Microstructural white matter abnormalities in overactive bladder syndrome evaluation with diffusion kurtosis imaging tract-based spatial statistics analysis.

PURPOSE: This prospective study aimed to explore the microstructural alterations of the white matter in overactive bladder syndrome (OAB) using the Tract-based Spatial Statistics (TBSS) method of diffusion kurtosis imaging (DKI). METHODS: A total of 30 patients were enrolled and compared with 30 controls. White matter (WM) status was assessed using tract-based spatial statistics for DKI. The differences in DKI-derived parameters, including kurtosis fractional anisotropy (KFA), fractional anisotropy (FA), mean kurtosis (MK), mean diffusivity (MD), radial kurtosis (RK), axial kurtosis (AK), axial diffusivity (AD), and radial diffusivity (RD), were compared between the two groups using the TBSS method. The correlation between the altered DKI-derived parameters and the (OABSS) scores was analyzed. A receiver operating characteristic curve (ROC) was used to evaluate the diagnostic performance of different white matter parameters. RESULTS: As a result, compared with the HC group, the KFA, and FA values decreased significantly in the OAB group. Compared with the HC group, the MK and MD values increased significantly in the OAB group. The KFA values of the genu of corpus callosum (GCC) were significantly correlated with the OABSS scores (r = - 0.509; p = 0.004). The FA values of anterior corona radiata (ACR) were significantly correlated with OABSS scores (r = - 0.447; p = 0.013). The area under the ROC curve (AUC) for the genu of corpus callosum KFA values was higher than FA for the diagnosis of OAB patients. CONCLUSION: DKI is a promising approach to the investigation of the pathophysiology of OAB and a potential biomarker for clinical diagnosis of OAB.

Hub-connected functional connectivity within social brain network weakens the association with real-life social network in schizophrenia patients.

Hubs in the brain network are the regions with high centrality and are crucial in the network communication and information integration. Patients with schizophrenia (SCZ) exhibit wide range of abnormality in the hub regions and their connected functional connectivity (FC) at the whole-brain network level. Study of the hubs in the brain networks supporting complex social behavior (social brain network, SBN) would contribute to understand the social dysfunction in patients with SCZ. Forty-nine patients with SCZ and 27 healthy controls (HC) were recruited to undertake the resting-state magnetic resonance imaging scanning and completed a social network (SN) questionnaire. The resting-state SBN was constructed based on the automatic analysis results from the NeuroSynth. Our results showed that the left temporal lobe was the only hub of SBN, and its connected FCs strength was higher than the remaining FCs in both two groups. SCZ patients showed the lower association between the hub-connected FCs (compared to the FCs not connected to the hub regions) with the real-life SN characteristics. These results were replicated in another independent sample (30 SCZ and 28 HC). These preliminary findings suggested that the hub-connected FCs of SBN in SCZ patients exhibit the abnormality in predicting real-life SN characteristics.

Intra- and inter-resting-state networks abnormalities in overactive bladder syndrome patients: an independent component analysis of resting-state fMRI.

PURPOSE: This study aims to determine whether intra-network and inter-network brain connectivities are altered using an independent component analysis (ICA). METHODS: Resting-state functional MRI (rs-fMRI) data were acquired from 26 patients with OAB and 28 healthy controls (HC). Eleven resting-state networks (RSNs) were identified via ICA. General linear model (GLM) was used to compare intra-network FC and inter-network FC of RSNs between the two groups. Pearson correlation analyses were performed to investigate the relationship between the identified RSNs and clinical variables. RESULTS: Compared with HC, the OAB group showed abnormal FC within the sensorimotor-related network (SMN), the dorsal attention network (DAN), the dorsal visual network (dVN), and the left frontoparietal network (LFPN). With respect to inter-network interactions, decreased FC was detected between the SMN and the anterior default mode network (aDMN). CONCLUSION: This study demonstrated that abnormal FC between RSNs may reflect the altered resting state of the brain-bladder network. The findings of this study provide complementary evidence that can help further understand the neural substrates of the overactive bladder.

