基于sMRI的阿尔茨海默症分类影响因素研究

本研究提出基于三类解剖特征的SVM建模方法,探索样本、特征及算法选择三个因素,对阿尔茨海默症(AD)及其前驱阶段分类的重要性。该方法以三维重构s MRI后不同大脑区域的灰质体积、皮层表面积及其平均厚度三类特征作为SVM模型的输入参数,并采用十折交叉验证方法对AD患者、轻度认知损害患者和健康者进行分类识别,并与其他文献结果进行比较分析。实验结果表明,为了达到更高的分类准确率,选择合适的样本和特征,比选择算法更重要。此结论为未来AD的计算机辅助诊断研究工作提供了有益的指导。     

轻度认知功能障碍患者动态脑电图的定量分析

探讨轻度认知功能障碍患者动态脑电图的量化指标,为认知功能障碍早期诊断预防提供依据。选取30例轻度认知功能障碍患者和30例正常老年人作为病例组和对照组,进行MMSE测试和动态脑电图监测,比较两组观察对象α、β、和慢波功率。病例组和对照组的双侧顶枕α功率及大脑各位点的θ和δ功率差别有统计学意义（P＜0．05）。病例组及对照组在睡眠2期纺锤波的时限、频率及密度差别有统计学意义（P＜0．05））。脑电图α功率下降,θ和δ功率增加可以提示认知功能下降,睡眠2期纺锤波的时限、频率及密度可以作为认知功能水平脑电图测试的参考指标。     

太极拳对遗忘型轻度认知功能障碍患者认知功能影响的研究

目的 探讨太极拳对遗忘型轻度认知功能障碍（a-MCI）患者认知功能的影响。方法 将62例a-MCI患者随机分为对照组和观察组,每组31例。对照组患者接受常规健康教育,治疗组在此基础上接受太极拳干预治疗。两组患者分别在治疗前、治疗后6个月采用简明精神状态检查量表（MMSE）、蒙特利尔认知评估量表（MoCA）以及事件相关电位P300对患者认知功能评价。结果 对照组治疗前后MMSE、MoCA评分分别比较,差异无统计学意义（P＞0.05）;治疗后观察组MMSE、MoCA评分分别为（25.12±4.17）分、     

北京城乡两社区轻度认知功能障碍发病率调查

目的:调查轻度认知功能障碍的发病率及其人群特别是城乡人群之间的分布特点,探讨轻度认知功能障碍发病的社会人口学及生物学危险因素。方法:根据2004年基线研究资料,对北京西城区和大兴区两个社区1859名≥65岁认知正常老人进行5年后再次调查;通过10/66国际痴呆研究项目组(简称10/66项目组)的全套神经心理学问卷(包括老年精神状况量表及计算机诊断系统,认知测验系统、知情人问卷及社会人口学背景问卷和危险因素问卷等)调查获得资料,运用10/66项目组广义轻度认知功能障碍标准诊断程序对随访对象进行诊断,描述轻度认知功能障碍5年累积发病率,探讨轻度认知功能障碍的社会人口学特点及生物学危险因素。采用5年累积发病率及年平均发病率的计算方法计算轻度认知功能障碍的发病率,采用单因素和多因素Cox回归方法分析轻度认知功能障碍发病的危险因素。结果:193名老人确诊为轻度认知功能障碍新发病例,5年累积发病率为10.38%[95%可信区间(95%CI):9.00%～11.82%],平均年发病率2.17%(95%CI:1.76%～2.30%)。高龄(大于90岁)、居住在农村、脑卒中史、糖尿病史以及肥胖是轻度认知功能障碍的危险因素[危险比值(HR)分别为4.66(95%CI:1.41～15.48);2.54(95%CI:1.72～3.75);3.04(95%CI:1.63～5.68);2.00(95%CI:1.14～3.50)和4.97(95%CI:3.53～7.01)],而有配偶以及较多的体育锻炼是轻度认知功能障碍的保护因素[HR分别为0.55(95%CI:0.40～0.76)和0.34(95%CI:0.14～0.84)]。结论:北京市城乡两社区≥65岁老年人轻度认知功能障碍5年累积发病率为10.38%,年平均发病率为2.17%,与国内外多数研究接近。高龄、居住在农村、脑卒中、糖尿病及肥胖是发病的危险因素;针对轻度认知功能障碍的危险因素进行干预有重要的社会意义和临床价值。     

