基于功能连接的复发缓解型多发性硬化患者默认网络静息态功能磁共振成像

目的 采用静息态功能磁共振成像(rs-fMRI)基于种子点相关性分析技术对复发缓解型多发性硬化(RRMS)患者默认网络的功能连接改变进行研究.方法 使用3.0T磁共振采集RRMS组和健康对照组(各27例)rs-fMRI数据.数据经预处理后,选择后扣带回(-5,-49,40)为种子点,采用基于种子点相关性分析技术进行功能连接分析,分别在默认网络内和默认网络外脑区比较两组功能连接的差异.分析差异脑区与临床参数如临床扩展残疾量表、同步听觉连续加法测验评分(PASAT)、脑实质分数、T2可见病灶数和病程的相关性.结果 基于种子点相关性分析技术构建的RRMS患者默认网络包含脑区主要有前额叶皮质腹侧、双侧顶下叶、后扣带回及楔前叶等脑区.在默认网络内比较,RRMS患者较健康对照组右侧额上回功能连接下降;右侧小脑后叶、右侧小脑脚、右侧颞中回、右侧额中回、左侧楔前叶及扣带回、右侧角回、右侧扣带回功能连接增高.RRMS患者组默认网络内差异脑区中,右侧颞中回功能连接系数(0.387±0.216)与PASAT呈负相关(r=-0.590,P =0.001);患者右侧额上回功能连接系数(0.039±0.293)与病程之间呈负相关(r=-0.390,P=0.041).在默认网络外比较,RRMS组后扣带回功能连接下降脑区有右侧额上回、左侧枕中回、左侧中央前回;功能连接增高脑区有右侧小脑前叶(含齿状核)、右侧额叶白质区.RRMS组后扣带回与左侧中央前回、右侧小脑前叶功能连接系数(-0.924±0.253和0.217±0.208)分别与病程之间存在正相关(r =0.650,P=0.000;r =0.436,P=0.023).结论 RRMS患者默认网络内和默认网络外均出现后扣带回静息态功能连接的异常改变,表明患者存在功能下降和代偿的复杂过程.RRMS患者存在有限功能重构或重组,以维持默认网络的功能稳定.     

海洛因成瘾者默认网络功能改变的静息态功能磁共振成像研究北大核心CSCD

目的 探讨海洛因成瘾者默认网络的功能影像学改变。方法 14例海洛因成瘾者（海洛因成瘾组）和14名对照者（对照组）进行静息态fMRI扫描,采用独立成分分析方法分别提取海洛因成瘾组和对照组的默认网络进行组内及组间分析,以了解成瘾者默认网络功能连接改变的脑区。结果 与对照组比较,海洛因成瘾组默认网络的额上回内侧（t＝-2.61）、前扣带回（t＝-3.32）及楔叶（t左＝-3.49,t右＝-3.40）的功能连接减弱,后扣带回（t＝4.55）、楔前叶（t左＝4.31,t右＝3.54）以及角回（t左＝2.57,t右＝6.39）的功能连接增强,均P〈0.05。结论 静息态下海洛因成瘾者的默认网络存在功能连接异常。     

单相和双相抑郁障碍患者前扣带回功能连接特征差异观察北大核心CSCD

目的比较单、双相抑郁障碍前扣带回功能连接的差异,探讨前扣带回功能连接与抑郁症状严重程度的关系。方法利用fMRI技术,对符合DSM-Ⅳ诊断标准的30例单相抑郁障碍(unipolar depression)患者(单相抑郁组)、30例双相抑郁障碍(bipolar depression)患者(双相抑郁组)及年龄、性别、受教育程度相匹配的32名对照者(对照组)进行静息态fMRI扫描,以前扣带回为感兴趣区进行功能连接分析,比较组间差异,并对功能连接强度与抑郁症状的严重程度之间的关联进行Pearson相关分析。结果(1)与对照组相比,单相抑郁组左侧前扣带回与左侧三角部额下回(t=3.48)、左侧顶下缘角回(t=3.15)之间的功能连接增强,右侧前扣带回与左侧三角部额下回(t=3.52)之间的功能连接增强;(2)与对照组相比,双相抑郁组左侧前扣带回与右侧颞中回(t=-4.00)之间的功能连接减低,右侧前扣带回与左侧中央后回(t=-3.46)、右侧颞上回(t=-2.86)、右侧颞中回(t=-3.40)之间的功能连接减低;(3)与双相抑郁组相比,单相抑郁组左侧前扣带回与左侧三角部额下回(t=3.58)、右侧三角部额下回(t=4.06)、右侧颞中回(t=3.25)、左侧顶下缘角回(t=3.27)、右侧顶下缘角回(t=3.99)之间的功能连接增强;右侧前扣带回与左侧三角部额下回(t=3.13)、左侧顶下缘角回(t=3.42)、右侧顶下缘角回(t=3.78)之间的功能连接增强(均采用Alphasim校正,P<0.001);(4)Pearson相关分析显示,以上差异脑区功能连接强度与HAMD17总分均无相关性(-0.20.05)。结论静息态下单相抑郁患者前扣带回功能连接增强,双相抑郁患者前扣带回功能连接减弱;单、双相抑郁障碍差异脑区功能连接强度与临床症状无相关性。     

