下腰痛患者脑网络的动态功能连接

目的:探究下腰痛（LBP）患者脑网络功能连接的动态变化。方法:对20例LBP患者及20例健康志愿者进行静息态 脑功能核磁共振扫描,采用连接数目熵（CNE）比较LBP患者与健康志愿者大脑的动态功能连接变化,分析LBP患者各独立 脑区的功能灵活性与年龄和日本骨科协会（JOA）量表评分的相关性。结果:全脑水平,LBP患者CNE低于正常人（P＜0.05）, 显著改变的脑区集中在额叶皮层、颞叶皮层、皮质下核团及部分枕叶皮层。脑区水平,LBP 患者中AAL 15（r=-0.525 5, P=0.020 8）、AAL32（r=-0.529 2,P=0.019 8）、AAL41（r=-0.546 9,P=0.015 4）、AAL62（r=0.601 5,P=0.006 4）、AAL76（r=-0.513 3, P=0.024 6）、AAL89（r=0.461 9, P=0.046 5）和AAL90（r=0.508 5, P=0.026 2）与年龄有临床相关性。LBP患者AAL17（r=-0.499 1, P=0.029 6）、AAL 47（r=0.481 4, P=0.036 9）、AAL 82（r=-0.554 8, P=0.013 7）、AAL 90（r=-0.562 1, P=0.012 3）与临床JOA量 表评分有相关性。结论:LBP患者全脑功能网络的功能灵活性是降低的。CNE动态功能连接的测量不仅为量化大脑活动 的时间与空间行为提供了一个新的框架,而且可以探索LBP脑功能变化的机理。     

强迫症患者脑岛功能连接异常磁共振成像研究

目的:探讨静息态下强迫症患者脑岛的功能连接特点。方法:纳入符合DSM-IV强迫症诊断标准的患者32例及性别、年龄、教育年限相匹配的正常对照37例,采用Y-BOCS量表评定强迫思维、强迫行为严重程度,应用3.0T磁共振成像系统进行静息态数据扫描。以双侧脑岛为感兴趣区(ROI)进行全脑功能连接(FC)分析,比较强迫症组与正常对照组之间的功能连接差异,并分析差异脑区功能连接强度与临床症状之间的关系。结果:与正常对照组相比,强迫症患者组的左侧脑岛与右侧缘上回、右侧顶下回、右侧顶上回的功能连接增强(FDR校正,P<0.01);右侧脑岛与右侧岛盖部额下回、左侧缘上回、右侧缘上回、右侧中央后回的功能连接增强(FDR校正,P<0.05);进一步分析发现,右侧脑岛与右侧中央后回的功能连接强度与强迫行为得分呈负相关(r=-0.35,P<0.05)。结论:强迫症患者脑岛的功能连接网络模式可能存在异常。     

Voxel‐wise brain‐wide functional connectivity abnormalities in first‐episode,drug‐naive patients with major depressive disorder

Due to different foci and single sample across studies, abnormal functional connectivity (FC) has been implicated in the pathophysiology of major depressive disorder (MDD) with inconsistent results. The inconsistency may reflect a combination of clinical and methodological variability, which leads to limited reproducibility of these findings. The samples included 59 patients with MDD and 31 controls from Sample 1, 29 patients with MDD and 24 controls from Sample 2, and 31 patients with schizophrenia and 37 controls from Sample 3. Global‐brain FC (GFC) and an overlapping technique were applied to analyze the imaging data. Compared with healthy controls, patients with MDD in Samples 1 and 2 showed increased GFC in the overlapped brain areas, including the bilateral insula, right inferior parietal lobule (IPL), and right supramarginal gyrus/IPL. By contrast, decreased GFC in the overlapped brain areas, including the bilateral posterior cingulate cortex/presuneus and left calcarine cortex, was found in patients with MDD. In addition, patients with schizophrenia in Sample 3 did not show any GFC abnormalities in the overlapped areas from the results of Samples 1 and 2. The present study is the first to examine voxel‐wise brain‐wide FC in MDD with two independent samples by using an overlapping technique. The results indicate that aberrant FC patterns of insula‐centered sensorimotor circuit may account for the pathophysiology of MDD.     

