Rare cavitary lymphoepithelioma-like carcinoma of lung: clinical experience and literature review.

BACKGROUND: Lymphoepithelioma-like carcinoma of the lung is a rare primary malignancy of the lung, accounting for only 0.9% of primary malignancies of the lung. Those associated with cavities are even rarer, with fewer than five cases reported in the English literature. Concurrently, the imaging findings of tumors are usually non-specific, resulting in insufficient understanding of the disease by clinicians, thus leading to misdiagnosis and delayed treatment. CASE PRESENTATION: A 42-year-old female presented with a right lower lung mass with cavities. First identified on chest computed tomography (CT) in 2021, the mass persisted for 1 year and subsequently enlarged on chemotherapy and routine follow-up CT. Right lower lobectomy was then performed. Postoperative pathology confirmed primary pulmonary lymphoepithelioma-like carcinoma. After 10 months of follow-up, the patient was still alive and no recurrence was observed. CONCLUSIONS: This article aims to describe a rare case of cavitary lymphoepithelioma-like carcinoma of the lung and review it clinical and imaging characteristics reported in previous cases, which will be helpful for clinicians and imaging physicians in diagnosing this disease.

An extremely rare case of a gastric accessory spleen: case report and review of the literature.

BACKGROUND: The accessory spleen has no anatomical or vascular relationship with the normal spleen, The tissue structure and physiological function of the accessory spleen are the same as those of the normal spleen, which usually locate in the splenic hilum and the tail of the pancreas. The aims of this manuscript are to present a rare case of the gastric accessory spleen and a review of the literature. CASE PRESENTATION: A 19-year-old male patient was sent to the emergency department with stomach bleeding after drinking alcohol. The computed tomographic scan showed a 1.2 cm × 1.7 cm mass at the lesser curvature of the gastric fundus. Gastrointestinal endoscopy displayed a submucosal elevated lesion on the gastric fundus, and gastrectomy was performed. Postoperative pathological examination proved an accessory spleen in the stomach. The postoperative course was uneventful, and the patient was discharged on the 6th day after the surgery. CONCLUSIONS: The accessory spleen at the fundus of stomach is extremely rare, especially in this case, which is accompanied by acute gastric bleeding, and it is difficult to diagnosis before operation. Many literatures reported that it was misdiagnosis as tumor, so it is necessary to diagnose accessory spleen correctly.

[Chemical Exchange Saturation Transfer Imaging of Creatine Metabolites: a 3.0 T MRI Pilot].

OBJECTIVE: To determine the feasibility of using chemical exchange saturation transfer (CEST) imaging to measure creatine (Cr) metabolites with 3.0 T MR. METHODS: Phantoms containing different concentrations of Cr under various pH conditions were studied with CEST sequence on 3.0 T MR imaging. CEST effect and Z spectra were analyzed. RESULTS: Cr exhibited significant CEST effect (± 1.8 ppm, F = 99.08, P < 0.001) on 3.0 T MR imaging, and positive correlation was found between the signal intensity and concentration of Cr (r = 0.963, P < 0.001). The CEST effect showed pH dependency of Cr (r = 0.41, P = 0.035). CONCLUSION: Creatine CEST imaging can be performed on 3.0 T MR imaging. Creatine concentrations and pH influence CEST effect.

Resting-state functional MRI study of conventional MRI-negative intractable epilepsy in children.