抑郁症静息态默认状态网络内功能连接的初步探讨

目的 通过分析静息态下抑郁症患者默认状态网络内脑区间功能连接效能,探讨默认状态网络在抑郁症病理机制中的作用.方法 15例符合中国精神障碍分类及诊断标准第3版(CCMD-3)抑郁发作和美国精神障碍诊断与统计手册第4版(DSM-Ⅳ)重性抑郁症诊断标准的首发抑郁症患者与14名正常对照完成功能磁共振成像扫描.分析受试者默认状态网络内脑区的功能连接强度并比较其组问差异.结果 与正常对照比较,抑郁症患者双侧前额中部与楔前叶、双侧后扣带回与前额中部、右后扣带回与楔前叶、双侧前扣带回腹侧与前额中部的功能连接减低(P＜0.05).结论 静息态下抑郁症患者默认状态网络内脑区间的连接效能存在异常,这可能在抑郁症的病理机制中发挥了重要作用.     

静息状态功能磁共振成像观察轻度阿尔茨海默病后扣带回功能连通性的变化

目的 利用静息状态功能磁共振成像(fMRI)研究阿尔茨海默病(AD)早期后扣带回相关的静息脑网络连通性是如何变化的.方法 运用fMRI研究了16例轻度AD患者和16名健康对照者在静息状态后扣带回的功能连通性.与后扣带回有功能连通性的脑区是通过检测低频波动信号的时程相关性获得的.应用通用的SPM2图像统计软件计算组间和组内连通性差异,激活区阈值设置:P<0.01(校正),像素范围>5.利用SPM2软件随机效应分析t检验(经校正P<0.01,t=2.47,像素范围>5),比较患者组和对照组连通性激活的脑区.结果 与后扣带回有功能连通性减弱的脑区包括前额叶中线区、楔前叶、双侧视皮质、双侧颞下回、左侧海马、右侧丘脑、右侧额叶背外侧区;偏左侧化的连通性增高的脑区包括前额叶中线区、左侧颞下回、左侧基底节区、双侧额叶背外侧区及左侧中央前区.结论 与后扣带回相关的静息状态脑网络连通性减低与AD早期情节记忆损害和高级视觉功能损害有关系,轻度AD保留着功能连接的重塑性以便维持脑功能.静息fMRI是一种探索AD脑功能机制的适宜方法.     

