Objective:To analyze the patterns of dynamic functional connectivity(dFC) at rest in different obsessive-compulsive disorder(OCD) subtypes based on gray matter volume, and explore the relationship between abnormal gray matter volume and dFC patterns and clinical symptoms in different OCD subtypes.Methods:Clinical data were prospectively collected from a total of 48 patients with OCD from inpatient and outpatient departments of the Fourth Affiliated Hospital of Qiqihar Medical College(20 cases) and Qiqihar Mental Health Center(28 cases) from September 2013 to March 2020. There were 33 males and 15 females, aged 18 to 42(27.1±6.7) years. During the same period, 39 age-matched healthy controls were also recruited, including 31 males and 8 females, aged 18 to 43(28.5±8.6) years. Structural and resting-state functional magnetic resonance imaging scans were performed on 48 OCD patients(OCD group) who met the ICD-10 diagnostic criteria and 39 healthy controls(control group). Using voxel-based morphometry(VBM) and semi-supervised machine learning methods, the patient group was characterized by gray matter volume to perform subtype analysis, and brain regions with abnormal gray matter volume were selected as regions of interest for whole-brain voxel-wise dFC analysis. Correlations between abnormal gray matter volume and dFC and clinical symptoms in OCD patients were analyzed.Results:Based on gray matter volume, OCD patients were computed into two subtypes, of which subtype 1 increased gray matter volume in the right central posterior gyrus(809 voxels; t=4.31; GRF corrected voxel P<0.001, cluster P<0.05 two-tailed), and subtype 2 showed reduced gray matter volume in the left superior temporal gyrus(1 118 voxels; t=-4.37; GRF corrected voxel P<0.001, cluster P<0.05 two-tailed). In subtype 1, the dFC between the right central posterior gyrus and left medial superior frontal gyrus was significantly reduced(187 voxels; t=-4.42; GRF corrected voxel P<0.001, cluster P<0.05 two-tailed); in subtype 2, dFC between the left superior temporal gyrus and left hippocampus, and left central opercular cortex was significantly reduced(272 voxels、99 voxels; t=-4.69, -5.01; GRF corrected voxel P<0.001, cluster P<0.05 two-tailed). In subtype 1, dFC between the right central posterior gyrus and left medial superior frontal gyrus was negatively correlated with illness duration( r=-0.579; P=0.002, uncorrected). In subtype 2, dFC between the left superior temporal gyrus and left hippocampus was positively correlated with illness duration( r=0.578; P=0.003, uncorrected). Conclusions:In the resting state, patients with different subtypes of OCD may have different patterns of dFC abnormalities based on gray matter volume.

Objective:To analyze the patterns of dynamic functional connectivity(dFC) at rest in different obsessive-compulsive disorder(OCD) subtypes based on gray matter volume, and explore the relationship between abnormal gray matter volume and dFC patterns and clinical symptoms in different OCD subtypes.Methods:Clinical data were prospectively collected from a total of 48 patients with OCD from inpatient and outpatient departments of the Fourth Affiliated Hospital of Qiqihar Medical College(20 cases) and Qiqihar Mental Health Center(28 cases) from September 2013 to March 2020. There were 33 males and 15 females, aged 18 to 42(27.1±6.7) years. During the same period, 39 age-matched healthy controls were also recruited, including 31 males and 8 females, aged 18 to 43(28.5±8.6) years. Structural and resting-state functional magnetic resonance imaging scans were performed on 48 OCD patients(OCD group) who met the ICD-10 diagnostic criteria and 39 healthy controls(control group). Using voxel-based morphometry(VBM) and semi-supervised machine learning methods, the patient group was characterized by gray matter volume to perform subtype analysis, and brain regions with abnormal gray matter volume were selected as regions of interest for whole-brain voxel-wise dFC analysis. Correlations between abnormal gray matter volume and dFC and clinical symptoms in OCD patients were analyzed.Results:Based on gray matter volume, OCD patients were computed into two subtypes, of which subtype 1 increased gray matter volume in the right central posterior gyrus(809 voxels; t=4.31; GRF corrected voxel P<0.001, cluster P<0.05 two-tailed), and subtype 2 showed reduced gray matter volume in the left superior temporal gyrus(1 118 voxels; t=-4.37; GRF corrected voxel P<0.001, cluster P<0.05 two-tailed). In subtype 1, the dFC between the right central posterior gyrus and left medial superior frontal gyrus was significantly reduced(187 voxels; t=-4.42; GRF corrected voxel P<0.001, cluster P<0.05 two-tailed); in subtype 2, dFC between the left superior temporal gyrus and left hippocampus, and left central opercular cortex was significantly reduced(272 voxels、99 voxels; t=-4.69, -5.01; GRF corrected voxel P<0.001, cluster P<0.05 two-tailed). In subtype 1, dFC between the right central posterior gyrus and left medial superior frontal gyrus was negatively correlated with illness duration( r=-0.579; P=0.002, uncorrected). In subtype 2, dFC between the left superior temporal gyrus and left hippocampus was positively correlated with illness duration( r=0.578; P=0.003, uncorrected). Conclusions:In the resting state, patients with different subtypes of OCD may have different patterns of dFC abnormalities based on gray matter volume.