注意缺陷多动障碍儿童静息态功能磁共振度中心度的研究

目的 运用静息态功能磁共振（functional magnetic resonance imaging,fMRI）度中心度（degree centrality,DC）的分析技术,从网络节点的角度对注意缺陷多动障碍（attention-deficit hyperactivity disorder,ADHD）儿童与正常儿童进行比较研究,探讨ADHD功能脑区的病理机制.方法 学龄期ADHD患儿与正常儿童各30名分别进行静息态fMRI扫描,使用度中心度的方法进行数据分析.结果 ADHD组DC值较正常组低的脑区,右侧后扣带回、左内侧额上回、右侧顶下小叶、右侧额中回、左侧额上回、右侧额上回（t=-5.21,-3.53,-4.87,-4.21,-3.56,-4.06）,组间差异有统计学意义（P＜0.05）;ADHD组DC值较正常组高的脑区,小脑前叶、右侧枕中回、左侧中扣带回、右侧中扣带回（t=4.27,4.25,4.80,5.33）,两组间差异有统计学意义（P＜0.05）.结论 在默认网络及前额叶区域DC值的降低引起中心结构的破坏,认为与ADHD患儿在记忆认知、执行控制等方面的障碍有关;在DC值增高的脑区,可能与ADHD脑功能失调代偿作用,引起执行控制障碍、注意力下降等症状有关.静息态功能磁共振度中心度技术为多动症儿童认知障碍的研究提供了一种新的方法.     

Distinctive spontaneous regional neural activity in patients with somatoform pain disorder: A preliminary resting-state fMRI study

This resting-state functional magnetic resonance imaging study found that nine patients with somatoform pain disorder exhibited atypical precentral gyrus activation compared with 20 healthy controls. The role of the precentral gyrus in pain-related processing is discussed.     

Network Mechanisms of Clinical Response to Transcranial Magnetic Stimulation in Posttraumatic Stress Disorder and Major Depressive Disorder

Background

Repetitive transcranial magnetic stimulation (TMS) therapy can modulate pathological neural network functional connectivity in major depressive disorder (MDD). Posttraumatic stress disorder is often comorbid with MDD, and symptoms of both disorders can be alleviated with TMS therapy. This is the first study to evaluate TMS-associated changes in connectivity in patients with comorbid posttraumatic stress disorder and MDD.

An automatic pre-processing pipeline for EEG analysis (APP) based on robust statistics

Objective

With the advent of high-density EEG and studies of large numbers of participants, yielding increasingly greater amounts of data, supervised methods for artifact rejection have become excessively time consuming. Here, we propose a novel automatic pipeline (APP) for pre-processing and artifact rejection of EEG data, which innovates relative to existing methods by not only following state-of-the-art guidelines but also further employing robust statistics.

Continuous theta-burst stimulation may improve visuospatial neglect via modulating the attention network: a randomized controlled study

Background: Visuospatial neglect (VSN) is devastating and common after stroke, and is thought to involve functional disturbance of the attention network. Non-invasive theta-burst stimulation (TBS) may help restore the normal function of attention network, therefore facilitating recovery from VSN.

Objective: This study investigated the effects of continuous TBS on resting-state functional connectivity (RSFC) in the attention network, and behavioral performances of patients with VSN after stroke.

Methods: Twelve patients were randomly assigned to receive 10-day cTBS of the left posterior parietal cortex delivered at 80% (the cTBS group), or 40% (the active control group) of the resting motor threshold. Both groups received daily visual scanning training and motor function treatment. Resting-state functional MRI (fMRI) and behavioral tests including line bisection test and star cancelation test were conducted at baseline and after the treatment.

Results: At baseline, the two groups showed comparable results in the resting-state fMRI experiments and behavioral tests. After treatment, the cTBS group showed lower functional connectivity between right temporoparietal junction (TPJ) and right anterior insula, and between right superior temporal sulcus and right anterior insula, as compared with the active control group; both groups showed improvement in the behavioral tests, with the cTBS group showing larger changes from baseline than the active control group.

Conclusion: cTBS of the left posterior parietal cortex in patients with VSN may induce changes in inter-regional RSFC in the right ventral attention network. These changes may be associated with improved recovery of behavioral deficits after behavioral training. The TPJ and superior temporal sulcus may play crucial roles in recovery from VSN.     

Alzheimer’s disease: The state of the art in resting-state magnetoencephalography

Alzheimer’s disease (AD) is accompanied by functional brain changes that can be detected in imaging studies, including electromagnetic activity recorded with magnetoencephalography (MEG). Here, we systematically review the studies that have examined resting-state MEG changes in AD and identify areas that lack scientific or clinical progress. Three levels of MEG analysis will be covered: (i) single-channel signal analysis, (ii) pairwise analyses over time series, which includes the study of interdependencies between two time series and (iii) global network analyses. We discuss the findings in the light of other functional modalities, such as electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). Overall, single-channel MEG results show consistent changes in AD that are in line with EEG studies, but the full potential of the high spatial resolution of MEG and advanced functional connectivity and network analysis has yet to be fully exploited. Adding these features to the current knowledge will potentially aid in uncovering organizational patterns of brain function in AD and thereby aid the understanding of neuronal mechanisms leading to cognitive deficits.     

