精神分裂症静息状态下的功能磁共振成像研究

目的：利用功能磁共振成像（fMRI）和局部一致性（regional homogeneity，ReHo）方法探测精神分裂症患者在静息状态下是否存在脑功能异常。方法：对18例精神分裂症患者和18例正常对照进行静息状态的fMRI检查，应用ReHo方法处理fMRI数据。结果：与正常人相比，精神分裂症患者静息状态下脑的BOLD信号的ReHo普遍降低（P〈0．05）。ReHo降低的脑区有双侧额叶内侧回、颞上回、颞下回、枕中回、枕下回和小脑后叶；左侧扣带回前部、海马回、颞中回、中央后回和脑桥；右侧额上回、顶上小叶、楔前叶、中央旁小叶、中央前回和小脑蚓部。结论：精神分裂症患者在静息状态下即可能存在脑功能异常，ReHo可能有助于精神分裂症静息状态的理解。     

膝骨性关节炎患者慢性疼痛静息态脑功能局部一致性研究

目的探讨膝骨性关节炎(KOA)慢性疼痛患者静息状态下脑功能活动改变情况。方法采用局部一致性(ReHo)分析方法分析21例KOA患者(KOA组)和21例健康人群(HC组)静息状态下脑功能活动差异。结果与HC组相比,KOA组患者双侧额叶、顶叶、颞叶、小脑、边缘系统及静息状态默认网络分布区ReHo值广泛异常。结论慢性疼痛疾病患者的脑功能异常除了包括了疼痛信息的处理,更是一种皮层广泛参与的情绪功能异常、认知功能损害的病理状态。     

精神分裂症患者吸烟的静息态功能磁共振研究

目的:精神分裂症患者高吸烟率的原因尚不明确,静息态功能磁共振是一个比较好的工具来探索该现象的神经影像学机制。方法:采用局部一致性(Regional homogeneity,ReHo)的方法比较吸烟精神分裂症患者和不吸烟精神分裂症患者,以及不吸烟精神分裂症患者和正常不吸烟对照者之间的静息态功能磁共振(fMRI)图像。结果:设P0.001,与不吸烟精神分裂症患者相比,吸烟精神分裂症患者在左内侧额回ReHo值下降,左侧小脑后叶与左侧舌回ReHo值升高,且吸烟精神分裂症患者左侧小脑后叶的ReHo值与患者每日吸烟支数显著相关(r=0.635,P=0.027);与正常不吸烟对照组相比,不吸烟精神分裂症患者双侧内侧额回、右侧颞叶、左侧楔叶ReHo值升高,右侧前扣带回、双侧中央后回、双侧丘脑ReHo值下降。结论:吸烟精神分裂症患者存在左侧小脑后叶,左内侧额回与左侧舌回的局部一致性异常,此发现可能有助于我们探索精神分裂症患者人群吸烟的脑影像学机制。     

吸烟青少年静息态脑电谱功率异常的研究

目的:采用静息态脑电(Resting-state EEG)技术探究吸烟对青少年大脑神经机制的影响。方法:16例青少年吸烟者与16例正常对照者,并在静息状态下采集10 min的脑电信号。利用快速傅里叶变换将时域信号转换成频域信号进行统计分析。结果:(1)与正常对照组相比,青少年吸烟组全脑(前、中、后部)的Delta、Theta以及前部Beta谱功率是降低的;(2)青少年吸烟组的前部Delta谱功率与渴求分数存在显著的负相关关系。结论:降低的EEG谱功率以及其与渴求的负相关关系反映了长期吸烟对青少年大脑神经机制的损害。该发现对以后青少年烟瘾者的临床诊断具有一定的现实意义和应用价值。     

青少年肌阵挛癫痫发作间期EEG-fMRI的研究

采用同步脑电与功能磁共振(Simultaneous electroencephalography-correlated functional magnetic resonance imaging,EEG-fMRI)技术,研究青少年肌阵挛癫痫患者发作间期痫样放电时脑部血氧水平依赖(Blood oxygen level-dependent,BOLD)信号变化。结果发现:双侧大脑半球的激活及失活信号变化普遍对称且各自独立存在,信号由枕顶至额区逐渐减少。阳性激活区有:楔叶、岛叶、额中部内侧、小脑中线两侧及丘脑。阴性激活区有:双侧额前部、顶部及扣带后回。由此推断:以棘慢复合波为表现形式的同步的神经元活动可能反映了丘脑皮层BOLD信号的激活,而失活区域反映了异常放电时的脑功能的静息状态;这类激活在神经元的活动(EEG)与fMRI结果之间有很好的对应关系;EEG-fMRI是研究脑功能状态有效的方式。     