电离辐射氧化应激致轻度认知功能障碍及其综合干预的研究

电离辐射氧化应激致机体细胞内水分子水解产生活性氧和自由基或直接损伤DNA等靶分子,脑组织细胞凋亡致海马体积缩小,并在脑膜、大脑皮层和海马的血管壁内可见β淀粉样蛋白沉积,神经组织的病理损伤,引起脑部认知功能障碍.神经功能发生改变轻度认知功能障碍成为当今研究的热点,本文系统阐述了电离辐射氧化应激致机体轻度认知功能障碍(MCI)的发生机制、临床表现与临床诊断,讨论了生物学标志物检测、影像学检查、综合干预对MCI的诊断和预防价值.     

蒙特利尔认知评估量表在成都市社区老年人轻度认知功能障碍筛查中的应用分析

目的:本文旨在研究蒙特利尔认知评估量表(MoCA)在成都市社区老年人轻度认知功能障碍(MCI)筛查中的价值,探讨该量表对社区老年人MCI筛查的最佳分界值。方法:采用简易精神状态量表(MMSE)和MoCA对成都市社区老年人进行MCI筛查,计算MoCA的信度、效度、敏感性、特异性和Youden指数,并计算适合本市老年人MCI患者的划界分。结果:参与此次社区调查并配合完成所有测试的人数为674人,其中MCI患者106人,MoCA量表的Cronbach’sα为0.852;其总分与MMSE相关系数为0.9392;MoCA以原版推荐26分为界,对MCI筛查的敏感性和特异性分别为98.11%和26.72%,Youden指数为0.2483。结论:用MoCA对成都市社区老年人认知功能的筛查是简便可行的,具有良好的信度、效度和敏感性。推荐以22分作为我市社区老年人的MCI分界值。     

糖尿病对脑白质病变伴轻度认知功能障碍患者认知功能的影响

目的 探讨糖尿病与脑白质病变(WML)伴轻度认知功能障碍(MCI)患者认知功能减退的关系。方法 2012年1—12月在大坪医院神经内科住院病人中选择257例WML伴MCI患者进行前瞻性研究,随访时间为1年。收集患者血管危险因素(VRFs)及颅脑MRI检查结果,同时行神经心理学测试了解认知功能状态;根据1年内简易精神状态检查量表(MMSE)减少值分为认知功能下降组(≥3分)及无认知功能下降组(≤2分),并比较两组各种危险因素的差异。结果 257例中有246例(95.7%)患者完成了1年的观察随访过程,11例删失者中8例死亡、3例退出观察。246例中,认知功能下降组154例(62.6%),无认知功能下降组92例(37.4%);其中36例在观察期间发生卒中,余210例患者纳入线性回归分析。除受教育水平及血脂异常外,年龄、性别、高血压、糖尿病、短暂性脑缺血发作等各危险因素两组比较差异均有统计学意义 (P值均＜0.05)。糖尿病、基线WML程度及随访期间WML程度的加重与1年内MMSE减少值呈显著的线性关系,且对认知功能减退的影响由大至小依次为基线WML程度(β_j′=0.570)、随访期间WML加重程度(β_j′=0.244)、糖尿病(β_j′=0.171)。结论 糖尿病可使WML伴MCI患者认知功能进一步减退。重度WML伴MCI的糖尿病患者应作为痴呆的高危人群进行早期干预。     

轻度认知功能损害的研究进展

轻度认知功能障碍(MCI)是一种发生在老年人群中的综合征,是介于正常衰老和痴呆之间的一种认知损伤状态,性质不稳定,具有转化为痴呆的高风险.本文将从一般情况、神经心理与生物学研究及目前研究中存在的问题三方面介绍其研究进展.     

