阿尔茨海默病患者脑白质损害与认知功能的关系

目的用磁共振扩散张量成像(DTI)研究阿尔茨海默病(AD)患者脑白质损害的特点及其与认知功能改变的相关性。方法对16例AD患者和12名年龄及性别相当的健康老年人行DTI、T1液体衰减反转恢复序列(FLAIR)及T2-FLAIR检查,测量胼胝体膝部和压部、内囊前肢和后肢、额颞顶枕叶白质的部分各向异性分数值(FA)和平均弥散度(MD),分析FA、MD值与简易精神状态量表(MMSE)评分之间的相关关系。结果AD患者胼胝体压部、额叶、顶叶、颞叶FA值分别为0.602±0.043、0.270±0.034、0.294±0.043、0.302±0.032,与健康老人组相比显著下降(P<0.05),且与MMSE评分呈正相关关系,而内囊前后肢、枕叶、胼胝体膝部的FA值则无明显变化(P>0.05);胼胝体压部、顶叶白质的MD值分别为(0.918±0.029)、(0.826±0.015)×10-9m2/s,与健康老人组相比显著升高(P<0.01),且与MMSE评分呈负相关,而内囊前后肢、额叶、颞叶、枕叶和胼胝体膝部的MD值则无明显变化(P>0.05)。结论AD患者表现为脑白质的选择性损害,且损害程度与认知功能密切相关;这种选择性损害反映了AD病理机制中皮质-皮质及皮质-皮质下联系的丢失;DTI技术可以用来监测疾病的进展情况及评价AD治疗药物的临床疗效。     

弥散张量成像对阿尔茨海默病脑白质改变的评价

目的分析阿尔茨海默病(Alzheimer's disease,AD)脑白质结构改变及与认知功能的关系。方法对37例AD组和32例对照组行简易精神状态量表(mini-mental State examinationn,MMSE)评估和DTI扫描。采用基于全脑体素分析法对两组全脑白质各向异性(fractional anisotropy,FA)图进行比较,采用t检验分析FA值差异,并评估AD组MMSE评分与FA值相关性。结果 AD患者出现FA值下降区域广泛分布在右侧额叶、颞叶、枕叶、丘脑及双侧扣带回、胼胝体、楔前叶、顶叶下回、顶下小叶、缘上回及海马旁回(其中P0.001,未经校正的P值);当使用经FWE校正的P0.05后,AD患者右侧扣带回、左侧胼胝体、颞叶下回及双侧顶叶下回、额叶下回、楔前叶区域FA值较对照组显著下降。AD患者FA值下降与MMSE量表评分呈正相关,(P0.001,未经校正)。结论 AD患者存在特定脑区白质结构改变,并与认知功能损害程度呈正相关。     

Alzheimer病患者扣带回后部损害磁共振扩散张量成像的研究

目的探讨Alzheimer病(AD)患者扣带回后部磁共振扩散张量成像(DTI)的特点及其与认知功能改变的相关性。方法对16例AD患者和12名健康老人(正常对照组)行DTI、T1Flair及T2Flari检查,测量扣带回后部各向异性分数值(FA)、平均弥散度(MD)及其λ1、λ2及λ33个特征值,分析上述诸项数值与简易精神状态检查量表(MMSE)评分之间的相关性。结果与正常对照组相比,AD组患者扣带回后部的FA值显著降低(P<0.05),而MD、λ1、λ2及λ3值明显升高(均P<0.05);FA值与MMSE评分不相关(r=-0.054,P>0.05),而MD值与MMSE评分呈显著负相关(r=-0.664,P<0.01);λ1、λ2及λ3值均与MMSE评分呈负相关(r=-0.643,r=-0.69,r=-0.654,均P<0.01)。结论AD患者表现为扣带回后部各向异性损害,且损害程度与临床认知功能评分呈负相关;这种损害反映了AD病理机制中皮质-皮质及皮质-皮质下联系的丢失;DTI可以用来监测AD疾病的进展及评价药物的临床疗效。     