Effects of transcutaneous auricular vagus nerve stimulation on brain functional connectivity of medial prefrontal cortex in patients with primary insomnia

As a representative of acupuncture and nonpharmaceutical therapy, auricular acupuncture has been widely for the treatment of insomnia. Transcutaneous auricular vagus nerve stimulation (taVNS) is a combination of auricular point stimulation and vagus nerve stimulation. It can not only treat primary insomnia effectively, but also is noninvasive, painless, portable and economical. The medial prefrontal cortex (mPFC) is a core region of default mode network (DMN), which is important for maintenance of sleep. However, the mechanism of taVNS in alleviating primary insomnia (PI) remains to be clarified. In this study, we found that taVNS could not only effectively reduce the score of Pittsburgh Sleep Quality Index, but also decreased functional connection (FC) between the left mPFC and bilateral dorsal anterior cingulate gyrus as well as FC between the right mPFC and the occipital cortex in patients with PI. Furthermore, the decrease in FC was positively correlated with the decline of sleep index score. Therefore, we proposed that treatment with taVNS can improve sleep quality and prolong sleep duration in patients with PI by reducing FC within DMN, FC between DMN and salience network, as well as FC between DMN and the occipital cortex. This may be one of mechanisms of taVNS in treating PI.     

基于动态功能连接分析的青少年吸烟者大脑静息态默认模式网络

采集30名青少年吸烟者和相匹配的30名非吸烟者的静息态功能性磁共振成像数据。通过独立成分分析、滑动窗相关法和k-均值聚类分析探讨青少年吸烟者的默认模式网络的动态功能连接变化。同时,使用斯皮尔曼相关分析评估动态功能连接指标（时间分数、平均停留时间和转换次数）与吸烟统计学数据（烟龄、包年和FTND）的关系。结果显示,相比于非吸烟组,青少年吸烟者大脑的默认模式网络的功能连接性降低,进一步的相关性分析表明动态功能连接指标中的平均停留时间与烟龄呈显著性正相关。此项研究从动态功能网络连接的角度分析吸烟对青少年吸烟者默认模式网络的影响,可以为进一步探索青少年吸烟成瘾机制提供新的视角。     

基于静息态功能磁共振图像的动态功能连接特征的智商预测

目的近年来越来越多的研究表明大脑不同脑区间的功能连接的动态波动具有生理意义,但关于智商(intelligence quotient,IQ)的相关研究较少。本文基于动态功能连接(dynamic functional connectivity,DFC)提取动态特征对智商进行评估,为智商预测探索新的特征参数和预测模型。方法基于97个儿童静息态功能磁共振图像(resting state functional magnetic resonance image,RS-fMRI),采用滑动窗相关计算方法构建DFC。基于DFC提取相应时域、频域特征,通过弹性网(elastic-net,E-Net)和最小角回归(least angle regression,LAR)算法建立智商回归模型进行个体智商预测,并通过置换检验验证其显著性。结果基于动态功能连接的特定频段(0.075~0.1 Hz)频域特征和波动均值特征,可以实现对智商的基本预测,且频域特征的表现优于时域特征。另外,基于LAR算法构建的预测模型的表现优于E-Net算法。结论个体脑功能连接随时间的动态波动足以预测个体智商,且特定频段的频域特征和LAR算法能够提高预测准确率,这可为个体智商评估研究和动态功能连接的应用提供新的思路。     

正常脑老化中静息态功能磁共振成像功能连接的研究进展

【摘要】静息态功能磁共振成像（fMRI）作为一种不需要任务刺激就能呈现功能脑影像的技术手段,在临床上被广泛应 用。基于静息态fMRI的静息态功能连接（RSFC）,作为一种重要的计算机辅助分析法,能够度量不同脑区的脑功能连接 强度,对脑老化相关的神经科学领域的研究具有重要意义。本文介绍了功能连接的基本概念,总结了近年来脑老化相关 的人脑功能连接的研究成果,最后提出了该研究领域存在的问题及未来的研究方向。     

注意缺陷多动障碍儿童动态功能连接的功能磁共振成像研究

目的:探索注意缺陷多动障碍儿童静态以及动态功能连接的异常。方法:收集智商高于80的6～16岁符合DSM-IV诊断的注意缺陷多动障碍儿童97例(男78例,女19例)和年龄匹配的正常对照儿童74例(男45例,女29例)的静息态功能磁共振成像数据,比较两组全脑静态功能连接和动态功能连接指标。结果:注意缺陷多动障碍组的静态功能连接与正常对照组的差异无统计学意义(P>0.05),注意缺陷多动障碍组腹外侧前额叶与全脑其他脑区功能连接的模式变异性大于正常对照组[(0.65±0.07)%vs.(0.60±0.08)%,P<0.01]。结论:动态分析提示腹外侧前额叶是注意缺陷多动障碍的关键脑区,为理解疾病的脑机制提供可能的新视角。     