KPCA和Adaboost算法在阿尔茨海默症功能磁共振影像分类中的 应用

本研究的目的在于使用机器学习方法,对脑部功能磁共振成像数据进行分析与特征提取,完成对阿尔茨海默症 （AD）的辅助诊断与分析。首先对数据进行预处理与去除协变量,并从大脑全局特征出发,根据现有的自动解剖标记模 板,把每个被试的大脑分为116个脑区,通过提取每个脑区的时间序列,构建全脑功能连接矩阵,然后使用核主成分分析 法进行特征提取,最后用Adaboost算法进行分类。在对34名AD患者、35名轻度认知障碍患者和35名正常对照组的功能 磁共振成像数据进行的实验结果表明,利用静息态功能磁共振成像,同时结合机器学习的方法,能够有效地实现AD的正 确分类,准确率可以达到96%,该结果可以为AD患者的临床辅助诊断提供有效的判断依据。     

基于BS结构对轻度认知功能障碍评估及健康管理网络系统的设计和实现

目的:本文所设计的是基于BS结构的轻度认知功能障碍网络评估及健康管理系统。方法:该系统由C#+ASP.NET 3.5设计开发完成,数据库采用Microsoft SQL 2005。结果:该系统具有用户管理、轻度认知功能障碍测评、测评信息查询、留言板及其他健康管理相关功能。结论:该系统能够对轻度认知功能障碍患者进行广泛的筛选和较精准的评估,可以在社区医院和健康咨询公司广泛应用。     

基于MR图像纹理特征的阿尔茨海默病分类模型

目的基于MR图像,提取脑部海马区域纹理特征参数建立阿尔茨海默病(Alzheimer disease,AD)的早期分类预测模型。方法研究数据来源于美国国立老年研究所ADNI数据库,收集研究对象的磁共振(magnetic resonance,MR)脑图像,分别基于左、右和双侧海马图像,通过区域增长法和Contourlet变换提取纹理特征参数,结合研究对象的基本信息作为特征变量采用高斯过程分类方法建立AD患者和健康对照的诊断模型以及轻度认知障碍(mild cognitive impairment,MCI)患者转变为AD的预测模型,并评价模型的灵敏度、特异度以及ROC曲线下面积。结果研究共纳入420例研究对象。基于AD和健康对照两组构建的分类模型,双侧海马区的灵敏度、特异度以及ROC曲线下面积分别为92.7%、87.1%和0.922,均大于基于左侧或右侧海马区图像建立的模型。基于MCI数据建立的AD早期预测模型中,灵敏度最高为82.4%,ROC曲线下面积最高为0.836。结论基于脑部海马区的Contourlet纹理特征构建预测模型,可以识别AD早期的病变情况,这将有助于早期监测MCI进展为AD,为减缓和治疗AD发病提供依据。     

Differences in and correlations between cognitive abilities and brain volumes in healthy control,mild cognitive impairment,and Alzheimer disease groups

The purpose of this study is to investigate differences in and correlations between cognitive abilities and brain volumes in healthy control (HC), mild cognitive impairment (MCI), and Alzheimer's disease (AD) groups. The Korean Version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD‐K), which is used to diagnose AD, was used to measure the cognitive abilities of the study subjects, and the volumes of typical brain components related to AD diagnosis—cerebrospinal fluid (CSF), gray matter (GM), and white matter (WM)—were acquired. Of the CERAD‐K subtests, the Boston Naming Test distinguished significantly among the HC, MCI, and AD groups. GM and WM volumes differed significantly among the three groups. There was a significant positive correlation between Boston Naming Test scores and GM and WM volumes. In conclusion, the Boston Naming Test and GM and WM brain volumes differentiated the three tested groups accurately, and there were strong correlations between Boston Naming Test scores and GM and WM volumes. These results will help to establish a test method that differentiates the three groups accurately and is economically feasible. Clin. Anat. 29:473–480, 2016. © 2016 Wiley Periodicals, Inc.     

