Functional Connectivity Changes In Patients Research Articles

The contribution of EEG to assess and treat motor disorders in multiple sclerosis

ObjectiveElectroencephalography (EEG) can highlight significant changes in spontaneous electrical activity of the brain produced by altered brain network connectivity linked to inflammatory demyelinating lesions and neuronal loss occurring in multiple sclerosis (MS). In this review, we describe the main EEG findings reported in the literature to characterize motor network alteration in term of local activity or functional connectivity changes in patients with MS (pwMS). MethodsA comprehensive literature search was conducted to include articles with quantitative analyses of resting-state EEG recordings (spectrograms or advanced methods for assessing spatial and temporal dynamics, such as coherence, theory of graphs, recurrent quantification, microstates) or dynamic EEG recordings during a motor task, with or without connectivity analyses. ResultsIn this systematic review, we identified 26 original articles using EEG in the evaluation of MS-related motor disorders. Various resting or dynamic EEG parameters could serve as diagnostic biomarkers of motor control impairment to differentiate pwMS from healthy subjects or be related to a specific clinical condition (fatigue) or neuroradiological aspects (lesion load). ConclusionsWe highlight some key EEG patterns in pwMS at rest and during movement, both suggesting an alteration or disruption of brain connectivity, more specifically involving sensorimotor networks. SignificanceSome of these EEG biomarkers of motor disturbance could be used to design future therapeutic strategies in MS based on neuromodulation approaches, or to predict the effects of motor training and rehabilitation in pwMS.

Brain network functional connectivity changes in patients with anterior knee pain: a resting-state fMRI exploratory study

BackgroundThis study investigates the functional brain connectivity in patients with anterior knee pain (AKP). While biomechanical models are frequently employed to investigate AKP, it is important to recognize that pain can manifest even in the absence of structural abnormalities. Leveraging the capabilities of functional magnetic resonance imaging (fMRI), this research aims to investigate the brain mechanisms present in AKP patients.MethodsForty-five female subjects (24 AKP patients, 21 controls) underwent resting-state fMRI and T1-weighted structural MRI. Functional brain connectivity patterns were analyzed, focusing on pain network areas, and the influence of catastrophizing thoughts was evaluated.ResultsComparing patients and controls, several findings emerged. First, patients with AKP exhibited increased correlation between the right supplementary motor area and cerebellum I, as well as decreased correlation between the right insula and the left rostral prefrontal cortex and superior frontal gyrus. Second, in AKP patients with catastrophizing thoughts, there was increased correlation of the left lateral parietal cortex with two regions of the right cerebellum (II and VII) and the right pallidum, and decreased correlation between the left medial frontal gyrus and the right thalamus. Furthermore, the correlation between these regions showed promising results for discriminating AKP patients from controls, achieving a cross-validation accuracy of 80.5%.ConclusionsResting-state fMRI revealed correlation differences in AKP patients compared to controls and based on catastrophizing thoughts levels. These findings shed light on neural correlates of chronic pain in AKP, suggesting that functional brain connectivity alterations may be linked to pain experience in this population.Relevance statementEtiopathogenesis of pain in anterior knee pain patients might not be limited to the knee, but also to underlying alterations in the central nervous system: cortical changes might lead a perpetuation of pain.Key points• Anterior knee pain patients exhibit distinct functional brain connectivity compared to controls, and among catastrophizing subgroups.• Resting-state fMRI reveals potential for discriminating anterior knee pain patients with 80.5% accuracy.• Functional brain connectivity differences improve understanding of pain pathogenesis and objective anterior knee pain identification.Graphical

Orbitofrontal cortex functional connectivity changes in patients with binge eating disorder and bulimia nervosa.

