小血管性轻度认知障碍的研究进展

轻度认知障碍（mild cognitive impairment,MCI）是指患者有记忆或认知损害,但对日常能力无明显影响,未达到痴呆的程度,是介于正常衰老和痴呆之间的中间状态的一组临床综合征.最近关于轻度认知障碍发病率的文章提到[1],轻度认知障碍的发病率为每年51‰～77‰.同时还发现轻度认知障碍是痴呆的高危人群,发展成痴呆的危险性是正常老人的10陪,部分患者是痴呆的前期阶段.轻度认知障碍根据病因或转归可分为阿尔茨海默病源性轻度认知障碍也可称为遗忘型轻度认知障碍（amnestic mild cognitive impairment,aMCI）、小血管性轻度认知障碍（small vessel mild cognitive impairment,svMCI）和其他类型的认知障碍.而其中svMCI有可能发展为血管性痴呆（vascular dementia,VaD）.     

轻度认知障碍认知训练的研究进展

正轻度认知障碍(mild cognitive impairment,MCI)是正常老化和老年痴呆(dementia)之间的中间状态。MCI患者虽然日常生活能力没有受到明显影响,但存在轻度认知功能的减退。根据不同病因或大脑损伤部位的不同,可以累及记忆、认知控制、语言、空间等认知能力的一项或以上。MCI可以分为遗忘型和非遗忘型,两者的核心区别为前者的记忆受损明显。根据累及认知能力领域的多少可以进一步分为单一认知域损害和多认知域损害。MCI患者在生活照料和经济支出方面给个人和家庭带来极大负担。更为严重的是,MCI个体发展成阿尔兹海默症或其他类型痴呆的风险很高,年转化率大约10%—15%~([1-2])。尽管当前有多种药物用于改善     

2型糖尿病认知功能障碍及其影像学研究进展

2型糖尿病损害中枢神经系统功能,是轻度认知障碍、痴呆、中风的独立风险因素。其中,认知损害发生最早,对其机制的研究和早期防治具有重要的临床意义。2型糖尿病导致认知障碍的机制复杂多样,涉及血管、神经、功能等多个方面。磁共振功能影像学技术可以从多个角度对糖尿病患者认知障碍的机制进行探索,将病理假说与临床表现相结合,从而达到早期诊断、提前预防的目的。作者就当前2型糖尿病认知障碍的机制及神经影像学研究进展予以综述。     

影像学技术、计算机技术在血管性认知障碍诊断及康复治疗中的应用

目的:综述血管性认知障碍的研究进展,以便预防和治疗血管性认知障碍,提高血管性认知障碍患者的生活质量。资料来源:应用计算检索万方数据库2002-01/2007-01与血管性认知障碍相关的文章,检索词“血管性认知障碍、轻度认知障碍、血管性痴呆、虚拟现实技术、无错性学习、远程康复”,限定语种为中文;同时应用计算机检索Pubmed 1998-01/2007-01的相关文章,检索词为vascular cognitive impairment,virtual reality,errorless learning,telerehabilitation,并限定文章语言种类为English。资料选择:就检索到的100余篇文献进行筛选,选取与血管性认知障碍相关的文章。资料提炼:共收集到相关文章34篇,将筛选到的文献分类,其中认知障碍诊断进展的22篇,康复治疗的12篇。资料综合:血管性认知障碍患者通过磁共振血流灌注加权成像、磁共振波谱成像、弥散加权成像、放射性核素功能显像等影像学检查都会呈现不同程度的异常。神经心理学测验、虚拟现实技术以及计算机辅助技术的应用能够探测到非常细微的认知功能损害,使这部分患者得到早期的诊断,加以治疗,可阻止或延缓痴呆的发生。无错性学习的应用和远程认知康复治疗可使患者的认知功能障碍和功能性活动得到良好的改善。结论:血管性认知障碍对日常生活活动能力影响很大,应对其进行早期的预防、诊断和相应的康复治疗以提高患者的生活质量。     

