MR and genetics in schizophrenia: focus on auditory hallucinations

Although many structural and functional abnormalities have been related to schizophrenia, until now, no single biological marker has been of diagnostic clinical utility. One way to obtain more valid findings is to focus on the symptoms instead of the syndrome. Auditory hallucinations (AHs) are one of the most frequent and reliable symptoms of psychosis. We present a review of our main findings, using a multidisciplinary approach, on auditory hallucinations. Firstly, by applying a new auditory emotional paradigm specific for psychosis, we found an enhanced activation of limbic and frontal brain areas in response to emotional words in these patients. Secondly, in a voxel-based morphometric study, we obtained a significant decreased gray matter concentration in the insula (bilateral), superior temporal gyrus (bilateral), and amygdala (left) in patients compared to healthy subjects. This gray matter loss was directly related to the intensity of AH. Thirdly, using a new method for looking at areas of coincidence between gray matter loss and functional activation, large coinciding brain clusters were found in the left and right middle temporal and superior temporal gyri. Finally, we summarized our main findings from our studies of the molecular genetics of auditory hallucinations. Taking these data together, an integrative model to explain the neurobiological basis of this psychotic symptom is presented.     

Chronic auditory hallucinations in schizophrenic patients: MR analysis of the coincidence between functional and morphologic abnormalities

PURPOSE: To prospectively evaluate if functional magnetic resonance (MR) imaging abnormalities associated with auditory emotional stimuli coexist with focal brain reductions in schizophrenic patients with chronic auditory hallucinations. MATERIALS AND METHODS: Institutional review board approval was obtained and all participants gave written informed consent. Twenty-one right-handed male patients with schizophrenia and persistent hallucinations (started to hear hallucinations at a mean age of 23 years +/- 10, with 15 years +/- 8 of mean illness duration) and 10 healthy paired participants (same ethnic group [white], age, and education level [secondary school]) were studied. Functional echo-planar T2*-weighted (after both emotional and neutral auditory stimulation) and morphometric three-dimensional gradient-recalled echo T1-weighted MR images were analyzed using Statistical Parametric Mapping (SPM2) software. Brain activation images were extracted by subtracting those with emotional from nonemotional words. Anatomic differences were explored by optimized voxel-based morphometry. The functional and morphometric MR images were overlaid to depict voxels statistically reported by both techniques. A coincidence map was generated by multiplying the emotional subtracted functional MR and volume decrement morphometric maps. Statistical analysis used the general linear model, Student t tests, random effects analyses, and analysis of covariance with a correction for multiple comparisons following the false discovery rate method. RESULTS: Large coinciding brain clusters (P < .005) were found in the left and right middle temporal and superior temporal gyri. Smaller coinciding clusters were found in the left posterior and right anterior cingular gyri, left inferior frontal gyrus, and middle occipital gyrus. CONCLUSION: The middle and superior temporal and the cingular gyri are closely related to the abnormal neural network involved in the auditory emotional dysfunction seen in schizophrenic patients.     

Combining functional and structural brain magnetic resonance imaging in Huntington disease

OBJECTIVE: To concurrently investigate with magnetic resonance (MR) the brain activation and regional brain atrophy in patients with Huntington disease (HD). METHODS: Nine symptomatic HD patients and 11 healthy subjects underwent an MR study including functional MR acquisition during finger tapping of the right hand and high-resolution T1-weighted images. Functional and structural data were analyzed using Statistical Parametric Mapping 2 software. RESULTS: As compared with control subjects, HD patients showed decreased activation in the left caudate nucleus and medial frontal and anterior cingulate gyri and increased activation in the right supplementary motor area and supramarginal gyrus and left intraparietal sulcus. The pattern of atrophy included thinning of the gray matter (GM) in the insula, inferior frontal gyrus, caudate, lentiform nucleus, and thalamus, bilaterally, in the left middle frontal, middle occipital, and middle temporal gyri, and of periventricular, subinsular, right temporal lobe, and left internal capsule white matter. Only the decreased activation in the caudate nucleus correlated topographically with the caudate GM loss. CONCLUSION: The cortical areas of functional changes do not correspond to those of GM atrophy in patients with HD and are likely to reflect decreased output of the motor basal ganglia-thalamo-cortical circuit and compensatory recruitment of accessory motor pathways.     