Mild encephalitis/encephalopathy with reversible splenial lesion (MERS) in adults-a case report and literature review.

BACKGROUND: Mild encephalitis/encephalopathy with reversible splenial lesion (MERS) is a rare clinico-radiological entity characterized by the magnetic resonance imaging (MRI) finding of a reversible lesion in the corpus callosum, sometimes involved the symmetrical white matters. Many cases of child-onset MERS with various causes have been reported. However, adult-onset MERS is relatively rare. The clinical characteristics and pathophysiologiccal mechanisms of adult-onset MERS are not well understood. We reviewed the literature on adult-onset MERS in order to describe the characteristics of MERS in adults and to provide experiences for clinician. METHODS: We reported a case of adult-onset MERS with acute urinary retension and performed literature search from PubMed and web of science databases to identify other adult-onset MERS reports from Januarary 2004 to March 2016. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was followed on selection process. And then we summarized the clinico-radiological features of adult-onset MERS. RESULTS: Twenty-nine adult-onset MERS cases were reviewed from available literature including the case we have. 86.2% of the cases (25/29) were reported in Asia, especially in Japan. Ages varied between 18 and 59 years old with a 12:17 female-to-male ratio. The major cause was infection by virus or bacteria. Fever and headache were the most common clinical manifestation, and acute urinary retention was observed in 6 patients. All patients recovered completely within a month. CONCLUSION: Adult-onset MERS is an entity with a broad clinico-radiological spectrum because of the various diseases and conditions. There are similar characteristics between MERS in adults and children, also some differences.

Effect of smoking on resting-state functional connectivity in smokers: An fMRI study.

BACKGROUND AND OBJECTIVE: Smoking is a leading cause of death in the world. Aberrant brain function has been repeatedly linked to tobacco smoking. However, little is known about insula-based resting-state functional connectivity (rsFC) in non-deprived tobacco-dependent smokers. This study characterized the correlation between insula-based rsFC and tobacco dependence severity in non-deprived smokers. METHODS: A total of 37 male smokers and 37 age-matched male non-smokers completed resting-state functional MRI (fMRI) scans. The insula-based rsFC differences between smokers and controls were investigated and the correlation between insula-based rsFC and FTND (Fagerström Test for Nicotine Dependence) scores were then assessed. RESULTS: Compared with controls, smokers showed significantly lower rsFC between orbitofrontal cortex, superior frontal gyrus, temporal lobe and insula. The rsFC between orbitofrontal cortex, temporal lobe, inferior parietal cortex, occipital lobe and insula was positively correlated with FTND. However, the rsFC between anterior cingulate cortex and insula was negatively correlated with FTND. CONCLUSION: Our findings suggest differences in brain functional connectivity between smokers and non-smokers. This study sheds new insights into the neural mechanisms of tobacco dependence.

Altered intra- and interregional synchronization in the absence of the corpus callosum: a resting-state fMRI study.

Agenesis of the corpus callosum (AgCC) can result in subtle to severe cognitive deficits. Individuals with impaired cognition often show abnormalities on resting-state functional magnetic resonance imaging (rs-fMRI). This study used rs-fMRI to investigate changes in regional homogeneity (ReHo) and functional connectivity (FC) among individuals with AgCC. AgCC individuals (n = 10) and age-, sex-, and education-matched healthy control subjects (n = 19) were included in this study. The ReHo values were calculated to represent spontaneous brain activity. The regions which showed altered ReHo were selected as seeds to compare FC with the whole brain between the AgCC group and the healthy control group. Compared with healthy control subjects, the AgCC individuals had increased ReHo in the left anterior cingulate gyrus, left rolandic operculum, and right precuneus and decreased ReHo in the right calcarine, right cingual gyrus and right cuneus gyrus. The right calcarine and the right lingual gyrus in the AgCC exhibited decreased FC with bilateral cuneus, superior occipital gyrus, Rolandic operculum, superior temporal gyrus, posterior central gyrus, and midcingulate gyrus.The right cuneus gyrus in the AgCC individuals exhibited decreased FC with the bilateral calcarine gyrus, left cuneus, and left superior occipital gyrus. Our study revealed several subareas within the visual cortex exhibited remarkable abnormalities of spontaneous brain activity and decreased FC with the higher-order cognitive cortex.The abnormalities of ReHo and FC in AgCC individuals may provide new insights into the neurological pathophysiology.