轻微型肝性脑病患者脑缺省模式网络研究

目的探讨轻微型肝性脑病(MHE)患者静息状态下脑缺省模式网络(DMN)分布区局部一致性(ReHo)的改变情况。方法 2013年1月至2015年12月采用ReHo分析方法分析重庆医科大学附属第二医院放射科18例MHE患者(MHE组)和18位健康志愿者(对照组)静息状态下的DMN功能活动差异。结果与对照组相比,MHE组DMN内ReHo值降低的脑区包括双侧内侧前额叶/前扣带回[V=13.257 cm~3、MNI坐标(3,24,66)、t=-3.493 7]、后扣带回/双侧前楔叶[V=4.752 cm~3、MNI坐标(9,-54,45)、t=-2.634 1];MHE组DMN内ReHo值升高的脑区包括右侧内侧前额叶[V=5.049 cm~3、MNI坐标(21,63,6)、t=4.017 5]。结论静息状态下,MHE患者大部分DMN脑区会出现ReHo值异常减低或增高,提示MHE患者DMN内自发活动一致性异常,反映了MHE患者的大脑内源性功能发生损伤,ReHo可用于观察MHE患者DMN的改变。     

基于ReHo方法的大学生网络成瘾静息功能磁共振成像研究

目的:探讨网络成瘾大学生静息状态脑功能特点。方法:采用ReHo分析方法 ,19名网络成瘾大学生及19名对照进行磁共振脑功能成像,比较两组平均脑ReHo图的差异。结果:IAD组ReHo值升高区域主要集中在小脑、脑干、扣带回(右侧)、双侧海马旁回、右侧额叶(直回,额中回及额下回)、左侧额上回、左侧楔前叶、右侧中央后回、右侧枕中回、右侧颞下回、左侧颞上回及颞中回;ReHo降低的区域仅表现在左侧顶叶的楔前叶。结论:网络成瘾大学生局域一致性存在异常,大部分脑区同步性增强,小脑、脑干、边缘叶、额顶叶同步性增强可能与网络成瘾奖赏通路有关。     

遭受多重侵害高职高专女生静息态脑功能局部一致性的研究

目的:探讨遭受多重侵害的高职高专女生静息态脑功能磁共振特点。方法:15名遭受多重侵害无创伤后应激症状被试(PV无PTSS组)、15名多重侵害有创伤后应激症状被试(PV有PTSS组)和15名正常对照接受静息态脑功能扫描。采用SPM8和静息态功能磁共振数据处理工具包分别进行数据预处理和ReHo分析。结果:静息状态下,与对照组相比,PV无PTSS组左侧额下回、左右额内侧回、右侧中央后回、左侧梭状回、左右海马旁回、右侧扣带回、左右豆状核和右侧岛叶的ReHo值降低;左右额上回、左右额中回、左右额下回、左右顶下小叶、左右楔前叶、左右颞上回、左侧颞横回、左右颞中回、右侧舌回和右侧扣带后回的ReHo值升高。与PV有PTSS组相比,PV无PTSS组在右侧额中回和额下回、左侧楔前叶、左侧舌回、左右海马旁回、左侧扣带回和左侧豆状核ReHo值降低;在左右额上回、左右额中回、左侧额内侧回、右侧中央后回、左侧缘上回、左右顶下小叶、左侧梭状回和左侧尾状核ReHo值升高。结论:遭受多重侵害但无创伤后应激症状的高职高专女生在静息状态下脑默认网络以及岛叶、基底神经节、海马旁回存在局部一致性信号异常,这些脑区异常可能为遭受多重侵害导致精神障碍的发病机制提供重要线索。     

基于低频振幅的吸烟成瘾者戒烟2周后脑功能活动变化的研究

探讨吸烟成瘾者戒烟前后的脑功能活动差异,使用3.0T磁共振扫描仪采集14名吸烟成瘾者戒烟前和戒烟后的静息态MRI数据,采用低频振幅(amplitude of low-frequency fluctuation, ALFF)的方法来比较分析吸烟成瘾者在戒烟前和戒烟两周后的脑功能活动情况.与戒烟前相比,吸烟成瘾者戒烟两周后静息状态下的右侧楔前叶、右侧后扣带回、左侧缘上回、左侧背外侧额上回和左侧额中回的ALFF活动降低;双侧距状裂周围皮层、双侧楔叶、左侧中央后回和左侧中央旁小叶的ALFF活动增加.研究结果表明:吸烟成瘾者在戒烟两周后额叶、边缘叶、顶叶和枕叶脑区的脑功能活动发生了改变,提示ALFF可作为监测或评价戒烟效果的潜在生理指标.     