Objective: The study aimed at investigating functional connectivity strength (FCS) changes in children with MRI-negative intractable epilepsy (ITE) and evaluating correlations between aberrant FCS and both disease duration and intelligence quotient (IQ). Methods: Fifteen children with ITE, 24 children with non-intractable epilepsy (nITE) and 25 matched healthy controls (HCs) were subjected to rs-fMRI. IQ was evaluated by neuropsychological assessment. Voxelwise analysis of covariance was conducted in the whole brain, and then pairwise comparisons were made across three groups using Bonferroni corrections. Results: FCS was significantly different among three groups. Relative to HCs, ITE patients exhibited decreased FCS in right temporal pole of the superior temporal gyrus, middle temporal gyrus, bilateral precuneus, etc and increased FCS values in left triangular part of the inferior frontal gyrus, parahippocampal gyrus, supplementary motor area, caudate and right calcarine fissure and surrounding cortex and midbrain. The nITE patients presented decreased FCS in right orbital superior frontal gyrus, precuneus etc and increased FCS in bilateral fusiform gyri, parahippocampal gyri, etc. In comparison to nITE patients, the ITE patients presented decreased FCS in right medial superior frontal gyrus and left inferior temporal gyrus and increased FCS in right middle temporal gyrus, inferior temporal gyrus and calcarine fissure and surrounding cortex. Correlation analysis indicated that FCS in left caudate demonstrated correlation with verbal IQ (VIQ) and disease duration. Conclusion: ITE patients demonstrated changed FCS values in the temporal and prefrontal cortices relative to nITE patients, which may be related to drug resistance in epilepsy. FCS in the left caudate nucleus associated with VIQ, suggesting the caudate may become a key target for improving cognitive impairment and seizures in children with ITE.

Altered White-Matter Functional Network in Children with Idiopathic Generalized Epilepsy.

RATIONALE AND OBJECTIVES: The white matter (WM) functional network changes offers insights into the potential pathological mechanisms of certain diseases, the alterations of WM functional network in idiopathic generalized epilepsy (IGE) remain unclear. We aimed to explore the topological characteristics changes of WM functional network in childhood IGE using resting-state functional Magnetic resonance imaging (MRI) and T1-weighted images. METHODS: A total of 84 children (42 IGE and 42 matched healthy controls) were included in this study. Functional and structural MRI data were acquired to construct a WM functional network. Group differences in the global and regional topological characteristics were assessed by graph theory and the correlations with clinical and neuropsychological scores were analyzed. A support vector machine algorithm model was employed to classify individuals with IGE using WM functional connectivity as features, and the model's accuracy was evaluated using leave-one-out cross-validation. RESULTS: In IGE group, at the network level, the WM functional network exhibited increased assortativity; at the nodal level, 17 nodes presented nodal disturbances in WM functional network, and nodal disturbances of 11 nodes were correlated with cognitive performance scores, disease duration and age of onset. The classification model achieved the 72.6% accuracy, 0.746 area under the curve, 69.1% sensitivity, 76.2% specificity. CONCLUSION: Our study demonstrated that the WM functional network topological properties changes in childhood IGE, which were associated with cognitive function, and WM functional network may help clinical classification for childhood IGE. These findings provide novel information for understanding the pathogenesis of IGE and suggest that the WM function network might be qualified as potential biomarkers.

Systematically altered connectome gradient in benign childhood epilepsy with centrotemporal spikes: Potential effect on cognitive function.

OBJECTIVE: Benign childhood epilepsy with centrotemporal spikes (BECTS) affects brain network hierarchy and cognitive function; however, itremainsunclearhowhierarchical changeaffectscognition in patients with BECTS. A major aim of this study was to examine changes in the macro-network function hierarchy in BECTS and its potential contribution to cognitive function. METHODS: Overall, the study included 50 children with BECTS and 69 healthy controls. Connectome gradient analysis was used to determine the brain network hierarchy of each group. By comparing gradient scores at each voxel level and network between groups, we assessed changes in whole-brain voxel-level and network hierarchy. Functional connectivity was used to detect the functional reorganization of epilepsy caused by these abnormal brain regions based on these aberrant gradients. Lastly, we explored the relationships between the change gradient and functional connectivity values and clinical variables and further predicted the cognitive function associated with BECTS gradient changes. RESULTS: In children with BECTS, the gradient was extended at different network and voxel levels. The gradient scores frontoparietal network was increased in the principal gradient of patients with BECTS. The left precentral gyrus (PCG) and right angular gyrus gradient scores were significantly increased in the principal gradient of children with BECTS. Moreover, in regions of the brain with abnormal principal gradients, functional connectivity was disrupted. The left PCG gradient score of children with BECTS was correlated with the verbal intelligence quotient (VIQ), and the disruption of functional connectivity in brain regions with abnormal principal gradients was closely related to cognitive function. VIQ was significantly predicted by the principal gradient map of patients. SIGNIFICANCE: The results indicate connectome gradient disruption in children with BECTS and its relationship to cognitive function, thereby increasing our understanding of the functional connectome hierarchy and providing potential biomarkers for cognitive function of children with BECTS.