阿尔茨海默病与轻度认知障碍弥散张量成像研究

目的:应用磁共振弥散张量成像技术(DTI)研究阿尔茨海默病(AD)与轻度认知障碍患者(MCI)脑白质损伤情况。方法:对21例AD患者、15例MCI患者和20名健康志愿者进行脑部DTI扫描后,测量双脑区感兴趣区的各向异性分数值(FA)且进行比较。结果:AD患者额叶、顶叶、颞叶和胼胝体的FA值与MCI组和对照组均存在显著性差异,MCI患者仅颞叶和胼胝体的FA值与对照组均存在显著性差异。结论:AD患者与MCI患者存在脑白质结构的差异,DTI技术能够在一定程度上提供MCI的早期诊断指标。     

儿童孤独症的脑扩散张量成像研究

目的 研究孤独症儿童脑扩散张量成像的异常.方法 对24例孤独症儿童(孤独症组)和10名正常儿童(正常对照组)进行脑扩散张量成像扫描,测量并比较两组的双侧胼胝体膝部、压部和双侧内囊后肢表观扩散系数(ADC值)和各向异性分数(FA值),分析孤独症儿童各被检测部位ADC值、FA值与孤独症治疗评估量表(ATEC)得分的相关性.结果 (1)孤独症组双侧内囊后肢[左右侧分别为(6.8±0.3)×10-9 mm2/s和(6.7±0.4)×10-9 mm2/s]、左侧胼胝体膝部[(8.0±0.5)×10-9 mm2/s]ADC值高于对照组[分别为(6.6±0.2)×10-9 mm2/s,(6.6±0.4)×10-9 mm2/s,(7.4±0.5)×10-9 mm2/s;P＜0.05～0.01];孤独症组右侧胼胝体压部(0.73±0.14)FA值低于正常对照组(0.84±0.07;P＜0.05),孤独症组右侧胼胝体膝部(0.75±0.07)FA值高于正常对照组(0.68±0.17;P＜0.05).(2)孤独症组右侧胼胝体压部ADC值与ATEC健康/行为评分呈正相关(r=0.490),右侧胼胝体压部FA值与ATEC说话/语言评分呈负相关(r=-0.453),右胼胝体膝部FA值与社交评分呈正相关(r=0.427),均P＜0.05.(3)孤独症组内囊后肢、胼胝体膝部FA值左右侧的差异有统计学意义(P＜0.05).结论 孤独症儿童胼胝体神经纤维连接存在异常.     

皮质下缺血性血管性认知损害扩散张量成像研究

目的通过扩散张量成像(DTI)探讨皮质下缺血性血管性认知损害患者白质微结构变化及其与认知功能之间的相关性。方法采集49例皮质下缺血性脑血管病患者[轻度血管性痴呆(VaD)10例、非痴呆型血管性认知损害(VCIND)20例、认知功能正常19例]DTI数据并观察皮质下白质微结构改变,分析VaD组患者DTI参数与认知功能间的相关性。结果与对照组相比,VaD组内侧前额叶、前扣带回、胼胝体干、双侧顶叶、右侧颞叶、双侧眶额叶,以及VCIND组右侧额下回、右侧海马、双侧楔前叶FA值减低(均P=0.000);与VCIND组比较,VaD组内侧前额叶、前扣带回、胼胝体、双侧顶叶、右侧颞叶FA值减低(P=0.000)。与对照组相比,VaD组内侧前额叶、胼胝体、双侧顶叶、双侧颞叶、前扣带回,以及VCIND组双侧楔前叶、右侧海马MD值升高(均P=0.000);与VCIND组相比,VaD组右侧内侧前额叶、前扣带回、胼胝体干、双侧顶叶、双侧颞叶MD值升高(均P=0.000)。VaD组内侧前额叶FA值与数字连线测验A时呈显著负相关(r=-0.782,P=0.007),双侧额下回MD值与数字连线试验A时程呈显著正相关(r=0.877,P=0.001)。结论 DTI对皮质下缺血性认知损害患者白质微结构改变更敏感,能够反映患者认知功能早期异常改变;内侧前额叶白质微结构的改变是影响患者执行能力的重要因素。     