肌萎缩侧索硬化症基于体素的形态测量扩散张量分析

目的 利用基于体素的形态测量学(VBM)及基于体素的扩散张量分析评价肌萎缩侧索硬化症(ALS)患者的脑灰质、白质体积及各向异性分数(FA)值的改变.方法 选取39例确诊或拟诊为ALS的患者(ALS组)及39名健康成年人(对照组)进行常规MR扫描及神经心理学评估,并采集3D快速扰相梯度回波(fast spoiled gradient echo,FSPGR)序列T_1WI和DTI数据.对3D T_1结构像进行配准、分割、平滑后,采用VBM分析,计算分割后的脑灰质、白质及脑脊液的体积.选取76名健康志愿者进行DTI,对原始图像进行后处理,制作FA模版,将ALS组和对照组受试者的FA图配准在所创建的FA模版上,测量FA值.统计方法采用协方差分析,因性别完全匹配,故对于VBM,年龄及全脑总体积作为协变量,而对于基于体素的扩散张量分析,仅年龄作为协变量,P＜0.01(未校正),相连像素＞20个的脑区为有差异的脑区.结果 全脑体积分析显示两组受试者的全脑灰质体积、全脑白质体积、全脑体积及脑灰质分数之间差异无统计学意义,但ALS患者的白质分数(0.29±0.02)小于健康对照组(0.30±0.02)(P=0.003).与健康对照组比较,ALS患者局部灰质体积减少脑区主要位于双侧额上回及中央前回,右侧额中回及颞中、下回,左侧枕上回、楔叶及左侧岛叶,ALS患者局部白质体积减少脑区主要位于胼胝体膝部,双侧额内侧回、旁中央小叶及岛叶,右侧额上回及额中回、左侧中央后回.ALS患者双侧扣带回及海马旁回FA值较对照组减低.结论 ALS并不是单纯的运动神经元病,是一种多系统受累的疾病,基于体素的扩散张量分析对于怀疑认知功能障碍的患者海马旁回及扣带回白质FA值变化的检出具有一定的潜在价值.     

Increased accumulation of N-isopropyl-(I-123) p-iodoamphetamine in the left auditory area in a schizophrenic patient with auditory hallucinations

A schizophrenic patient with auditory hallucinations is reported in which IMP markedly accumulated in the left superior temporal and inferior parietal lobes which correspond to the left primary and secondary cortical auditory areas and angular gyrus, respectively.     

VBM-DARTEL法观察带状疱疹后遗神经痛患者脑灰质体积的形态学改变

目的 观察带状疱疹后遗神经痛(PHN)患者全脑灰质形态学改变,探讨其形态学改变与PHN患者视觉模拟评分(VAS)及病程之间的相关性.方法 对17例PHN患者及17例正常对照的3D T1WI结构图像进行预处理,采用VBM-DARTEL法比较2组分割后的脑灰质体积,并分析脑灰质体积改变与PH患者VAS及病程之间的相关性.结果 相对于正常对照组,PHN患者脑灰质体积减小的脑区包括:双侧眶额区(眶回及直回)、左侧额下回、左侧岛叶、左侧尾状核、右侧扣带回、左侧颞上回、左侧楔叶、双侧小脑前后叶;PHN患者脑灰质体积增加的脑区包括:双侧额上回、左侧额中回、小脑蚓部、脑桥;PHN组两侧半球脑灰质体积改变不对称(左侧>右侧);PHN患者脑灰质体积异常脑区与VAS及病程之间均无相关性.结论 VBM-DARTEL法揭示PHN患者存在广泛脑灰质体积异常,这些改变可能在疼痛的形成及慢性状态维持中发挥重要作用.     

MR imaging of the human brain at 1.5 T: regional variations in transverse relaxation rates in the cerebral cortex.