Disconnections of Cortico-Subcortical Pathways Related to Cognitive Impairment in Patients with Leukoaraiosis: A Preliminary Diffusion Tensor Imaging Study.

BACKGROUND: We aimed to explore the relation between the microstructural integrity of white matter using the technique of diffusion tensor imaging (DTI) and changes of cognition in leukoaraiosis (LA). METHODS: Fifty patients with LA and 50 age- and gender-matched controls were recruited consecutively. The average values of mean diffusivity (MD) and fractional anisotropy (FA) were quantified both within white matter lesions (WMLs) and normal-appearing white matter (NAWM) from the regions of interest (ROIs). RESULTS: We found significantly decreased FA and increased MD in WMLs at the 5 ROIs than that in NAWM and controls (p < 0.05). The values of FA in NAWM were significantly lower at centrum semiovale and posterior periventricular white matter than those of controls (p < 0.05). The values of MD in NAWM were significantly higher at the anterior periventricular white matter and corpus callosum than those of controls (p < 0.05). The values of FA in NAWM located at anterior periventricular white matter correlated inversely with the Z scores of executive function (r = -0.420, p = 0.028). CONCLUSIONS: DTI may provide some important information about the cognitive dysfunction in patients with LA, which may largely attribute to the "disconnection" of cortico-subcortical pathways, with the evidence of reduced FA and increased MD.

[Association of diffusion tensor imaging abnormalities with executive dysfunction in patients with leukoaraiosis].

OBJECTIVE: To explore abnormal microstructural changes of white matter using diffusion tensor imaging (DTI) in patients with leukoaraiosis (LA), and to determine the association of such abnormalities of DTI parameters with cognitive function, especially executive function. METHODS: A total of 44 patients with LA and 36 healthy controls were recruited from the department of Neurology, Beijing Chaoyang Hospital, Capital Medical University between July 2010 and June 2011. The two groups were matched for age, sex, education, and vascular risk factors. All the subjects underwent the scans of conventional magnetic resonance imaging (MRI), DTI and neuropsychological assessment. The values of mean diffusivity (MD) and fractional anisotropy (FA) were measured within white matter lesions (WML) and normal appearing white matter (NAWM). Three regions of interest (ROIs) were located in the white matter of centrum semiovale, anterior periventricular white matter and posterior periventricular white matter. The relationships between the cognitive function and the abnormalities of DTI parameters were analyzed. RESULTS: (1) Patients with LA performed significantly worse cognitive function, especially in the fields of executive function. The results of our study showed that patients with LA were associated with comprehensive cognitive function deficits, including mini mental state examination (MMSE) (24.4 ± 3.2 vs 28.3 ± 1.2), montreal cognitive assessment (MoCA) (21.2 ± 3.4 vs 25.7 ± 1.7), Stroop B (69.2 ± 13.5 vs 43.3 ± 5.0), Stroop C (141.2 ± 42.6 vs 64. 8 ± 10.0), Stroop (C-B) (72.0 ± 41.9 vs 21.5 ± 9.4), trail making test (TMT)-A (73.4 ± 15.4 vs 31.1 ± 7.1), TMT-B (126.2 ± 17.5 vs 81.4 ± 5.7), digit symbol test (25.2 ± 5 .4 vs 36.7 ± 5.1) (all P<0.05). (2) The values of FA were lower, and MD were higher in WML than NAWM and controls in all the three ROIs (P<0.05). The values of FA in NAWM located in centrum semiovale and posterior periventricular white matter were lower than controls (P<0.05). The values of MD in NAWM located in anterior periventricular white matter were higher than controls (P<0.05). (3) The values of FA of NAWM located in anterior periventricular correlated inversely with the Z scores of executive function (r=-0.311, P=0.04). CONCLUSIONS: Patients with LA are related with significant cognitive impairment, especially in the domains of executive dysfunction. Microstructural integrity of both white matter lesions and NAWM is associated with executive function. The underlying executive dysfunction in LA may attribute to the damage of the prefrontal-subcortical circle.

