遗忘型轻度认知损害基于体素的脑形态学研究

目的利用优化的基于体素的形态学研究方法,比较遗忘型轻度认知损害(aMCI)和轻度阿尔茨海默病(AD)患者脑灰质体积。方法选取aMCI患者9例(aMCl组)、轻度AD患者13例(AD组)和正常老年志愿者7例(对照组),经T_2加权像排除颅内存在白质高密度信号,对其进行高分辨率三维T_1加权像扫描,数据在参数统计软件包SPM5下进行头颅标准化、优化、分割和平滑等处理。结果 aMCI组的双侧颞上回、额中回、中央前回、扣带回、顶下小叶、左侧颞中回、中央后回、海马旁回、右侧岛回和旁中央小叶等结构灰质体积小于对照组,差异有统计学意义(P<0.01)。aMCI组的双侧颞上回、齿状回、额上回、额中回、岛回、左侧楔前叶、中央后回、右侧颞中回、颞下回、额下回、顶上小叶和海马旁回等结构灰质体积大于AD组,差异有统计学意义(P<0.01)。结论基于体素的形态学研究能够发现aMCI患者颞、顶、额叶均存在一定程度萎缩,其萎缩程度与累及范围均介于正常老人与轻度AD之间。     

Relation between aerobic fitness and brain structures in amnestic mild cognitive impairment elderly

Mild cognitive impairment (aMCI) is a clinical condition, with high risk to develop Alzheimer’s disease. Physical exercise may have positive effect on cognition and brain structure in older adults. However, it is still under research whether these influences are true on aMCI subjects with low Ab_42 and high total tau in cerebrospinal fluid (CSF), which is considered a biomarker for AD. Therefore, we aimed to investigate a possible relation between aerobic fitness (AF) and gray matter (GM) volume and AF and white matter (WM) integrity in aMCI with a CSF biomarker. Twenty-two participants with aMCI acquired the images on a 3.0-T MRI. AF was assessed by a graded exercise test on a treadmill. Voxel-based morphometry and tract-based spatial statistic methods were used to analyze the GM volume and WM microstructural integrity, respectively. We correlated AF and GM volume and WM integrity in aMCI (p < 0.05, FWE corrected, cluster with at least five voxels). There was a positive relation between AF and GM volume mostly in frontal superior cortex. In WM integrity, AF was positively correlated with fractional anisotropy and negatively correlated with mean diffusivity and radial diffusivity, all in the same tracts that interconnect frontal, temporal, parietal, and occipital areas (longitudinal fasciculus, fronto-occipital fasciculus, and corpus callosum). These results suggest that aerobic fitness may have a positive influence on protection of brain even in aMCI CSF biomarker, a high-risk population to convert to AD.     

Efficacy of cognitive intervention programs in amnesic mild cognitive impairment: A systematic review

Background: Amnesic mild cognitive impairment (aMCI) is considered a prodromal stage of Alzheimer's disease. Given the absence of an effective pharmacological treatment for aMCI, increasing numbers of studies are attempting to understand how cognitive interventions could benefit aMCI patients. The aim of this systematic review was to evaluate the current evidence regarding the efficacy on cognition of cognitive intervention programs in older adults with aMCI.Methods: We searched for randomized controlled trials and clinical trials published until March 2020 on PubMed, Web of Science, Cochrane Library, SCOPUS, and OTseeker. A total of 454 works were identified and 7 studies that met the inclusion criteria, were included in this review. PRISMA guidelines were followed and PEDro scale was included for the measurement of the quality of the selected studies.Results: Cognitive interventions showed positive effects on cognition. Cognitive training programs considerably enhanced the Mini Mental State Examination scores. However, no relevant differences in global cognition were found using other assessment tools as DRS-2 or ADAS-Cog Scale. Cognitive training and cognitive rehabilitation programs seemed to improve several cognitive domains as memory, language or executive function in aMCI patients in both post-training and at follow-up analysis.Conclusions: Our findings support that cognitive interventions can be an effective option for people with aMCI. Cognitive interventions improved global cognitive function post-intervention, but also seemed to enhance some cognitive domains post-intervention and at follow-up. However, more studies are needed to analyze the potential benefits of cognitive intervention on aMCI.     

