BACKGROUND & AIMS: PURPOSE:This paper examines and reviews studies on the efficacy of computer-based cognitive intervention programmes in the elderly affected by Mild Cognitive Impairment (MCI). MCI patients are at higher risk to progress to dementia. Recent effort has been made to slow the cognitive decline and delay the onset of dementia in this population. METHOD:MEDLINE sources were searched with the following subject headings: computer-based cognitive intervention, cognitive stimulation, cognitive training, aging, elderly, cognitive impairment. Selected studies were quality assessed and data extracted by two reviewers. RESULTS:Several studies reported encouraging results on cognitive interventions programmes as a means to improve cognitive abilities and emotional states and to decrease subjective memory complaints in MCI patients. CONCLUSION:Though both traditional and computer-based cognitive intervention programmes seem to be effective, the computer-based ones present more advantages: 1) they could individualize the programme tailored to the patient's neuropsychological pattern and needs. 2) they permit the user to make an immediate objective comparison with data collected earlier and thus help in setting up a systematic training plan by providing instant value-free feedback. 3) they offer a possibility of a widescale dissemination.

背景与目标：

BACKGROUND & AIMS: :Conventional Functional connectivity (FC) analysis focuses on characterizing the correlation between two brain regions, whereas the high-order FC can model the correlation between two brain region pairs. To reduce the number of brain region pairs, clustering is applied to group all the brain region pairs into a small number of clusters. Then, a high-order FC network can be constructed based on the clustering result. By varying the number of clusters, multiple high-order FC networks can be generated and the one with the best overall performance can be finally selected. However, the important information contained in other networks may be simply discarded. To address this issue, in this paper, we propose to make full use of the information contained in all high-order FC networks. First, an agglomerative hierarchical clustering technique is applied such that the clustering result in one layer always depends on the previous layer, thus making the high-order FC networks in the two consecutive layers highly correlated. As a result, the features extracted from high-order FC network in each layer can be decomposed into two parts (blocks), i.e., one is redundant while the other might be informative or complementary, with respect to its previous layer. Then, a selective feature fusion method, which combines sequential forward selection and sparse regression, is developed to select a feature set from those informative feature blocks for classification. Experimental results confirm that our novel method outperforms the best single high-order FC network in diagnosis of mild cognitive impairment (MCI) subjects.

背景与目标： : 传统的功能连通性 (FC) 分析侧重于表征两个大脑区域之间的相关性，而高阶FC可以对两个大脑区域对之间的相关性进行建模。为了减少大脑区域对的数量，应用聚类将所有大脑区域对分组为少量聚类。然后，可以根据聚类结果构造高阶FC网络。通过改变群集的数量，可以生成多个高阶FC网络，并最终选择具有最佳整体性能的网络。但是，其他网络中包含的重要信息可能会被简单地丢弃。为了解决这个问题，在本文中，我们建议充分利用所有高阶FC网络中包含的信息。首先，应用了一种聚集的层次聚类技术，使得一层中的聚类结果始终依赖于前一层，从而使两个连续层中的高阶FC网络高度相关。结果，从每一层中的高阶FC网络中提取的特征可以分解为两个部分 (块)，即，相对于其先前的层，一个是冗余的，而另一个可能是信息性的或互补的。然后，开发了一种选择性特征融合方法，该方法结合了顺序前向选择和稀疏回归，以从那些信息性特征块中选择特征集进行分类。实验结果证实，我们的新方法在诊断轻度认知障碍 (MCI) 受试者方面优于最佳的单个高阶FC网络。