[Imaging characteristics of basilar artery hypoplasia].

OBJECTIVE: To determine the imaging characteristics of basilar artery hypoplasia (BAH). METHODS: From October 2009 to August 2013, 10 193 magnetic resonance angiogram (MRA) and 31 716 magnetic resonance imaging (MRI) consecutive cases were retrospectively retrieved from our institutional Picture Archiving and Communication System (PACS) database. BAH was defined as a continuous diameter reduction all over artery and a basilar artery diameter ≤ 2 mm. The same cut-off value was applied for vertebral artery hypoplasia (VAH). We measured the diameters of basilar and vertebral arteries with PACS in all patients according to source imaging and IMP construction of MRA. The carotid arterial computed tomography angiogram (CTA) profiles were reviewed in 50 patients. The fetal-type posterior circle of Willis (FTP) was assessed. The diagnosis of acute cerebral infarction was based on clinical symptoms, signs and a high signal on diffusion-weighted imaging (DWI). Acute cerebral infarction was divided into anterior circulation stroke (ACS) and posterior circulation stroke (PCS). RESULTS: A total of 210 BAH were identified among 10 193 consecutive patients. BAH was more common in females (56.7%) than males (43.3%) in the patient group. They had a fetal-type of posterior cerebral artery (FTP) (175 bilateral (83.3%), 35 unilateral (16.7%)). 99.5% patients had V4 VAH and 56.0% (28/50) V1-V3 VAH. Among 210 BAH, there are 74 patients (mean age 64 years, average 25-91 years, 44 males) with a diagnosis of acute cerebral infarction (ACI). The males were predominant in ACI (59.5% in males vs 40.5% in females, P = 0.021). The frequency of BAH was detected in 74 (2.2%) among 3 294 ACI patients. CONCLUSION: As a relatively rare vascular abnormality, BAH has always unilateral or bilateral FTP and V4 VAH.

Flexible Multimodal Magnetoresistive Sensors Based on Alginate/Poly(vinyl alcohol) Foam with Stimulus Discriminability for Soft Electronics Using Machine Learning.

Flexible foam-based sensors have attracted substantial interest due to their high specific surface area, light weight, superior deformability, and ease of manufacture. However, it is still a challenge to integrate multimodal stimuli-responsiveness, high sensitivity, reliable stability, and good biocompatibility into a single foam sensor. To achieve this, a magnetoresistive foam sensor was fabricated by an in situ freezing-polymerization strategy based on the interpenetrating networks of sodium alginate, poly(vinyl alcohol) in conjunction with glycerol, and physical reinforcement of core-shell bidisperse magnetic particles. The assembled sensor exhibited preferable magnetic/strain-sensing capability (GF ≈ 0.41 T-1 for magnetic field, 4.305 for tension, -0.735 for bending, and -1.345 for pressing), quick response time, and reliable durability up to 6000 cycles under external stimuli. Importantly, a machine learning algorithm was developed to identify the encryption information, enabling high recognition accuracies of 99.22% and 99.34%. Moreover, they could be employed as health systems to detect human physiological motion and integrated as smart sensor arrays to perceive external pressure/magnetic field distributions. This work provides a simple and ecofriendly strategy to fabricate biocompatible foam-based multimodal sensors with potential applications in next-generation soft electronics.

BOLD-MRI of breast invasive ductal carcinoma: correlation of R2* value and the expression of HIF-1α.