Interaction of white matter hyperintensities (WMHs) and apolipoprotein E (APOE) genotypes on cognition in patients with amnestic mild cognitive impairment (aMCI)

The clinical implications of WMHs in aMCI are inconclusive. Moreover, clinical interactions between APOE genotypes and WMHs remain unclear. This study was conducted to investigate the relationship between WMHs and cognitive functions and how this relationship interacted with APOE genotype in people with aMCI. This study included a total of 1472 patients with aMCI from the Clinical Research Center for Dementia of South Korea (CREDOS) and divided them into 3 groups according to the severity of WMHs as assessed by visual ratings of brain magnetic resonance images. The associations of WMHs with the various cognitive domains and with APOE epsilon 4 (?4) status were evaluated. After multivariable adjustments, the severity of WMHs was independently associated with semantic/phonemic verbal fluency and Stroop test-color reading, while APOE ?4 status was associated with verbal and visual memory-immediate, delayed recall, and recognition. Moreover, there were interaction between WMHs and APOE ?4 status in semantic verbal fluency (animal, P = 0.033; supermarket, P = 0.047)/Stroop test-color reading (P = 0.024). WMHs independently deleteriously affected frontal executive functions in aMCI patients, regardless of APOE ?4 presence. Furthermore, APOE ?4 possession caused a rapid decline in frontal executive functions with the increase in the WMHs severity (vs. absence), suggesting that WMHs and APOE ?4 genotypes synergistically contribute to frontal executive dysfunctions in aMCI.     

Interaction of white matter hyperintensities (WMHs) and apolipoprotein E (APOE) genotypes on cognition in patients with amnestic mild cognitive impairment (aMCI)

The clinical implications of WMHs in aMCI are inconclusive. Moreover, clinical interactions between APOE genotypes and WMHs remain unclear. This study was conducted to investigate the relationship between WMHs and cognitive functions and how this relationship interacted with APOE genotype in people with aMCI. This study included a total of 1472 patients with aMCI from the Clinical Research Center for Dementia of South Korea (CREDOS) and divided them into 3 groups according to the severity of WMHs as assessed by visual ratings of brain magnetic resonance images. The associations of WMHs with the various cognitive domains and with APOE epsilon 4 (ɛ4) status were evaluated. After multivariable adjustments, the severity of WMHs was independently associated with semantic/phonemic verbal fluency and Stroop test-color reading, while APOE ɛ4 status was associated with verbal and visual memory-immediate, delayed recall, and recognition. Moreover, there were interaction between WMHs and APOE ɛ4 status in semantic verbal fluency (animal, P = 0.033; supermarket, P = 0.047)/Stroop test-color reading (P = 0.024). WMHs independently deleteriously affected frontal executive functions in aMCI patients, regardless of APOE ɛ4 presence. Furthermore, APOE ɛ4 possession caused a rapid decline in frontal executive functions with the increase in the WMHs severity (vs. absence), suggesting that WMHs and APOE ɛ4 genotypes synergistically contribute to frontal executive dysfunctions in aMCI.     

Inhaled Sevoflurane May Promote Progression of Amnestic Mild Cognitive Impairment: A Prospective,Randomized Parallel-Group Study