有氧运动对轻度认知障碍患者脑结构重塑的研究进展

轻度认知障碍是介于正常脑老化和痴呆之间的一种过渡状态。既往结构影像学研究表明,轻度认知障碍患者不仅可见大脑灰质的明显萎缩,而且还伴有白质异常,集中体现为白质的萎缩和白质神经纤维通路完整性被破坏。大量的试验结果表明,有氧运动可以对轻度认知障碍患者的大脑结构发生不同程度的改变,能延缓或逆转大脑灰质以及白质的萎缩,从而维持认知功能的稳定性。现有的结构影像学研究主要基于结构磁共振成像、弥散加权成像或弥散张量成像技术,分别从大脑形态学及大脑白质结构等方面,致力于有氧运动对轻度认知障碍患者脑结构重塑的影响及其与认知功能之间的关系进行研究。本文综述现有的有氧运动对轻度认知障碍患者的脑结构重塑影响的研究进展。     

轻度认知障碍的认知训练研究进展

轻度认知障碍是介于正常衰老导致的认知功能障碍和痴呆之间的一种认知能力受损状态,早期识别轻度认知障碍并尽早干预对延缓认知功能进一步受损是非常必要的,以避免患者发展成痴呆。目前,改善认知功能药物治疗的疗效有限,且鉴于药物治疗的不良影响及用量等存在很大争议。本综述旨在通过回顾轻度认知障碍认知训练方法,为临床轻度认知障碍患者的认知训练提供参考。     

遗忘型轻度与非痴呆血管性认知障碍认知损害及睡眠障碍对照研究

目的 探讨遗忘型轻度认知障碍和非痴呆性血管性认知障碍患者认知损害及睡眠障碍的临床特征.方法 对60例遗忘型轻度认知障碍患者(aMCI组)、60例非痴呆性血管性认知障碍患者(VCIND组)、60名健康志愿者(对照组)采用相关认知功能测评量表及睡眠评估量表进行测评分析.结果 (1)两组患者数字符号编码测验、定步调听觉连续加法测验评分均显著低于对照组(P＜0.01),VCIND组评分显著低于aMCI组(P＜0.01).(2) VCIND组威斯康星卡片分类测验-64、连线A、连线B评分均显著高于aMCI组和对照组(P＜0.01),aMCI组连线B评分显著高于对照组(P＜0.01).(3) VCIND组、aMCI组Benton线方向判定评分显著低于对照组(P＜0.01),VCIND组评分显著低于aMCI组(P＜0.01).(4)aMCI组和VCIND组爱泼沃斯嗜睡量表、失眠严重程度指数量表、匹兹堡睡眠质量指数量表评分均显著高于对照组(P＜0.05或0.01),aMCI组爱泼沃斯嗜睡量表评分显著高于VCIND组,失眠严重程度指数量表、匹兹堡睡眠质量指数量表评分显著低于VCIND组(P＜0.01).结论 遗忘型轻度认知障碍和非痴呆性血管性认知障碍患者均存在不同程度的认知损害与睡眠障碍,但非痴呆性血管性认知障碍较遗忘型轻度认知障碍患者的注意力、信息处理速度、视空间加工能力和执行能力受损更严重,睡眠障碍更加明显.     

Rs-fMRI与DTI在轻度认知障碍中的联合应用

轻度认知障碍是介于正常衰老和痴呆之间的一种中间状态,是发展为阿尔茨海默病的高危因素,其特征是记忆衰退比正常衰老更快。近年来,随着神经影像学的迅速发展,静息态功能磁共振成像(resting-state functional magnetic resonance imaging,rs-fMRI)、扩散张量成像(diffusion tensor imaging,DTI)逐渐应用于轻度认知障碍的早期诊断,在展现出各自优势的同时,又表现出一些不足。因此,人们尝试将它们联合起来进行分析,其基本分为3种方法:rs-fMRI辅助DTI、DTI辅助rs-fMRI及rs-fMRI和DTI的等位联合,从而获得了更高的诊断效能。笔者将从上述3种方法分别在轻度认知障碍中的联合应用进行阐述。     