We aimed to define the shared and unshared functional neurobiological underpinnings of binge eating disorder (BED) and bulimia nervosa (BN). These disorders both involve loss of control over binge eating, but differ based on purging behavior and body image distortion. BED and BN have also been found to show differences in brain activation patterns in reward sensitivity. We enrolled 13 and 12 drug-naive and medication-free women with BED and BN, respectively, and 22 age- and sex-matched healthy controls. We performed an orbitofrontal cortex (OFC)-seeded resting-state whole brain functional connectivity (FC) analysis among the groups. In this study, BED patients exhibited significantly higher impulsivity than controls, whereas the difference in impulsivity between BN and controls was not significant. Participants with BED and BN showed weaker FC between the left lateral OFC and the right precuneus than controls. In the BED only group, the FC strength between these regions was negatively correlated with self-reported impulsivity. In both BED and BN, FC between the left lateral OFC and the right dorsolateral prefrontal cortex was weaker than that in controls. In BED, FC between the left medial OFC and the right cerebellar lobule IV was stronger than that of other groups. Our current results suggest similarities and differences between BED and BN in OFC-seeded FC with respect to reward processing. In particular, FC of the OFC in BED patients showed a significant correlation with their high impulsivity, which may reflect a decline in executive control over binge eating.

Alternations of interhemispheric functional connectivity in patients with optic neuritis using voxel-mirrored homotopic connectivity: A resting state fMRI study.

We used the voxel-mirrored homotopic connectivity (VMHC) method to investigate brain interhemispheric functional connectivity changes in patients with optic neuritis (ON). A total of 22 ON patients and 22 healthy controls (HCs) closely matched in age, sex, and weight were enrolled. All participants underwent resting-state functional magnetic resonance imaging (rs-fMRI). Functional interaction between the hemispheres was assessed with the VMHC method. Correlation analysis was applied to explore the association between altered VMHC values in different brain areas and cognitive features. Receiver operating characteristic (ROC) curve analysis was applied to distinguish ON patients from HCs. Compared with HCs, ON patients had obviously reduced VMHC values in the right superior temporal gyrus, left margin superior gyrus, right superior motor cortex, and left middle cingulate gyrus. a negative relationship between best-corrected visual acuity and VMHC values in left margin superior gyrus was found, besides, the VMHC values within the right superior motor cortex and the right superior temporal gyrus were also anti-correlated with the Hamilton Depression Scales. The ROC curve displayed high diagnostic values in those altered regions. Abnormal VMHC values may reflect the underlying neuropathologic mechanism of ON.

Mental imagery content is associated with disease severity and specific brain functional connectivity changes in patients with Parkinson's disease.

Mental imagery is the mental re-creation of perceptual experiences, events and scenarios, and motor acts. In our previous study, we assessed whether motor imagery (MI) training combined with functional magnetic resonance imaging-based neurofeedback could improve the motor function of nondemented subjects with mild Parkinson's disease (PD) (N = 22). We used visual imagery (VI) (e.g., of scenes or events, but not of self-movements) training without neurofeedback for the control group (N = 22). Notably, both groups showed significant and comparable improvement in motor function after four weeks of daily imagery practice. In this study, we further examined the neural correlates of the motor enhancement as a result of the VI training by analyzing the self-reported VI content during daily practice and relating its quality to the functional connectivity characteristics of the same subjects. We demonstrated that the VI practice encompassed multisensory, spatial, affective, and executive processes all of which are also important for motor function in real life. Subjects with worse global disease severity also showed poorer quality of the VI content. Finally, the quality of the VI content showed significant positive correlations with the functional connectivity changes during the VI tasks in brain areas supporting visuospatial and sensorimotor processes. Our findings suggest that mental imagery training combining VI and MI may enhance motor function in patients with mild PD, and more broadly, underline the importance of incorporating self-reports of thoughts and experiences in neuroimaging studies that examine the brain mechanisms of complex cognitive processes especially in neuropsychiatric patient populations.

Postoperative Changes in Resting State Functional Connectivity and Clinical Scores in Patients With Cervical Myelopathy

Resting state functional magnetic resonance imaging (rs-fMRI) is a technique for the analyzing functional connectivity (FC) between anatomically distant brain regions at rest. The purpose of this study was to analyze postoperative FC changes in patients with compression cervical myelopathy, to evaluate their relationship with clinical scores, and to examine the changes in spinal cord function associated with brain networks. This prospective study comprised 15 patients with cervical myelopathy who underwent planned surgery. Rs-fMRI was performed preoperatively and 6 months postoperatively with the similar protocol. Clinical function was assessed by the Japanese Orthopedic Association (JOA) score, the Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and the numerical rating scale (NRS). We performed a seed-based analysis, and identified the networks that changed significantly following surgery. Furthermore, we performed a correlation analysis to compare the postoperative changes in FC with clinical scores. Five FCs were significantly increased postoperatively; 4 were between the sensorimotor network (SMN) and other regions. We observed a significant correlation between the FC of the right SMN and the left precentral gyrus with the JOA score, the left SMN with the JOACMEQ for upper extremity function, and the left postcentral gyrus with the NRS. The reorganization of the sensorimotor cortex occurred postoperatively in patients with compression cervical myelopathy. In addition, each change in FC was significantly correlated with the clinical scores, thus indicating an association between the recovery of spinal cord function and plastic changes in the sensorimotor cortex.