BackgroundAmnestic mild cognitive impairment (aMCI) is thought to be a transitional stage between normal aging and the development of Alzheimer’s disease (AD). Recent studies have suggested that the inhalational anesthetic isoflurane can induce caspase activation and apoptosis, increase aggregates of β-amyloid (Aβ) levels, and enhance Aβ aggregation. The aim of this study was to investigate whether previous exposure to different anesthetics induced progression of aMCI.MethodsA prospective, randomized parallel-group study was completed with 180 patients with aMCI who were randomly assigned to a sevoflurane, propofol or lidocaine epidural anesthesia group (n = 60 per group) during an L3 to L4 or an L4 to L5 spinal surgery. Sixty additional outpatients with aMCI served as a control group. Before surgery, all subjects underwent a neuropsychological assessment. Cerebrospinal fluid (CSF) was obtained by lumbar puncture, and neuropsychological assessments were completed in the clinic. CSF Aβ₄₂, total tau and phosphorylated tau181 were quantitatively assayed. The neuropsychological assessments were repeated after 2 years.ResultsTwo years after anesthesia, the number of AD cases that emerged did not differ significantly between the groups. However, the number of cases of progressive MCI was greater in the sevoflurane group than in the control group. Age correlated linearly with aMCI progression, whereas sex did not. Both patients with AD and progressive MCI had decreased CSF Aβ₄₂, increased total tau and increased phosphorylated tau levels compared with those with stable MCI and the controls.ConclusionsInhaled sevoflurane accelerated the progression of aMCI to progressive MCI in this selected Chinese population.     

对内嗅皮质和内侧颞叶萎缩的阿尔茨海默病与遗忘型轻度认知功能障碍患者的研究

目的探讨阿尔茨海默痛(AD)与遗忘型轻度认知功能障碍(aMCD)患者内嗅皮质和内侧颞叶萎缩(MTA)的关系。方法选择轻中度AD患者18例(AD组),aMC1患者1 7例(aMCI组)。认知功能通过长谷川痴呆量表修订版(HDS-R)和AD评定量表认知部分(ADAS-cog)评价。通过基于体素的AD特异性局部分析系统的Z评分来评价内嗅皮质的萎缩程度。同时视觉评分系统对MTA程度进行分级。结果 AD组HDS R评分明显低于aMCI组,ADAS-cog和MTA评分明显高于aMCI组(P<0.01)。AD组Z评分与MTA评分呈正相关(P<0.01)。aMCI组Z评分与年龄、MTA评分呈正相关(P<0.01),MTA评分与年龄呈正相关(P<0.05)。结论 aMCI患者中,内嗅皮质萎缩与认知功能改变相关;而AD患者中;MTA更可能的与认知功能相关。MTA评分比Z评分能更有效地区别aMCI和AD患者。在aMCI阶段,内嗅皮质萎缩起了主要的作用;而AD阶段海马等结构作用更突出。     

Acupuncture for amnestic mild cognitive impairment: A pilot multicenter,randomized, parallel controlled trial

Introduction:Patients with amnesic mild cognitive impairment (aMCI) are more likely to develop Alzheimer disease than corresponding age normal population. Because Alzheimer disease is irreversible, early intervention for aMCI patients seems important and urgent. We have designed a pilot multicenter, randomized, parallel controlled trial to assess the efficacy and safety of acupuncture on aMCI, explore the feasibility of acupuncture in the treatment of aMCI, so as to provide a reference for large-sample clinical trials in the next stage.Method:We designed a pilot multicenter, randomized, parallel controlled trial. This trial aims to test the feasibility of carrying out a large-sample clinical trial. In this trial, 50 eligible patients with aMCI will be included and allocated to acupuncture group (n = 25) or sham acupuncture group (n = 25) at random. Subjects will accept treatment 2 times a week for 12 weeks continuously, with a total of 24 treatment sessions. We will select 6 acupoints (GV20, GV14, bilateral BL18, bilateral BL23). For the clinical outcomes, the primary outcome is Montreal cognitive assessment, which will be assessed from baseline to the end of this trial. And the secondary outcomes are Mini-mental State Examination, Delayed Story Recall, Clinical Dementia Rating scale, Global Deterioration Scale, Activity of Daily Life, Alzheimer Disease Assessment Scale-Cognitive Section, brain magnetic resonance imaging, brain functional magnetic resonance imaging, and event-related potential P300, which will be assessed before and after treatment. In addition, we will assess the safety outcomes from baseline to the end of this trial and feasibility outcome after treatment. We will evaluate neuropsychological assessment scale (Montreal cognitive assessment, Mini-mental State Examination, Alzheimer Disease Assessment Scale-Cognitive Section) at 3 months and 6 months after treatment.Discussion:This pilot trial aims to explore the feasibility of the trial, verify essential information of its efficacy and safety. This pilot study will provide a preliminary basis for carrying out a larger clinical trial of acupuncture on aMCI in near future.     

