抑郁症及其一级亲属脑基础活动的BOLD-fMRI研究

目的 运用功能磁共振成像(fMRI)研究抑郁症(MDD)及其一级亲属静息状态下脑区的低频振幅(ALFF)及低频振幅比率(fALFF)的特点及差异,以了解MDD患者早期的脑功能状态.方法 对10例MDD患者(MDD组)、10例MDD一级亲属(一级亲属组)、10例健康志愿者(对照组)进行3.0T静息状态脑功能磁共振成像 (fMRI),分别计算各组的ALFF、fALFF,进行统计学分析.结果 与一级亲属组相比,MDD组的左侧小脑、左侧楔前叶、左侧内侧前额叶皮质的ALFF、fALFF值均显著性降低(P<0.05);而右侧背侧扣带回皮质、右侧顶上小叶的ALFF值显著减低(P<0.05);与对照组相比,MDD组的左侧小脑、左侧楔前叶、左侧顶上小叶的ALFF、fALFF值均显著性降低(P<0.05),而右侧扣带回皮质、内侧前额叶皮质的ALFF值显著减低(P<0.05);一级亲属组与对照组相比,ALFF值无统计学差异,一级亲属组的左侧顶上小叶的fALFF值显著降低(P<0.05).结论 MDD患者及一级亲属脑区均存在广泛的ALFF、fALFF异常,这些异常的脑区可能与MDD认知网络障碍及情感低落相关.     

采用fMRI研究感音聋儿相关脑区的ALFF及ReHo改变

目的 探讨采用静息态功能磁共振研究0～4岁的双侧先天性重度感音神经性耳聋患儿听觉、语言、视觉及其他相关脑区的ALFF值及ReHo的变化情况,判断人工耳蜗置入前患儿的听觉、语言、视觉及其他有关脑区的功能重塑.方法 选取0～4岁双侧先天性重度感音神经性耳聋患儿25例,正常听力组20例,以2岁为大脑发育的关键期分为4组:0～...     

低级别肝性脑病静息态低频振幅变化研究

目的探讨低级别肝性脑病静息态下脑低频振幅变化及其意义。方法研究对象共59例,分三组：正常对照,单纯肝硬化组与低级别肝性脑组。组内ALFF强度检验使用单样本t检验。两组间ALFF差别使用双样本t检验。三组间ALFF比较使用单因素方差分析。结果组内t检验显示扣带回后部、楔前叶、额叶前内侧和顶下小叶等脑DMN相关区域内ALFF明显增高。与对照组相比,低级别HE组ALFF在楔叶、楔前叶、视觉皮层等脑叶显著减低;增高区域主要位于皮层和皮层下区。与单纯肝硬化组相比,低级别肝性脑病组ALFF在楔叶、楔前叶、视觉皮层、小脑左后叶显著减低;扣带回前部、双侧额上回,双侧额中回ALFF增高。单纯肝硬化组合对照组间没有差异。结论在低阶级肝性脑病患者中存在ALFF的异常变化,这些神经元活动异常可能是低级别HE患者神经病理机制的基础。     

脑瘫儿认知功能损害的3T多模态脑功能MR成像

目的:探索BOLD及DKI磁共振功能成像技术在认知功能损害脑瘫儿的应用。方法:选取伴有认知功能障碍脑瘫患儿(CP组)52例及正常小儿(CG组)50例,使用PhilipsIngenia3.0T多模态磁共振功能成像技术,在静息状态下行高分辨T1WI、BOLD及可行性DKI扫描,采集统计及分析MR功能数据。结果:CP组与CG组比较:①BOLD成像ALFF值:左丘脑、左壳核、左楔前回及右角回、右扣带回后部的ALFF值升高(P <0.05)。②ReHo值:左额上回、左岛叶皮质、左枕回、右额中回、右颞上回Reho值降低(P<0.05);左额叶白质、左顶下小叶、左丘脑、右额叶白质、右扣带回Reho值升高(P <0.05)。③DKI成像MK值:CP组双额叶、双顶叶、双枕叶MK值均低于CG组(P <0.05)。结论:RS-fMRI为无创性敏感研究认知功能障碍脑瘫儿脑灰白质功能、微观结构及病损的重要影像学方法。     