TH-227. Structural and functional connectivity changes in patients with Alzheimer’s disease after six months of repetitive transcranial magnetic stimulation over precuneus

TH-227. Structural and functional connectivity changes in patients with Alzheimer’s disease after six months of repetitive transcranial magnetic stimulation over precuneus

Correlation between cognitive deficits and dorsolateral prefrontal cortex functional connectivity in first-episode depression

IntroductionAlthough depression is commonly accompanied by cognitive deficits, the underlying mechanism remains unclear. One possibility is that such deficits are related to abnormal brain network connections. The purpose of this study was thus to investigate changes in brain functional connectivity (FC) in depression and its relationship with cognitive deficits. MethodsWe enrolled 37 first-episode MDD patients and 53 matched healthy controls (HC). All participants completed clinical and neurocognitive assessments and underwent resting-state functional MRI. Seed-based analysis was used to define the dorsolateral prefrontal cortex (DLPFC) and FC analysis was then performed. We used bias correlation to analyze the correlation between FC and clinical and neurocognitive scores. ResultsMDD patients showed increased FC of the right DLPFC with the left inferior temporal gyrus, left cuneus, right inferior frontal gyrus, right anterior cingulate cortex, left BA39, right angular gyrus, right precuneus, left middle frontal gyrus, and right precentral gyrus. MDD patients also showed stronger FC in the left thalamus and reduced FC between the left superior occipital gyrus and left DLPFC seed region. Interestingly, increased FC was related to disease severity (with the right precentral gyrus) and social cognitive dysfunction (with the right angular gyrus) in MDD patients. LimitationsThe sample size was relatively small and it is unclear how age may influence FC changes in patients with depression. ConclusionsThese findings support changes in FC of the DLPFC in early MDD patients related to cognitive function. FC is a potential biomarker for the diagnosis of MDD.

The Resting-State Brain Network Functional Connectivity Changes in Patients With Acute Thyrotoxic Myopathy Based on Independent Component Analysis.

ObjectiveThe independent component analysis (ICA) was applied to explore the correlation between clinical manifestation and the functional connectivity changes of the sensorimotor network (SMN) and left frontoparietal network (LFPN) in patients with acute thyrotoxic myopathy (ATM), which was expected to provide a functional imaging basis for the exploration of the pathophysiological mechanism of ATM.Methods13 ATM patients (ATM) and 12 non-ATM patients (nATM) who met the diagnostic and inclusion criteria were enrolled. Their resting-state brain function images were obtained with resting-state functional magnetic resonance imaging (rs-fMRI). GIFT software was used for independent component analysis to obtain the brain regions with SMN and LFPN changes. The correlation between the functional connectivity of these brain regions and clinical indicators was calculated.ResultsThe SMN functional connectivity of ATM patients was increased at the posterior lobe of cerebellum, anterior lobe of cerebellum, right superior temporal gyrus, left cingulate gyrus, left precuneus, and left postcentral gyrus compared with that of nATM patients. However, it was decreased at the occipital lobe, right dorsolateral superior frontal gyrus, paracentral lobule, angular gyrus, and superior parietal gyrus (FDR correction, P<0.05). The LFPN functional connectivity of ATM patients was increased at the posterior lobe of cerebellum, middle temporal gyrus, inferior temporal gyrus, and right cingulate gyrus compared with that of nATM patients; but was decreased at frontal lobe, parahippocampal gyrus, precentral gyrus and postcentral gyrus (FDR correction, P<0.05) Correlation analysis results showed that the enhancement of SMN functional connection at right superior temporal gyrus was significantly negatively correlated with the free thyroxine level, and the decrease of SMN functional connectivity at occipital lobe was significantly positively correlated to the thyroid stimulating hormone level. The SMN and LFPN functional connectivity changes in other brain regions were not found to be significantly correlated with thyroid function parameters.ConclusionThe bulbar paralysis (such as dysphagia, dysarthria) in ATM patients may be related to the functional connectivity changes of resting-state SMN and LFPN. The fMRI is expected to be one of the objective imaging indicators for the early clinical intervention of ATM patients.