Impact of the Alberta Stroke Program CT Score subregions on long-term functional outcomes in acute ischemic stroke: Results from two multicenter studies in China.

Background and Objectives: The Alberta Stroke Program CT Score (ASPECTS) is a widely used rating system for assessing infarct extent and location. We aimed to investigate the prognostic value of ASPECTS subregions' involvement in the long-term functional outcomes of acute ischemic stroke (AIS). Materials and Methods: Consecutive patients with AIS and anterior circulation large-vessel stenosis and occlusion between January 2019 and December 2020 were included. The ASPECTS score and subregion involvement for each patient was assessed using posttreatment magnetic resonance diffusion-weighted imaging. Univariate and multivariable regression analyses were conducted to identify subregions related to 3-month poor functional outcome (modified Rankin Scale scores, 3-6) in the reperfusion and medical therapy cohorts, respectively. In addition, prognostic efficiency between the region-based ASPECTS and ASPECTS score methods were compared using receiver operating characteristic curves and DeLong's test. Results: A total of 365 patients (median age, 64 years; 70% men) were included, of whom 169 had poor outcomes. In the reperfusion therapy cohort, multivariable regression analyses revealed that the involvement of the left M4 cortical region in left-hemisphere stroke (adjusted odds ratio [aOR] 5.39, 95% confidence interval [CI] 1.53-19.02) and the involvement of the right M3 cortical region in right-hemisphere stroke (aOR 4.21, 95% CI 1.05-16.78) were independently associated with poor functional outcomes. In the medical therapy cohort, left-hemisphere stroke with left M5 cortical region (aOR 2.87, 95% CI 1.08-7.59) and caudate nucleus (aOR 3.14, 95% CI 1.00-9.85) involved and right-hemisphere stroke with right M3 cortical region (aOR 4.15, 95% CI 1.29-8.18) and internal capsule (aOR 3.94, 95% CI 1.22-12.78) affected were related to the increased risks of poststroke disability. In addition, region-based ASPECTS significantly improved the prognostic efficiency compared with the conventional ASPECTS score method. Conclusion: The involvement of specific ASPECTS subregions depending on the affected hemisphere was associated with worse functional outcomes 3 months after stroke, and the critical subregion distribution varied by clinical management. Therefore, region-based ASPECTS could provide additional value in guiding individual decision making and neurological recovery in patients with AIS.

Changed cortical thickness and sulcal depth in pediatric acute lymphoblastic leukemia survivors treated with chemotherapy only.

The purpose of this study is to observe the changes of cortical morphological characteristics and their potential contribution to cognitive function in ALL survivors by using surface-based morphometry (SBM). Using SBM analysis, we calculated and compared group differences in cortical thickness, sulcal depth, gyrification, and fractal dimension of the cerebral cortex between 18 pediatric ALL survivors treated on chemotherapy-only protocols and off treatment within 2 years, and 18 healthy controls (HCs) with two-sample t-tests [P < 0.05, family-wise error (FWE) corrected]. Relationships between abnormal cortical characteristic values and cognitive function parameters were investigated with partial correlation analysis, taking age as a covariate. We found decreased cortical thickness mainly located in the prefrontal and temporal region, and increased sulcal depth in left rostral middle frontal cortex and left pars orbitalis in the ALL survivors compared to HCs. There were no statistically significant differences in the gyrification and fractal dimension between the two groups. In ALL survivors, cortical thickness and sulcal depth of above areas values revealed no significant correlation with the cognitive function parameters. In conclusion, pediatric ALL survivors show decreased cortical thickness in prefrontal and temporal regions, and increased sulcal depth in prefrontal region. These results suggest that SBM-based approach can be used to assess changes of cortical morphological characteristics in pediatric ALL survivors.