磁共振扩散成像技术在轻度认知障碍的研究进展

轻度认知障碍(mild cognitive impairment,MCI)被认为是正常老龄化和阿尔茨海默病(Alzheimer'disease,AD)以及其他类型痴呆的中间状态。给予MCI患者积极的干预治疗,有助于改善认知功能并减缓MCI向AD的转变。因此,寻找MCI诊断和进展监测的敏感影像标记物是非常必要的。磁共振扩散成像技术能够通过描述脑组织中水分子的扩散运动来检测微观结构的变化,可以为MCI的病理机制研究和认知障碍严重程度的评估提供重要的信息。近年来,新型磁共振扩散成像技术的不断发展为MCI的研究提供了额外的价值。作者对扩散张量成像(diffusion tensor imaging,DTI)、扩散峰度成像(diffusion kurtosis imaging,DKI)、自由水扩散磁共振成像(free-water diffusion magnetic resonance imaging,FW diffusion MRI)、神经突方向离散度和密度成像(neurite orientation dispersion and density imaging,NODDI)技术在MCI中的研究进行综述。     

轻度认知功能障碍患者的神经心理学特点初步探讨

目的 通过比较遗忘型轻度认知障碍(amnestic mild cognitive impairment,aMCI)和血管性认知障碍非痴呆型(vascular cognitive impairment-no dementia,VCFND)患者及正常老年人群在简易智能精神状态检查量表(mini mental state e...     

Mild Cognitive Impairment and Mild Dementia: A Clinical Perspective

Mild cognitive impairment and mild dementia are common problems in the elderly. Primary care physicians are the first point of contact for most patients with these disorders and should be familiar with their diagnosis, prognosis, and management. Both mild cognitive impairment and mild dementia are characterized by objective evidence of cognitive impairment. The main distinctions between mild cognitive impairment and mild dementia are that in the latter, more than one cognitive domain is invariably involved and substantial interference with daily life is evident. The diagnosis of mild cognitive impairment and mild dementia is based mainly on the history and cognitive examination. The prognosis for mild cognitive impairment and mild dementia is an important motivation for diagnosis because in both, there is a heightened risk for further cognitive decline. The etiology of mild cognitive impairment and mild dementia can often be established through the clinical examination, although imaging and other laboratory tests may also contribute. Although Alzheimer disease is the most common cause of both, cerebrovascular disease and Lewy body disease make important contributions. Pharmacological treatments are of modest value in mild dementia due to Alzheimer disease, and there are no approved pharmacological treatments for mild cognitive impairment of any etiology. Nonetheless, new-onset cognitive impairment is a worrisome symptom to patients and families that demands answers and advice. If a patient is having difficulties managing medications, finances, or transportation independently, diagnosis and intervention are necessary to ensure the health and safety of the patient.     

轻度认知功能障碍海马磁共振成像的研究进展

轻度认知功能障碍(MCI)是介于正常老化和痴呆之间的过渡阶段。MCI患者的主要特征是情景记忆损害,而海马结构在情景记忆的过程中扮演重要角色。因此,对海马区域结构及功能变化的检测将是早期诊断MCI的关键。本文就近年关于MCI的海马磁共振成像研究进展做简要综述。     

多模态MRI在阿尔茨海默病早期诊断中的研究进展

阿尔茨海默病(Alzheimer's disease,AD)是发生于中老年人中最常见的中枢神经系统退行性疾病,以进行性认知障碍和行为非认知功能能力的减低为主要症状。近年来,随着磁共振成像(magnetic resonance imaging,MRI)多种序列的逐渐成熟,多模态MRI诊断在AD早期诊断中占有越来越重要的角色;作者就磁共振成像中结构性磁共振(structural magnetic resonance imaging,s MRI)、磁共振波谱成像(magnetic resonance spectroscopy,MRS)、磁共振弥散张量成像(diffusion tensor imaging,DTI)和磁共振扩散峰度成像(diffusion kurtosis imaging,DKI)、磁敏感加权成像(susceptibility weighted imaging,SWI)和定量磁敏感成像(quantitative susceptibility mapping,QSM)及静息态功能磁共振(functional MRI,f MRI)在AD早期诊断中的应用进行综述。     

