基于低频振幅算法的血氧水平依赖功能磁共振成像在无灶性癫痫中的应用

目的 采用基于低频振幅算法的血氧水平依赖功能磁共振成像技术,探讨无灶性癫痫脑活动的神经机制及其意义. 方法 运用功能性磁共振成像技术观察安徽医科大学附属省立医院自2010年9月至2011年3月收治的16例无灶性癫痫患者和同期招募的15名健康对照者脑血氧水平依赖信号的改变;收集其静息态数据,然后运用低频振幅算法对数据进行分析,得到每个受试者的低频振幅统计图,观察无灶性癫痫患者相对于健康对照者低频振荡幅度(ALFF)增高和减弱的区域. 结果 无灶性癫痫组和健康对照组相比ALFF增强的脑区分布在右侧颞叶(MNI坐标分别为15,-90,-21)、内侧额叶(0,24,-24)、腹侧前扣带回(-12,30,27)及右侧小脑半球(-51,-57,-4);而ALFF减弱的脑区分布在左侧小脑半球及相邻后缘枕叶(-48,-15,39)、后扣带回(60,-21,33)及楔前叶(-6,-54,66). 结论 无灶性癫痫患者静息状态下表现出异常的脑功能活动方式,ALFF升高的脑区反映了大脑对癫痫活动的产生、传播等易化作用,表明了癫痫的高活动:而ALFF减低的脑区则反映了大脑对癫痫活动的抑制.     

精神分裂症首次发病未治疗患者静息态下局部脑区自发活动的研究

目的探讨精神分裂症首次发病未治疗患者静息态下局部脑区自发活动的情况:方法:利用低频振幅(ALFF)方法,对27例首次发病未治疗的精神分裂症患者(患者组)进行静息状态下功能磁共振(fMRI)扫描,对影像学数据进行ALFF方法处理,结果与22名年龄、性别及受教育程度相匹配的健康对照者(正常对照组)比较。结果:与正常对照组相比,患者组ALFF显著增高的脑区是运动前区、辅助运动区和眶额回;ALFF显著降低的脑区是楔前叶、后扣带回、内侧前额叶和角回(P0.05,Alphaism矫正)。结论:精神分裂症首次发病未治疗患者在静息态下运动前区、辅助运动区、眶额回、楔前叶、后扣带回、内侧前额叶和角回的局部脑区自发活动异常,这些异常脑区可能有助于解释精神分裂症的病理机制。     

基于ReHo方法的精神分裂症幻听患者静息态fMRI的研究

目的 基于静息态功能磁共振(fMRI)图像数据,运用局部一致性(ReHo)方法研究精神分裂症幻听患者静息态脑区活动情况.方法 对18例精神分裂症幻听患者和18例与之相匹配的健康对照人群进行静息态fMRI研究,运用ReHo方法对静息态fMRI数据进行统计分析,并将其结果进行组内和组间分析.结果 组内分析结果显示,两组静息态下脑区BOLD信号的ReHo值升高大多位于大脑“默认网络区域”(额叶、颞叶、扣带回等);就激活脑区面积大小来说,病例组明显减少,即精神分裂症幻听患者静息态脑区活动整体而言是减弱的.组间分析结果显示,与健康对照组相比精神分裂症幻听患者静息状态右侧额叶BOLD信号ReHo值明显降低(P＜0.001,纠正后cluster水平).结论 精神分裂症幻听患者颞叶功能活动增强且存在额叶活动异常,提示颞叶功能活动增强和额叶功能活动减弱可能是精神分裂症患者产生幻听的神经影像基础.     

轻度阿尔茨海默病患者静息态脑默认活动网络的fMRI研究

目的 采用静息态功能磁共振(fMRI)技术,探讨轻度阿尔茨海默病(AD)患者的脑默认活动网络(DMN)是否存在异常及其可能的神经机制. 方法 以复旦大学附属华山医院和同济大学附属同济医院神经内科门诊自2009年1月至2010年6月收治的24名轻度AD患者和同期上海社区中整群抽样选择的25名正常老年人为研究对象,对其进行简易智能状态(MMSE)、Mattis痴呆评定量表(DRS)检查和静息态脑功能成像.利用低频振幅(ALFF)算法对全脑静息态数据进行对比分析,观察AD患者相对于正常老年人ALFF有显著差异的区域. 结果 行为学结果显示:轻度AD患者相对对照组成员记忆功能存在明显损害.静息态fMRI结果显示:与对照组比较,AD患者中与记忆密切相关的后扣带回、前额叶中内侧腹侧、前额叶中内侧背侧等脑区ALFF明显减弱. 结论 AD患者静息态脑DMN中与记忆密切相关的脑区节点活动强度减弱,DMN异常在其早期记忆损害的病理机制中起着非常重要的作用.     