Undifferentiated carcinoma with osteoclast­like giant cells of the pancreas: A case report.

Undifferentiated carcinoma with osteoclast-like giant cells of the pancreas (UCOGCP) is a rare pancreatic tumor that accounts for <1% of all primary pancreatic malignant tumors. Although the tumor is considered a variant of pancreatic ductal adenocarcinoma, there are substantial differences in the clinicopathological characteristics between UCOGCP and pancreatic ductal adenocarcinoma. Imaging examinations are useful in making a correct diagnosis, and providing a reasonable and effective surgical treatment regimen; however, the imaging characteristics of UCOGCP require further investigation. The present report describes a rare case of UCOGCP with rapid progression and poor prognosis. The patient could not undergo surgery and received chemotherapy drugs only. Chemotherapy did not markedly improve the outcome, and a follow-up 6 months after discharge showed that the patient had died. The present report describes this case and summarizes the available imaging findings to increase awareness, and to improve early diagnosis of this rare disease and therapeutic outcomes.

Altered neurovascular coupling in children with idiopathic generalized epilepsy.

AIMS: Alterations in neuronal activity and cerebral hemodynamics have been reported in idiopathic generalized epilepsy (IGE) patients, possibly resulting in neurovascular decoupling; however, no neuroimaging evidence confirmed this disruption. This study aimed to investigate the possible presence of neurovascular decoupling and its clinical implications in childhood IGE using resting-state fMRI and arterial spin labeling imaging. METHODS: IGE patients and healthy participants underwent resting-state fMRI and arterial spin labeling imaging to calculate degree centrality (DC) and cerebral blood flow (CBF), respectively. Across-voxel CBF-DC correlations were analyzed to evaluate the neurovascular coupling within the whole gray matter, and the regional coupling of brain region was assessed with the CBF/DC ratio. RESULTS: The study included 26 children with IGE and 35 sex- and age-matched healthy controls (HCs). Compared with the HCs, the IGE group presented lower across-voxel CBF-DC correlations, higher CBF/DC ratio in the right posterior cingulate cortex/precuneus, middle frontal gyrus, and medial frontal gyrus (MFG), and lower ratio in the left inferior frontal gyrus. The increased CBF/DC ratio in the right MFG was correlated with lower performance intelligence quotient scores in the IGE group. CONCLUSION: Children with IGE present altered neurovascular coupling, associated with lower performance intelligence quotient scores. The study shed a new insight into the pathophysiology of epilepsy and provided potential imaging biomarkers of cognitive performances in children with IGE.

High-field MRI reveals an acute impact on brain function in survivors of the magnitude 8.0 earthquake in China.

Besides the enormous medical and economic consequences, national disasters, such as the Wenchuan 8.0 earthquake, also pose a risk to the mental health of survivors. In this context, a better understanding is needed of how functional brain systems adapt to severe emotional stress. Previous animal studies have demonstrated the importance of limbic, paralimbic, striatal, and prefrontal structures in stress and fear responses. Human studies, which have focused primarily on patients with clinically established posttraumatic stress disorders, have reported abnormalities in similar brain structures. At present, little is known about potential alterations of brain function in trauma survivors shortly after traumatic events. Here, we show alteration of brain function in a cohort of healthy survivors within 25 days after the Wenchuan earthquake by a recently discovered method known as "resting-state" functional MRI. The current investigation demonstrates that regional activity in frontolimbic and striatal areas increased significantly and connectivity among limbic and striatal networks was attenuated in our participants who had recently experienced severe emotional trauma. Trauma victims also had a reduced temporal synchronization within the "default mode" of resting-state brain function, which has been characterized in humans and other species. Taken together, our findings provide evidence that significant alterations in brain function, similar in many ways to those observed in posttraumatic stress disorders, can be seen shortly after major traumatic experiences, highlighting the need for early evaluation and intervention for trauma survivors.

Identifying epilepsy based on machine-learning technique with diffusion kurtosis tensor.