Mild cognitive impairment: an opportunity to identify patients at high risk for progression to Alzheimer's disease

BACKGROUND: There is increasing evidence that subtle losses in cognitive function may be symptomatic of a transition to early Alzheimer's disease (AD). Ongoing research is focusing on the identification of those individuals with mild cognitive impairment (MCI) who are most likely to convert to AD. Of the MCI subtypes, patients with amnestic MCI (a-MCI) are at greatest risk. OBJECTIVES: The objectives of this article were to review the relationship between MCI, normal aging, and AD, and to summarize recent research on the diagnosis and potential treatment of MCI. METHODS: Relevant articles were identified through searches of MEDLINE and EMBASE using the terms mild cognitive impairment; cognitive impairment, no dementia; and dementia prodrome, with no restrictions as to year. Additional papers of interest were identified from the reference lists of the identified articles. The search was current as of February 2006. RESULTS: Guidelines and recommendations are being developed to assist physicians in diagnosing MCI, identifying its subtype and etiology, understanding the risks for conversion to AD, and managing disease progression. Given the existence of a subset of individuals with a-MCI, who are at greatest risk for progression to AD but still have high levels of cognition and function, the ability to improve symptoms and delay progression to AD would be particularly beneficial. In a 3-year, randomized, double-blind, placebo-controlled study in 769 patients with a-MCI, treatment with the cholinesterase inhibitor donepezil was associated with a significantly lower rate of progression to AD compared with placebo during the first 12 months of treatment (hazard ratio=0.42; 95% CI, 0.24-0.76; P=0.004) but not at later time points. Of other types of agents that have been investigated (antioxidants, estrogen replacement therapy, cyclooxygenase-2-selective inhibitors), none have shown significant beneficial effects in delaying cognitive decline or progression to AD. New drugs such as secretase inhibitors, small molecules that disrupt amyloid aggregation, and immunotherapies are in preclinical development. CONCLUSIONS: MCI involves more substantial cognitive and memory decline than normal aging and represents a significant risk factor for the development of dementia. Further research is needed into treatments to delay the conversion from MCI to AD.     