颞叶癫痫患者警觉功能的脑功能磁共振研究

目的利用注意网络测试(ANT)软件和功能核磁共振(fMRI)成像技术探讨颞叶癫痫(TLE)患者的警觉网络功能特点、激活模式及其脑功能状态。方法对12例TLE患者及匹配的8名健康志愿者进行研究。使用ANT软件进行警觉功能行为学测试,记录反应时间(RT);并采用ANT改良的警觉网络功能组块模式fMRI扫描,fMRI数据采用统计参数图(SPM2)软件分析。结果 TLE患者组与健康对照组ANT警觉网络功能的反应时间无差异。健康对照组警觉网络fMRI显示右枕叶、小脑明显激活;右边缘叶、右额叶及左侧颞叶、脑干部分激活。TLE患者组存在相同警觉网络相关脑区,但激活明显减弱且颞叶和脑干无激活。结论健康对照警觉网络功能与右侧枕叶、小脑、右额叶、脑干及颞叶等脑区相关。TLE患者存在警觉网络相关脑区功能明显低下,可能是TLE患者出现警觉功能损害的脑功能基础。     

部分性发作癫痫患者静息状态功能磁共振默认模式网络的功能连接改变

目的 应用静息状态功能磁共振成像(fMRI)探讨部分性发作癫痫患者静息状态下的脑功能改变.方法 对60例部分性发作癫痫患者(患者组)和60名性别、年龄和教育程度匹配的健康对照者(对照组),使用3.0T磁共振采集两组的静息状态下fMRI数据,采用功能连接方法分析计算脑区的默认模式网络的功能连接,利用SPM5软件分析比较患者组和对照组脑功能的差异.结果 患者组的默认模式网络的功能连接主要包括左侧楔前叶/后扣带回和角回、扣带回;对照组的功能连接主要包括左侧楔前叶/后扣带回和右侧角回,双侧内侧额叶和颞叶;患者组的左侧顶下小叶[坐标值(x,y,z):-57,-39,48;t=4.90,P＜0.01]、左侧缘上回[坐标值(x,y,z):-63,- 48,33;t=4.25,P＜0.01]、左侧海马旁回[坐标值(x,y,z):-30,-6,-21;t =4.05,P＜0.01]、左侧颞上回[坐标值(x,y,z):-48,-39,6;t=3.72,P＜0.01],左侧钩回[坐标值(x,y,z):-24,6,- 36;=4.56,P＜0.01]及右侧钩回[坐标值(x,y,z):33,-15,- 36;t=4.00,P＜0.01]的默认模式网络功能连接较对照组降低;未发现功能连接升高的脑区.结论 部分性发作癫痫患者静息状态下脑区的功能连接改变,可能是部分性发作癫痫潜在的病理生理机制.静息状态fMRI能发现常规MRI正常的癫痫患者的广泛脑功能异常,是一种无创的研究癫痫患者脑功能的有效方法.     

创伤后应激障碍患者杏仁核为主的边缘系统静息态脑功能磁共振研究

目的 观察静息状态下创伤后应激障碍(posttraumatic stress disorder,PTSD)患者以杏仁核为主的脑区的脑功能改变.方法 采用基于低频振幅(amplitude of low frequency fluctuation,ALFF)算法的静息功能磁共振成像技术(fMRI)对10例临床确诊的PISD患者和10例性别、年龄及受教育年限匹配的正常对照进行静息fMRI检查,采用t检验比较两组的杏仁核等脑区基于血氧水平依赖活动的差异.结果 与正常对照组相比,PTSD患者组右侧杏仁核ALFF活性明显增加(P<0.01),海马旁回、钩回等边缘系统其他脑区亦见ALFF活性增加(P<0.01),而前额叶、岛叶及楔前叶ALFF活性减低(P<0.01).结论 PTSD患者静息态下包括杏仁核在内的边缘系统多个脑区活动增强,前额叶、岛叶、楔前叶等脑区功能抑制.     