轻度认知功能障碍与脑白质弥散张量成像的相关性研究

目的通过磁共振弥散张量成像研究不同区域脑白质损害与轻度认知功能(MCI)的关系。方法纳入2015年7月至2016年2月我院的住院患者56例为研究对象,其中MCI组34例,认知功能正常组22例。所有研究对象进行一般情况检查,完成神经心理学量表检测。通过头颅磁共振弥散张量成像(DTI)检查对不同脑区白质纤维进行部分各向异性(FA)值测量。结果 MCI组患者与认知功能正常组相比,右侧额叶FA值(0.335±0.068)、左侧颞叶白质FA值(0.391±0.032)及胼胝体膝部FA值(0.658±0.053)降低,差异具有统计学意义(P0.05)。将上述FA值和MMSE、Mo CA量表中各认知域进行典型相关分析,结果显示右侧额叶白质FA值与注意与计算力呈正相关,左侧颞叶白质和胼胝体膝部FA值与记忆力呈正相关(P0.05)。结论 MCI患者注意与计算力的障碍可能与右侧额叶白质损害有关,而左侧颞叶白质及胼胝体膝部白质的损害可能导致早期的记忆障碍。DTI可能成为超早期识别与诊断MCI的新方法。     

阿尔茨海默病患者扣带回后部各向异性与葡萄糖代谢关系研究

目的 用磁共振扩散张量成像(DTI)研究阿尔茨海默病患者扣带回后部各向异性损害的特点及其与葡萄糖代谢改变的关系.方法 对16例AD患者和12例年龄及性别相当的健康老年人行DTI、T1液体衰减反转恢复序列(FLAIR)及T2-FLAIR检查,测量扣带回后部部分各向异性分数值(FA)和平均弥散度(MD),分析FA、MD值与MMSE评分之间的相关关系;正电子发射计算机断层摄影(PET)观察扣带回后部葡萄糖代谢改变,并分析FA、MD与葡萄糖代谢改变的关系.结果 与对照组相比,AD患者扣带回后部的FA值显著降低(P=0.018),MD值显著升高(P=0.020),葡萄糖代谢率显著降低(P=0.020);MD值与葡萄糖代谢率呈负相关(r=-0.700,P=0.05),而FA值与葡萄糖代谢率无相关关系(r=-0.054,P=0.844).结论 AD患者表现为扣带回后部各向异性损害,且损害程度与葡萄糖代谢率呈负相关;这种损害反应了AD病理机制中皮质-皮质及皮质-皮质下联系的丢失;扣带回后部FA、MD值可以用来监测疾病的进展情况及评价AD治疗药物的临床疗效.     

CADASIL脑弥散张量成像特点及与临床的关系

目的 分析常染色体显性遗传性脑动脉病伴皮层下梗死和白质脑病(cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy,CADASIL)患者的弥散张量成像特点及与临床的关系.方法 患者和同龄健康志愿者各14例,进行头颅MRI常规扫描和弥散张量成像扫描,测量两组受试者各脑叶、内囊后肢、外囊以及胼胝体的部分各向异性(fractional anisotropy,FA)值及总和,比较两组问FA值的差异.对患者的认知功能和卒中后神经功能状态分别进行MMSE和NIHSS评分.校正年龄影响,分析患者各个脑白质区域FA值及总和与MMSE分值、NIHSS评分的相关关系.结果 患者组各脑区的FA值均显著低于对照组.FA值总和、右额叶、右颞叶、左顶叶、左枕叶、双侧内囊后肢以及外囊白质的FA值和MMSE分值存在相关性(P＜0.05).FA值总和及各脑区FA值与NIHSS评分无相关性.结论 CADASIL患者不同脑白质区域的FA值显著下降,部分区域的白质损害与患者的认知功能减退有关.     