青少年非自杀性自伤患者静息态功能磁共振研究北大核心CSCD

目的探讨非自杀性自伤(non-suicidal self-injury,NSSI)青少年静息态功能磁共振成像下脑功能特征。方法采用病例对照研究设计,纳入NSSI青少年患者23例(NSSI组)与健康青少年18名(healthy control,HC组),进行静息态功能MRI扫描,分析NSSI组与HC组低频振幅(amplitude of low frequency fluctuation,ALFF)有差异的脑区,以差异脑区为种子点计算全脑功能连接(functional connectivity,FC),并分析NSSI组差异脑区的ALFF值与青少年非自杀性自伤行为评定问卷及汉密尔顿抑郁量表评分相关性。结果与HC组比较,NSSI组ALFF升高的脑区包括双侧杏仁核(x=-27,y=3,z=-24,t=2.492,P<0.05,FDR校正;x=27,y=3,z=-12,t=2.746,P<0.05,FDR校正)、右侧背外侧额上回(x=15,y=21,z=45,t=4.051,P<0.05,FDR校正)。以双侧杏仁核作为种子点分别计算全脑FC,与HC组比较,NSSI组左侧杏仁核与右侧前扣带回(t=3.352,P<0.05,FDR校正)、左侧前扣带回(t=2.843,P<0.05,FDR校正)、右侧丘脑(t=3.026,P<0.05,FDR校正)、左侧丘脑(t=2.352,P<0.05,FDR校正)FC强度增高,与左侧眶部额上回(t=-2.181,P<0.05,FDR校正)、左侧眶部额中回(t=-3.378,P<0.05,FDR校正)FC强度减低。NSSI组左侧杏仁核ALFF值与汉密尔顿抑郁量表评分呈正相关(r=0.627,P=0.004)。结论NSSI青少年静息态下多个脑区存在神经元异常活动,左侧杏仁核与多个脑区的FC存在异常,这可能是NSSI神经病理发病机制。     

“临床治愈”抑郁症患者默认网络静息态功能连接研究

目的:结合静息态功能连接方法,探讨"临床治愈"抑郁症(remitted major depressive disorder,r MDD)患者默认网络(default mode network,DMN)功能连接的变化。方法:对22例经过住院治疗达到r MDD标准的患者(患者组)和22名相匹配正常对照组进行静息态功能磁共振扫描,以DMN公认的内侧前额叶(medial prefrontal cortex,m PFC)和后扣带回(posterior cingulate cortex,PCC)为种子点,通过种子点与全脑的功能连接分析,使用双样本t检验比较两组的功能连接差异。结果:与正常对照组比较,患者组m PFC与右侧角回(t=3.96,P0.01)、右侧旁扣带回(t=4.57,P0.01)、右侧额下回(t=4.25,P0.01)功能连接增加,与左侧前扣带回(t=-3.50,P0.01)、右侧PCC(t=-3.57,P0.01)功能连接降低;PCC与左侧枕中回(t=3.47,P0.01)、右侧枕中回(t=4.18,P0.01)功能连接增加。结论:r MDD患者DMN功能连接仍存在异常,可能与反刍症状及注意等认知偏向未完全改善有关。     

双相障碍抑郁发作患者静息态脑功能特征北大核心CSCD

目的探讨双相抑郁发作患者的静息态脑功能自发神经活动特征。方法对双相抑郁组（26例）和健康对照组（26例）的静息态功能影像数据进行预处理并计算比率低频振荡振幅分数（fractional amplitude of low frequency fluctuation,fALFF）值,分析各脑区自发神经活动的变化;对2组被试者fALFF均值进行两样本t检验,fALFF均值差异有统计学意义的脑区定义为P〈0.01（AlphaSim校正,体素个数〉13,P〈0.001）。结果与健康对照组相比,双相抑郁组fALFF值显著降低的脑区为右侧后扣带回（t=-4.49）、左侧顶下小叶（t=-4.29）、左侧楔前叶（t=-5.05）及右侧额上回（t=-5.04,t=-3.86）;fALFF值显著增强的脑区为左侧枕中回（t=3.92）、双侧舌回（t=5.04）,均P〈0.01。结论双相抑郁患者存在默认网络及视觉认知网络相关脑区的自发神经活动异常。     

难治性癫痫患者楔前叶功能连接的静息态功能磁共振成像研究

目的应用静息态功能磁共振成像(rs-f MRI)探讨难治性癫痫患者楔前叶与全脑功能连接的改变及其意义。方法对23例难治性癫痫患者(癫痫组)及23名健康人(对照组)进行rs-f MRI检查,采集数据后采用功能连接的方法,分别计算以左侧楔前叶和右侧楔前叶为感兴趣区与全脑的功能连接,运用双样本t检验的统计学方法发现两组的显著性差异并进行分析。结果癫痫组左侧楔前叶与双侧顶下小叶、双侧岛叶、右侧缘上回、右侧额中回和双侧额下回的功能连接较对照组减弱(均P0.05);癫痫组左侧楔前叶与双侧海马旁回、双侧额上回、左侧后扣带回的功能连接较对照组增强(均P0.05)。癫痫组右侧楔前叶与左侧顶下小叶、右侧缘上回、右侧额中回、右侧额下回的功能连接较对照组减弱(均P0.05);癫痫组右侧楔前叶与双侧楔叶、左侧后扣带回的功能连接较对照组增强(均P0.05)。结论难治性癫痫患者静息状态下楔前叶与全脑的功能连接存在异常,"默认网络"功能的抑制可能是癫痫患者意识及认知等功能损害的重要原因。     