Tract-specific white matter hyperintensities disrupt neural network function in Alzheimer's disease

Introduction

White matter hyperintensities (WMHs) increase the risk of Alzheimer's disease (AD). Whether WMHs are associated with the decline of functional neural networks in AD is debated.

Intrinsic inter-network brain dysfunction correlates with symptom dimensions in late-life depression

Prior studies have demonstrated dysfunctions within the core neurocognitive networks (the executive control [ECN], default mode [DMN] and salience [SN] networks) in late-life depression (LLD). Whether inter-network dysfunctional connectivity is present in LLD, and if such disruptions are associated with core symptom dimensions is unknown. A cross-sectional resting-state functional connectivity magnetic resonance imaging investigation was conducted of LLD (n = 39) and age- and gender-equated healthy comparison (HC) (n = 29) participants. Dual regression independent component analysis approach was used to identify components that represented the ECN, DMN and SN. The intrinsic inter-network connectivity was compared between LLD and HC participants and the relationship of inter-network connectivity abnormalities with dimensional measures was examined. Relative to HC participants, LLD subjects showed decreased inter-network connectivity between the bilateral ECN and default mode subcortical (thalamus, basal ganglia and ventral striatum) networks, and the left ECN and SN insula component; and increased inter-network connections between the left ECN and posterior DMN and salience (dorsal anterior cingulate) network components. Distinct inter-network connectivity abnormalities correlated with depression and anxiety severity, and executive dysfunction in LLD participants. LLD subjects also showed pronounced intra-network connectivity differences within the ECN, whereas fewer but significant DMN and SN disruptions were also detected. Investigating the intrinsic inter-network functional connectivity could provide a mechanistic framework to better understand the neural basis that underlies core symptom dimensions in LLD. Inter-network connectivity measures have the potential to be neuroimaging biomarkers of symptom dimensions comprising LLD, and may assist in developing symptom-specific treatment algorithms.     

Resting state brain network function in major depression – Depression symptomatology,antidepressant treatment effects,future research

The alterations of functional connectivity brain networks in major depressive disorder (MDD) have been subject of a large number of studies. Using different methodologies and focusing on diverse aspects of the disease, research shows heterogeneous results lacking integration. Disrupted network connectivity has been found in core MDD networks like the default mode network (DMN), the central executive network (CEN), and the salience network, but also in cerebellar and thalamic circuitries. Here we review literature published on resting state brain network function in MDD focusing on methodology, and clinical characteristics including symptomatology and antidepressant treatment related findings. There are relatively few investigations concerning the qualitative aspects of symptomatology of MDD, whereas most studies associate quantitative aspects with distinct resting state functional connectivity alterations. Such depression severity associated alterations are found in the DMN, frontal, cerebellar and thalamic brain regions as well as the insula and the subgenual anterior cingulate cortex. Similarly, different therapeutical options in MDD and their effects on brain function showed patchy results. Herein, pharmaceutical treatments reveal functional connectivity alterations throughout multiple brain regions notably the DMN, fronto-limbic, and parieto-temporal regions. Psychotherapeutical interventions show significant functional connectivity alterations in fronto-limbic networks, whereas electroconvulsive therapy and repetitive transcranial magnetic stimulation result in alterations of the subgenual anterior cingulate cortex, the DMN, the CEN and the dorsal lateral prefrontal cortex. While it appears clear that functional connectivity alterations are associated with the pathophysiology and treatment of MDD, future research should also generate a common strategy for data acquisition and analysis, as a least common denominator, to set the basis for comparability across studies and implementation of functional connectivity as a scientifically and clinically useful biomarker.     

伴自杀意念抑郁症患者静息态下比率低频振幅特征研究

目的探讨伴自杀意念抑郁症患者的脑活动特征及其与抑郁严重程度、自杀意念和自杀危险的关系。方法运用比率低频振幅方法对30例伴自杀意念、22例不伴自杀意念抑郁症患者和21名正常对照的静息态功能磁共振图像进行比较,采用汉密尔顿抑郁量表17项(Hamilton depression scale 17-item,HAMD-17)评估抑郁症患者的抑郁严重程度,Beck自杀意念量表评估抑郁症患者的自杀意念和自杀危险,并分析伴自杀意念抑郁症组与不伴自杀意念抑郁症组差异脑区的比率低频振幅值与抑郁症严重程度、自杀意念和自杀危险的关系。结果伴自杀意念抑郁症组左侧枕上回/枕中回、右侧枕中回/枕下回fALFF值高于对照组(P0.05,AlphaSim校正),不伴自杀意念抑郁症组左侧枕中回fALFF值高于对照组(P0.05,AlphaSim校正),伴自杀意念抑郁症患者左侧枕中回、右侧枕中回fALFF值高于不伴自杀意念组(P0.05,AlphaSim校正)。伴自杀意念组左侧枕中回(r=0.366,P=0.046)、右侧枕中回(r=0.513,P=0.004)fALFF值分别与HAMD-17总分呈正相关,与Beck自杀意念量表相关无统计学意义(P0.05)。结论伴自杀意念抑郁症患者的双侧枕中回脑功能存在异常,但本研究未发现这种异常脑功能活动与Beck自杀意念量表的自杀意念和自杀危险因子具有相关性。