INTRODUCTION: Epilepsy is a serious hazard to human health. Minimally invasive surgery is an extremely effective treatment to refractory epilepsy currently if the location of epileptic foci is given. However, it is challenging to locate the epileptic foci since a multitude of patients are MRI-negative. It is well known that DKI (diffusion kurtosis imaging) can analyze the pathological changes of local tissues and other regions of epileptic foci at the molecular level. In this article, we propose a new localization way for epileptic foci based on machine-learning method with kurtosis tensor in DKI. METHODS: We recruited 59 children with hippocampus epilepsy and 70 age- and sex-matched normal controls; their T1-weighted images and DKI were collected simultaneously. Then, the hippocampus in DKI is segmented based on a mask as a local brain region, and DKE is utilized to estimate the kurtosis tensor of each subject's hippocampus. Finally, the kurtosis tensor is fed into SVM (support vector machine) to identify epilepsy. RESULTS: The classifier produced 95.24% accuracy for patient versus normal controls, which is higher than that obtained with FA (fractional anisotropy) and MK (mean kurtosis). Experimental results show that the kurtosis tensor is a kind of remarkable feature to identify epilepsy, which indicates that DKI images can act as an important biomarker for epilepsy from the view of clinical diagnosis. CONCLUSION: Although the classification task for epileptic patients and normal controls discussed in this article did not directly achieve the location of epileptic foci and only identified epilepsy on certain brain region, the epileptic foci can be located with the results of identifying results on other brain regions.

Case Report: Biatrial Myxoma With Pulmonary Embolism and Cerebral Embolism: Clinical Experience and Literature Review.

Cardiac myxoma is a common benign primary intracardiac tumor in the general population, and it is generally characterized as a benign tumor, and the morbidity of biatrial myxoma is low. Cases of biatrial myxoma in young patients are extremely rare. Furthermore, severe complications of cardiac myxoma, such as cerebral embolism, can have fatal consequences. Imaging can effectively assist in making a correct diagnosis and a safe and efficient surgical treatment plan. In this case report, we describe a unique case of a young woman who presented with biatrial myxoma accompanied by pulmonary embolism and cerebral embolism. Computed tomography pulmonary angiography (CTPA) detected multiple filling defects in the bilateral cardiac and bilateral inferior pulmonary artery basal branches. Transthoracic echocardiography (TTE) revealed irregular isoechoic masses in the bilateral atrium. Postoperative histopathology confirmed a biatrial myxoma. The patient was discharged on the ninth day after surgery.

Disrupted functional connectivity patterns of the left inferior frontal gyrus subregions in benign childhood epilepsy with centrotemporal spikes.

Background: Benign epilepsy with centrotemporal spikes (BECTS) is one of the most common pediatric epileptic syndromes. Recent studies have shown that BECTS can lead to significant language dysfunction. Although research supports the role of the left inferior frontal gyrus (LIFG) in BECTS, it is unclear whether the subregions of the LIFG show different change patterns in patients with this syndrome. Methods: Using resting-state functional magnetic resonance imaging (fMRI) data in a group of 49 BECTS patients and 49 healthy controls, we investigated whether the BECTS patients show abnormal connectivity patterns of the LIFG subregions. Results: Compared with healthy controls, the BECTS patients exhibited higher connectivity between the following: the inferior frontal sulcus (IFS) and the right anterior cingulate cortex (ACC), and the ventral area 44 (A44v) region and the left hippocampus/parahippocampus. Also, a decreased connectivity was found between the IFS and the left inferior temporal gyrus (ITG). No other significant differences in functional connectivity were found in the other 4 functional subregions of the LIFG in the BECTS. Conclusions: These findings provide evidence for BECTS-related functional connectivity patterns of the LIFG subregions and suggest that different subregions may be involved in different neural circuits associated with language function in the BECTS.

Prediction of Communication Impairment in Children With Bilateral Cerebral Palsy Using Multivariate Lesion- and Connectome-Based Approaches: Protocol for a Multicenter Prospective Cohort Study.