男性酒依赖患者戒断期静息态功能磁共振低频振幅研究

目的探讨男性酒依赖患者戒断期静息态下脑区神经元自发活动改变及其与认知功能关系。方法对23例男性酒依赖患者和20名健康成年男性进行脑静息态功能磁共振扫描,比较其全脑各脑区低频振幅(amplitude of low-frequency fluctuation,ALFF),并用简易精神状态量表(mini mental status scale,MMSE)、语言流畅性测验(verbal fluency test,VFT)、数字广度测验(digit span test,DST)、霍普金斯词语学习修订版(Hopkins verbal learning test revised,HVLT-R)及连线测试B(trail making test-B,TMT-B)分别评估两组认知功能。结果酒依赖组与对照组相比ALFF减弱脑区为左侧额上回(t=-4.49,P0.01)、右侧额中回(t=-3.55,P0.01)、右侧颞上回(t=-5.36,P0.01)、左侧前扣带回(t=-5.41,P0.01);ALFF增强的脑区有左侧枕叶(t=3.90,P0.01)、左侧小脑后叶(t=3.58,P0.01)。神经心理测评中,酒依赖组MMSE(t=-4.33,P0.01)、VFT(t=-2.86,P0.01)、DST(t=-4.93,P0.01)和HVLT-R(t=-5.16,P0.01)评分均低于对照组;TMT-B完成时间高于对照组(t=4.67,P0.01)。酒依赖患者右侧额中回ALFF值与VFT评分呈正相关(r=0.49,P=0.04)。结论男性酒依赖患者戒断期在静息态下存在双侧额叶、右侧颞叶、左侧前扣带回、左侧枕叶、左侧小脑脑区功能活动异常,且右侧额叶脑区功能活动改变与语言功能异常有相关性。     

基于局域一致性分析的BOLD-fMRI探讨无灶性癫痫的发作机制

目的利用基于局域一致性（regional homogeneity,ReHo）分析方法的血氧水平依赖功能磁共振成像技术,探讨无灶性癫痫的发作机制。方法运用功能性磁共振成像技术,采集无灶性癫痫患者17例和健康对照组16例的静息态数据,然后运用局域一致性分析方法对数据进行分析,观察无灶性癫痫患者脑局域一致性与正常对照组的变化。结果无灶性癫痫组和健康对照组相比ReHo值增强的脑区主要分布在双侧海马;ReHo值降低的脑区主要分布在右顶叶、右中央前回、右额叶、右侧小脑半球及左楔前叶、左前额。结论无灶性癫痫患者静息状态下脑功能活动较对照组有所改变,ReHo值升高的脑区反映了该脑区参与了癫痫的高活动,而降低的脑区可能反应了由于长期癫痫发作导致这些区域的神经元受损。     

网络游戏成瘾者前扣带回功能连接静息态fMRI研究

目的 探讨青少年网络游戏成瘾者静息态下前扣带回功能连接的变化情况,从功能连接的角度解释前扣带回在网络游戏成瘾中的作用.方法 选择自2011年3月至10月在安徽医科大学附属省立医院心理门诊就诊的网络成瘾者17例为成瘾组,同期招募17例健康志愿者为正常对照组.对34例被试者一般情况进行了解并比较两组之间差异;成瘾组和正常对照组分别进行静息态fMRI扫描,数据采集后进行预处理,分别以左、右前扣带回为感兴趣脑区与全脑进行功能连接分析,比较成瘾组和正常对照组前扣带回功能连接的变化情况.结果 成瘾组每日或每周平均网络游戏时间及网络游戏渴求程度明显高于正常对照组,差异有统计学意义(P＜0.05);在静息态下,正常对照组与网络成瘾组的前扣带回都与前额叶、中后扣带回、伏核、中脑、颞叶及枕叶等脑区存在功能连接关系,与全脑其他脑区比较差异(体素差异)有统计学意义(P＜0.05);但与正常对照组比较,在静息态下成瘾组前扣带回与中脑、扣带回皮层、伏核及辅助运动区功能连接增强,与双侧前额叶、颞叶及枕叶功能连接减弱(P＜0.05).结论 网络游戏成瘾者前扣带回功能连接存在异常并可能与网络游戏成瘾的产生和维持有关.     