Global Functional Connectivity Analysis Indicating Dysconnectivity of the Hate Circuit in Major Depressive Disorder.

BackgroundAbnormalities of functional connectivity (FC) in certain brain regions are closely related to the pathophysiology of major depressive disorder (MDD). Findings are inconsistent with different presuppositions in regions of interest. Our research focused on voxel-wise brain-wide FC changes in patients with MDD in an unbiased manner.MethodWe examined resting-state functional MRI in 23 patients with MDD and 26 healthy controls. Imaging data were analyzed by using global-brain FC (GFC) and used to explore the correlation of abnormal GFC values with clinical variables.ResultsIncreased GFC values in the left medial superior frontal gyrus (SFGmed) and decreased GFC values in the right supplementary motor area (SMA) were observed in the patients with MDD compared with the controls. The decreased GFC values in the right SMA had a positive correlation with vitamin D and Hamilton Anxiety Scale (HAM-A) scores.ConclusionAbnormal GFC in the hate circuit, particularly increased GFC in the left SFGmed and decreased GFC in the right SMA, appears to be a new sight for comprehending the pathological alterations in MDD.

Impairment of EEG functional connectivity in dementia during recognition of emotional facial expression

AbstractBackgroundThe performance of facial expression recognition is affected both in neurocognitive disorders and in healthy elderly. Emotional content processing is expected to be adversely affected in dementia and as well in Parkinson's disease patients. The present study aims to compare the impaired facial expression recognition between different types of dementia patients, functional connectivity changes in patients with mild cognitive impairment, and patients with dementia were investigated by event‐related EEG‐coherence.Method25 Healthy elderly controls (HC), 25 Mild Cognitive Impairment patients (MCI), 25 patients with Alzheimer's disease (AD), 15 patients with Parkinson's disease with Mild Cognitive Impairment (PDMCI), and 16 patients with Parkinson's disease Dementia (PDD) were included in the study. EEG was recorded while angry, happy, and neutral facial expressions were presented. The artifacts were rejected by using Independent‐Component‐Analysis and Current‐Source‐Density. Magnitude‐squared coherence values of theta (4‐7Hz, 50‐400ms) responses were calculated. Inter‐hemispheric and intra‐hemispheric (frontal and central centered) pairs of F3, F4, C3, C4, T7, T8, Tp7, Tp8, P3, P4, O1, O2 channels were used. Two separate inter and intra hemispheric repeated‐measures‐ANOVA models were used for group comparisons.ResultThere were no group differences for intra‐hemispheric comparisons, but GroupXLocation comparison (p=.040) was significant, HE and MCI groups had higher coherence values in central‐ temporal, central‐ temporoparietal, and central‐ occipital connections compared to PDMCI, PDD, and AD patient groups (Figure 1). FaceXGroup (p=.009) interaction was significant for inter‐hemispheric coherence values, HC and MCI groups had higher interhemispheric coherence values than the PDMCI, PDD, and AD, especially during recognition of "angry" facial expression.ConclusionThe connectivity between the central and posterior regions increased with emotional face content; this increase seems to be preserved in MCI. On the other hand, it wasn't maintained in patients with more severe neurocognitive impairment; PDMCI, PDD, and AD groups had reduced central‐posterior connectivity and interhemispheric connectivity during the facial expression recognition paradigm. The decrease in inter and intra‐connectivity in the posterior regions is consistent with behavioral scores and may indicate neural losses as a phenomenon.

Disrupted Motion-Related Functional Connectivity Changes in Patients With Generalized Epilepsy

Disrupted Motion-Related Functional Connectivity Changes in Patients With Generalized Epilepsy

Brain Functional Connectivity Changes in Patients with Acute Eye Pain: A Resting-State Functional Magnetic Resonance Imaging (fMRI) Study.

