Voxel-based alterations in spontaneous brain activity among very-late-onset schizophrenia-like psychosis: A preliminary resting-state functional magnetic resonance imaging study

Figure 1 Brain regions with significant differences in amplitude of low-frequency fluctuations, fractional amplitude of low-frequency fluctuations, regional homogeneity, and voxel-mirrored homotopic connectivity between the very-late-onset schizophrenia-like psychosis and healthy controls groups, corrected using Gaussian random field (voxel P < 0. 001, cluster P < 0.01). A: Compared with healthy controls (HCs), the very-late-onset schizophrenia-like psychosis (VLOSLP) group showed decreased amplitude of low-frequency fluctuations (ALFF) values in the left cuneus, right precuneus, right precentral gyrus and left paracentral lobule; B: Compared with HCs, the VLOSLP group showed increased fractional ALFF values in the left caudate nucleus and decreased fractional ALFF values in the right calcarine fissure and surrounding cortex and right precuneus; C: Compared with HCs, the VLOSLP group showed increased regional homogeneity values in the right putamen; D: Compared with HCs, the VLOSLP group showed decreased voxel-mirrored homotopic connectivity values in the bilateral calcarine fissure and surrounding cortex (clusters A, B, C, and D), bilateral superior temporal gyrus, and bilateral cuneus. The colored bars show t values. ALFF: Amplitude of low-frequency fluctuations; fALFF: Fractional amplitude of low-frequency fluctuations; ReHo: Regional homogeneity; VMHC: Voxel-mirrored homotopic connectivity.

Figure 2 Boxplot with scattered points of amplitude of low-frequency fluctuations, fractional amplitude of low-frequency fluctuations, regional homogeneity, and voxel-mirrored homotopic connectivity values in brain regions with significant differences between the very-late-onset schizophrenia-like psychosis and healthy controls groups. A: Compared with healthy controls (HCs), the very-late-onset schizophrenia-like psychosis (VLOSLP) group showed decreased amplitude of low-frequency fluctuations (ALFF) values in the left cuneus, right precuneus, right precentral gyrus and left paracentral lobule; B: Compared with HCs, the VLOSLP group showed increased fractional ALFF values in the left caudate nucleus and decreased fractional ALFF values in the right calcarine fissure and surrounding cortex (CAL) and right precuneus; C: Compared with HCs, the VLOSLP group showed increased regional homogeneity values in the right putamen; D: Compared with HCs, the VLOSLP group showed decreased voxel-mirrored homotopic connectivity values in the bilateral CAL (clusters A, B, C, and D), bilateral superior temporal gyrus, bilateral cuneus. ^aP < 0.01. VL: Very-late-onset schizophrenia-like psychosis; HCs: Healthy controls; ALFF: Amplitude of low-frequency fluctuations; fALFF: Fractional amplitude of low-frequency fluctuations; ReHo: Regional homogeneity; VMHC: Voxel-mirrored homotopic connectivity; CUN.L: Left cuneus; CUN.R: Right cuneus; PCUN.R: Right precuneus; PreCG.R: Right precentral gyrus; PCL.L: Left paracentral lobule; CAU.L: Left caudate nucleus; PUT.R: Right putamen; CAL.R: Right calcarine fissure and surrounding cortex; CAL.L: Left calcarine fissure and surrounding cortex; STG.R: Right superior temporal gyrus; STG.L: Left superior temporal gyrus; A: Cluster A; B: Cluster B; C: Cluster C; D: Cluster D.

Figure 3 Scatter plots show partial correlations between indices of brain function and cognitive function and clinical symptom severity in very-late-onset schizophrenia-like psychosis, with age, sex, education, and head motion as covariates. A: The amplitude of low-frequency fluctuations values in the right precuneus were negatively correlated with the Mini Mental State Examination score; B: The amplitude of low-frequency fluctuations values in the right precuneus were negatively correlated with the Positive and Negative Syndrome Scale positive subscale score; C: The voxel-mirrored homotopic connectivity (VMHC) values in the bilateral calcarine fissure and surrounding cortex (CAL, clusters C and D, which have the same VMHC values) were negatively correlated with the Repeatable Battery for the Assessment of Neuropsychological Status total score; D: The VMHC values in the bilateral CAL (clusters C and D) were negatively correlated with the Repeatable Battery for the Assessment of Neuropsychological Status delayed memory score; E: The VMHC values in the bilateral CAL (clusters C and D) were negatively correlated with the Positive and Negative Syndrome Scale positive subscale score. MMSE: Mini Mental State Examination; ALFF: Amplitude of low-frequency fluctuations; PCUN.R: Right precuneus; PANSS: Positive and Negative Syndrome Scale; RBANS: Repeatable Battery for the Assessment of Neuropsychological Status; VMHC: Voxel-mirrored homotopic connectivity; CAL: Calcarine fissure and surrounding cortex.