Xiaofen Ma

Regional homogeneity changes in patients with primary insomnia.

PurposeThe study aimed to explore the regional spontaneous activity changes in primary insomnia (PI) patients.Materials and methodsBased on the resting-state fMRI datasets acquired from 59 PI patients and 47 healthy controls, a two-sample t-test was performed on individual normalized regional homogeneity (ReHo) maps. Relationships between abnormal ReHo values and the Pittsburgh Sleep Quality Index (PSQI), the self-rating anxiety scale (SAS) and the self-rating depression scale (SDS) were investigated with Pearson correlation analysis.ResultsIn PI patients, we found increased ReHo in the left insula, right anterior cingulate gyrus, bilateral precentral gyrus and left cuneus, as well as decreased ReHo in the right middle cingulate cortex and left fusiform (p < 0.05, AlphaSim-corrected). We also found a significant positive correlation between increased ReHo in the left insula and SAS scores, decreased ReHo in the right middle cingulated cortex and SDS, SAS scores as well as a negative correlation between increased ReHo in the right precentral gyrus and SDS scores (p < 0.05).ConclusionsOur study found abnormal spontaneous activities in multiple brain regions, especially in emotion-related areas in PI patients. Alterative activities in these regions might contribute to an understanding the intrinsic functional architecture of insomnia and its clinical features.Key Points• Regional spontaneous activity changes were detected in PI patients.• Decreased or increased ReHo of some regions was identified in PI patients.• Significant correlations between mean ReHo and SDS scores were found.

Abnormal cortical thickness in heroin-dependent individuals

Accumulating evidence from brain structural imaging studies on heroin dependence has supported links between brain morphological alterations and heroin exposure, particularly in gray matter volume or gray matter density. However, the effects of heroin exposure on cortical thickness and the relationship between cortical thickness and heroin addiction are not yet known. In this study, we acquired 3D high-resolution brain structural magnetic resonance imaging (MRI) data from 18 heroin-dependent individuals (HDIs) and 15 healthy controls (HCs). Using FreeSurfer, we detected abnormalities in cortical thickness in the HDIs. Based on a vertex-wise analysis, the HDIs showed significantly decreased cortical thickness in the bilateral superior frontal, left caudal middle frontal, right superior temporal, and right insular regions compared to the HCs but significantly increased cortical thickness in the left superior parietal, bilateral lingual, left temporal pole, right inferior parietal, right lateral occipital, and right cuneus regions. To supplement these results, a subsequent ROI-wise analysis was performed and showed decreased cortical thickness in the left superior frontal sulcus, left precuneus gyrus, left calcarine sulcus, left anterior transverse collateral sulcus, and the right medial occipital-temporal and lingual sulcus. These regions partially overlapped with the areas identified using the vertex-wise analysis. In addition, we found that the thickness in the right superior frontal and right insular regions was negatively correlated with the duration of heroin use. These results provide compelling evidence for cortical abnormality in HDIs and also suggest that the duration of heroin use may be a critical factor associated with the brain alteration.

Disrupted topological organization in whole-brain functional networks of heroin-dependent individuals: a resting-state FMRI study.

Neuroimaging studies have shown that heroin addiction is related to abnormalities in widespread local regions and in the functional connectivity of the brain. However, little is known about whether heroin addiction changes the topological organization of whole-brain functional networks. Seventeen heroin-dependent individuals (HDIs) and 15 age-, gender-matched normal controls (NCs) were enrolled, and the resting-state functional magnetic resonance images (RS-fMRI) were acquired from these subjects. We constructed the brain functional networks of HDIs and NCs, and compared the between-group differences in network topological properties using graph theory method. We found that the HDIs showed decreases in the normalized clustering coefficient and in small-worldness compared to the NCs. Furthermore, the HDIs exhibited significantly decreased nodal centralities primarily in regions of cognitive control network, including the bilateral middle cingulate gyrus, left middle frontal gyrus, and right precuneus, but significantly increased nodal centralities primarily in the left hippocampus. The between-group differences in nodal centralities were not corrected by multiple comparisons suggesting these should be considered as an exploratory analysis. Moreover, nodal centralities in the left hippocampus were positively correlated with the duration of heroin addiction. Overall, our results indicated that disruptions occur in the whole-brain functional networks of HDIs, findings which may be helpful in further understanding the mechanisms underlying heroin addiction.

Altered brain spontaneous activity and connectivity network in irritable bowel syndrome patients: A resting-state fMRI study.