原发性闭角型青光眼不同频段低频振幅的静息态功能磁共振研究

目的：应用静息态功能磁共振(rs-fMRI)分析原发性闭角型青光眼(PACG)患者不同频段(slow-4：0.027~0.073 Hz, slow-5：0.01~0.027 Hz)大脑低频振幅(ALFF)值改变。方法40例 PACG 患者及36例年龄、性别匹配的正常健康对照(HC)均接受 rs-fMRI 检查,应用 rs-fMRI 数据处理助手(DPARSF)对数据进行预处理。Statistical Parametric Mapping (SPM8)2因素水平重复方差分析比较 PACG 及 HC 组组间效应以及 slow-4,slow-5频段间效应。随后,两样本 t 检验分别比较 PACG 组及 HC 组2个频段 ALFF 值差异并分析差异脑区 ALFF 值与临床参数的相关性。结果频段间结果显示右侧尾状核、左侧眶部额下回 slow-5频段的 ALFF 值较 slow-4频段高(P <0.05,FDR 校正)。与 HC 组相比,楔前叶、楔叶、双侧舌回、双侧枕中回、双侧距状裂、双侧中央后回、右侧中央前回、右侧颞中回、右侧额中回、双侧顶上小叶、右侧中央旁小叶、左侧顶下小叶 ALFF 减低;PACG 组 ALFF 值增高的脑区包括左侧颞下回、左侧颞上回、左侧小脑后叶、双侧海马旁回、左侧额下回、右侧边缘叶、右侧岛叶、后扣带回(P <0.05, FDR 校正)。此外,笔者发现 slow-4、slow-5频段均能检出 PACG 患者异常脑功能活动区。结论PACG 患者存在视觉以及视觉以外相关脑区神经元活动异常,slow-4、slow-5能从不同的角度发现异常脑区,为进一步探究 PACG 的神经病理机制提供了新思路。     

脑功能磁共振对梗死后抑郁症的研究

目的 采用功能性磁共振方法对梗死后抑郁症(PSD)患者观察正性、中性、负性情绪图片后的脑功能成像差异.资料与方法 对11例PSD患者和15名健康志愿者(NORM)进行正性、中性、负性情绪图片刺激下的脑功能磁共振成像研究.结果 PSD组及NORM组观察情绪图片时均主要激活额叶皮层-皮层下网状系统、基底节区(丘脑、苍白球、尾状核)和边缘系统(海马、海马旁回、杏仁核)、岛叶、颞叶,脑干及小脑.两组间有显著组间差异的激活脑区主要有海马旁回、海马、额中回、顶上小叶,扣带回(中性),右侧背侧丘脑、岛叶(正性),右侧杏仁核(负性).结论 PSD与边缘系统(海马、海马旁回、杏仁核)以及额中回、顶上小叶、扣带回、背侧丘脑、岛叶等有密切关系,上述脑区的损害可能参与了PSD的病理生理机制.     

脑梗死运动性失语患者的静息态脑功能研究

目的：采用基于低频振幅（ALFF）和功能连接（FC）算法的静息态功能磁共振成像（RS-fMRI）技术,探讨脑梗死运动性失语症患者静息态下脑功能的变化及其意义。方法对脑梗死运动性失语症患者及志愿者行RS-fMRI扫描。采用双样本t检验对病例组和对照组的进行ALFF分析,并以左侧后扣带回为种子点比较两组脑FC的差异。结果与正常对照组相比,病例组ALFF明显降低的脑区有左侧小脑前叶、梭状回,左侧后扣带回,左侧额内侧回;ALFF明显增高的脑区有右侧后扣带回。病例组与对照组相比,FC下降的脑区主要位于左侧额内侧回、左侧颞中回、左侧丘脑、右侧额中下回、右侧中央前回、右侧中央后回、右侧颞中回、右侧枕中回、右侧海马旁回、两侧楔前叶、后扣带回、胼胝体压部;FC增高的脑区主要以左侧大脑半球、左侧小脑齿状核、左侧小脑、右侧眶回、直回、右侧小脑后叶、右侧脑干较为显著。结论结合ALFF和FC两种技术,能从脑局部功能与功能网络的变化两个方面对脑神经活动进行评价,有助于脑梗死运动性失语病理生理机制的探索。     