Abnormal baseline brain activity in low-grade hepatic encephalopathy: a resting-state fMRI study

Resting-state functional magnetic resonance imaging (fMRI) has been used to detect the alterations of spontaneous neuronal activity in various neuropsychiatric diseases, but rarely in low-grade hepatic encephalopathy (HE), a common neuropsychiatric complication of liver cirrhosis. We conducted a resting-state fMRI in 19 healthy controls, 18 cirrhotic patients without HE, and 22 cirrhotic patients with low-grade HE. The amplitude of low-frequency fluctuations (ALFF) of fMRI signal was computed to measure the spontaneous neuronal activity. Several regions showing significant ALFF differences among three groups were the precuneus, occipital lobe, left frontal lobe and anterior/middle cingulate cortex, and left cerebellum posterior lobe. Compared to controls or patients without HE, patients with low-grade HE showed decreased ALFF in the precuneus and adjacent cuneus, visual cortex, and left cerebellum posterior lobe. Compared to controls, patients with low-grade HE showed higher ALFF in both cortical and subcortical regions, including the right middle cingulate gyrus, and left anterior/middle cingulate gyrus, inferior frontal gyrus, insula lobe, parahippocampal gyrus, middle temporal gyrus and lentiform nucleus; compared to patients without HE, patients with low-grade HE showed higher ALFF in the left medial frontal gyrus and anterior cingulate gyrus, bilateral superior frontal gyrus, and right middle frontal gyrus. Moreover, correlations between ALFF changes and poor neurocognitive performances were found in patients with low-grade HE. These results suggested the existence of aberrant brain activity at the baseline state in low-grade HE, which may be implicated in the neurological pathophysiology underlying HE.     

早发精神分裂症静息态脑功能低频振幅研究

目的通过静息态功能磁共振研究早发未用药精神分裂症患者局部脑功能低频振幅(amplitude of low-frequency fluctuation,ALFF)的变化,探讨其静息态下功能异常的脑区。方法收集20例早发未用药精神分裂症患者与20名性别、年龄、受教育年限相匹配的正常对照,分别对其进行全脑静息态功能磁共振扫描,计算ALFF值。结果与对照组相比,患者组左侧额上回、左侧楔前叶、左侧扣带回、左侧枕叶、左侧海马旁回、左侧距状沟ALFF值增高(P0.05,Alpha Sim校正),右侧颞上回和右侧小脑后叶ALFF值降低(P0.05,Alpha Sim校正)。结论早发精神分裂症患者在静息态下有多处脑区ALFF值改变,提示其在静息态下存在脑功能异常。     

Altered baseline brain activity in children with ADHD revealed by resting-state functional MRI

In children with attention deficit hyperactivity disorder (ADHD), functional neuroimaging studies have revealed abnormalities in various brain regions, including prefrontal-striatal circuit, cerebellum, and brainstem. In the current study, we used a new marker of functional magnetic resonance imaging (fMRI), amplitude of low-frequency (0.01-0.08Hz) fluctuation (ALFF) to investigate the baseline brain function of this disorder. Thirteen boys with ADHD (13.0+/-1.4 years) were examined by resting-state fMRI and compared with age-matched controls. As a result, we found that patients with ADHD had decreased ALFF in the right inferior frontal cortex, left sensorimotor cortex, and bilateral cerebellum and the vermis as well as increased ALFF in the right anterior cingulated cortex, left sensorimotor cortex, and bilateral brainstem. This resting-state fMRI study suggests that the changed spontaneous neuronal activity of these regions may be implicated in the underlying pathophysiology in children with ADHD.     

fMRI study of mesial temporal lobe epilepsy using amplitude of low‐frequency fluctuation analysis