BACKGROUND & AIMS: BACKGROUND:To use valid subjective reports sensible to cognitive decline is vital to identify very early signs of dementia development. Use of everyday technology (ET) has been shown to be sensitive to differentiate adults with mild cognitive impairment (MCI) from controls, but the group with subjective cognitive impairment (SCI) has not yet been examined. This study aims to investigate and compare self-perceived ability in ET use and number of ETs reported as actually used in a sample of older adults with SCI, MCI, and older adults with no known cognitive impairment, i.e. CONTROLS: METHODS:Older adults with MCI (n = 29), SCI ( n = 26), and controls (n = 30) were interviewed with the short version of the Everyday Technology Use Questionnaire (S-ETUQ) to capture self-perceived ability in ET use and number of ETs used. To generate individual measures of ability to use ET, Rasch analysis was used. The measures were then compared group-wise using ANCOVA. The numbers of ETs used were compared group-wise with ANOVA. RESULTS:Controls versus SCI and MCI differed significantly regarding ETs reported as used, but not SCI versus MCI. Similarly, in ability to use ET, controls versus SCI and MCI differed significantly but not SCI versus MCI. CONCLUSIONS:The significantly lower numbers of ETs reported as actually used and the lower ability in SCI and MCI groups compared to controls suggest that ET use is affected already in very minor cognitive decline. This indicates that self-reported ET use based on the S-ETUQ is sensitive to detect changes already in SCI.

背景与目标：

BACKGROUND & AIMS: OBJECTIVE:To analyze outcomes of patients with compressive nontoxic multinodular goiter after 131I-iodine 30 mCi treatment without previous use of recombinant human thyroid-stimulating hormone or methimazole. METHODS:We evaluated fixed-dose radioiodine therapy outcomes in patients with nontoxic multinodular goiter who did not accept thyroidectomy as a therapeutic option. Laboratory thyroid function and thyroid volume estimated by ultrasound were assessed before and one year after radioiodine therapy. RESULTS:Twenty euthyroid female patients received 30 mCi of 131I-iodine without recombinant human thyroid-stimulating hormone or methimazole pretreatment. Median thyroid volume and Tc-99m sodium pertechnetate thyroid uptake before radioiodine therapy were 68.05 cm (31.3-295.3) and 0.5% (0.1%-1.2%), respectively. One year after radioiodine therapy, thyroid volume decreased to 55.4 cm (19.8-149.9), and merely 4 patients (20%) developed hypothyroidism. Thyroid volume decreased significantly after radioiodine therapy, presenting a variation of -21.1 cm (-161.3 to -0.8) and -30.61% (-73.88 to -1.02), both with P < 0.0001. Thyroid volume variation was positively correlated with thyroid uptake in Spearman's correlation (r = 0.4730; P = 0.0352). The group satisfied with radioiodine therapy (85%, n = 17) showed a significant reduction in thyroid volume, -25.8 cm (-161.3 to -6.2) and -36.74% (-73.88 to -9.95). The dissatisfied group (15%, n = 3) showed -1.0 cm (-2.0 to -0.8) and -1.67% (-3.38 to -1.02) in thyroid volume, P = 0.0081. Patients that complained about dysphagia presented a lower percentage of thyroid volume decrease after radioiodine therapy, -21.97% (-70.12 to -1.02, P = 0.0430). CONCLUSIONS:A substantial reduction in thyroid volume associated with a low incidence of hypothyroidism and a high satisfaction rate support the use of conventional radioiodine therapy with a fixed dose of 30 mCi. This therapy is an attractive and cheaper therapeutic alternative in selected patients with nontoxic multinodular goiter.

背景与目标：

BACKGROUND & AIMS: :Although both human epidemiologic and animal model studies have suggested that caffeine/coffee protects against Alzheimer's disease, direct human evidence for this premise has been lacking. In the present case-control study, two separate cohorts consisting of 124 total individuals (65-88 years old) were cognitively assessed and a blood sample taken for caffeine/biomarker analysis. Subjects were then monitored for cognitive status over the ensuing 2-4 year period to determine the extent to which initial plasma caffeine/biomarkers levels would be predictive of changes in cognitive status. Plasma caffeine levels at study onset were substantially lower (-51%) in mild cognitive impairment (MCI) subjects who later progressed to dementia (MCI→DEM) compared to levels in stable MCI subjects (MCI→MCI). Moreover, none of the MCI→DEM subjects had initial blood caffeine levels that were above a critical level of 1200 ng/ml, while half of stable MCI→MCI subjects had blood caffeine levels higher than that critical level. Thus, plasma caffeine levels greater than 1200 ng/ml (≈6 μM) in MCI subjects were associated with no conversion to dementia during the ensuing 2-4 year follow-up period. Among the 11 cytokines measured in plasma, three of them (GCSF, IL-10, and IL-6) were decreased in MCI→DEM subjects, but not in stable MCI→MCI subjects with high plasma caffeine levels. Coffee would appear to be the major or perhaps only source of caffeine for such stable MCI patients. This case-control study provides the first direct evidence that caffeine/coffee intake is associated with a reduced risk of dementia or delayed onset, particularly for those who already have MCI.