Cortical deactivation in mild cognitive impairment: high-field-strength functional MR imaging

PURPOSE: To prospectively identify brain regions in which task-related changes in activation during a memory encoding task, measured with functional magnetic resonance (MR) imaging, correlate with degree of memory impairment across Alzheimer disease (AD), mild cognitive impairment (MCI), and elderly control subjects. MATERIALS AND METHODS: The institutional review board approved this HIPAA-compliant study, and each patient gave written informed consent. Seventy-five subjects (mean age, 72.9 years+/-7.2 [standard deviation]; 37 men, 38 women)-13 patients with mild AD, 34 individuals with amnestic MCI, and 28 healthy elderly control subjects-were imaged at 4.0 T during novel encoding (NE) and familiar encoding (FE) of face-name pairs presented within a block design for later retrieval. Blood oxygen level-dependent (BOLD) changes were assessed across the entire brain for each group. Between-subject analysis identified brain regions demonstrating a monotonic increase or decrease in activation magnitude, from control subjects to patients with MCI to patients with mild AD. BOLD response was also correlated with score on the delayed portion of the California Verbal Learning Test (CVLT). RESULTS: In controls, the task elicited positive activation (NE>FE) in the dorsolateral prefrontal, lateral parietal, and medial temporal regions, and negative activation (FE>NE) in the midline frontal and parietal regions. Along the spectrum from control subjects to patients with AD, there was decreasing activation in the medial temporal lobe (MTL), including the hippocampus and parahippocampal and fusiform gyri, and increasing activation in the posteromedial cortices (PMCs), primarily in the precuneus and posterior cingulate gyrus. Activation magnitude in the PMCs significantly (P<.001, r=-0.502) correlated with CVLT score. CONCLUSION: Compared with activation in the MTL, deactivation in the PMCs could be a more sensitive marker of early AD at functional MR imaging.     

不同动机特质在静息态下脑功能相关研究

目的?动机特质包括趋近系统（BAS）和行为抑制系统（BIS）,利用静息态功能MRI研究不同动机特质的被试在静息态下大脑活动的差别,以及与默认网络（DMN）、背侧注意网络（DAN）和额顶控制网络（FPN）之间功能连接强度的相关性。方法? 将38例完成BIS/BAS问卷的健康在校女大学生分为3组：高BAS低BIS组（高BAS组）,高BIS低BAS组（高BIS组）,低BAS低BIS组（对照组）。采集静息态fMRI及结构像数据并进行预处理及统计。计算低频振幅（ALFF）值,将高BAS组及高BIS组分别与对照组比较,利用双样本t检验的统计学方法,得出显著差异的脑区。利用种子相关分析法获得3个脑网络并获得其间的功能连接强度,将功能连接强度同每个被试BAS、BIS得分进行Spearman相关分析。结果? 两实验组与对照组比较,ALFF值呈显著性增高的脑区分别为：高BAS组主要位于左侧距状回、左侧楔前叶、后扣带回皮质、右侧尾状核、两侧前扣带回皮质、左侧额中回;高BIS组主要位于右侧顶下小叶、额叶、颞叶、距状回及左侧后扣带回。ALFF值呈显著性减低的脑区分别为：高BAS组主要位于两侧丘脑、右侧颞上回及左侧顶叶;高BIS组主要位于左侧顶叶、额叶及两侧前扣带回。BAS分值与DMN-FPN、DAN-FPN功能连接强度呈显著相关（r=0.69,P＜0.001;?r=-0.40,P=0.037）;BIS分值与DMN-DAN功能连接强度呈显著相关（r=-0.41,P=0.036）。?结论? 静息态下不同动机特质呈现前额叶偏侧化活动。动机特质与网络间功能连接强度存在一定相关性。动机特质是多个脑区组成的网络水平负载的神经活动。     