BackgroundBy using functional magnetic resonance imaging (fMRI), we aimed to study the changes in potential brain function network activity in patients with acute eye pain. Also, by using the voxel-wise degree centrality (DC) method, we aimed to explore the relationship between spontaneous brain activity and the clinical features of patients with acute eye pain.Material/MethodsA total of 15 patients with acute eye pain (5 women and 10 men; EP group) and 15 healthy controls (5 women and 10 men; HC group), were scanned by fMRI. The DC method was used to evaluate changes in spontaneous brain activity. Receiver operating characteristic (ROC) curves were analyzed, and Pearson correlation analysis was used to study the relationship between DC values and clinical manifestations in different regions of brain.ResultsThe area of the left limbic lobe showed a reduction in DC value in patients in the EP group. DC values were elevated in the left cerebellum posterior lobe, left inferior parietal lobule, left inferior temporal gyrus, left precuneus, and right cerebellum posterior lobe in the EP group. The visual analog scale value of the eyes in the EP group was negatively correlated with the left limbic lobe signal value and positively correlated with the left inferior parietal lobule signal value. Further, the scores of the hospital anxiety and depression scale and DC value of the left limbic lobe were negatively correlated.ConclusionsCompared with the HC group, patients with acute eye pain had abnormal patterns of intrinsic brain activity in different brain regions, which may help reveal the potential neural mechanisms involved in eye pain.

Abnormal Whole Brain Functional Connectivity Pattern Homogeneity and Couplings in Migraine Without Aura.

Previous studies have reported abnormal amplitude of low-frequency fluctuation and regional homogeneity in patients with migraine without aura using resting-state functional magnetic resonance imaging. However, how whole brain functional connectivity pattern homogeneity and its corresponding functional connectivity changes in patients with migraine without aura is unknown. In the current study, we employed a recently developed whole brain functional connectivity homogeneity (FcHo) method to identify the voxel-wise changes of functional connectivity patterns in 21 patients with migraine without aura and 21 gender and age matched healthy controls. Moreover, resting-state functional connectivity analysis was used to reveal the changes of corresponding functional connectivities. FcHo analyses identified significantly decreased FcHo values in the posterior cingulate cortex (PCC), thalamus (THA), and left anterior insula (AI) in patients with migraine without aura compared to healthy controls. Functional connectivity analyses further found decreased functional connectivities between PCC and medial prefrontal cortex (MPFC), between AI and anterior cingulate cortex, and between THA and left precentral gyrus (PCG). The functional connectivities between THA and PCG were negatively correlated with pain intensity. Our findings indicated that whole brain FcHo and connectivity abnormalities of these regions may be associated with functional impairments in pain processing in patients with migraine without aura.

Differential Effects of Confluent and Nonconfluent White Matter Hyperintensities on Functional Connectivity in Mild Cognitive Impairment.

Background: White matter hyperintensities (WMHs) indicate active small vessel disease. Emerging evidence suggests that confluent WMH (C-WMH) results in greater cognitive impairment compared with nonconfluent WMH (NC-WMH) visualized as punctate lesions. However, the mechanism linking C-WMH and early cognitive impairment is not clearly understood. Aims: To investigate the effects of C-WMH and NC-WMH on whole-brain functional connectivity (FC) across 138 regions of interest (ROIs) and cognition in 63 subjects with mild cognitive impairment (MCI). Methods: MCI subjects were classified as C-WMH or NC-WMH using the Staals criteria on the Fazekas WMH scale. Group-level ROI-to-ROI FC trends and differences based on WMH subtypes were computed using standard resting-state functional magnetic resonance imaging analysis. Global cognitive performance was measured with mini-mental state examination (MMSE). Results: Subjects with C-WMH exhibited increased inter-regional FC in the fronto-parietal, fronto-occipital, parieto-occipital, and temporo-parietal regions of the salience, dorsal-attention, default-mode, and visual networks compared with NC-WMH. Increased intra-regional FC was also observed within the frontal and parietal lobes in C-WMH. In addition to widespread increased FC in C-WMH, a few regions in the fronto-temporal and intra-frontal areas demonstrated reduced FC in C-WMH compared with NC-WMH. Analyses of cognitive correlates demonstrated increased parieto-occipital FC to be negatively associated with MMSE in the C-WMH. The increased parieto-occipital FC may be related to loss of higher order inhibitory control in the parieto-occipital regions induced by C-WMH or alternatively a compensatory mechanism to FC alterations induced by C-WMH. Conclusion: C-WMH in subjects with MCI is associated with widespread increase in intra- and inter-regional FC. These findings provide novel insights into divergent FC related to confluence of WMH in MCI. Impact statement White matter hyperintensities (WMHs) have been demonstrated to be a major risk factor for progressive cognitive decline. However, the relationship between structural and functional brain changes related to different types of WMH lesions as well as different stages of WMH progression remains unclear. In this study, we demonstrate that confluent WMH is significantly associated with divergent functional connectivity changes in patients with mild cognitive impairment (MCI). This finding may allow identification of MCI subjects who are adversely affected by WMH and thus provides a window of opportunity to introduce pharmacological and nonpharmacological interventional measures.