BACKGROUND: Bilateral cerebral palsy (BCP) is the most common type of CP in children and is often accompanied by different degrees of communication impairment. Several studies have attempted to identify children at high risk for communication impairment. However, most prediction factors are qualitative and subjective and may be influenced by rater bias. Individualized objective diagnostic and/or prediction methods are still lacking, and an effective method is urgently needed to guide clinical diagnosis and treatment. The aim of this study is to develop and validate an objective, individual-based model for the prediction of communication impairment in children with BCP by the time they enter school. METHODS: A multicenter prospective cohort study will be conducted in four Chinese hospitals. A total of 178 children with BCP will undergo advanced brain magnetic resonance imaging (MRI) at baseline (corrected age, before the age of 2 years). At school entry, communication performance will be assessed by a communication function classification system (CFCS). Three-quarters of children with BCP will be allocated as a training cohort, whereas the remaining children will be allocated as a test cohort. Multivariate lesion- and connectome-based approaches, which have shown good predictive ability of language performance in stroke patients, will be applied to extract features from MR images for each child with BCP. Multiple machine learning models using extracted features to predict communication impairment for each child with BCP will be constructed using data from the training cohort and externally validated using data from the test cohort. Prediction accuracy across models in the test cohort will be statistically compared. DISCUSSION: The findings of the study may lead to the development of several translational tools that can individually predict communication impairment in children newly diagnosed with BCP to ensure that these children receive early, targeted therapeutic intervention before they begin school. TRIAL REGISTRATION: The study has been registered with the Chinese Clinical Trial Registry (ChiCTR2100049497).

Alterations of Cerebral Perfusion and Functional Connectivity in Children With Idiopathic Generalized Epilepsy.

Background: Studies have demonstrated that adults with idiopathic generalized epilepsy (IGE) have functional abnormalities; however, the neuropathological pathogenesis differs between adults and children. This study aimed to explore alterations in the cerebral blood flow (CBF) and functional connectivity (FC) to comprehensively elucidate the neuropathological mechanisms of IGE in children. Methods: We obtained arterial spin labeling (ASL) and resting state functional magnetic resonance imaging data of 28 children with IGE and 35 matched controls. We used ASL to determine differential CBF regions in children with IGE. A seed-based whole-brain FC analysis was performed for regions with significant CBF changes. The mean CBF and FC of brain areas with significant group differences was extracted, then its correlation with clinical variables in IGE group was analyzed by using Pearson correlation analysis. Results: Compared to controls, children with IGE had CBF abnormalities that were mainly observed in the right middle temporal gyrus, right middle occipital gyrus (MOG), right superior frontal gyrus (SFG), left inferior frontal gyrus (IFG), and triangular part of the left IFG (IFGtriang). We observed that the FC between the left IFGtriang and calcarine fissure (CAL) and that between the right MOG and bilateral CAL were decreased in children with IGE. The CBF in the right SFG was correlated with the age at IGE onset. FC in the left IFGtriang and left CAL was correlated with the IGE duration. Conclusion: This study found that CBF and FC were altered simultaneously in the left IFGtriang and right MOG of children with IGE. The combination of CBF and FC may provide additional information and insight regarding the pathophysiology of IGE from neuronal and vascular integration perspectives.

Corrigendum: Alterations of cerebral perfusion and functional connectivity in children with idiopathic generalized epilepsy.

[This corrects the article DOI: 10.3389/fnins.2022.918513.].

Abnormal regional spontaneous neural activity in treatment-refractory depression revealed by resting-state fMRI.