应用局部一致性研究静息态脑功能磁共振成像的性别差异

目的:应用局部一致性的数据分析方法,将fMRI应用于正常人静息态的研究,从局部一致性的角度探讨静息态的性别差异。方法:将21例健康志愿者分为男性组、女性组,采集静息态下的fMRI数据,应用局部一致性方法个体激活图及组激活图;对数据行双样本t检验。结果:男性组较女性组差异有统计意义的激活区为右侧枕叶舌回(BA18)、左侧小脑、右侧枕叶(BA19)、右侧颞下回(BA20)、右侧颞上回(BA22)、左侧顶下小叶(BA22)、右侧楔前叶(BA7)、左侧后扣带回(BA31)、左侧额上回后外侧(BA9)、右侧额中回后部(BA6)、左侧缘上回(BA40)、右侧前扣带回(BA24);激活范围最大区域和激活强度最强均为右侧枕叶舌回(BA18)。女性组较男性组差异有统计意义的激活区为右侧颞下回(BA20)、左侧颞下回(BA20)、桥脑、左侧小脑、左侧颞极区(BA38)、右侧额极区(BA10)、左侧海马旁回(BA34)、左侧中央后回(BA3);激活范围最大区域为右侧额极区(BA10);激活强度最强为桥脑。结论:正常人静息态下的局部一致性存在性别差异。     

特发性全身性癫痫分数低频振幅及局部一致性的静息态f MR I研究

目的：观察特发性全身性癫痫(IGE)患者静息状态下全脑功能改变情况。方法采用3.0T MR扫描仪对23例 IGE患者(IGE组)及23例健康志愿者(对照组)行全脑3D 结构相及静息态功能磁共振成像(RS-fMRI)扫描,进行全脑分数低频振幅(fALFF)及局部一致性(ReHo)功能分析,并对比 IGE组相比对照组 fALFF及 ReHo 改变的脑区,分析 IGE 组差异脑区与患者病程的相关性。结果与正常对照组相比,IGE组 fALFF升高的脑区位于双侧中央前回、左侧辅助运动区、左侧扣带回、左侧中央旁小叶、左侧距状裂周围皮层、左侧枕上回、左侧枕中回及右侧楔前叶;fALFF降低的脑区位于双侧颞下回、右侧海马旁回、右侧岛叶、右侧楔前叶及左侧顶下小叶(P<0.005)。ReHo 升高的脑区位于左侧距状裂周围皮层、左顶上小叶、左中央后回及右中央前回;ReHo降低的脑区位于右侧梭状回、左侧豆状核、右侧额下回、右内侧额上回、左侧枕中回、右侧岛叶及双侧顶下小叶(P<0.005)。IGE组 fALFF及 ReHo的差异脑区与患者病程均无相关性。结论 IGE患者脑内广泛的脑区功能异常改变可能是 IGE复杂临床表现的神经病理基础。联合应用 RS-fMRI的2种分析方法能较全面地评价静息状态下脑功能状态的改变情况,为 IGE 神经病理生理机制的研究提供可靠的功能神经解剖学依据。     