慢性失眠患者大脑蓝斑的异常静息态功能连接

目的:利用功能连接方法观察慢性失眠患者静息态下蓝斑的异常功能连接。方法:采集49例慢性失眠患者以及47例性别年龄和受教育程度相匹配的健康对照组的功能磁共振图像,以蓝斑为感兴趣区域,与全脑其他体素进行功能连接分析,得到两组之间功能连接的差异脑区,再对异常连接脑区的功能连接值与临床量表分数做相关分析。结果:与对照组相比,慢性失眠患者蓝斑与右楔前叶皮质、右后扣带回皮质、左颞中回皮质、左距状沟周围皮质、右眶部额上回皮质之间的功能连接增强（P<0.05, FDR校正）,并且蓝斑与左颞中回皮质之间功能连接值与抑郁自评量表呈正相关（P=0.021）。结论:慢性失眠患者蓝斑与多个脑区（主要是默认模式网络）出现的异常功能连接,可能有助于更好地理解慢性失眠的神经生物学机制,可能为失眠的高度唤醒假说提供新的影像学证据。     

2型糖尿病患者海马体脑功能连接的磁共振成像研究

目的:应用功能磁共振成像技术研究2 型糖尿病（T2D）患者静息状态下海马功能连接的变化。方法:采集27 例 T2D患者和32例正常人的脑功能磁共振成像信号,选择海马的4个分区作为种子点计算功能连接,对海马与其他脑区的 功能连接强度与临床指标进行相关性分析。结果:与正常人相比,T2D患者的右前海马与梭状回、枕中回之间的功能连接 减弱;左前海马与梭状回功能连接增强;右后海马与距状回功能连接减弱;左后海马与舌回功能连接增强。结论:T2D患 者相关脑区功能连接的改变可能与视觉相关认知功能的损伤有关,这为理解T2D患者海马体的功能提供线索。     

Comparative study of regional homogeneity in schizophrenia and major depressive disorder

Compelling evidence suggests that there is a considerable overlap in structural and functional alternation in the brain between different neuropsychiatric disorders. However, whether these overlaps are specific for schizophrenia has yet to be investigated. A total of 36 patients with paranoid schizophrenia, 43 patients with major depressive disorder (MDD), and 44 healthy controls were recruited to undergo resting‐state functional magnetic resonance imaging (rs‐fMRI) for analysis of regional homogeneity (ReHo). Twelve regions of interest (ROIs) in the frontal and temporal lobes were generated and one‐way ANOVA was performed to test the ReHo differences within these ROIs between the above three groups. The ReHo values within ROIs were extracted to investigate whether a left‐right asymmetry existed in a mental disorder. One‐way ANOVA showed significant differences in ReHo in the right superior frontal gyrus and left superior temporal gyrus; post hoc analysis revealed that schizophrenic patients had lower ReHo in the left superior temporal gyrus than either control subjects or patients with MDD. Increased ReHo was observed in the right superior frontal gyrus in schizophrenic patients compared with control subjects, and a left‐less‐than‐right asymmetry was also found in this region in schizophrenic patients. The above alterations in ReHo were not affected by age and genders. Our study suggests that the altered ReHo in the superior frontal and temporal gyrus may be specific for schizophrenia rather than MDD. A left‐less‐than‐right asymmetry activation pattern may exist in the resting‐state superior frontal gyrus in schizophrenia. This finding would be helpful for better understanding the pathological mechanisms of schizophrenia. © 2012 Wiley Periodicals, Inc.     

基于独立成分分析的青年吸烟者大脑静息态执行网络功能连接变化研究

采用独立成分分析方法探索40名青年吸烟者和40名年龄与性别相匹配的非吸烟者的静息态功能磁共振数据,并结合“双重回归”方法探索吸烟者执行网络功能连接变化,同时将有变化的脑区与吸烟统计学数据进行Pearson’s双变量相关分析,例如年龄、包年、FTND、烟龄等。通过研究发现,青年吸烟者的大脑右中央执行网络的功能连接性增强,相关分析表明执行网络包含的背外侧前额叶皮质与烟龄呈显著性负相关（r=-0.339, P=0.032）。此项研究结果表明,吸烟对右侧中央执行网络的功能连接有一定的影响,研究结果可能为青年吸烟成瘾者的神经机制的特征提供额外的新见解。     