老年人轻度认知损害危险因素的调查分析

目的 调查北京老年人轻度认知损害(MCD)与年龄、性别、体质指数等的关系.方法 应用简易精神状态检查,对北京东直门社区招募的129例老年人进行认知功能评估.结果 检出记忆型轻度认知损害(aMCI)37例(28.7%),阿尔茨海默病(AD)36例(27.9%),认知正常者56例(43.4%).aMCI和AD患者年龄高于认知正常者,分别为(67.6±7.5)岁、(66.6±8.2)岁和(62.5±7.9)岁,两两比较差异均有统计学意义(t值分别为2.847、-1.747和-2.429,P>0.05、P<0.01和P<0.01);aMCI和AD患者受教育年限低(P<0.05);aMCI和AD患者的血压较认知正常者高(P<0.05);aMCI体质指数高于其他两组(P<0.05),不同性别老年人aMCI和AD患病率差异无统计学意义(P>0.05);不同月份出生aMCI和AD患病率差异无统计学意义(P>0.05).结论 aMCI患病率与年龄、教育程度、高血压和体质指数等因素有关,与性别、出生月份无关.     

Bioavailable testosterone is associated with a reduced risk of amnestic mild cognitive impairment in older men

Objective We investigated the risk of amnestic mild cognitive impairment (aMCI) in relation to serum bioavailable (BT) and total testosterone (TT) levels in older men. Design, setting and subjects A cross‐sectional study in an ambulatory setting, with older men aged 55–93 years with normal cognition, aMCI and Alzheimer's disease (AD). Measurements Morning serum BT and TT levels were determined. AD was diagnosed by the Neurological and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association (NINCDS‐ADRDA) criteria for probable AD and aMCI by the Petersen criteria. Results We recruited 203 Chinese older men (48 aMCI, 66 AD and 89 with normal cognition). Mean serum BT, but not TT, levels were significantly lower in the aMCI (mean BT ± SEM 1·06 ± 0·10 nmol/l) and AD (0·99 ± 0·08 nmol/l) groups than in the normal controls (1·82 ± 0·12 nmol/l) (P < 0·001, one‐way anova ) with no significant difference between the aMCI and AD groups. After adjustment for education, age and apolipoprotein E (apoE) genotype, logistic regression analyses showed that the serum BT level [adjusted odds ratio (OR) = 0·52, 95% confidence interval (CI) 0·32–0·85] was an independent protective factor for aMCI. For the combined outcome of aMCI and AD, the serum BT level was an independent protective factor but age and apoE ?4 were independent risk factors. There was no interaction between BT and age. Conclusions In older men, serum BT, but not TT, levels were associated with a lower risk of aMCI and AD.     

Neurochemical alterations of the entorhinal cortex in amnestic mild cognitive impairment (aMCI): a three-year follow-up study

The neurochemical alterations in the entorhinal cortex have not yet been measured, even though the entorhinal cortex is the earliest involved brain region in aMCI. In this study, we investigated whether brain regions including the entorhinal cortex would show early involvement of neurochemical abnormalities in aMCI, and whether magnetic resonance spectroscopy (MRS) abnormalities might be a predictive marker of conversion of aMCI to Alzheimer's disease (AD). MRS was performed on 13 aMCI patients and 11 patients with no cognitive impairment (NCI). Localizing voxels were placed within the entorhinal cortex, hippocampus, posterior cingulate gyrus, and occipital white matter in the dominant hemisphere. N-acetyl aspartate/creatinine (NAA/Cr) ratios in the entorhinal cortex were significantly lower in aMCI patients than in NCI subjects. After a three-year follow-up, seven aMCI patients converted to AD and six remained stable. Baseline NAA/Cr ratios of entorhinal cortex were decreased in converters, compared to NCI. Our study suggested the entorhinal cortex is the earliest site that is subject to neurochemical alteration in aMCI patients, and baseline MRS metabolite ratios in the entorhinal cortex can be a marker for predicting conversion of aMCI to AD.     