视觉刺激下心算减法与乘法相关皮层的fMRI研究

目的研究正常成年人在执行减法与乘法任务时的脑功能状态及激活模式。方法对13例右利手正常青年志愿者分别给予组块设计的减法和乘法2种实验任务,同时运用1.5T的Marconi磁共振成像系统采集其脑部的血氧水平依赖性功能成像(BOLD-fMRI)数据。运用SPM99软件包进行t检验统计学处理,以获取执行不同任务与静息状态对比的脑功能图像。结果减法任务中,明显激活左侧额中回(MFG)、额下回(IFG)、顶上小叶(SPL)、顶下小叶(IPL)、角回(AG)、颞上回(STG),右侧MFG、SPL、IPL以及两侧视觉联合皮质、两侧小脑半球。乘法任务中,明显激活左侧额上回(SFG)、MFG、IFG、SPL、AG,右侧SPL,以及中央前回(PCG)、两侧视觉联合皮质。结论(1)额前区、顶叶、颞枕交界区参与计算并对应工作记忆、数量操作、视空间注意等作用机制;(2)小脑参与个体的数字计算的认知活动。     

fMRI成像技术在OSAHS患者中的临床价值研究

目的 采用fMRI图像处理技术对阻塞性睡眠呼吸暂停低通气综合征（obstructive sleep apnea-hypopnea syndrome, OSAHS）患者神经影像学进行研究,运用ReHo法探索患者脑功能及结构变化。方法 选取2021年1月-2022年12月厦门市海沧医院就诊的20例OSAHS患者作为研究对象,另选同期来院体检的健康志愿者20例作为健康对照组,分析比较两组受试者的一般情况并对两组患者进行睡眠监测,同时进行fMRI检查,并运用ReHo法对各组及两组间受试者睡眠前后脑区功能改变情况进行比较。结果 两组受试者一般情况资料差异无统计学意义（P>0.05）,健康对照组AHI(2.35±1.27)低于OSAHS组（32.93±14.90）,最低SpO2值（88.25±3.01）高于OSAHS组（67.25±8.06）,差异均有统计学意义（P<0.05）。健康人群睡眠后ReHo增强脑区有左右侧颞下回、左右侧前扣带回、右侧杏仁核、右侧海马,减弱脑区有左右侧前额叶、左右顶叶。OSAHS患者睡眠后ReHo增强脑区有左右侧颞下回、右侧脑干,减弱脑区有右侧额中回、两侧额上...     

基于体素的形态测量学在阿尔茨海默病和轻度认知障碍中的应用价值

目的：应用基于体素的形态测量学（VBM）方法比较阿尔茨海默病（AD）和轻度认知障碍（MCI）患者和健康老年人灰质体积的不同,探讨VBM方法在AD、MCI诊断中的应用价值。方法：本研究包括10例AD患者（AD组）、9例MCI患者（MCI组）、10例老年健康志愿者（健康对照组）,检查系列包括头常规轴面T2WI、T1WI、轴面FLAIR、矢状面T1WI,全脑3D-SPGR。应用VBM方法处理数据,把脑组织分割成灰质、白质和脑脊液,最后应用两样本t检验两两比较灰质体积改变。结果：AD组与正常对照组脑灰质体积比较：AD组大脑皮层灰质体积弥漫减少,激活区域几乎分布整个大脑半球,以两侧内侧颞叶（海马、梨状皮层、内嗅皮层）为著。右侧海马减少的体素总数为2358个,左侧海马减少的体素总数为2967个,前后扣带回体素明显减少;MCI组与正常对照组比较：MCI组灰质减少的区域依然较多,但与AD和对照组相比,激活区域明显减少。其中最明显的是内侧颞叶内嗅皮层、海马旁回区域,右侧体素减少总数为1368,左侧1135;MCI组和AD组的比较：MCI组较AD组灰质减少的区域更多,内侧颞叶和海马区域基本没有激活区域,较明显的激活区域位于双侧额顶颞叶、扣带回。双侧尾状核头部和左侧丘脑亦有较明显激活,而豆状核没有明显激活。结论：内侧颞叶和海马体积减小是评价AD和MCI最敏感的区域,VBM可以有效评价灰质体积的改变。     

FMRI of working memory in patients with mild cognitive impairment and probable Alzheimer’s disease