OBJECTIVE: To explore the reliability and feasibility of blood oxygenation level-dependent-based functional magnetic resonance imaging (BOLD-fMRI) to depict hypoxia in breast invasive ductal carcinoma. METHODS: A total of 103 women with 104 invasive ductal carcinomas (IDCs) underwent breast BOLD-fMRI at 3.0 T. Histological specimens were analysed for tumour size, grade, axillary lymph nodes and expression of oestrogen receptors, progesterone receptors, human epidermal growth factor receptor 2, p53, Ki-67 and hypoxia inducible factor 1α (HIF-1α). The distribution and reliability of R2* were analysed. Correlations of the R2* value with the prognostic factors and HIF-1α were respectively analysed. RESULTS: The R2* map of IDC demonstrated a relatively heterogeneous signal. The mean R2* value was (53.4 ± 18.2) Hz. The Shapiro-Wilk test (W = 0.971, P = 0.020) suggested that the sample did not follow a normal distribution. The inter-rater and intrarater correlation coefficient was 0.967 and 0.959, respectively. The R2* values of IDCs were significantly lower in patients without axillary lymph nodes metastasis. The R2* value had a weak correlation with Ki67 expression (r = 0.208, P = 0.038). The mean R2* value correlated moderately with the level of HIF-1α (r = 0.516, P = 0.000). CONCLUSION: BOLD-fMRI is a simple and non-invasive technique that yields hypoxia information on breast invasive ductal carcinomas.

CT-based radiomics signature for differentiating pyelocaliceal upper urinary tract urothelial carcinoma from infiltrative renal cell carcinoma.

Objectives: To develop a CT-based radiomics model and a combined model for preoperatively discriminating infiltrative renal cell carcinoma (RCC) and pyelocaliceal upper urinary tract urothelial carcinoma (UTUC), which invades the renal parenchyma. Materials and methods: Eighty patients (37 pathologically proven infiltrative RCCs and 43 pathologically proven pyelocaliceal UTUCs) were retrospectively enrolled and randomly divided into a training set (n = 56) and a testing set (n = 24) at a ratio of 7:3. Traditional CT imaging characteristics in the portal venous phase were collected by two radiologists (SPH and ZXL, who have 4 and 30 years of experience in abdominal radiology, respectively). Patient demographics and traditional CT imaging characteristics were used to construct the clinical model. The radiomics score was calculated based on the radiomics features extracted from the portal venous CT images and the random forest (RF) algorithm to construct the radiomics model. The combined model was constructed using the radiomics score and significant clinical factors according to the multivariate logistic regression. The diagnostic efficacy of the models was evaluated using receiver operating characteristic (ROC) curve analysis and the area under the curve (AUC). Results: The RF score based on the eight validated features extracted from the portal venous CT images was used to build the radiomics model. Painless hematuria as an independent risk factor was used to build the clinical model. The combined model was constructed using the RF score and the selected clinical factor. Both the radiomics model and combined model showed higher efficacy in differentiating infiltrative RCC and pyelocaliceal UTUC in the training and testing cohorts with AUC values of 0.95 and 0.90, respectively, for the radiomics model and 0.99 and 0.90, respectively, for the combined model. The decision curves of the combined model as well as the radiomics model indicated an overall net benefit over the clinical model. Both the radiomics model and the combined model achieved a notable reduction in false-positive and false-negativerates, resulting in significantly higher accuracy compared to the visual assessments in both the training and testing cohorts. Conclusion: The radiomics model and combined model had the potential to accurately differentiate infiltrative RCC and pyelocaliceal UTUC, which invades the renal parenchyma, and provide a new potentially non-invasive method to guide surgery strategies.

[Characteristics of cognitive impairment in patients with leukoaraiosis].