基于功能连接算法的斜视性弱视儿童静息态功能磁共振成像的研究

目的探索斜视性弱视儿童脑功能区及其功能连接的改变,揭示斜视性弱视的发生与脑功能改变的相关性。方法在静息态下采集22位斜视性弱视儿童和10名健康儿童脑功能磁共振图像,利用DPARSF软件计算全脑与ROI功能区的连接系数,并应用t检验对实验组和健康对照组进行组内和组间功能连接系数分析。结果发现斜视性弱视儿童部分脑功能连接低于正常对照组的相应脑区连接,这些功能区主要分布于枕叶、颞叶、小脑后叶、顶叶、额叶、扣带回等脑区。结论基于静息态的f MRI的脑功能连接算法可以反映斜视性弱视儿童视皮层的变化和多脑区神经活动的变化。     

Altered cortical and subcortical local coherence in obstructive sleep apnea: a functional magnetic resonance imaging study

Obstructive sleep apnea (OSA) syndrome is the most common sleep‐related breathing disorder, characterized by excessive snoring and repetitive apneas and arousals, which leads to fragmented sleep and, most importantly, to intermittent nocturnal hypoxaemia during apneas. Considering previous studies about morphovolumetric alterations in sleep apnea, in this study we aimed to investigate for the first time the functional connectivity profile of OSA patients and age–gender–matched healthy controls, using resting‐state functional magnetic resonance imaging (fMRI). Twenty severe OSA patients (mean age 43.2 ± 8 years; mean apnea–hypopnea index, 36.3 h^?1) and 20 non‐apneic age–gender–body mass index (BMI)‐matched controls underwent fMRI and polysomnographic (PSG) registration, as well as mood and sleepiness evaluation. Cerebro‐cerebellar regional homogeneity (ReHo) values were calculated from fMRI acquisition, in order to identify pathology‐related alterations in the local coherence of low‐frequency signal (<0.1 Hz). Multivariate pattern classification was also performed using ReHo values as features. We found a significant pattern of cortical and subcortical abnormal local connectivity in OSA patients, suggesting an overall rearrangement of hemispheric connectivity balance, with a decrease of local coherence observed in right temporal, parietal and frontal lobe regions. Moreover, an increase in bilateral thalamic and somatosensory/motor cortices coherence have been found, a finding due possibly to an aberrant adaptation to incomplete sleep–wake transitions during nocturnal apneic episodes, induced by repetitive choke sensation and physical efforts attempting to restore breathing. Different hemispheric roles into sleep processes and a possible thalamus key role in OSA neurophysiopathology are intriguing issues that future studies should attempt to clarify.     

Spontaneous BOLD event triggered averages for estimating functional connectivity at resting state

Recent neuroimaging studies have demonstrated that the spontaneous brain activity reflects, to a large extent, the same activation patterns measured in response to cognitive and behavioral tasks. This correspondence between activation and rest has been explored with a large repertoire of computational methods, ranging from analysis of pairwise interactions between areas of the brain to the global brain networks yielded by independent component analysis. In this paper we describe an alternative method based on the averaging of the BOLD signal at a region of interest (target) triggered by spontaneous increments in activity at another brain area (seed). The resting BOLD event triggered averages ("rBeta") can be used to estimate functional connectivity at resting state. Using two simple examples, here we illustrate how the analysis of the average response triggered by spontaneous increases/decreases in the BOLD signal is sufficient to capture the aforementioned correspondence in a variety of circumstances. The computation of the non linear response during rest here described allows for a direct comparison with results obtained during task performance, providing an alternative measure of functional interaction between brain areas.     

Reduced functional connectivity in early-stage drug-naive Parkinson's disease: a resting-state fMRI study

Although cardinal motor symptoms in Parkinson's disease (PD) are attributed to dysfunction of corticostriatal loops, early clinical nonmotor features are more likely to be associated with other pathologic mechanisms. We enrolled 52 early-stage drug-naive PD patients and 52 age- and sex-matched healthy controls and used resting-state functional connectivity magnetic resonance imaging to evaluate alteration of the functional brain network in PD, focusing in particular on the functional connectivity of the striatum subregions. Relative to healthy controls, the PD patient group showed reduced functional connectivity in mesolimbic-striatal and corticostriatal loops. Although the deceased functional connectivity within cortical sensorimotor areas was only evident in the most affected putamen subregion, reduced functional connectivity with mesolimbic regions was prevalent throughout the striatum. No increased functional connectivity was found in this cohort. By studying a cohort of early-stage drug-naive PD patients, we ruled out the potential confounding effect of prolonged antiparkinson medication use on the functional integration of neural networks. We demonstrate decreased functional integration across neural networks involving striatum, mesolimbic cortex, and sensorimotor regions in these patients and postulate that the prevalent disconnection in mesolimbic-striatal loops is associated with some early clinical nonmotor features in PD. This study offers additional insight into the early functional integration of neural networks in PD.     