The goals of this study were to evaluate brain activation in patients with probable Alzheimers disease (AD), mild cognitive impairment (MCI), and controls while performing a working memory (WM) task. Eleven AD patients, ten MCI subjects, and nine controls underwent functional magnetic resonance imaging (fMRI) while performing a visual WM task. Statistical parametric maps of brain activation were obtained in each group, and group activation difference maps were generated. Ability to perform the task did not differ among the groups. Activation was observed in the parahippocampal region, superior-middle-inferior frontal gyri, parietal region, anterior–posterior cingulate, fusiform gyrus, and basal ganglia. MCI and AD groups showed more activation than the controls in the right superior frontal gyrus, bilateral middle temporal, middle frontal, anterior cingulate, and fusiform gyri. Activation in the right parahippocampal gyrus, left inferior frontal gyrus, bilateral cingulate and lingual gyri, right lentiform nucleus, right fusiform gyrus, and left supramarginal gyrus in the AD group was less than in the MCI group. The WM task evoked activation in widely distributed regions, consistent with previous fMRI studies. AD and MCI patients showed an increased extent of activation and recruitment of additional areas.Presented at the 8th International Conference on Alzheimers Disease and Related Disorders, Stockholm, Sweden, July 20–25, 2002.Supported by a Pilot Project grant from the Alzheimers Disease Center at the University of Texas Southwestern Medical Center (NIA Grant # 1-P-30-AG-12300-08)     

Changes in thalamus connectivity in mild cognitive impairment: evidence from resting state fMRI

Purpose

The subcortical region such as thalamus was believed to have close relationship with many cerebral cortexes which made it especially interesting in the study of functional connectivity. Here, we used resting state functional MRI (fMRI) to examine changes in thalamus connectivity in mild cognitive impairment (MCI), which presented a neuro-disconnection syndrome.

Materials and methods

Data from 14 patients and 14 healthy age-matched controls were analyzed. Thalamus connectivity was investigated by examination of the correlation between low frequency fMRI signal fluctuations in the thalamus and those in all other brain regions.

Results

We found that functional connectivity between the left thalamus and a set of regions was decreased in MCI; these regions are: bilateral cuneus, middle occipital gyrus (MOG), superior frontal gyrus (SFG), medial prefrontal cortex (MPFC), precuneus, inferior frontal gyrus (IFG) and precentral gyrus (PreCG). There are also some regions showed reduced connectivity to right thalamus; these regions are bilateral cuneus, MOG, fusiform gyrus (FG), MPFC, paracentral lobe (PCL), precuneus, superior parietal lobe (SPL) and IFG. We also found increased functional connectivity between the left thalamus and the right thalamus in MCI.

Conclusion

The decreased connectivity between the thalamus and the other brain regions might indicate reduced integrity of thalamus-related cortical networks in MCI. Furthermore, the increased connectivity between the left and right thalamus suggest compensation for the loss of cognitive function. Briefly, impairment and compensation of thalamus connectivity coexist in the MCI patients.     

应用功能磁共振研究学习对复杂加法的影响

目的:应用功能磁共振(fMRI)对复杂加法的脑功能区进行研究,并分析学习记忆对复杂加法的影响。材料和方法:20名年轻成人右利手正常志愿者参加实验,任务采用组块设计,应用AFNI软件进行数据分析和功能定位,并比较学习前后的脑区激活结构。结果:在未学习复杂计算任务中,两侧枕叶视区、两侧额中回、两侧额叶内侧前部及中部(辅助运动区)、两侧额下回、左侧中央前回、两侧楔前叶、两侧顶间沟周围脑区、两侧顶下小叶、小脑出现激活。学习后复杂加法任务所显示的激活区域有:两侧枕叶视区、两侧额中回、左侧额下回、左侧中央前回、两侧辅助运动区、两侧顶上小叶和顶下小叶、两侧楔前叶。比较学习前后的脑区激活结构,学习前右侧额下回、左侧扣带回后部、左侧顶间沟周围脑区、左侧颞中回激活明显强于学习后;而学习后两侧楔前叶、两侧缘上回及右侧角回的激活相对增强。结论:学习能对复杂加法计算时神经网络功能活动方式产生影响,主要反映在前额叶和顶叶等与工作记忆相关脑区激活的改变上。     