磁共振扩散张量成像在缺血缺氧脑病患儿中的临床应用

目的探讨磁共振扩散张量成像(DTI)在缺血缺氧脑病患儿中的应用价值。方法前瞻性纳入2016-12—2018-12于河南中医药大学第一附属医院行MRI头颅平扫及DTI检查的年龄2岁患儿40例,所有患儿在围生期均有缺氧缺血脑病史,根据最终随访结果分为脑瘫组及非脑瘫组各20例。测量双侧大脑脚、内囊前肢、内囊膝部、内囊后肢、半卵圆中心、皮质脊髓束、下纵束、丘脑后辐射、额叶白质、顶叶白质、胼胝体膝部、胼胝体体部及胼胝体压部的FA值。结果 2组间双侧大脑脚、内囊后肢、半卵圆中心、皮质脊髓束、下纵束、丘脑后辐射、顶叶白质、胼胝体膝部、胼胝体体部、胼胝体压部FA值差异均有统计学意义(P0.05),而双侧内囊前肢、内囊膝部、额叶白质FA值差异无统计学意义(P0.05)。结论 DTI可以定量评估缺血缺氧脑病患儿的损伤程度,有助于早期评估病情及预测预后。     

Semantic knowledge in mild cognitive impairment and mild Alzheimer's disease

The aim of this study was to investigate memory in patients with mild cognitive impairment (MCI) and mild Alzheimer's disease (AD). Ten patients with MCI, 11 with AD and a group of age and education matched healthy control participants were assessed on a comprehensive battery of semantic memory tests, including traditional semantic memory measures and a non-verbal test of knowledge of object use. The MCI group was impaired on tests of category fluency and all three conditions of an object knowledge test (matching to recipient, function and action), plus a difficult object-naming test. The mild AD group showed additional impairments on traditional measures of semantic memory, including naming high frequency items, comprehension and semantic association. Together these findings suggest that semantic memory impairments occur early in the course of AD, more specifically in patients with "amnesic" MCI, and provide further evidence that impaired category fluency reflects semantic breakdown.     

Peripheral oxidative damage in mild cognitive impairment and mild Alzheimer's disease

Oxidative stress has been shown to be a triggering event in the pathogenesis of Alzheimer's disease (AD). However, little evidence exists on the role of oxidative imbalance in Mild Cognitive Impairment (MCI), a group with a high risk of progression to AD. We therefore assessed the peripheral blood levels of a broad spectrum of non-enzymatic and enzymatic antioxidant defenses, as well as lipid and protein oxidation markers and nitrogen oxidative species in 85 MCI patients, 42 mild AD patients and 37 age-matched controls. In mild AD patients, the plasma levels of vitamin E were significantly decreased, while the plasma concentration of oxidized glutathione was increased in both MCI and mild AD patients. An increase in plasmatic and erythrocytes oxidative markers was also observed in MCI and mild AD patients as compared to controls. In both patients groups, increased levels of plasma antioxidants were found in females, whereas apolipoprotein E epsilon4 allele carriers showed higher indices of intracellular oxidative markers. Moreover, in MCI patients, cognitive function positively correlates with antioxidant levels. This study shows that most of the oxidative changes found in mild AD patients are already present in the MCI group, and that progression to AD might be accompanied by antioxidant depletion.     

Anosognosia and neuropsychiatric symptoms and disorders in mild Alzheimer disease and mild cognitive impairment

Anosognosia is a multidimensional phenomenon that negatively affects course of illness. This study aimed to explore the association between anosognosia and neuropsychiatric phenomena in mild Alzheimer's disease (AD) and in mild cognitive impairment (MCI). The Anosognosia Questionnaire for Dementia to assess anosognosia, and the Neuropsychiatric Inventory to assess neuropsychiatric symptoms were administered to 209 patients (103 mild AD, 52 amnestic-MCI, and 54 amnestic multidomain-MCI). Categorical diagnoses of apathy, depression, and psychosis were made using specific criteria for dementia. With regard to continuous scores, in mild AD, we found positive correlation between symptoms of anosognosia and apathy, agitation and aberrant motor behaviors, while in MCI, we did not find significant association. At a categorical level, the diagnosis of anosognosia in mild AD was associated with the diagnosis of apathy. In mild AD, the frequent co-occurrence of frontally mediated behavioral disorders and anosognosia, particularly apathy, supports the hypothesis of a shared neuropsychogenic process due to the disruption of frontal brain networks.     