Treatment-refractory depression (TRD) represents a large proportion of the depressive population, yet has seldom been investigated using advanced imaging techniques. To characterize brain dysfunction in TRD, we performed resting-state functional MRI (rs-fMRI) on 22 TRD patients, along with 26 matched healthy subjects and 22 patients who were depressed but not treatment-refractory (NDD) as comparison groups. Results were analyzed using a data-driven approach known as Regional Homogeneity (ReHo) analysis which measures the synchronization of spontaneous fMRI signal oscillations within spatially neighboring voxels. Relative to healthy controls, both depressed groups showed high ReHo primarily within temporo-limbic structures, and more widespread low ReHo in frontal, parietal, posterior fusiform cortices, and caudate. TRD patients showed more cerebral regions with altered ReHo than did NDD. Moderate but significant correlations between the altered regional ReHo and measures of clinical severity were observed in some identified clusters. These findings shed light on the pathophysiological mechanisms underlying TRD and demonstrate the feasibility of using ReHo as a research and clinical tool to monitor persistent cerebral dysfunction in depression, although further work is necessary to compare different measures of brain function to elucidate the neural substrates of these ReHo abnormalities.

Microstructural brain abnormalities in patients with obsessive-compulsive disorder: diffusion-tensor MR imaging study at 3.0 T.

PURPOSE: To use diffusion-tensor (DT) magnetic resonance (MR) imaging to explore the integrity and connectivity of brain white matter in patients with obsessive-compulsive disorder (OCD) and to correlate DT parameters with clinical measures. MATERIALS AND METHODS: This study was approved by the local ethical committee, and written informed consent was obtained from all participants. DT imaging was performed by using a 3.0-T MR imager in 23 patients with OCD and 23 healthy control subjects matched for age, sex, education level, and handedness. By using voxel-based analysis, fractional anisotropy (FA) and axial and radial diffusivities were compared between patients and control subjects with a two-sample t test and were tested for correlation with symptom severity, as measured by using the Yale-Brown Obsessive-Compulsive Scale and obsessive-compulsive subscale scores, and with illness duration, as measured by using simple regression in statistical parametric mapping program. RESULTS: Compared with control subjects, OCD patients demonstrated significantly increased FA in the genu and body of corpus callosum and white matter of right superior frontal gyrus and corpus callosum; no areas of significantly decreased FA were found. For areas of increased FA, axial diffusivity was higher than that in control subjects, while radial diffusivity was not significantly different. The FA values in the white matter of left middle temporal gyrus in OCD patients correlated positively with clinical measures (r = 0.542, P < .001). CONCLUSION: OCD is associated with axonal microstructural abnormalities within the white matter, which may indicate impaired axonal integrity and increased connectivity. The positive correlation between DT abnormalities and symptom severity suggests that DT imaging may be of clinical value in measuring and following disability in OCD patients.

Abnormal small-world architecture of top-down control networks in obsessive-compulsive disorder.

BACKGROUND: Obsessive-compulsive disorder (OCD) is a common neuropsychiatric disorder that is characterized by recurrent intrusive thoughts, ideas or images and repetitive ritualistic behaviours. Although focal structural and functional abnormalities in specific brain regions have been widely studied in populations with OCD, changes in the functional relations among them remain poorly understood. This study examined OCD-related alterations in functional connectivity patterns in the brain's top-down control network. METHODS: We applied resting-state functional magnetic resonance imaging to investigate the correlation patterns of intrinsic or spontaneous blood oxygen level-dependent signal fluctuations in 18 patients with OCD and 16 healthy controls. The brain control networks were first constructed by thresholding temporal correlation matrices of 39 brain regions associated with top-down control and then analyzed using graph theory-based approaches. RESULTS: Compared with healthy controls, the patients with OCD showed decreased functional connectivity in the posterior temporal regions and increased connectivity in various control regions such as the cingulate, precuneus, thalamus and cerebellum. Furthermore, the brain's control networks in the healthy controls showed small-world architecture (high clustering coefficients and short path lengths), suggesting an optimal balance between modularized and distributed information processing. In contrast, the patients with OCD showed significantly higher local clustering, implying abnormal functional organization in the control network. Further analysis revealed that the changes in network properties occurred in regions of increased functional connectivity strength in patients with OCD. LIMITATIONS: The patient group in the present study was heterogeneous in terms of symptom clusters, and most of the patients with OCD were medicated. CONCLUSION: Our preliminary results suggest that the organizational patterns of intrinsic brain activity in the control networks are altered in patients with OCD and thus provide empirical evidence for aberrant functional connectivity in the large-scale brain systems in people with this disorder.