基于体素的遗忘型轻度认知障碍和轻度阿尔茨海默病全脑白质MR扩散张量成像分析

目的 采用基于体素的分析(VBA)方法研究遗忘型轻度认知障碍(aMCI)患者和轻度阿尔茨海默病(AD)患者全脑白质微观结构改变的特点及其与灰质萎缩模式的关系.方法 选取33例aMCI患者(aMCI组)、32例轻度AD患者(轻度AD组)和31名正常老年人(健康对照组),对全脑进行3.0 T DTI及三维快速扰相梯度反转回波(3DFSPGR)脉冲序列扫描.采用统计参数图(SPM)5软件对被试者的结构图像及各向异性(FA)图进行预处理,然后采用t检验对aMCI组、轻度AD组和正常对照组的全脑灰质体积及FA值进行基于体素的统计学比较,计算出有统计学意义的脑区.结果 与正常对照组比较,aMCI组的双侧额颞叶和左侧枕叶白质、左侧扣带前部、左侧顶下小叶、右侧脑室三角区外上方白质的FA值减低;轻度AD组的双侧额颞枕叶、海马旁白质、扣带前部、胼胝体、侧脑室三角区旁白质、顶下小叶、左侧颞于、左侧丘脑、右侧楔前叶FA值减低.基于体素的形态测量学(VBM),分析发现,aMCI患者组左侧海马、海马旁回、舌回、颞上回,双侧岛叶、颞中回出现了灰质萎缩;轻度AD患者组双侧海马、海马旁回、杏仁核、丘脑、额叶、颞叶、顶叶、枕叶皮质出现了灰质萎缩.aMCI与轻度AD患者组全脑白质FA值减低的模式与灰质萎缩模式不同.aMCI组与轻度AD组比较未发现具有统计学意义的FA值减低脑区.aMCI、轻度AD患者组全脑白质FA值与简易智能精神状态检查量表(MMSE)评分没有相关性.结论 基于体素的MR DTI全脑白质分析能够较全面、客观地揭示aMCI、轻度AD的脑白质损害的模式.aMCI、轻度AD患者白质损害的模式与灰质不同,提示脑白质病变是多种病理机制导致的.aMCI患者向轻度AD进展过程中,脑白质各向异性改变不显著,脑白质FA值的改变可能无法反映患者认知功能障碍的严重程度.

Abstract：

Objective To evaluate the microstructural integrity of white matter (WM) in patients with amnestic mild cognitive impairment (aMCI) and mild Alzheimer's disease (AD) using voxel-based analysis (VBA), and investigate the relationship between WM abnormalities and gray matter(GM) atrophy.Methods Thirty-three cases with aMCI, 32 cases with mild AD and 31 normal aging volunteers as control subjects were scanned on a 3.0 T MR system using diffusion tensor imaging (DTI) and three-dimensional spoiled gradient-recalled(3DSPGR) sequences. Fractional anisotropy (FA) maps and morphological images were preprocessed by SPM5 and voxel-based comparisons between the 2 patient groups and the control group were performed by t test. Results Relative to the control group, patients with aMCI showed significantly reduced FA value in bilateral frontal, temporal and left occipital WM, left anterior part of cingulum, left inferior parietal lobule, and the W M adjacent to the triangular part of the right lateral ventricle(k≥20 voxels).In mild AD,significantly reduced FA value was found in bilateral hippocampal,inferior parietal lobular,frontal,temporal,and occipital WM,bilateral corpus callosum,anterior part of cingulums,the WM adjacent to the triaangular part of the bilateral lateral ventricles,left temporal stem,left thalamus,right precuneus(k≥20 voxels).Significantly reduced GM volume was found in left hippocampus,parahippocampal gyrus,lingual gyrus and superior temporal gyrus,bilateral insulae and middle temporal gyri in aMCl group whencompared with control group(k≥50 voxels).In mild AD,significantly reduced GM volume was found in bilateral hippoeampi,parahippocampal gyri,amygdalae,thalami,temporal,parietal,frontal,occipital cortex(k≥50 voxels).The pattern of areas with reduced FA differs;from that of the GM volumetric reduction.No areas with significantlv reduced FA was detected in aMCl compared with mild AD. There was no significant correlation between FA value of WM in patient groups and Mini-Mental State Examination(MMSE)scores.Conclusions Voxel-based MRI DTI analysis of whole brain white matter can objectively reveal widespread white matter abnormalities in early-stage AD.The difierence between WM FA reduction pattern and GM volumetric reduction pattern indicates that the pathological WM changes in earlyslage AD were caused by multiple mechanisms. FA did not vary significantly in patients pr0gressing from aMCI to mild AD and can hardly reflect the severitv of cognitive function damage in these patients.     