背景与目标： : 尽管人类流行病学和动物模型研究都表明咖啡因/咖啡可以预防阿尔茨海默氏病，但缺乏直接的人类证据。在本病例对照研究中，认知评估了由124个总个体 (65-88岁) 组成的两个独立队列，并采集了血液样本进行咖啡因/生物标志物分析。然后在随后的2-4年中监测受试者的认知状态，以确定初始血浆咖啡因/生物标志物水平对认知状态变化的预测程度。与稳定的MCI受试者 (MCI → MCI) 的水平相比，后来发展为痴呆 (MCI → dem) 的轻度认知障碍 (MCI) 受试者在研究开始时的血浆咖啡因水平明显较低 (-51%)。此外，没有一个mci → dem受试者的初始血液咖啡因水平高于1200 ng/ml的临界水平，而一半稳定的mci → mci受试者的血液咖啡因水平高于该临界水平。因此，在随后的2-4年随访期间，MCI受试者的血浆咖啡因水平大于1200 ng/ml (≈ 6μm) 与未转化为痴呆相关。在血浆中测量的11种细胞因子中，mci → dem受试者中的三种 (GCSF，IL-10和IL-6) 降低，但在血浆咖啡因水平较高的稳定mci → mci受试者中却没有降低。对于这种稳定的MCI患者，咖啡似乎是咖啡因的主要或唯一来源。这项病例对照研究提供了第一个直接证据，表明咖啡因/咖啡的摄入与痴呆症或延迟发作的风险降低有关，特别是对于那些已经患有MCI的人。

BACKGROUND & AIMS: INTRODUCTION:Shared-housing arrangements (SHAs) are small, home-like care environments in Germany. Residents are predominantly people with dementia. The risk for all-cause hospitalisation is consistently higher for people with dementia compared with people without dementia and there is currently no evidence-based intervention to reduce the risk of hospitalisation. Thus, the DemWG study investigates whether a complex intervention is effective in reducing hospitalisation (primary outcome), behavioural and psychological symptoms of dementia and falls and for stabilising cognitive functioning and quality of life in people with dementia and mild cognitive impairment (MCI) in German SHAs. METHODS AND ANALYSIS:Based on the UK Medical Research Council framework 'Developing and evaluating complex interventions', a prospective, mixed-methods, multicentre, cluster-randomised controlled trial combining primary and secondary data analyses as well as quantitative and qualitative research methods is being conducted. The intervention consists of three parts: (A) education of nursing staff in SHAs; (B) awareness raising and continuing medical education (CME) of general practitioners; (C) multicomponent non-pharmacological group intervention MAKS-mk+ ('m'=motor training; 'k'=cognitive training; '+'=fall prevention) for people with dementia and MCI. Randomisation is stratified by the German federal states and type of setting (rural vs urban). Neither the trained professionals nor the participants are blinded. Data are collected at baseline and after 6, 12 and 18 months with standardised instruments. Quantitative data will be analysed by multivariate analyses according to the general linear model, qualitative data using qualitative content analysis. Recruitment is still ongoing until 31 December 2020. ETHICS AND DISSEMINATION:All procedures were approved by the Ethics Committee of the University of Bremen (Ref. 2019-18-06-3). Informed consent will be obtained before enrolment of participants. Due to findings of previous randomised controlled trials, serious adverse events are not expected. Results will be disseminated in peer-reviewed journal publications and conference presentations. TRIAL REGISTRATION NUMBER:ISRCTN89825211.