首发Tourette综合征静息态功能磁共振脑比率低频振幅的研究

目的 探讨首发Tourette综合征(TS)静息态下功能磁共振(fMRI)脑比率低频振幅(fALFF)的特征.方法 16例TS患儿(研究组)和16例良好匹配的健康受试者(对照组)均接受静息态功能共振(fMRI)扫描.在0.01～0.1 Hz频段内计算fALFF值,两组进行独立样本t检验.结果 研究组患儿基于BOLD信号的fALFF值在如下脑区强于对照组:左侧梭状回(t =4.36,P＜0.05)、右侧壳核(t=3.81,P＜0.05);研究组患儿基于BOLD信号的fALFF值在如下脑区弱于对照组:左侧额下回三角部(t=-6.13,P＜0.05)、右侧额中回(t=-4.35,P＜0.05)、左侧额上回(t=-4.51,P＜0.05)、左侧枕中回(t=-6.13,P＜0.05)、左侧罗兰迪克岛盖(t=-4.58,P＜0.05)、右侧罗兰迪克岛盖(t=-4.28,P＜0.05).结论 首发Tourette综合征患儿在一些脑区存在脑功能活动的异常,有助于揭示Tourette综合征的神经生理机制.     

Aberrant functional brain network dynamics in patients with functional constipation

The aberrant static functional connectivity of brain network has been widely investigated in patients with functional constipation (FCon). However, the dynamics of brain functional connectivity in FCon patients remained unknown. This study aimed to detect the brain dynamics of functional connectivity states and network topological organizations of FCon patients and investigate the correlations of the aberrant brain dynamics with symptom severity. Eighty‐three FCon patients and 80 healthy subjects (HS) were included in data analysis. The spatial group independent component analysis, sliding‐window approach, k‐means clustering, and graph‐theoretic analysis were applied to investigate the dynamic temporal properties and coupling patterns of functional connectivity states, as well as the time‐variation of network topological organizations in FCon patients. Four reoccurring functional connectivity states were identified in k‐means clustering analysis. Compared to HS, FCon patients manifested the lower occurrence rate and mean dwell time in the state with a complex connection between default mode network and cognitive control network, as well as the aberrant anterior insula–cortical coupling patterns in this state, which were significantly correlated with the symptom severity. The graph‐theoretic analysis demonstrated that FCon patients had higher sample entropy at the nodal efficiency of anterior insula than HS. The current findings provided dynamic perspectives for understanding the brain connectome of FCon and laid the foundation for the potential treatment of FCon based on brain connectomics.     

Predictors of change in functional competence and functional behavior after functional adaptation skills training for schizophrenia

ABSTRACT: Functional recovery is an important treatment target in schizophrenia. Although medication is effective at reducing positive symptoms of the disorder, these improvements do not translate to improved functioning. In this study, schizophrenia outpatients (N = 54) received the psychosocial treatment Functional Adaptation Skills Training. Hierarchical regression analyses determined whether baseline neurocognitive, symptom, course of illness, and demographic variables predicted improvement in performance-based measures of functional competence and case manager-rated real-world behavior after the intervention. Consistent with previous research, neurocognition emerged as a predictor of improved competence and behavior. Symptoms played a minor role in predicting change; however, institutionalization history seemed to be an important rate limiter for functional recovery. Correlations among change scores were modest, with evidence for concomitant changes in competence and performance. The predictors of change after psychosocial treatment vary by the domain (e.g., adaptive and interpersonal) of functioning and the level of assessment (e.g., competence and performance).     