BACKGROUND AND PURPOSE: Heterogeneity in cortical signal intensity on T2-weighted MR images has been recently documented. Using a whole-brain, multiecho MR imaging technique, we sought to determine the T2 relaxation times of nine predefined regions in the cerebral cortex and one region in the deep gray matter. METHODS: Ten adult volunteers (nine men and one woman; age range, 18-40 y; average age, 30.8 y) underwent whole-brain imaging with an oblique coronal multiecho 3D Carr-Purcell-Meiboom-Gill MR sequence at 1000/25, 50, 75, 100, 125, and 150 (TR/TE). T2 measurements were obtained, with variably sized regions of interest, from the primary auditory cortex, primary visual cortex, caudate nucleus, superior frontal gyrus, inferior temporal gyrus, middle temporal gyrus, superior temporal gyrus, insula cortex, cingulate gyrus, and hippocampus. Repeated-measures analysis of variance was used to assess the existence of differences in T2 measurements among the anatomic locations. RESULTS: On the basis of T2 measurements, the gray matter structures examined could be divided into four statistically different groups. In ascending order of T2 measurements, the first group consisted of the primary auditory cortex and primary visual cortex; the second group, the caudate nucleus, superior frontal gyrus, inferior temporal gyrus, middle temporal gyrus, and superior temporal gyrus; the third group, the insula cortex; and the fourth group, the cingulate gyrus and hippocampus. CONCLUSION: Significant variation in T2 values among the cortical gray matter of the human brain exists.     

静息状态下帕金森病患者脑部功能连接的MR研究

目的 探讨帕金森病患者在静息状态下脑部功能连接情况.方法 选取9例Ⅱ～Ⅲ级原发性帕金森病患者及8名年龄分布相同的健康志愿者在静息状态下进行MR扫描,选择双侧苍白球作为种子点,分析其脑部功能连接情况,并采用两样本t检验与健康对照组相比较.结果 正常健康对照组中,双侧颞极、双侧海马、双侧丘脑、扣带回后部、右侧枕中区、右侧顶上回等部位存在着功能连接.帕金森病患者的双侧小脑半球、左侧海马、双侧颞上回、后扣带同、左侧额下回、左侧额中回、左侧中央前回、左侧顶下回、左侧顶上回等部位存在功能联系,与对照纽相比,帕金森病患者的双侧小脑、双侧颞叶、左侧额叶、左侧运动前区、左侧顶叶等部位存在着功能连接增强,双侧丘脑的功能连接减弱.结论静息状态下,帕金森病脑部存在着功能连接异常现象.     

首发精神分裂症药物治疗前后的fMRI研究

目的:探讨首发精神分裂症患者治疗前后倒背数字作业测验(BDST)fMRI脑内激活区的特点.方法:符合ICD-10精神分裂症诊断标准的首发患者及正常志愿者各18例,以BDST作为刺激任务,进行fMRI检查,氯丙嗪治疗后的患者中9例再次接受fMRI检查.结果:在BDST的fMRI检查中,对照组的左侧额上回、双侧额中回、左侧额下回、左侧中央前回、左侧顶上小叶、左侧缘上回、左侧颞下回及左侧枕颞外侧回等脑区均有明显激活;而首发精神分裂症患者的左侧额上回、左侧额下回及双侧顶叶后下部等脑区激活低下.9例用氯丙嗪治疗后的患者左侧额上回及左侧额下回的激活低下明显改善(P＜0.05).结论:fMRI不仅可以为首发精神分裂症患者的临床诊断提供可靠的诊断依据,而且还能为精神分裂症临床药物疗效的评价提供了一个新的客观指标.     

Functional MR to localize sustained visual attention activation in patients with attention deficit hyperactivity disorder: a pilot study.

PURPOSETo evaluate brain control activation in patients with attention deficit hyperactivity disorder (ADHD) and to provide an initial comparison between activated regions in ADHD subjects and those previously localized in an unaffected population.METHODSTen patients with ADHD underwent imaging with a functional blood oxygen level-dependent MR technique during sustained visual vigilance. Pixel activation was inspected visually and statistical group analysis was performed.RESULTSActivation was seen over the bilateral middle frontal gyri, the superior parietal lobules, and the inferior parietal lobules. The predominant activity occurred in the right middle frontal gyrus. Application of an additional statistical constraint revealed significant activity in the right inferior and left superior parietal lobules.CONCLUSIONADHD patients effectively tolerated the necessary MR imaging constraints despite their difficulty with confinement and immobility. Single-section functional MR imaging revealed activation in brain regions known to be involved in the maintenance of the attention in healthy subjects responding to auditory, tactile, or visual stimulation; additional areas of activity that were identified may represent true abnormal regions in the affected population or artifacts.     