Various functional imaging tools have been used to detect epileptic activity in the neural network underlying mesial temporal lobe epilepsy (mTLE). In the present fMRI study, a data‐driven approach was employed to map interictal epileptic activity in mTLE patients by measuring the amplitude of low‐frequency fluctuation (ALFF) of the blood oxygen level‐dependent (BOLD) signal. Twenty‐four left mTLE patients and 26 right mTLE patients were investigated by comparing with 25 healthy subjects. In the patients, the regions showing increased ALFF were consistently distributed in the mesial temporal lobe, thalamus, and a few of other cortical and subcortical structures composing a mesial temporal epilepsy network proposed previously, while the regions showing decreased ALFF were mostly located in the areas of so‐called default‐mode network. Data of simultaneous EEG‐fMRI from a portion of the patients suggested that the increases in ALFF might be associated with the interictal epileptic activity. Individual analyses based on statistic parametric mapping revealed a moderate sensitivity and a fairly high specificity for the lateralization of unilateral mTLE. We conclude that the ALFF analysis may provide a useful tool in fMRI study of epilepsy. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.     

男性偏执型精神分裂症患者静息态功能磁共振脑自发低频振幅的变化

目的:利用静息态功能性磁共振成像(fMRI)技术观察男性偏执型精神分裂症患者脑自发低频振幅(ALFF)的变化。方法:对36例男性偏执型精神分裂症患者(病例组)和19名年龄、利手、性别、受教育程度相匹配的健康者(对照组)进行静息态fMRI扫描;分析两组全脑各区域ALFF的差异。结果:与对照组比较,病例组双侧额中回、右颞中回、右顶下回、左中央前回ALFF明显减低;右颞上回、双侧颞下回、左枕下回ALFF明显增强(P均0.01)。结论:男性偏执型精神分裂症患者脑部广泛区域存在ALFF异常。     

Precuneus-related regional and network functional deficits in social anxiety disorder: A resting-state functional MRI study

BackgroundNeuroimaging findings suggest that social anxiety disorder (SAD) may be correlated with changes in regional- or network-level brain function. However, few studies have explored alterations in intrinsic resting cerebral function in patients with SAD at both the regional and network levels, particularly focusing on the theory of mind (ToM)-related regions. This study was performed to investigate changes in neural activity and functional connectivity (FC) in ToM-related regions during the resting state in SAD patients and to determine how these alterations are correlated with the clinical symptoms of SAD.MethodsForty-three SAD patients and 43 matched healthy controls underwent resting-state functional magnetic resonance imaging (rsfMRI) scans. First, the amplitude of low-frequency fluctuation (ALFF) approach was used to explore regional activity. Then, the ToM-related region, i.e., the left precuneus, which showed altered ALFF values, was adopted as a seed for further FC analyses to assess network-level alterations in SAD. Between-group differences were compared using voxel-based two-sample t-tests (P < 0.05, with Gaussian random field correction). Pearson's correlation analyses were performed to examine relationships between alterations in ALFF and FC and clinical symptoms.ResultsCompared with the healthy controls, SAD patients showed decreased ALFF in the bilateral putamen (PUT) and left supplementary motor area (SMA) and increased ALFF in the right inferior parietal lobule (IPL), left precuneus and right cerebellar posterior lobe. Moreover, SAD patients exhibited lower connectivity between the left precuneus and the cerebellar posterior lobe, right inferior temporal gyrus (ITG), right parahippocampal gyrus (PHG) and left medial prefrontal cortex (mPFC). The altered ALFF values in the left precuneus and the hypoconnectivity between the left precuneus and left cerebellar posterior lobe were correlated with the patients' clinical symptoms (P < 0.05).ConclusionThe precuneus, a ToM-related region, was altered at both the regional and network level in patients with SAD. Pathological fear and avoidance in SAD were correlated with abnormal regional function in the precuneus, whereas depression and anxiety were primarily correlated with functional deficits in the precuneus-related network. The altered FC within the precuneus-cerebellar region may reflect an imbalance in the neuromodulation of anxiety and depressive symptoms in SAD. These findings may facilitate a greater understanding of potential SAD neural substrates and could be used to identify potential targets for further treatment.     