老年人快速认知筛查量表筛查早期阿尔茨海默病性痴呆的试测

目的:考查老年人快速认知筛查量表(QCSS-E)筛查社区老年人轻度认知功能障碍(MCI)及轻中度阿尔茨海默病(AD)的性能。方法:在社区募集≥55岁老年人1298人,参照Peterson MCI诊断标准和DSM-5神经认知障碍AD诊断标准为金标准,将其分为正常对照(NC)组(n=629)、MCI组(n=573)及轻中度AD组(n=96)。计算量表总分及各维度得分筛查MCI和轻中度AD的阳性预测值、阴性预测值;采用ROC曲线分析检验量表总分的区分度。结果:量表总分筛查MCI的阳性预测值为67.6%,阴性预测值为83.9%;筛查轻中度AD的阳性预测值为64.2%,阴性预测值为96.9%。ROC曲线分析发现QCSS-E总分筛查正常与MCI、正常与轻中度AD、MCI与轻中度AD的AUC分别为83.5%、98.0%及85.6%。结论:QCSS-E总分及各维度得分在早期AD筛查中性能良好。     

Conversion from mild cognitive impairment to Alzheimer's disease is predicted by sources and coherence of brain electroencephalography rhythms

Objective. Can quantitative electroencephalography (EEG) predict the conversion from mild cognitive impairment (MCI) to Alzheimer’s disease (AD)?     

Cortical asymmetries in normal, mild cognitive impairment, and Alzheimer's disease

There are functional and structural neocortical hemispheric asymmetries in people with normal cognition. These asymmetries may be altered in patients with Alzheimer's disease (AD) because there is a loss of neuronal connectivity in the heteromodal cortex. The purpose of this study is to test the hypothesis that individuals with amnestic mild cognitive impairment (aMCI), mild AD, and moderate to severe AD have progressive reductions in thickness asymmetries of the heteromodal neocortex. Right-handed elderly volunteers including normal cognition (NC), aMCI, and AD underwent 3-D volume imaging for cortical thickness. Although the cortical asymmetry pattern observed in normal cognition brains was generally maintained in aMCI and AD, there was a progressive decrease in the degree of asymmetry, especially in the inferior parietal lobule. A reduction of neocortical asymmetries may be a characteristic sign that occurs in patients with AD. Future studies are needed to evaluate whether this loss is specific to AD and if measurements of asymmetry can be used as diagnostic markers and for monitoring disease progression.     

Conceptual implicit memory impaired in amnestic mild cognitive impairment patient

Explicit memory has been well proven to be impaired in amnestic mild cognitive impairment (aMCI), and conceptual implicit memory is impaired in Alzheimer's disease. However, it is unclear whether implicit memory is affected in aMCI. In the present study, 35 patients with aMCI and 35 healthy elderly subjects were administered a neuropsychological battery of tests including conceptual and perceptual implicit memory tasks (category exemplar generation, image identification) as well as explicit memory tasks. Patients with aMCI exhibited impairment in explicit memory tasks and selective impairment in conceptual priming tasks, while the effect of perceptual priming was preserved. More importantly, category exemplar generation task priming, but not perceptual priming, was positively correlated with verbal fluency test performance in the aMCI group. The dissociation between the 2 components of implicit priming suggests that conceptual priming impairment in aMCI patients may be related to frontal lobe dysfunction.     

Prognosis of mild cognitive impairment syndrome: Data from a two-year clinical follow-up study

The psychopathological structure and prognostic significance of mild cognitive impairment syndrome (MCI) were studied in a two-year prospective study of randomized cohorts of elderly subjects whose mental state corresponded to the criteria for MCI. A total of 40 patients aged from 50 to 80 years were studied. Patients underwent clinical history-taking, neuropsychological, psychometric, and genetic investigations (genotyping for ApoE), as well as brain imaging studies. The psychopathological structure and psychometric characteristics of MCI syndrome are presented. Clinical and genetic factors with prognostic significance are identified. __________ Translated from Zhurnal Nevrologii i Psikhiatrii imeni S. S. Korsakova, Vol. 107, No. 1, pp. 4–10, January, 2007.     