OBJECTIVE: To explore the characteristics of cognitive impairment in patients with leukoaraiosis (LA). METHODS: Forty-six LA patients and 38 age and gender-matched healthy subjects were recruited from the Department of Neurology, Beijing Chaoyang Hospital, Capital Medical University between September 2010 and March 2011. All participants underwent the neuropsychological tests recommended by the National Institute of Neurological Disorders and Stroke-Canadian Stroke Network Vascular Cognitive Impairment Harmonization Standards (NINDS/CSN). The were divided into 3 different groups (mild, moderate and severe) according to the Fazekas scale. The differences of neuropsychological performances were compared among 3 groups. RESULTS: The LA patients were associated with comprehensive cognitive function deficits, including MMSE (24.4 ± 3.2 vs 28.3 ± 1.2), MoCA (20.4 ± 3.0 vs 26.2 ± 0.8), digital span forward (5.7 ± 0.9 vs 6.8 ± 1.0), digital span backward (3.5 ± 0.7 vs 4.1 ± 0.7), Stroop-B (69 ± 13 vs 43 ± 5), Stroop-C (141 ± 42 vs 65 ± 10), trail making test-A (73 ± 15 vs 31 ± 7), trail making test-B (126 ± 18 vs 82 ± 6) and digit symbol test (25 ± 6 vs 37 ± 5, P < 0.05). However, there was no difference in the performance of verbal fluency (12.7 ± 2.5 vs 13.4 ± 2.5, P > 0.05). Correlation analysis showed that the severity of LA had a negative correlation with the performance of MoCA (r = -0.601, P = 0.002). CONCLUSIONS: The LA patients are closely correlated with cognitive impairments of attention, memory, executive function and information processing speed. It may be attributed to the frontal-subcortical circuitry dysfunction.

[Correlates of cognitive impairment in patients with leukoaraiosis by magnetic resonance spectroscopy].

OBJECTIVE: To explore the pathological changes in patients with leukoaraiosis (LA) by magnetic resonance spectroscopy (MRS) and examine its relationship with cognitive function. METHODS: Twenty-three LA patients and 23 age and gender-matched healthy subjects were recruited from the Department of Neurology, Beijing Chaoyang Hospital, Capital Medical University between August 2010 and November 2010. All participants underwent the neuropsychological tests. Multi-voxel chemical shift imaging was performed and the regions of interest were positioned in bilateral frontal white matter. The relative metabolite ratios, involving N-acetyl aspartate/choline ratio (NAA/Cho), N-acetyl aspartate/creatine (NAA/Cr) and choline/creatine (Cho/Cr), were estimated. The correlation of the MRS data and the performance of cognitive function was analyzed. RESULTS: The LA patients were associated with a worse performance of mini mental state examination (MMSE) versus the healthy controls (24 ± 3 vs 28 ± 1, P < 0.05). Univariate analysis of the MRS data revealed the ratios of NAA/Cho and NAA/Cr significantly decreased in bilateral frontal white matter lesions in the LA group versus the control group (1.72 ± 0.20 vs 1.96 ± 0.36, 1.67 ± 0.17 vs 1.85 ± 0.21, P < 0.05). The values of NAA/Cr and NAA/Cho in normal appearing white matter increased versus the LA group (1.83 ± 0.24 vs 1.72 ± 0.20, 1.78 ± 0.28 vs 1.67 ± 0.17) and decreased versus the control group (1.83 ± 0.24 vs 1.96 ± 0.36, 1.78 ± 0.28 vs 1.85 ± 0.21). But no significant differences were found (P > 0.05). The ratio of Cho/Cr did not differ among 3 groups (P > 0.05). The pathological change of NAA/Cr in white matter lesion in LA patients was markedly correlated with the performance of MMSE (r = 0.47, P < 0.05). CONCLUSION: NAA may be a marker of axonal loss/dysfunction in LA patients. And the changes of NAA/Cr have a positive correlation with cognitive impairment.

Investigation into a Lightweight Polymeric Porous Sponge with High Magnetic Field and Strain Sensitivity.