早发和晚发遗忘型轻度认知损害与阿尔茨海默病的神经心理学比较研究

目的:比较早发性与晚发性阿尔茨海默病(AD)、早发性和晚发性遗忘型轻度认知损害(aMCI)的神经心理学表现。方法:记忆障碍门诊患者根据首诊年龄分组,70岁为晚发组。接受简明精神状态量表(MMSE)、听觉词语学习测验(AVMT)、逻辑记忆测验(LM)、斯特鲁普(Stroop)色词测验(CWT)、Rey-Osterrich复杂图形测验(CFT)、言语流畅性测验(VFT)、连线测验(TMT)、画钟测验(CDT)等。结果:共257例患者,分为4组,分别为早发AD34例,晚发AD78例,早发aMCI58例,晚发aMCI87例;早发、晚发AD间大部分神经心理学表现相似;早发aMCI患者在大部分测验上的表现优于晚发患者,听觉词语延迟回忆、言语流畅性、TMTB耗时等项目的差异最为显著(P<0.01)。晚发aMCI患者逻辑记忆即刻、延迟回忆更佳。结论:早发与晚发AD认知损害较为相似,晚发aMCI患者的认知损害较早发aMCI患者更为弥漫。     

Conversion pattern and predictive factor of mild cognitive impairment in elderly Koreans

ObjectiveWe aimed to understand conversion characteristics of mild cognitive impairment (MCI) in elderly Koreans.MethodsWe analyzed clinical data of 760 individuals who participated in a two-year follow-up study. Neuropsychological assessments and clinical examination were conducted in the follow-ups. Logistic regression model was used to estimate predictive risk factors of MCI conversion.ResultThe participants at baseline (n = 760) represented 462 cognitively normal individuals (60.8%), 286 individuals with MCI (37.6%), and 12 individuals with dementia (1.6%). Among the cognitively normal individuals (n = 462), 108 (23.4%) progressed to MCI during the two-year follow-up period, including 92 with amnestic mild cognitive impairment (aMCI; 19.9%) and 16 with non-amnestic mild cognitive impairment (non-aMCI; 3.5%). Interestingly, 3.7% of participants with aMCI converted to non-aMCI, while 45.5% of participants with non-aMCI converted to aMCI. Moreover, a higher proportion of non-aMCI (27.3%) reverted to a cognitively normal state, compared to aMCI participants (18.6%), indicating that non-amnestic cognitive impairment is more unstable than amnestic cognitive impairment, and probably converges toward aMCI. Additionally, we found that weight loss was associated with incident MCI and future MCI. Weight loss was negatively correlated with Clinical Dementia Rating (p = 0.005), and significantly associated with a higher risk of MCI conversion from a cognitively normal state (OR = 1.10, 95% CI: 1.00–1.21, p = 0.042).ConclusionThis study supports that non-amnestic MCI is prone to converge toward amnestic MCI, and the elderly people with weight loss are at risk for developing cognitive decline.     

Specific saccade deficits in patients with Alzheimer’s disease at mild to moderate stage and in patients with amnestic mild cognitive impairment

Saccadic impairment in Alzheimer’s disease (AD) was found in horizontal saccades. The present study extends investigation to vertical saccades in a large number of subjects, including AD and amnestic mild cognitive impairment (aMCI). We examined both horizontal and vertical saccades in 30 healthy elderly, 18 aMCI, and 25 AD. Two tasks were used: gap (fixation target extinguishes prior to target onset) and overlap (fixation stays on after target onset). Eye movements were recorded with the Eyeseecam system. (1) Robust gap effect (shorter latencies in gap than in overlap) exists for AD and aMCI patients as for healthy elderly; (2) abnormal long latency of saccades in gap and overlap tasks for AD relative to healthy elderly and aMCI patients; (3) longer latency for aMCI patients than for healthy elderly for the overlap task; (4) significant correlation between scores of Mini-Mental State Examination (MMSE) and latencies of saccades considering the AD group only; (5) higher coefficient of variation in latency for AD patients than for healthy elderly and for aMCI patients; (6) variability of accuracy and speed is abnormally higher in AD patients than in aMCI and healthy elderly. Abnormalities of latency and latency–accuracy–speed variability reflect deficits of cerebral areas involved in the triggering and execution of saccades; latency of saccades can be used as follow-up test for aMCI and AD patients with its significant correlation with the changes of MMSE scores.     