帕金森病认知障碍患者脑结构的体素形态学研究

目的：分析帕金森病(PD)患者脑灰质异常区域及分布特征,探寻与轻度认知障碍(MCI)有关的脑结构变化。方法采用基于体素的形态学测量(VBM)方法,对20例伴 PD-MCI 患者、17例无轻度认知障碍 PD(PD-nMCI)患者及20例正常对照组(NC)的3组3D-T1 WI 脑容积数据进行处理统计,得到3组全脑灰质图像。结果与 NC 组相比,PD-nMCI 组脑灰质体积异常减少的脑区包括：右侧梭状回、右颞中下回、右钩回及左侧颞上回。与 PD-nMCI 组相比,PD-MCI 组脑灰质体积异常减少的脑区包括：两侧额叶(两额中下回、左侧中央前回)、颞叶(右颞中回、左颞上回)、岛叶、右枕叶(右楔叶、舌回)、右后扣带回。结论PD-nMCI 患者灰质体积的缺失相对局限,随认知障碍的出现、发展,缺失脑区的范围逐渐扩大,其中两侧额叶中下回、左侧中央前回的体积缺失与 PD 患者的 MCI 关系密切。     

Material-dependent activation in prefrontal cortex: working memory for letters and texture patterns--initial observations

PURPOSE: To prospectively evaluate whether a distinction between verbal and nonverbal short-term memory systems, as predicted with the multicomponent working memory model, is reflected in the material-specific patterns of activation in the prefrontal cortex. MATERIALS AND METHODS: Informed written consent was obtained from all participants, and the institutional review board approved the study protocol. Echo-planar MR imaging was performed in 12 healthy subjects (five female and seven male subjects), with a mean age of 23.52 years +/- 2.52 (standard deviation) and a range of 20-29 years. A two-back task was used in the verbal and nonverbal versions. In the first version, letters were used as stimuli, and in the second version, the stimuli were abstract texture patterns. Timing parameters for both versions were the same. Statistical analysis of the functional data involved a fixed-effects general linear model. Regions of activation were identified from specific t-statistic contrasts between baseline and active tasks (corrected for whole-brain multiple comparisons). RESULTS: The following suprathreshold voxels for the verbal condition were observed predominantly in the left hemisphere (middle frontal gyrus, precentral gyrus, middle temporal gyrus, and occipital cortex). Bilateral activations were in inferior frontal gyri, insulae inferior, superior parietal lobules, and cingulate gyri. In the nonverbal condition, suprathreshold voxels were located mostly bilaterally in the following regions: inferior, middle, and medial frontal gyri and inferior parietal lobules. Active regions were also found in the precentral gyrus and precuneate gyrus in the left parietal lobe and the occipital cortex in the right hemisphere. CONCLUSION: Results of this study are consistent with the multicomponent model of working memory.     

The influence of gender on auditory and language cortical activation patterns: preliminary data

PURPOSE AND BACKGROUND: Intersex cortical and functional asymmetry is an ongoing topic of investigation. In this pilot study, we sought to determine the influence of acoustic scanner noise and sex on auditory and language cortical activation patterns of the dominant hemisphere. MATERIALS AND METHODS: Echoplanar functional MR imaging (fMRI; 1.5T) was performed on 12 healthy right-handed subjects (6 men and 6 women). Passive text listening tasks were employed in 2 different background acoustic scanner noise conditions (12 sections/2 seconds TR [6 Hz] and 4 sections/2 seconds TR [2 Hz]), with the first 4 sections in identical locations in the left hemisphere. Cross-correlation analysis was used to construct activation maps in subregions of auditory and language relevant cortex of the dominant (left) hemisphere, and activation areas were calculated by using coefficient thresholds of 0.5, 0.6, and 0.7. RESULTS: Text listening caused robust activation in anatomically defined auditory cortex, and weaker activation in language relevant cortex of all 12 individuals. As a whole, there was no significant difference in regional cortical activation between the 2 background acoustic scanner noise conditions. When sex was considered, men showed a significantly (P < .01) greater change in left hemisphere activation during the high scanner noise rate condition than did women. This effect was significant (P < .05) in the left superior temporal gyrus, the posterior aspect of the left middle temporal gyrus and superior temporal sulcus, and the left inferior frontal gyrus. CONCLUSION: Increase in the rate of background acoustic scanner noise caused increased activation in auditory and language relevant cortex of the dominant hemisphere in men compared with women where no such change in activation was observed. Our preliminary data suggest possible methodologic confounds of fMRI research and calls for larger investigations to substantiate our findings and further characterize sex-based influences on hemispheric activation patterns.     