韵律恢复加工脑机制的fMRI研究

目的：利用功能磁共振成像技术（fM RI）,考察大脑在韵律恢复加工中的作用,对韵律恢复加工的神经机制进行探讨。方法应用3T磁共振成像系统与标准头线圈对18名在校大学生进行fM RI检查,年龄22～26岁,选择三种刺激条件（正常句、换词句、拉平正常句、拉平换词句）,每个条件各30个句子,共计120个句子。其中,通过两种拉平的语句条件（拉平正常句、拉平换词句）与相应的未拉平条件（正常句、换词句）相比,显示韵律恢复引起的脑激活区。结果 fM-RI研究结果显示,拉平正常句主要激活双侧颞上回、右侧颞叶前部、右侧海马旁回、右侧枕中回、内侧额叶区域以及左侧前运动区等脑区;拉平换词句主要激活右侧额下盖部、右侧枕中回、双侧颞下回、左侧枕上、左侧前运动区和辅助运动区、左侧额下回等脑区。结论双侧大脑多个脑区参与韵律恢复加工,f M RI对研究韵律恢复加工脑机制有重要作用。     

Cerebral perfusion (HMPAO-SPECT) in patients with depression with cognitive impairment versus those with mild cognitive impairment and dementia of Alzheimer’s type: a semiquantitative and automated evaluation

Purpose  Comparative evaluation of regional brain perfusion measured by HMPAO-SPECT of patients with mild cognitive impairment (MCI), dementia of Alzheimer’s type (DAT) and depression with cognitive impairment (DCI). Methods  A total of 736 patients were investigated because of suspected cognitive dysfunction. After exclusion of patients with other forms of dementia than DAT or relevant accompanying disorders, SPECT data from 149 MCI, 131 DAT and 127 DCI patients, and 123 controls without any cognitive impairment, were analysed. Relative cerebral blood flow of 34 anatomical regions was assessed with automated analysis software (BRASS). Results  Calculation of global forebrain perfusion discriminated demented from nondemented patients. Compared to controls DCI patients showed hypoperfusion of the thalamus, lentiform nucleus and medial temporal cortex. MCI patients differed significantly from controls concerning perfusion in both hemispheric temporal and parietal areas, and in the (right hemispheric) posterior part of the cingulate gyrus. MCI and DCI patients differed in the parietal, temporal superior and right hemispheric cingulate gyrus posterior cortices. Global forebrain and regional perfusion was more extensively reduced in DAT patients and discriminated them from controls, and MCI and DCI patients. Frontal perfusion disturbance was only present in DAT patients. Conclusion  Automated analysis of HMPAO-SPECT data from MCI patients showed significant perfusion deficits in regions also involved in DAT patients, but ROC analysis demonstrated only moderate sensitivity and specificity for differentiating DAT patients from controls and DCI patients. Frontal hypoperfusion seems to correspond with conversion from MCI to DAT. Finally, the results in DCI patients again raise the question of depression as an early symptom of neurodegeneration.