The effect of severity of white matter hyperintensities on loss of functional independency in patients with mild cognitive impairment: A CREDOS-LTCI (clinical research center for dementia of South Korea-long term card insurance) study

ObjectiveBy combining data from the Clinical Research Center for Dementia of South Korea(CREDOS) study and long-term care insurance(LTCI), we aimed to assess whether the severity of white matter hyperintensity(WMH) predicted functional decline in cases of amnestic mild cognitive impairment(MCI).MethodsWMH was evaluated in 3,569 patients with amnestic MCI using the visual rating scale developed for the CREDOS study. The participants were classified as having amnestic MCI with minimal WMH change(aMCI), with moderate WMH change(maMCI) and with severe WMH change(saMCI) according to the severity of the WMH measurements. A Kaplan–Meier survival probability estimate was used to compute median time from the diagnosis of MCI to LTCI enrollment for the three MCI groups. The effect of various risk factors of LTCI enrollment was evaluated using Cox’s proportional hazards model, adjusted for covariates.ResultsAs compared with aMCI cases, maMCI and saMCI patients required help with daily activities of living at a younger age. The saMCI and maMCI patients had higher risk of LTCI enrollment as compared with that of the aMCI patients. Younger patients(≤ 65y) with MCI had a 3.201 times higher risk of early LTCI enrollment than older patients(> 65y) did. High clinical dementia rating score and female sex were also risk factors of early LTCI enrollment.ConclusionsWMH predicted the rate of global functional decline and loss of independence in patients with MCI. The findings support the use of neuroimaging of WMH, in conjunction with biomarkers, as a tool in predicting functional decline in patients with MCI.     

Could language deficits really differentiate Mild Cognitive Impairment (MCI) from mild Alzheimer's disease?

Naming abilities seem to be affected in Alzheimer's disease (AD) patients, though MCI individuals tend to exhibit greater impairments in category fluency. In this study we: (1) detect language deficits of amnestic MCIs (aMCIs) and mild AD (mAD) participants and present their language performance (the Boston Diagnostic Aphasia Examination – BDAE scores) according to educational level, (2) study the diagnostic value of language deficits according to the cognitive state of the participants. One hundred nineteen participants, 38 normal controls (NC), 28 aMCIs and 53 mADs, were recruited randomly as outpatients of 2 clinical departments and administered clinical, neuropsychological and neuroimaging assessment. Language abilities were assessed by the adapted Greek edition of the BDAE (2nd edition). Our results indicate that verbal fluency, auditory, reading comprehension and narrative ability are the main language abilities to be affected in mADs, although they are almost intact in NCs and less vulnerable in aMCIs. Narrative ability seems to be significantly impaired in mADs but not so in aMCIs. Six language subtests of the BDAE assess safely the above deficits. This brief version of the BDAE discriminated mADs from the other 2 groups 92.5% of the time, NCs 86.8% and aMCI 67.9% of the time in order to save time and to be accurate in clinical practice.     

Could language deficits really differentiate Mild Cognitive Impairment (MCI) from mild Alzheimer's disease?