轻度认知障碍和轻度Alzeimer病的磁共振波谱分析

目的探讨氢质子磁共振波谱（1H—MRs）在轻度认知障碍（MCI）、轻度Alzheimer病（AD）诊断与鉴别诊断中的作用。方法对20例MCI患者、20例AD患者、20例正常对照者行。H—MRS检查,采用点分辨自旋回波波谱序列（PRESS）,测定双侧内侧颞叶的N-乙酰天门冬氨酸（NAA）、胆碱（Cho）和肌醇（mI）与肌酸（Cr）的比值,并比较各组闻NAA／Cr、mI／Cr、Cho／Cr比值的差别。结果轻度AD组及MCI组与正常对照组间双侧NAA／Cr有显著性差异（P〈0．05）,MCI组、轻度AD组、正常对照组三组间双侧mI／Cr有显著性差异（P〈0．05）,三组间Cho／Cr比值差异无统计学意义。结论1H—MRs能无创性提供MCI、AD患者脑部的代谢情况,NAA／Cr降低和mI／Cr升高有助于MCI、轻度AD的早期诊断。     

Three-dimensional gray matter atrophy mapping in mild cognitive impairment and mild Alzheimer disease

BACKGROUND: Alzheimer disease (AD) is the most common form of dementia worldwide. Mild cognitive impairment (MCI) is the recent terminology for patients with cognitive deficiencies in the absence of functional decline. Most patients with MCI harbor the pathologic changes of AD and demonstrate transition to dementia at a rate of 10% to 15% per year. Patients with AD and MCI experience progressive brain atrophy. OBJECTIVE: To analyze the structural magnetic resonance imaging data for 24 patients with amnestic MCI and 25 patients with mild AD using an advanced 3-dimensional cortical mapping technique. DESIGN: Cross-sectional cohort design. Patients/ METHODS: We analyzed the structural magnetic resonance imaging data of 24 amnestic MCI (mean MMSE, 28.1; SD, 1.7) and 25 mild AD patients (all MMSE scores, >18; mean MMSE, 23.7; SD, 2.9) using an advanced 3-dimensional cortical mapping technique. RESULTS: We observed significantly greater cortical atrophy in patients with mild AD. The entorhinal cortex, right more than left lateral temporal cortex, right parietal cortex, and bilateral precuneus showed 15% more atrophy and the remainder of the cortex primarily exhibited 10% to 15% more atrophy in patients with mild AD than in patients with amnestic MCI. CONCLUSION: There are striking cortical differences between mild AD and the immediately preceding cognitive state of amnestic MCI. Cortical areas affected earlier in the disease process are more severely affected than those that are affected late. Our method may prove to be a reliable in vivo disease-tracking technique that can also be used for evaluating disease-modifying therapies in the future.     

Investigation of neuropsychological characteristics of very mild and mild dementia with Lewy bodies

Introduction: The study aimed to compare the profile of very mild and mild dementia with Lewy bodies (DLB) patients with disease duration up to 5 years in order to find markers for faster progression in this early stage. Method: We investigated 45 DLB patients with disease duration up to 5 years and 22 normal controls. DLB patients were divided into two subgroups on the basis of the Mini-Mental State Examination (MMSE): very mild and mild. Results: Compared to normal controls, very mild DLB patients show significant deficits on tests for attention/executive functions, language, visuospatial/constructional abilities, and retrieval of the episodic memory. In addition, mild DLB (mDLB) patients show a significantly lower score on recall and recognition of the Free and Cued Selective Reminding Test (FCSRT), Trail Making Test Part B (TMT–B), Stroop test, verbal fluency, and Clock Drawing Test than did very mild DLB (vmDLB) patients. Patients with mDLB also have more visual hallucinations, but not significant motor differences compared to vmDLB. Conclusions: In the present work we found that faster progression to the mild DLB stage in the first few years of the disease is mainly related to deterioration of memory, attention/executive functions, and visuospatial abilities, as well as an increased frequency of visual hallucinations.