OCD patients have abnormal information integration and separation functions in the frontoparietal network(inferior frontal gyrus, posterior central gyrus) and abnormal information integration functions in the superior temporal gyrus rostral area. Higher global efficiency and shorter the shortest path length of the superior temporal gyrus rostral area suggest more obsessive thoughts in OCD patients.