老年人轻度认知损害的发病率及向痴呆或阿尔茨海默病的转化率:基于人群的队列研究

背景:老年人轻度认知损害已成为目前阿尔茨海默病临床研究的新热点。目前国内有多少轻度认知损害对象发展为阿尔茨海默病还是一个未知数。目的:分析老年人轻度认知损害的发病率及向痴呆和阿尔茨海默病的转化率。设计:以诊断为依据的队列研究。单位:解放军白求恩国际和平医院干部病房二科。对象:为2001-08/2001-09对石家庄市26个部队干休所60岁及以上的离退休干部进行基线调查时诊断为轻度认知损害的216例患者和2302名认知正常受试者。方法:轻度认知损害的诊断参考美国精神障碍诊断与统计手册第4版轻度神经认知损害研究用诊断标准。痴呆的诊断采用美国精神病学会的精神障碍诊断和统计手册第四修订版(DSM-IV)标准。阿尔茨海默病采用美国神经病学、语言障碍和卒中-老年性痴呆和相关疾病学会标准。对216例轻度认知损害患者和2302名认知正常受试者进行为期3年的队列研究。主要观察指标:认知正常受试者轻度认知损害的平均年发病率、认知正常受试者和轻度认知损害患者阿尔茨海默病的平均年发病率以及轻度认知损害患者与认知正常受试者比较转化为阿尔茨海默病的相对危险性(RR)和95%可信区间。结果:轻度认知损害组与认知正常组均每年随访1次,共随访3年。216例轻度认知损害患者死亡7例,实际随访209例,随访率96.8%。2302名认知正常者死亡36例,实际随访2266例,随访率98.4%。①认知正常的老年人轻度认知损害的平均年发病率为4.8%,痴呆和阿尔茨海默病的平均年发病率分别为1.3%和0.8%;②轻度认知损害患者痴呆和阿尔茨海默病的平均年发病率分别为8.1%和5.6%;男性和女性轻度认知损害患者痴呆和阿尔茨海默病的平均年发病率差别无显著性(P>0.05)。③随着文化程度的提高,轻度认知损害患者痴呆(趋势χ2=5.57,P=0.02)和阿尔茨海默病(趋势χ2=4.92,P=0.03)的发病率有降低的趋势;认知正常受试者痴呆(趋势χ2=23.1,P<0.001)和阿尔茨海默病(趋势χ2=18.0,P<0.001)的发病率亦有降低的趋势。④随着年龄的增长,轻度认知损害患者痴呆(趋势χ2=14.6,P<0.01)和阿尔茨海默病(趋势χ2=13.9,P<0.01)的平均年发病率有增高的趋势;认知正常受试者痴呆(趋势χ2=32.3,P<0.01)和阿尔茨海默病(趋势χ2=23.8,P<0.01)的平均年发病率亦有增高的趋势。⑤轻度认知损害转化为痴呆或阿尔茨海默病的相对危险性分别为认知正常者的6.4倍和7.4倍。结论:老年轻度认知损害患者转化为痴呆的危险性远远大于认知正常的老年人。应加强对老年轻度认知损害患者这一痴呆高危人群的监测。     

Detection of changed regional cerebral blood flow in mild cognitive impairment and early Alzheimer's dementia by perfusion-weighted magnetic resonance imaging

The utility of perfusion-weighted magnetic resonance imaging (PW-MRI) for detecting changes in regional cerebral blood flow (rCBF) in patients with mild cognitive impairment (MCI) and early Alzheimer's disease (AD) was evaluated. Thirteen cognitively normal (CN) elderly subjects, 35 mostly amnestic MCI subjects and 20 subjects with mild probable AD were enrolled. During i.v. injection of gadopentetate dimeglumine, a dynamic T2*-weighted single-shot EPI sequence was conducted using a 1.5-T scanner. Frontobasal (FROB), temporoparietal (TPAR), mesiotemporal (MTMP), anterior and posterior cingular (ACING, PCING), amygdala (AMYG), thalamus and cerebellar brain regions were studied. rCBF was computed from regional cerebral blood volume and arterial input function and normalised to white matter. Images were analysed by manually placed regions of interest using anatomical coregistration. Significant decreases of rCBF were detected in MCI vs. CN in MTMP (-23%), AMYG (-20%) and ACING (-15%) with no further decline in mild AD. In PCING hypoperfusion (-10%) was confined to AD. These hypoperfusional changes are a possible correlate of localised impairment of CNS function. In FROB no perfusion changes were observed between diagnostic groups, but hyperperfusion was observed in mild dementia stages, possibly reflecting functional compensatory mechanisms. These data suggest that PW-MRI detects specific changes in rCBF not only in AD, but also in amnestic MCI, a disorder suggested to largely represent a pre-dementia stage of AD. This method may thus be useful in both research and clinical applications to detect early functional brain changes in the pathogenesis of dementias.     

非痴呆老年人认知功能的差异性:从成功老化到轻度认知损伤

目的对非痴呆的自诉记忆力减退的老年人,就其总体认知水平而言可能存在相对同源的不同亚型进行初步探讨.方法2000/2001对34例调查者进行临床记忆量表等17种神经心理测验,将结果进行Q型聚类分析.结果15例调查者被诊断为轻度认知损伤,占44%;聚类分析产生6类新样本.结论在正常老化与早期阿尔茨海默病这一过渡期内,老年人的认知状态是不均质的,其中既有成功老化,也有一般老化,尤其是还存在着具有痴呆发病危险性的认知损伤.