OBJECTIVE We aimed to provide additional evidence that brain functional alterations induced by IBS are not limited to local changes but also express at a level of functional integration within related brain regions involved in processing of visceral afferent information and somatic pain. METHODS With fMRI data acquired from 21 IBS and healthy control (HC) subjects. We investigated the amplitude of low-frequency fluctuation (ALFF) and region of interest (ROI)-based functional connectivity (FC) to reveal the changes of the brain spontaneous activity and the interaction among different related regions. RESULTS IBS patients showed decreased ALFF values in the left superior frontal gyrus, right hippocampus, right middle frontal gyrus, bilateral postcentral, and right superior temporal pole, while increased ALFF values in the left median cingulate and left calcarine. There was significant correlation between ALFF values in the altered regions and duration of disease in IBS. FC analysis revealed the increased connectivity between cingulate and frontal cortex in IBS. CONCLUSIONS Our findings could provide both regional and brain connectivity spontaneous neuronal activity properties in IBS. SIGNIFICANCE Our study may lead to a better understanding of intrinsic functional architecture of brain activity in IBS and highlight the potential for using the ALFF and FC metrics as a disease biomarker.

Aberrant Default-Mode Functional and Structural Connectivity in Heroin-Dependent Individuals

Background Little is known about connectivity within the default mode network (DMN) in heroin-dependent individuals (HDIs). In the current study, diffusion-tensor imaging (DTI) and resting-state functional MRI (rs-fMRI) were combined to investigate both structural and functional connectivity within the DMN in HDIs. Methods Fourteen HDIs and 14 controls participated in the study. Structural (path length, tracts count, (fractional anisotropy) FA and (mean diffusivity) MD derived from DTI tractography)and functional (temporal correlation coefficient derived from rs-fMRI) DMN connectivity changes were examined in HDIs. Pearson correlation analysis was performed to compare the structural/functional indices and duration of heroin use/Iowa gambling task(IGT) performance in HDIs. Results HDIs had lower FA and higher MD in the tract connecting the posterior cingulate cortex/precuneus (PCC/PCUN) to right parahippocampal gyrus (PHG), compared to the controls. HDIs also had decreased FA and track count in the tract connecting the PCC/PCUN and medial prefrontal cortex (MPFC), as well as decreased functional connectivity between the PCC/PCUN and bilateral PHG and MPFC, compared to controls. FA values for the tract connecting PCC/PCUN to the right PHG and connecting PCC/PCUN to the MPFC were negatively correlated to the duration of heroin use. The temporal correlation coefficients between the PCC/PCUN and the MPFC, and the FA values for the tract connecting the PCC/PCUN to the MPFC were positively correlated to IGT performance in HDIs. Conclusions Structural and functional connectivity within the DMN are both disturbed in HDIs. This disturbance progresses as duration of heroin use increases and is related to deficits in decision making in HDIs.

Abnormal spontaneous regional brain activity in primary insomnia: a resting-state functional magnetic resonance imaging study

Objective Investigating functional specialization is crucial for a complete understanding of the neural mechanisms of primary insomnia (PI). Resting-state functional magnetic resonance imaging (fMRI) is a useful tool to explore the functional specialization of PI. However, only a few studies have focused on the functional specialization of PI using resting-state fMRI and results of these studies were far from consistent. Thus, the current study aimed to investigate functional specialization of PI using resting-state fMRI with amplitude of low frequency fluctuations (ALFFs) algorithm. Methods In this study, 55 PI patients and 44 healthy controls were included. ALFF values were compared between the two groups using two-sample t-test. The relationship of abnormal ALFF values with clinical characteristics and duration of insomnia was investigated using Pearson’s correlation analysis. Results PI patients showed lower ALFF values in the left orbitofrontal cortex/inferior frontal gyrus, right middle frontal gyrus, left inferior parietal lobule, and bilateral cerebellum posterior lobes, while higher ALFF values in the right middle/inferior temporal that extended to the right occipital lobe. In addition, we found that the duration of PI negatively correlated with ALFF values in the left orbitofrontal cortex/inferior frontal gyrus, and the Pittsburgh Sleep Quality Index score negatively correlated with ALFF values in the left inferior parietal lobule. Conclusion The present study added information to limited studies on functional specialization and provided evidence for hyperarousal hypothesis in PI.