Presurgical functional mapping with functional MRI

PURPOSE OF REVIEW: The present article describes current indications for functional MRI in the preoperative planning of neurosurgical patients. Functional MRI continues to have an expanding role. RECENT FINDINGS: There are three main categories of patients who commonly undergo preoperative functional MRI. Patients with lesions close to eloquent cortex can benefit from preoperative functional MRI to assess resectability and reduce the possibility of functional deficit. The second group are those patients who have functional MRI as part of their preoperative planning to localize language dominance and for functional localization of memory. The final group are those patients in whom attempts are made to image and localize abnormal brain function. This has a specific application in the field of epilepsy surgery (electroencephalographic-correlated functional MRI). These three roles require different spatial resolutions. Advances in multimodality imaging are enabling more accurate localization of function intraoperatively. SUMMARY: It is hoped that the increasing use of functional MRI in combination with both preoperative and intraoperative imaging modalities may reduce the risk of neurological deficit while improving completeness of resection. Electroencephalographic-correlated functional MRI may provide an additional method for localization of epileptogenic foci.     

Widespread functional disconnectivity in schizophrenia with resting-state functional magnetic resonance imaging

Using resting-state functional magnetic resonance imaging, we examined the functional connectivity throughout the entire brain in schizophrenia. The abnormalities in functional connectivity were identified by comparing the correlation coefficients of each pair of 116 brain regions between 15 patients and 15 controls. Then, the global distribution of the abnormal functional connectivities was examined. Experimental results indicated, in general, a decreased functional connectivity in schizophrenia during rest, and such abnormalities were widely distributed throughout the entire brain rather than restricted to a few specific brain regions. The results provide a quantitative support for the hypothesis that schizophrenia may arise from the disrupted functional integration of widespread brain areas.     

Residual functional connectivity in the split-brain revealed with resting-state functional MRI

Split-brain patients present a unique opportunity to address controversies regarding subcortical contributions to interhemispheric coordination. We characterized residual functional connectivity in a complete commissurotomy patient by examining patterns of low-frequency BOLD functional MRI signal. Using independent components analysis and region-of-interest-based functional connectivity analyses, we demonstrate bilateral resting state networks in a patient lacking all major cerebral commissures. Compared with a control group, the patient's interhemispheric correlation scores fell within the normal range for two out of three regions examined. Thus, we provide evidence for bilateral resting state networks in a patient with complete commissurotomy. Such continued interhemispheric interaction suggests that, at least in part, cortical networks in the brain can be coordinated by subcortical mechanisms.     

Adoption studies in functional psychosis

Summary The scientific rationale of the adoptive methods in genetic studies has been discussed. Three strategies have been employed in psychiatric research. In the adoptee's study method, one examines the adopted away offspring of biological parents, known to be affected by the disorder. A higher prevalence of the disorder among adoptees born to affected biological parents indicates that genetic factors are important. In the adoptee's relatives method, one starts with adoptees known to be disturbed, and then continues by investigating their biological and adoptive families. Comparisons of prevalence rates between relatives of the biological and the rearing index and control families permits one to estimate the influence of the genetic factors. A third method is crossfostering, which is rarely employed. Children of normals who are cross-fostered to adoptive parents who later became ill, are studied. Adoption studies in the field of schizophrenia and manic depressive illness are more specifically discussed. Taken all together, the family, twin and adoption studies support the genetic etiology in schizophrenia and manic depressive illness, although it must be admitted that we need replications to arrive at firm conclusions in the last group of disorder.     

Dietary factors in functional dyspepsia

Functional dyspepsia (FD) is characterized by upper gastrointestinal symptoms, which are frequently exacerbated by meal ingestion. While subgroups of FD patients exhibit a range of disturbances in upper gastrointestinal motor function, including delayed gastric emptying and abnormal intragastric meal distribution, which may reflect impaired proximal gastric relaxation and/or antral dysmotility, the association between symptoms and abnormalities in motor function appears to be relatively weak. More recently, the concept of visceral hypersensitivity to mechanical and chemical/nutrient stimuli has been promoted as important in the aetiology of dyspeptic symptoms. Somewhat surprisingly, the role of 'dietary' factors, that is, those factors, related directly to food ingestion, including patterns of nutrient intake, potential intolerance to specific foods or macronutrients, as well as cognitive factors, have been largely ignored. Moreover, presently available treatments fail to take into account the fact that symptoms are frequently induced by eating. This review focuses on the relevance of 'dietary' factors to FD.