Altered functional brain networks in Prader–Willi syndrome

Prader–Willi syndrome (PWS) is a genetic imprinting disorder characterized mainly by hyperphagia and early childhood obesity. Previous functional neuroimaging studies used visual stimuli to examine abnormal activities in the eating‐related neural circuitry of patients with PWS. It was found that patients with PWS exhibited both excessive hunger and hyperphagia consistently, even in situations without any food stimulation. In the present study, we employed resting‐state functional MRI techniques to investigate abnormal brain networks related to eating disorders in children with PWS. First, we applied amplitude of low‐frequency fluctuation analysis to define the regions of interest that showed significant alterations in resting‐state brain activity levels in patients compared with their sibling control group. We then applied a functional connectivity (FC) analysis to these regions of interest in order to characterize interactions among the brain regions. Our results demonstrated that patients with PWS showed decreased FC strength in the medial prefrontal cortex (MPFC)/inferior parietal lobe (IPL), MPFC/precuneus, IPL/precuneus and IPL/hippocampus in the default mode network; decreased FC strength in the pre‐/postcentral gyri and dorsolateral prefrontal cortex (DLPFC)/orbitofrontal cortex (OFC) in the motor sensory network and prefrontal cortex network, respectively; and increased FC strength in the anterior cingulate cortex/insula, ventrolateral prefrontal cortex (VLPFC)/OFC and DLPFC/VLPFC in the core network and prefrontal cortex network, respectively. These findings indicate that there are FC alterations among the brain regions implicated in eating as well as rewarding, even during the resting state, which may provide further evidence supporting the use of PWS as a model to study obesity and to provide information on potential neural targets for the medical treatment of overeating. Copyright © 2013 John Wiley & Sons, Ltd.     

吸烟成瘾者戒烟前后的静息态功能磁共振研究

为了发现吸烟成瘾者在戒烟前后的脑功能特征改变,探索戒烟过程的神经生理理论基础,14名吸烟成瘾者同意戒烟并完成了试验,另外11名健康不吸烟的志愿者参与了对照试验。采取两因素混合实验设计方法,以静息态功能磁共振影像技术为技术手段,利用区域一致性算法来研究吸烟成瘾者在戒烟前后的神经活动及其与正常人之间的差异,并对这些差异进行组内与组间交互分析。戒烟两周后,在补充运动区、中央旁小叶、距状裂周围皮层、楔叶和舌回等区域的Re Ho值明显上升,意味着在这些脑区的神经活动同步性增强,而在楔前叶和后扣带回脑区同步性降低。在补充运动区、中央旁小叶、中央前回、中央后回、眶部额上回等脑区存在组间交叉效应。本研究结果显示吸烟成瘾者戒烟2周后在补充运动区的功能显著增强。     

Resting state functional connectivity of five neural networks in bipolar disorder and schizophrenia

Background

Bipolar disorder (BPD) and schizophrenia (SCZ) share clinical characteristics and genetic contributions. Functional dysconnectivity across various brain networks has been reported to contribute to the pathophysiology of both SCZ and BPD. However, research examining resting-state neural network dysfunction across multiple networks to understand the relationship between these two disorders is lacking.

Methods

We conducted a resting-state functional connectivity fMRI study of 35 BPD and 25 SCZ patients, and 33 controls. Using previously defined regions-of-interest, we computed the mean connectivity within and between five neural networks: default mode (DM), fronto-parietal (FP), cingulo-opercular (CO), cerebellar (CER), and salience (SAL). Repeated measures ANOVAs were used to compare groups, adjusting false discovery rate to control for multiple comparisons. The relationship of connectivity with the SANS/SAPS, vocabulary and matrix reasoning was investigated using hierarchical linear regression analyses.

Results

Decreased within-network connectivity was only found for the CO network in BPD. Across groups, connectivity was decreased between CO-CER (p<0.001), to a larger degree in SCZ than in BPD. In SCZ, there was also decreased connectivity in CO-SAL, FP-CO, and FP-CER, while BPD showed decreased CER-SAL connectivity. Disorganization symptoms were predicted by connectivity between CO-CER and CER-SAL.

Discussion

Our findings indicate dysfunction in the connections between networks involved in cognitive and emotional processing in the pathophysiology of BPD and SCZ. Both similarities and differences in connectivity were observed across disorders. Further studies are required to investigate relationships of neural networks to more diverse clinical and cognitive domains underlying psychiatric disorders.