慢性精神分裂症患者加服利培酮治疗静息态功能磁共振研究

目的:应用功能磁共振(fMRI)分析慢性精神分裂症(SCH)患者加服利培酮治疗前后静息态大脑影像改变。方法:采集慢性SCH患者9例和正常对照组9名的一般人口学资料、临床资料及基线、治疗12周后静息态fMRI数据,对采集的数据进行统计学分析。结果:与正常对照组比较,SCH组服药前静息态下局部一致性(ReHo)及低频振幅(ALFF)均有若干脑区存在差异;SCH组在利培酮治疗12周后,ReHo及ALFF发生改变。结论:慢性精神分裂症患者存在明显的认知功能异常及静息态脑fMRI异常;慢性精神分裂症患者中加服或改服利培酮可改善患者的认知功能和阳性、阴性症状,且脑影像学有相应改变。     

Altered regional spontaneous neuronal activity in blepharospasm: a resting state fMRI study

The resting state amplitude of low-frequency fluctuations (ALFF) in functional magnetic resonance imaging (fMRI) is believed to reflect spontaneous cerebral neural activity. The pathophysiology of blepharospasm (BSP), which is characterized by motor symptoms and also sensory symptoms, remains unclear. The present study aims to localize possible cerebral functional abnormalities in BSP patients using resting state fMRI, and explore their possible associations with clinical variables. Voxel-based analysis was used to characterize the difference of ALFF between eighteen BSP patients and eighteen matched healthy controls. Separate correlation analyses were conducted to explore the possible association between ALFF values of significantly different areas and clinical measures including onset age, disease duration, symptom severity evaluated by Jankovic rating scale (JRS), and presence of geste antagoniste. The whole-brain analysis indicated that the BSP group had significantly decreased ALFF in the left thalamus while increased ALFF in the left orbitofrontal areas extending from middle frontal gyrus to inferior frontal gyrus. The mean ALFF in the left thalamus was negatively correlated with the subscore of JRS-frequency (r = ?0.484, p = 0.042) and JRS total score (r = ?0.477, p = 0.045). A borderline positive correlation was detected between the mean ALFF in the left orbitofrontal area and disease duration(r = 0.485, p = 0.049). Our findings suggest sensorimotor integration is abnormal in BSP, and dysfunctional activity of thalamus may be used to measuring symptom severity in BSP patients.     

Intrinsic low-frequency oscillation changes in multiple-frequency bands in stable patients with chronic obstructive pulmonary disease

Abnormal local spontaneous brain activity during the resting state has been observed in chronic obstructive pulmonary disease (COPD). However, it is still largely unclear whether the abnormalities are related to specific frequency bands. Our purpose was to explore intrinsic neural activity changes in different frequency bands by using the amplitude of low-frequency fluctuation (ALFF) method in stable COPD patients. Nineteen stable COPD patients and twenty gender-, age- and education-matched normal controls (NCs) underwent functional magnetic resonance imaging scans, cognitive function tests and lung function tests. Two different frequency bands (slow-4: 0.027–0.073 Hz; slow-5: 0.01–0.027 Hz) were calculated and analyzed for frequency-dependent intrinsic neural activity by using the ALFF method. A two-way analysis of variance test was used to compare the main effects of the groups and the frequency bands in the ALFF method. Further post-hoc t-tests were used to compare the differences between COPD patients and NCs in terms of the different frequency bands. A Pearson’s correlation analysis was performed to explore the relationship between the altered ALFF brain areas in the different frequency bands and the clinical evaluations in the COPD patients. There were main effects of the groups including significantly higher ALFF values in the right superior temporal gyrus (STG), the bilateral cerebellum posterior lobe (CPL), the right lingual gyrus (LG) and the right brainstem, and as well as significantly decreased ALFF values in the right inferior parietal lobule (IPL) and the angular. The main effect of frequency was demonstrated in the CPL, the STG, the prefrontal cortex and the middle cingulate gyrus. Furthermore, COPD patients exhibited more widespread alterations in intrinsic brain activity in the slow-5 band than in the slow-4 band. Moreover, the abnormal intrinsic brain activity in the slow-4 and slow-5 bands were associated with PaCO₂ in COPD patients. These current results indicated that COPD patients showed abnormal intrinsic brain activity in two different frequency bands, and abnormal intrinsic neuronal activity in different brain regions could be better detected by slow-5 band. These observations may provide a neoteric view into understanding the local neural psychopathology in stable COPD patients.