Naming abilities seem to be affected in Alzheimer's disease (AD) patients, though MCI individuals tend to exhibit greater impairments in category fluency. In this study we: (1) detect language deficits of amnestic MCIs (aMCIs) and mild AD (mAD) participants and present their language performance (the Boston Diagnostic Aphasia Examination – BDAE scores) according to educational level, (2) study the diagnostic value of language deficits according to the cognitive state of the participants. One hundred nineteen participants, 38 normal controls (NC), 28 aMCIs and 53 mADs, were recruited randomly as outpatients of 2 clinical departments and administered clinical, neuropsychological and neuroimaging assessment. Language abilities were assessed by the adapted Greek edition of the BDAE (2nd edition). Our results indicate that verbal fluency, auditory, reading comprehension and narrative ability are the main language abilities to be affected in mADs, although they are almost intact in NCs and less vulnerable in aMCIs. Narrative ability seems to be significantly impaired in mADs but not so in aMCIs. Six language subtests of the BDAE assess safely the above deficits. This brief version of the BDAE discriminated mADs from the other 2 groups 92.5% of the time, NCs 86.8% and aMCI 67.9% of the time in order to save time and to be accurate in clinical practice.     

轻度认知障碍患者多模态磁共振特征

目的 探讨轻度认知损害者(MCI)和阿尔茨海默病(AD)患者多模态磁共振成像特征与认知功能的关系.方法 共纳入9例遗忘型MCI,15例轻度AD及11例正常对照,以简明精神状况检查(MMSE)和认知功能筛查测验(CASI)评估总体认知功能,对高分辨率结构像进行基于体素形态学分析(VBM),测量扩散张量成像(DTI)图像、各脑区白质各向异性比值(FA)和平均表观弥散系数(ADC),分析脑结构萎缩及白质DTI指标与认知评分的相关性.结果 MMSE和CASI评分与颞、额、顶、扣带回、海马旁回等结构灰质体积改变呈正相关(P<0.001),MMSE和CASI总分与颞、顶叶以及海马旁回的FA值呈正相关,与ADC值呈负相关(P<0.05).结论 MCI和AD患者认知功能与颞、顶、海马旁回等脑区萎缩及白质微观结构损伤密切相关,多模态影像技术可作为认知损害脑机制研究的重要技术手段.     

轻度认知功能障碍的磁共振弥散张量成像研究

目的 应用磁共振弥散张量成像技术以及自动化影像分析工具研究遗忘型轻度认知功能障碍(aMCI)大脑白质结构的变化.方法 对受试者进行临床和神经心理评估,31例受试者(aMCI组15例,对照组16例)接受磁共振弥散张量成像技术扫描.所有影像资料经与标准模板配准后,采用基于像素的图像分析法确定两组各向异性分数有差异的脑区.结果 aMCI组简易智力状态检查量表(MMSE)(26.93±1.49)分,蒙特利尔认知评估量表(MoCA)(22.73±1.91)分,对照组MMSE(29.44±0.81)分,MoCA(26.50±1.17)分,差异有统计学意义(P<0.05).在aMCI组双侧额叶部分白质区域异性分数值低于对照组(P<0.1301).结论 额叶白质损伤可能参与了aMCI的病理生理过程的变化.     

多奈哌齐对遗忘型轻度认知损伤干预作用的临床研究

目的观察遗忘型轻度认知损伤(aMCI)患者服用小剂量多奈哌齐(商品名：安理申)后其认知功能及脑内代谢产物变化,以期为痴呆的防治用药探索有效途径。方法入选33例aMCI患者,治疗组21例服多奈哌齐2．5mg／d,连续3个月,对照组12例,两组均维持既往基础用药。用药前后均行临床记忆量表,简易智力状态测查(MMSE),词语流畅性及画钟表等认知功能评定,并对治疗组中5例患者分别在用药前后行海马区磁共振质子波谱(MRS)检查。结果治疗组用药前后测记忆商,MMSE总分以及延迟记忆成绩显著提高;MRS检测示用药后海马区N-乙酰基天门冬氨酸(NAA)／肌酸复合物(Cr)稳定,肌醇(MI)／Cr升高。结论小剂量多奈哌齐可有效改善aMCI患者总体认知功能及记忆功能;NAA／Cr稳定,MI／Cr升高,提示多奈哌齐有可能通过星形胶质细胞活化、稳定神经元功能以及调控突触间传递而改善记忆功能。