Functional connectivity changes in patients with brain tumours—A systematic review on resting state-fMRI

AimResting-state functional magnetic resonance imaging (rs-fMRI) has been utilised to explore the brain's functional changes in patients with brain tumours. However, it remains unclear how such alterations affect functional connectivity (FC) and thus lead to changes in behaviour. To better understand the present state of knowledge, we conducted a systematic review. Material and methodsA systematic literature search of patients with brain tumours with rs-fMRI methods was conducted using the PubMed/MEDLINE and Cochrane Library electronic databases following PRISMA guidelines. References and citations were checked in Scopus database. ResultsTen independent studies were identified, comprising of 361 adult participants (218 had brain tumours; and the remainder were healthy controls). In comparison to healthy controls, patients with brain tumours demonstrated network distortions, alterations, and associated changes in the resting state networks (RSNs). Location and types of tumour affected RSNs integrity, particularly in the Default Mode Network (DMN). The left hemisphere was reported to have the largest effect on RSNs regardless of size or type of tumour. Result also demonstrate significant alterations to the local networks (decreases in the intra-hemispheric and inter-hemispheric FC). Studies also demonstrated that alterations in rs-fMRI were related to poorer neuropsychological task performance. ConclusionHowever, more studies utilising rs-fMRI to investigate effects of brain tumours on different types of RSNs are needed to draw clear conclusions about effects of tumour growth on properties of brain functional networks. Notably, not all studies have used the same nodes or regions for the networks, even though tumour locations often overlap.

Inter-Network Functional Connectivity Changes in Patients With Brain Tumors: A Resting-State Functional Magnetic Resonance Imaging Study

Measuring functional connectivity (FC) and resting state networks (RSNs) using resting state functional magnetic resonance imaging is a method of preoperative planning in patients with brain tumors. However, the baseline FC and RSNs are altered in patients with brain tumors. In this study, we examined changes in inter-network FC in patients with brain tumors. We performed region of interest (ROI) analysis of FC in 34 patients with supratentorial gliomas and 14 healthy subjects. We performed bivariate correlation analyses at the level of each subject. Resulting correlations were Fischer Z-transformed. The used nodes included 132 ROIs from the automated anatomical labeling atlas in addition to 32 ROIs representing the different functional brain networks. We investigated second-level effects by contrasting dummy encoded covariates representing the effects of group membership on functional connectivity. The significant 2-sided P value with corrected false discovery rate was set to 0.05. We set the t contrast between the group of patients with brain tumors and the group of healthy subjects to detect the effects of tumors on inter-network connectivity. Overall, the inter-network FC was significantly higher in patients with brain tumors compared with healthy subjects. The anterior and posterior cerebellar networks, as well as the supratentorial network, showed significantly higher connectivity in patients with brain tumors than in healthy subjects. Although brain tumors affect the FC and RSNs, the current study showed higher baseline inter-network connectivity in patients with brain tumors, which could indicate an intrinsic neural compensatory mechanism.

Reduced Global-Brain Functional Connectivity and Its Relationship With Symptomatic Severity in Cervical Dystonia.