采用优化的基于体素的形态学方法研究智力障碍儿童脑灰质容积变化

目的 利用优化的基于体素的形态测量学(VBM)方法,比较病因不明且常规影像检查正常的智力障碍儿童与正常同龄儿童脑灰质容积的差异,探究患儿脑灰质发育与智力障碍间的联系.方法 选取21例智力障碍患儿和30名正常儿童进行高分辨率脑MR扫描,然后进行VBM分析,应用独立样本t检验比较两组儿童脑灰质容积总量以及不同区域灰质容积的差别.同时,对智力障碍儿童的智商评分与脑灰质容积总量进行偏相关性分析.结果 智障儿童脑灰质容积总量[(1.012±0.079)×106 mm3]明显大于正常儿童[(0.956±0.059)×106mm3],智障组与正常对照组儿童脑灰质总容积的差异具有统计学意义(t=-2.80,P＜0.05).智障组儿童脑局部区域灰质容积较正常对照组高,脑区包括双侧丘脑、额上回、直回和颞极,以及右侧额下回、海马旁回和右侧小脑.智障组儿童脑灰质容积与智商无相关性(r=0.078,P＞0.05).结论 VBM能够显示常规MRI表现正常的智力障碍儿童中的脑灰质发育异常.额叶-丘脑环路的脑灰质容积增加,提示其发育滞后,可能是导致儿童智力障碍的原因之一.

Abstract：

Objective To detect brain structural difference between children with unexplained mental retardation and children with typically normal development. Methods The high-resolution magnetic MR imaging were obtained from 21 children with unexplained mental retardation and 30 age-matched control children without intellectual disabilities. Voxel-based morphometry analysis with an optimization of spatial segmentation and normalization procedures were applied to compare differences of gray matter volume between the two groups. The total and regional gray matter volume were compared between the two groups with independent t test. Meanwhile, correlation was conducted to analyze the relationship between the total gray matter volume and intelligence quotient (IQ) with partial correlation test. Results The total gray matter volume was significantly increased in the mental retardation children [(1. 012 ±0. 079) × 106 mm3]in relative to the controls [(0. 956 ± 0. 059) × 106 mm3, t = - 2. 80, P ＜ 0. 05]. Compared to controls,children with unexplained mental retardation showed significantly increased gray matter volume in different regions, including the bilateral thalami, the bilateral superior frontal gyri, the bilateral gyri rectus, the bilateral temporal poles, the right inferior frontal gyrus, right parahippocampal gyrus and the right cerebellum. No correlation was detected between the total gray matter volume and IQ in children with mental retardation (r = 0. 078 ,P ＞ 0. 05). Conclusions VBM would detect the gray matter abnormalities that were not founded in routine MR scanning. The increase of gray matter volume in the frontal-thalamus network might indicate the delayed maturation of the brain development. This might be one of the causations of mental retardation in children.     

精神分裂症患者脑结构及功能的多模态影像Meta分析

目的 研究在未用药物干扰前提下精神分裂症患者的脑结构及功能变化及两者之间的关系.方法 系统地从PubMed、Embase、Web of Science和The Cochrane Library数据库上检索相应文献.多模态分析方法采用软件"Seed-based d Mapping".结果 纳入14篇结构研究,包括446例患者和461例正常对照.纳入的15篇功能MRI及PET研究中,共有360例患者和396例正常对照.多模态结果分析表明结构和功能大部分重叠的脑区在额颞叶,双侧扣带回/扣带旁回,双侧岛叶,基底节及左侧小脑.结论 排除药物干扰后发现精神分裂症患者结构和功能重叠的脑区大部分在默认网络(DMN)和听觉网络(AN).在这2种网络中,结构和功能变化的方向不一致,可能反映了精神分裂症患者大脑不同的病理生理改变.     