Recently, flexible sensors have gained significant attention due to their potential applications in soft robotics and biomimetic intelligent devices. However, the successful production of favorable flexible sensors integrated with high flexibility, sensitivity and excellent environment adaptability toward multiple external stimuli is still an enormous challenge. Herein, a lightweight polymeric porous sponge capable of detecting an external magnetic field and strain excitations is proposed by assembling a sodium alginate/chitosan (SA/CHI) porous sponge with micron carbonyl iron and nanoscale Fe3O4 magnetic particles (MPs). Based on the double network structure, the SA/CHI sponge possesses preferable mechanical strength and hydrophilicity, demonstrating its high flexibility and deformability. More importantly, the electrical response of the SA/CHI sponge sensors can display remarkable variation under external magnetic and mechanical stimuli due to their superior magnetic characteristics and electrical conductivity. Meanwhile, their sensing properties can maintain relatively stable recoverability and repeatability towards the periodic excitations and releases. Additionally, a potential mechanism is provided to investigate their stimuli-sensitive behavior. It is highly dependent on the microstructure variations in MPs and conductive multi-walled carbon nanotube (MWCNTs) networks. Due to its exceptional magnetic controllability and appropriate electrical sensitivity, the proposed sensor shows high potential in wearable multi-sensing electronics and intelligent transport devices.

Regional brain atrophy in overactive bladder syndrome: a voxel based morphometry study.

OBJECTIVES: To investigate whether patients with overactive bladder syndrome (OAB) have brain volume changes using voxel-based morphometry (VBM) and correlations with clinical tests. METHODS: With institutional review board approval and after obtaining written informed consent, structural magnetic resonance imaging data were prospectively acquired in 28 patients and 28 control subjects. OAB symptoms were assessed using the OAB symptom score (OABSS) scale. The gray matter volume (GMV) of each voxel was compared between the two groups while controlling for the effects of age, sex, and education level. Correlation analysis was performed to identify correlations between abnormal GMV regions and OABSS scores in patients. Multiple comparisons were corrected using a false discovery rate (FDR) method. RESULTS: Patients with OAB exhibited a GMV reduction in the right cerebellum, bilateral hippocampus, left insula, right superior temporal gyrus, left anterior cingulate gyrus, bilateral caudate nucleus and right middle frontal gyrus. Furthermore, there was a significant negative correlation between the local GMV of the right cerebellar hemisphere and OABSS score. CONCLUSIONS: Patients with OAB have abnormal GMV in brain regions localized within the brain-bladder control network. It deepens our understanding of the structural changes in the brain area of the network. The patterns of structural reorganization in patients with OAB may provide useful information in the neuropathological mechanisms of the OAB.

The structural basis for interhemispheric functional connectivity: Evidence from individuals with agenesis of the corpus callosum.

Agenesis of the corpus callosum (AgCC) is a rare congenital malformation characterized by partial or complete absence of the corpus callosum (CC). The effects of AgCC on cerebral structural and functional networks are not clear. We aimed to utilize AgCC as a model to characterize the relationship between brain structure and function. Diffusion tensor imaging and resting-state fMRI data were collected from nine AgCC and ten healthy subjects. The interhemispheric functional connectivity (FC) was quantified using a voxel-mirrored-homotopic-connectivity (VMHC) method, and its correlation with the number (FN) and fractional anisotropy (FA) of the fibers crossing the CC was calculated. Graph-based network analyses of structural and functional topologic properties were performed. AgCC subjects showed markedly reduced VMHC compared to controls. VMHC was significantly correlated with the FN and FA of the fibers crossing the CC. Structural network analyses revealed impaired global properties, but intact local properties in AgCC compared to controls. Functional network analyses showed no significant difference in network properties between the groups. Finally, in both groups, brain areas with more fiber connections were more likely to build a positive FC with each other, while areas with decreased white matter connections were more likely to result in negative FC. Our observations demonstrate that interhemispheric FC is highly dependent on CC structure. Increased alternative intrahemispheric SC might be a compensatory mechanism in AgCC that helps to maintain normal global brain function. Our study provides insights into the underlying neurological pathophysiology of brain malformations, thereby helping to elucidate the structure-function relationship of normal human brain.

Abnormal Brain Functional Connectivity Strength in the Overactive Bladder Syndrome: A Resting-State fMRI Study.