一种基于静息态功能磁共振成像的快速丘脑分割算法

目的 探讨基于静息态功能磁共振成像(fMRI)的快速有效的丘脑分割方法.方法 静息态fMRI技术是通过测量血氧水平依赖(BOLD)信号的变化间接反映神经元的活动情况.利用丘脑内部的BOLD信号相关并结合聚类分析算法将丘脑进行功能性分割.结果 丘脑被划分为7个区域,同一区域内信号相似度高.此分割结果与利用丘脑-大脑皮层的功能连接强度所得的分割结果相似.结论 静息态fMRI不仅可以分析丘脑-大脑皮层之间的功能连接,还可分析丘脑内部的功能特征.仅利用丘脑内部信息分割丘脑具有运算量小、计算速度快的优点.     

利用脑局部一致性方法对儿童全身强直发作性癫痫的研究

目的　应用静息态功能磁共振局部一致性方法研究儿童全身强直发作性癫痫患者脑区异常活动,探讨其发生的病理生理机制。 方法　对8例儿童全身强直发作性癫痫患者和30例正常儿童进行磁共振扫描,并计算全脑局部一致性的值,进行组间比较并研究局部一致性与病程的相关性。 结果　与对照组相比,癫痫组ReHo值增高的脑区为大脑深部核团（扣带回,丘脑,楔前叶等）,运动相关脑区,额下回,枕叶,颞叶和小脑;ReHo值降低的脑区为双侧额中回、右侧颞中回、左侧颞上回、双侧中央后回、左侧舌回。全身强直发作性癫痫与病程呈正相关的脑区为左侧楔前叶、左侧顶上小叶、右侧中央前回、右侧中央后回;与病程呈负相关的脑区为右侧楔前叶、右侧角回、中央旁小叶。 结论　局部一致性分析方法可以有效地反映癫痫患者异常的神经功能变化,有助于发现强直发作性癫痫发生的病理生理机制。     

Feedback-related negativity encodes outcome uncertainty in the gain domain but not in the loss domain

Resting-state functional magnetic resonance imaging (fMRI) has facilitated the study of spontaneous brain activity by measuring low-frequency oscillations in blood-oxygen-level-dependent signals. Analyses of regional homogeneity (ReHo), which reflects the local synchrony of neural activity, have been used to reveal the mechanisms underlying the brain dysfunction in various neuropsychiatric diseases. However, it is not known whether the ReHo is altered in cirrhotic patients with minimal hepatic encephalopathy (MHE). We recruited 18 healthy controls and 18 patients with MHE. The ReHo was calculated to assess the strength of the local signal synchrony. Compared with the healthy controls, the patients with MHE had significantly decreased ReHo in the cuneus and adjacent precuneus, and left inferior parietal lobe, whereas the regions showing increased ReHo in patients with MHE included the left parahippocampal gyrus, right cerebellar vermis, and bilateral anterior cerebellar lobes. We found a positive correlation between the mean ReHo in the cuneus and adjacent precuneus and the score on the digit-symbol test in the patient group. In conclusion, the analysis of the regional homogeneity of resting-state brain activity may provide additional information with respect to a clinical definition of MHE.     

Alterations in regional homogeneity of resting-state brain activity in ketamine addicts

Ketamine is a non-competitive anatognist of the N-methyl-d-aspartate (NMDA) receptor commonly used as an anesthetic and analgesic. In sub-anesthetic doses, it can induce temporary psychotic symptoms and has served as a pharmacological model for schizophrenia. While its acute effects on brain and behavior have been studied, the effects of long-term exposure to ketamine on brain activity have been largely unexplored. In this study, we aimed to examine such effects on spontaneous brain dynamics measure using resting-state functional magnetic resonance imaging (fMRI). Forty-one patients with ketamine dependence and forty-four healthy control subjects were imaged with BOLD fMRI using a 3.0-Tesla Siemens scanner at the Magnetic Resonance Center of Hunan Provincial People's Hospital, analyzed with the regional homogeneity (ReHo) method. Compared with healthy controls, decreased ReHo was found in ketamine users in the right anterior cingulate cortex and increased ReHo was found in left precentral frontal gyrus (p < 0.05, cluster-level corrected). We also observed negative correlations between increased ReHo in precentral frontal gyrus and estimated total lifetime ketamine consumption and ketamine craving levels. To our knowledge, this is the first study the long-term effects of ketamine exposure on brain functional activity. Our findings indicate that ketamine dependence is associated with alterations in the functional connectivity of medial and lateral prefrontal cortices.     