Reduced hippocampal glutamate in Alzheimer disease

Altered neurometabolic profiles have been detected in Alzheimer disease (AD) using ¹H magnetic resonance spectroscopy (MRS), but no definitive biomarker of mild cognitive impairment (MCI) or AD has been established. This study used MRS to compare hippocampal metabolite levels between normal elderly controls (NEC) and subjects with MCI and AD. Short echo-time (TE = 46 ms) ¹H spectra were acquired at 4 T from the right hippocampus of 23 subjects with AD, 12 subjects with MCI and 15 NEC. Absolute metabolite levels and metabolite ratios were compared between groups using a multivariate analysis of covariance (covariates: age, sex) followed by post hoc Tukey's test (p < 0.05 significant). Subjects with AD had decreased glutamate (Glu) as well as decreased Glu/creatine (Cr), Glu/myo-inositol (mI), Glu/N-acetylaspartate (NAA), and NAA/Cr ratios compared to NEC. Subjects with AD also had decreased Glu/mI ratio compared to MCI. There were no differences between subjects with MCI and NEC. Therefore, in addition to NAA/Cr, decreased hippocampal Glu may be an indicator of AD.     

Sex differences in the prevalence and incidence of mild cognitive impairment: A meta-analysis

ObjectiveMore women have Alzheimer’s disease (AD) than men. Understanding sex differences in mild cognitive impairment (MCI) may further knowledge of AD etiology and prevention. We conducted a meta-analysis to examine sex differences in the prevalence and incidence of MCI, which included amnestic and non-amnestic subtypes.MethodSystematic searches were performed in July 2015 using MEDLINE/PubMed, Scopus, and PsycINFO for population-or community-based studies with MCI data for men and women. Random-effects model were used.ResultsFifty-six studies were included. There were no statistically significant sex differences in prevalence or incidence of amnestic MCI. There was a significantly higher prevalence (p = 0.038), but not incidence, of non-amnestic MCI among women. There were no sex differences in studies that combined both subtypes of MCI.ConclusionThe only statistically significant finding emerging from this study was that women have a higher prevalence of non-amnestic MCI. To better understand sex differences in the preclinical stages of dementia, studies must better characterize the etiology of the cognitive impairment.     

MicroRNAs and mild cognitive impairment: A systematic review

BackgroundMild cognitive impairment (MCI) is usually described as an intermediate phase between normal cognition and dementia. Identifying the subjects at a higher risk of progressing from MCI to AD is essential to manage this condition. The diagnosis of MCI is mainly clinical. Several biomarkers have been proposed, but mostly for research purposes, as they are based on an invasive procedure to obtain the sample, such as cerebrospinal fluid (CSF). As a consequence, rapid and non-invasive biomarkers are needed to improve diagnosis. The objective of this systematic review is to summarize available evidence on the use of miRNAs as biomarkers in subjects with MCI.MethodsRelevant literature published up to June 2018 was retrieved searching the databases PubMed, ISI Web of Knowledge and the Cochrane Database. Only studies considering microRNAs (miRNAs) and a diagnosis of MCI were included. Data were extracted using a specifically-designed standardized form, and their methodological quality was assessed using QUADAS-2 and QUIPS.ResultsTwenty-one studies of 153 retrieved articles met the predefined inclusion/exclusion criteria. Studies included participants ranging from 6 to 330. More than 40 miRNAs resulted as dysregulated, and miR-206 was the only miRNA that was found as differentially expressed in patients with MCI by more than two studies. However, these results have either not yet been confirmed in other independent cohorts, or data are still inconsistent. Inconsistencies among included studies could be due to several issues including the selection of participants, pre-analytical and analytical procedures, and statistical analyses.