Statistical parametric mapping analysis of the relationship between regional cerebral blood flow and symptom clusters of the depressive mood in patients with pre-dialytic chronic kidney disease

OBJECTIVE: The aim of this study is to investigate the relationship between regional cerebral blood flow (rCBF) and symptom clusters of depressive mood in pre-dialytic chronic kidney disease (CKD). METHODS: Twenty-seven patients with stage 4-5 CKD were subjected to statistical parametric mapping analysis of brain single-photon emission computed tomography. Correlation analyses between separate symptom clusters of depressive mood and rCBF were done. RESULTS: The first factor (depressive mood) was negatively correlated with rCBF in the right insula, posterior cingulate gyrus, and left superior temporal gyrus, and positively correlated with rCBF in the left fusiform gyrus. The second factor (insomnia) was negatively correlated with rCBF in the right middle frontal gyrus, bilateral cingulate gyri, right insula, right putamen, and right inferior parietal lobule, and positively correlated with rCBF in left fusiform gyrus and bilateral cerebellar tonsils. The third factor (anxiety and psychomotor aspects) was negatively correlated with rCBF in the left inferior frontal gyrus, right superior frontal gyrus, right middle temporal gyrus, right superior temporal gyrus, and left superior frontal gyrus, and positively correlated with rCBF in the right ligual gyrus and right parahippocampal gyrus. CONCLUSIONS: In this study, the separate symptom clusters were correlated with specific rCBF patterns similar to those in major depressive disorder patients without CKD. However, some areas with discordant rCBF patterns were also noted when compared with major depressive disorder patients. Further larger scale investigations are needed.     

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.     

Granger因果检验对创伤后应激障碍杏仁核效应连接网络的研究

目的探讨创伤后应激障碍(posttraumatic stress disorder,PTSD)患者杏仁核与全脑其它脑区间效应连接的改变。方法对经历汶川大地震的57例PTSD患者及77例对照行静息状态下的功能磁共振扫描,采用Granger因果(granger causality,GC)检验方法分析双侧杏仁核与全脑其它脑区间影响的因果关系,进行组间比较并计算患者的临床用PTSD诊断量表(clinician-Administered PTSD Scale,CAPS)评分和异常脑区GC平均值的相关性。结果与对照组相比,PTSD患者杏仁核对内侧额回、扣带回、额上回、额下回、颞上回、颞下回和壳核的影响减弱,对海马和海马旁回、楔叶、楔前叶、丘脑的影响增强;而内侧额回、额中回、颞上回、颞中回、岛叶和壳核对杏仁核的影响减弱,楔叶、楔前叶和海马旁回对杏仁核的影响增强。PTSD患者的CAPS评分与杏仁核对颞上回和颞下回,额中回对杏仁核的影响呈负相关;而与杏仁核对楔前叶的影响呈正相关。结论 PTSD患者杏仁核与全脑其它脑区间的效应连接存在广泛异常,且与患者的症状严重程度相关。     

Cerebral white matter degeneration in frontotemporal dementia detected by diffusion-weighted magnetic resonance imaging

RATIONALE AND OBJECTIVE: Brain tissue damage in frontotemporal dementia (FTD) has never been systematically studied using diffusion-weighted imaging (DWI). We studied FTD patients using DWI to determine whether microstructural changes in white matter can be detected in vivo. MATERIALS AND METHODS: Thirteen FTD patients and 15 aged healthy subjects were studied. Mean diffusivity (MD) abnormalities in 28 white matter regions were visually evaluated. In addition, MD values in 10 white matter regions relative to that in the ipsilateral postcentral gyrus were measured. The results were compared between healthy subjects and FTD patients. RESULTS: The visual rating resulted in a significant MD elevation in FTD patients in the bilateral high superior frontal gyri, right orbitofrontal gyrus, bilateral anterior temporal lobes, and left middle temporal lobe (P < .01, respectively). Relative MD comparison revealed a significant MD elevation in FTD patients in the bilateral high superior frontal gyri, bilateral orbitofrontal gyri, and bilateral anterior temporal lobes (P < .05 after Bonferroni correction, respectively). CONCLUSION: Our results demonstrated white matter MD abnormalities in FTD patients. It was suggested that the observed white matter MD abnormalities are secondary to damage in the overlying cortex.     

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～...