OBJECTIVE: To investigate the whole-brain functional connectivity strength (FCS) of patients with the overactive bladder syndrome (OAB). METHODS: This study investigates the changes of intrinsic whole brain functional connectivity pattern in OAB using FCS. We acquired resting-state fMRI data from 26 OAB patients and 28 healthy controls. FCS was used to compute the long-range and short-range FCS values for each voxel in the brain of each subject. The long or short-range FCS maps were compared between OAB patients and healthy controls. Pearson's correlation coefficients was also performed between abnormal FCS regions and clinical/psychometric scores in patients. RESULTS: Compared with healthy control subjects, the OAB patients exhibited significantly decreased short-range FCS in the right medial superior frontal gyrus and bilateral anterior cingulate gyrus, and increased short-range FCS in the middle frontal gyrus, the precentral gyrus, and bilateral caudate nucleus. In addition, significantly decreased long-range FCS was found in bilateral middle cingulate gyrus and posterior cingulate gyrus. Furthermore, the abnormal FCS values in the right caudate nucleus showed significantly negative correlation with Self-Rating Depression Scale of OAB patients. CONCLUSION: Patients with OAB have abnormal short-range and long-range FCS in brain regions associated with brain-bladder network. Our study provides new insights into the underlying brain network topology of OAB.

Functional connectivity of the default mode network is associated with prospection in schizophrenia patients and individuals with social anhedonia.

BACKGROUND: Prospection, which is closely related to negative symptoms in patients with schizophrenia, is mainly associated with the Default Mode Network (DMN). Although abnormalities of the DMN have been reported in schizophrenia patients and at-risk individuals, little is known about the relationship between functional connectivity of the DMN and prospection in these clinical and subclinical populations. METHOD: Study 1 recruited 40 schizophrenia patients and 29 healthy controls, while 31 individuals with social anhedonia (SocAhn) and 28 controls participated in Study 2. Participants in both studies were asked to complete a prospection task and underwent resting-state functional MRI scans. Eleven regions of interest (ROIs) in the DMN were defined. Functional connectivity between each ROI and whole brain voxels were calculated and compared between groups (schizophrenia vs. control and SocAhn vs. control). Correlation analysis was conducted between altered functional connectivity and prospection variables in the schizophrenia and SocAhn groups. RESULTS: Schizophrenia patients showed both hyper-connectivity and hypo-connectivity at the medial temporal lobe (MTL) subsystem of the DMN. Decreased connectivity between the ventral medial prefrontal cortex (vMPFC) and the right superior temporal gyrus (rSTG) was correlated with poor thought/emotion details in prospection. In individuals with SocAhn, decreased connectivity between the retrosplenial cortex (Rsp), a region of the MTL subsystem, and the right fusiform gyrus, was found and this was correlated with their prospection performance. CONCLUSION: Altered functional connectivity of the key nodes of the MTL subsystem was found in both patients with schizophrenia and individuals with SocAhn. Moreover, hypo-connectivity of the vMPFC was found to be correlated with prospection impairments in schizophrenia patients.

Neural correlates of prospection impairments in schizophrenia: Evidence from voxel-based morphometry analysis.

Prospection, which has a close relationship with motivation and goal-directed behavior, could be a potential target for alleviating negative symptoms. The present study aimed to examine the structural neural correlates of prospection impairments and the involvement of working memory in prospection in schizophrenia patients. Thirty-seven patients with schizophrenia and 28 healthy controls were recruited and all of them completed a prospection task. Working memory was assessed with the Letter Number Span test. In addition, all participants underwent a structural MRI scan. Voxel-based morphometry (VBM) analysis was used to measure grey matter (GM) volume. We found that in schizophrenia patients, GM loss in the right lateral prefrontal cortex (PFC) and the right ventral medial PFC was correlated with decreased internal details in the prospection task. Moreover, GM volume of the right lateral PFC was found to mediate the relationship between working memory and internal details in these patients. In conclusion, GM loss in the PFC is associated with prospection impairments in schizophrenia patients. Working memory deficits may partially account for prospection impairments in schizophrenia patients.