Changes in regional homogeneity of parieto-temporal regions in panic disorder patients who achieved remission with antidepressant treatment

Objective

This study was aimed to study the treatment effects of antidepressant for regional homogeneity (ReHo), an indicator of synchronization of brain function, in panic disorder (PD) patients.

Method

Twenty-one remitted PD patients with escitalopram treatment and 21 healthy controls all received 3-T magnetic resonance imaging scanning at baseline and sixth week. We utilized REST (Resting State FMRI Data Analysis Toolkit, version 1.4) to calculate regional homogeneity (ReHo) of patients and controls at baseline and sixth week. We compared the ReHo at baseline with the ReHo at sixth week to estimate the treatment effects for the ReHo of remitted patients. Besides, inter-scan effects were evaluated in the control group. The group-related differences between remitted patients and controls were also estimated.

Results

Remitted PD patients had increases in ReHo of right Heschl gyrus (superior temporal lobe) and decreases in ReHo of right angular gyrus (parietal lobe). The improvements in severity of panic symptoms were negatively correlated with the changes of ReHo in right superior parietal lobe. However, remitted patients still had lower ReHo than controls in right Heschl gyrus and left thalamus.

Conclusion

The changes in ReHo of temporo-parietal regions might represent treatment-related ReHo changes for remission of PD. The residual alterations in ReHo of temporo-thalamic regions might represent group-related ReHo differences for patients with PD.     

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.     

Regional homogeneity of the resting-state brain activity correlates with individual intelligence

Resting-state functional magnetic resonance imaging has confirmed that the strengths of the long distance functional connectivity between different brain areas are correlated with individual differences in intelligence. However, the association between the local connectivity within a specific brain region and intelligence during rest remains largely unknown. The aim of this study is to investigate the relationship between local connectivity and intelligence. Fifty-nine right-handed healthy adults participated in the study. The regional homogeneity (ReHo) was used to assess the strength of local connectivity. The associations between ReHo and full-scale intelligence quotient (FSIQ) scores were studied in a voxel-wise manner using partial correlation analysis controlling for age and sex. We found that the FSIQ scores were positively correlated with the ReHo values of the bilateral inferior parietal lobules, middle frontal, parahippocampal and inferior temporal gyri, the right thalamus, superior frontal and fusiform gyri, and the left superior parietal lobule. The main findings are consistent with the parieto-frontal integration theory (P-FIT) of intelligence, supporting the view that general intelligence involves multiple brain regions throughout the brain.     

基于fMRI的原发全面性癫痫脑活动的局域一致性研究

癫痫是一种以神经活动同步性异常增高为特征的中枢神经系统疾病。我们利用基于局域一致性（regional homogeneity,ReHo）分析方法的功能磁共振成像（functional Magnetic Resonance Imaging,fMRI）技术对原发全面性癫痫（idiopathic generalized epilepsy,IGE）进行研究。观察IGE患者相比正常对照组局域一致性的改变情况。结果表明：在静息状态下,患者大脑的局域一致性在某些脑区较正常人低,主要集中在楔前叶、内侧前额叶、双侧颞叶、双侧额中回;另外,在某些脑区较正常人高,主要集中在底丘脑等中缝核团。提示该方法可检出癫痫活动造成的局部脑组织血氧水平依赖（blood oxygen level dependent,BOLD）信号同步性的改变,从而有助于原发全面性癫痫的病理生理机制的探索。     

Regional homogeneity abnormalities in patients with interictal migraine without aura: a resting-state study

Previous studies have provided evidence of structural and task-related functional changes in the brains of patients with migraine without aura. Resting-state brain activity in patients with migraine provides clues to the pathophysiology of the disease. However, few studies have focused on the resting-state abnormalities in patients with migraine without aura. In the current study, we employed a data-driven method, regional homogeneity (ReHo), to analyze the local features of spontaneous brain activity in patients with migraine without aura during the resting state. Twenty-six patients with migraine without aura and 26 age-, education- and gender-matched healthy volunteers participated in this study. Compared with healthy controls, patients with migraine without aura showed a significant decrease in ReHo values in the right rostral anterior cingulate cortex (rACC), the prefrontal cortex (PFC), the orbitofrontal cortex (OFC) and the supplementary motor area (SMA). In addition, we found that ReHo values were negatively correlated with the duration of disease in the right rACC and PFC. Our results suggest that the resting-state abnormalities of these regions may be associated with functional impairments in pain processing in patients with migraine without aura. We hope that our results will improve the understanding of migraine.