Background: Altered functional connectivity (FC) is related to pathophysiology of patients with cervical dystonia (CD). However, inconsistent results may be obtained due to different selected regions of interest. We explored voxel-wise brain-wide FC changes in patients with CD at rest in an unbiased manner and analyzed their correlations with symptomatic severity using the Tsui scale.Method: A total of 19 patients with CD and 21 sex- and age-matched healthy controls underwent resting-state functional magnetic resonance imaging scans. Global-brain FC (GFC) was applied to analyze the images. Support vector machine was used to distinguish the patients from the controls.Results: Patients with CD exhibited decreased GFC in the right precentral gyrus and right supplementary motor area (SMA) that belonged to the M1-SMA motor network. Significantly negative correlation was observed between GFC values in the right precentral gyrus and symptomatic severity in the patients (r = −0.476, p = 0.039, uncorrected). Decreased GFC values in these two brain regions could be utilized to differentiate the patients from the controls with good accuracies, sensitivities and specificities (83.33, 85.71, and 80.95% in the right precentral gyrus; and 87.59, 89.49, and 85.71% in the right SMA).Conclusions: Our investigation suggests that patients with CD show reduced GFC in brain regions of the M1-SMA motor network and provides further insights into the pathophysiology of CD. GFC values in the right precentral gyrus and right SMA may be used as potential biomarkers to recognize the patients from the controls.

Abnormal dynamic functional connectivity density in patients with generalized anxiety disorder

BackgroundNumerous studies have revealed the abnormal static functional connectivity (FC) among different brain regions in patients with generalized anxiety disorder (GAD). However, little is known about the dynamic changes of FC in patients with GAD. MethodsThis study investigated the whole-brain dynamic changes of FC in patients with GAD by combining global FC density (FCD) and sliding window correlation analyses. The standard deviation of dynamic FCD (dFCD) was calculated to evaluate its temporal variability along time. Support vector regression was then employed to predict the symptom severity of patients based on abnormal dynamic connectivity patterns. ResultsThe abnormal dFCD variability between 81 GAD patients and 80 healthy controls showed that the patients had higher dFCD variability in the bilateral dorsomedial prefrontal cortex (dmPFC) and left hippocampus while lower dFCD variability in the right postcentral gyrus. The abnormal dFCD variability of the left dmPFC is an important feature for anxiety prediction. LimitationsThe selection of sliding window length remains controversial, and most of our patients have been treated with medications. Future studies are expected to rule out the potential confounding effects from applying different parameters of the sliding window and recruiting large samples of medication-free patients. ConclusionThe altered patterns of time-varying brain connectivity in the frontolimbic and sensorimotor areas may reflect abnormal dynamic neural communication between these regions and other regions of the brain, which may deepen our understanding of the disease.

Alteration of functional connectivity in patients with Alzheimer's disease revealed by resting-state functional magnetic resonance imaging.

The main symptom of patients with Alzheimer's disease is cognitive dysfunction. Alzheimer's disease is mainly diagnosed based on changes in brain structure. Functional connectivity reflects the synchrony of functional activities between non-adjacent brain regions, and changes in functional connectivity appear earlier than those in brain structure. In this study, we detected resting-state functional connectivity changes in patients with Alzheimer's disease to provide reference evidence for disease prediction. Functional magnetic resonance imaging data from patients with Alzheimer's disease were used to show whether particular white and gray matter areas had certain functional connectivity patterns and if these patterns changed with disease severity. In nine white and corresponding gray matter regions, correlations of normal cognition, early mild cognitive impairment, and late mild cognitive impairment with blood oxygen level-dependent signal time series were detected. Average correlation coefficient analysis indicated functional connectivity patterns between white and gray matter in the resting state of patients with Alzheimer's disease. Functional connectivity pattern variation correlated with disease severity, with some regions having relatively strong or weak correlations. We found that the correlation coefficients of five regions were 0.3-0.5 in patients with normal cognition and 0-0.2 in those developing Alzheimer's disease. Moreover, in the other four regions, the range increased to 0.45-0.7 with increasing cognitive impairment. In some white and gray matter areas, there were specific connectivity patterns. Changes in regional white and gray matter connectivity patterns may be used to predict Alzheimer's disease; however, detailed information on specific connectivity patterns is needed. All study data were obtained from the Alzheimer's Disease Neuroimaging Initiative Library of the Image and Data Archive Database.