Abnormal degree centrality in neurologically asymptomatic patients with end-stage renal disease: A resting-state fMRI study

OBJECTIVE End-stage renal disease (ESRD), characterized by multi-organ dysfunction, has been shown to co-occur with abnormal brain function. Previous resting-state fMRI studies suggested that regional brain spontaneous activity and functional connectivity within the default mode network are abnormal in ESRD patients. The current study aimed to depict intrinsic dysconnectivity pattern of whole-brain functional networks in voxel level in neurologically asymptomatic patients with ESRD. METHODS fMRI datasets were acquired from 22 ESRD patients (without clinical neurological disease) and 29 healthy control (HC) subjects. We investigated the degree centrality for a given element in a network to reveal the changes of functional connectivity throughout the huge human functional network. In the brain regions showing a difference between the HC and ESRD groups, we further conducted receptive operation characteristic (ROC) analyses to confirm the accuracy, sensitivity and specificity of our results. RESULTS ESRD patients showed decreased functional connectivity in the left inferior parietal and left precuneus within the brain network; both regions are important components of the default-mode network (DMN). In contrast, patients showed increased connectivity in depression-related regions including bilateral inferior frontal gyrus and right superior temporal gyrus. These regions showed an acceptable accuracy (0.68-0.75), sensitivity (0.64-0.70) and high specificity (0.82-0.96) in distinguishing between the two groups. CONCLUSIONS Our findings reveal abnormal intrinsic dysconnectivity pattern of whole-brain functional networks in ESRD patients. SIGNIFICANCE Our results could lead to a better understanding of the intrinsic dysconnectivity patterns of default-mode network-related regions in ESRD patients from the whole brain network perspective.

Abnormal white matter structural networks characterize heroin-dependent individuals: a network analysis

Neuroimaging studies suggested that drug addiction is linked to abnormal brain functional connectivity. However, little is known about the alteration of brain white matter (WM) connectivity in addictive drug users and nearly no study has been performed to examine the alterations of brain WM connectivity in heroin‐dependent individuals (HDIs). Diffusion tensor imaging (DTI) offers a comprehensive technique to map the whole brain WM connectivity in vivo. In this study, we acquired DTI datasets from 20 HDIs and 18 healthy controls and constructed their brain WM structural networks using a deterministic fibre tracking approach. Using graph theoretical analysis, we explored the global and nodal topological parameters of brain network for both groups and adopted a network‐based statistic (NBS) approach to assess between‐group differences in inter‐regional WM connections. Statistical analysis indicated the global efficiency and network strength were significantly increased, but the characteristic path length was significantly decreased in the HDIs compared with the controls. We also found that in the HDIs, the nodal efficiency was significantly increased in the left prefrontal cortex, bilateral orbital frontal cortices and left anterior cingulate gyrus. Moreover, the NBS analysis revealed that in the HDIs, the significant increased connections were located in the paralimbic, orbitofrontal, prefrontal and temporal regions. Our results may reflect the disruption of whole brain WM structural networks in the HDIs. Our findings suggest that mapping brain WM structural network may be helpful for better understanding the neuromechanism of heroin addiction.

Intrinsic brain network abnormalities in codeine-containing cough syrup-dependent male individuals revealed in resting-state fMRI

To identify codeine‐containing cough syrups (CCS)‐related modulations of intrinsic connectivity network (ICN) and to investigate whether these changes of ICN can be related to duration of CCS use and to impulsivity behavior in CCS‐dependent individuals.

Increased insular connectivity with emotional regions in primary insomnia patients: a resting-state fMRI study

ObjectiveTo explore the abnormal connectivity patterns between the insular and the voxels of the brain in primary insomnia (PI) with insular-based functional connectivity (FC).MethodsWith the resting-state fMRI data acquired from 57 PI patients and 46 healthy controls, a two-sample t test was performed on individual FC correlation maps from two groups. The person correlation analysis was used to evaluate the relationship between the abnormal FC and clinical features.ResultsPI patients show enhanced connectivity between the left insula with the right anterior cingulate cortex (p < 0.05 and p < 0.001, AlphaSim-corrected), right frontal sup orb, bilateral thalamus and left precuneus,as well as decreased connectivity with the left middle temporal gyrus and right fusiform (p < 0.05, AlphaSim-corrected). Correlation analysis indicated the enhanced connectivities in the PI patients have significant negative correlations with Self-Rating Depression Scale(SDS)and Self-Rating Anxiety Scale(SAS)scores. In addition, the decreased functional connectivities showed positive correlations with SDS and SAS scores.ConclusionOur study showed the increased connectivity regions with insula were mainly in the emotional circle and decreased connectivity was in cognitive-related regions. These provide additional evidence from functional integration view to understand the possible underlying neural- mechanisms of PI.Key Points• The aberrant insular-based connectivity pattern of PI patients was detected.• Regions showing increased connectivity with left insular were mainly in emotional circle.• Significant correlations between changed FC and SDS and SAS score were found.