背景与目标：

BACKGROUND & AIMS: :This study aimed to validate the TICS and modified TICS (TICSm) in Korean elderly population and to compare MCI and dementia screening ability between TICS and TICSm. TICS and TICSm were administered to 70 cognitively normal (CN), 75 MCI, and 85 dementia subjects, with mini-mental state examination (MMSE) and other cognitive and functional measures. TICS and TICSm scores were highly correlated with other global cognitive and functional scores. The CN vs. dementia discrimination ability of both instruments was as excellent as that of MMSE (sensitivity/specificity at optimal cutoff: 87.1/90.1 for TICS; 88.2/90.0 for TICSm). Although their CN vs. MCI discrimination performances were comparable to that of MMSE, they were far from perfect (sensitivity/specificity: 69.3/68.6 for TICS; 73.3/67.1 for TICSm). There was no significant difference in dementia or MCI screening accuracy between TICS and TICSm. Both of them also showed high test-retest reliability. Our findings indicate that TICS and TICSm are reliable and as valid as MMSE in regard of screening cognitively impaired elderly. In terms of the comparison between TICSm and TICS, however, TICSm has little advantage over TICS for screening dementia and even MCI, in spite of longer administration time and more efforts required.

背景与目标： : 本研究旨在验证韩国老年人群的TICS和改良TICS (TICSm)，并比较TICS和TICSm之间的MCI和痴呆症筛查能力。对70名认知正常 (CN)，75名MCI和85名痴呆症受试者进行了TICS和TICSm，并进行了迷你精神状态检查 (MMSE) 和其他认知和功能测量。TICS和TICSm评分与其他全球认知和功能评分高度相关。两种仪器的CN与痴呆鉴别能力与MMSE一样出色 (最佳临界点的敏感性/特异性: TICS的87.1/90.1; TICSm的88.2/90.0)。尽管它们的CN与MCI区分性能与MMSE相当，但它们远非完美 (敏感性/特异性: TICS的69.3/68.6; TICSm的73.3/67.1)。TICS和TICSm在痴呆或MCI筛查准确性方面没有显着差异。两者也都显示出很高的重测可靠性。我们的发现表明，在筛查认知受损的老年人方面，TICS和TICSm是可靠的，并且与MMSE一样有效。然而，就TICSm和TICS之间的比较而言，TICSm在筛查痴呆症甚至MCI方面比TICS没有什么优势，尽管给药时间更长，需要更多的努力。

BACKGROUND & AIMS: :Data support the evidence that neuropsychological rehabilitation is effective in Alzheimer disease (AD), to strengthen the pharmacological treatment to delay the progression of dementia. At moment, a few studies have examined the efficacy of non-pharmacological treatment in MCI. This is a controlled study that assesses the effectiveness of neuropsychological rehabilitation on cognitive and behavioral symptoms and functional status in a group of community-dwelling subjects with MCI and MD. Our results demonstrate that a systematic rehabilitation, that provides a computerized cognitive program training, produces an improvement in cognitive and affective status of patients with MCI and MD, while a rehabilitation program not providing a punctual stimulation of cognitive functions, does not have significant effects.

背景与目标： : 数据支持神经心理康复对阿尔茨海默病 (AD) 有效的证据，以加强药物治疗以延缓痴呆症的进展。目前，一些研究已经检查了MCI中非药物治疗的功效。这是一项对照研究，旨在评估一组患有MCI和MD的社区居民中神经心理康复对认知和行为症状以及功能状态的有效性。我们的结果表明，提供计算机化认知程序训练的系统康复可以改善MCI和MD患者的认知和情感状态，而康复程序不提供准时的认知功能刺激，则没有显着效果。

BACKGROUND & AIMS: BACKGROUND:The timed up and go (TUG) is a test used to assess mobility in older adults and patients with neurological conditions. This study aims to compare brain gray matter (GM) correlates and structural covariance networks associated with the TUG time in cognitively healthy individuals (CHI) and in patients with mild cognitive impairment (MCI). METHODS:The TUG time was measured in 326 non-demented older community-dwellers (age 71.3 ± 4.5; 42% female) - 156 CHI and 170 MCI. GM covariance networks were computed using voxel-based morphometry with the main neural correlates of TUG for each group as seed regions. RESULTS:Increased TUG time (i.e., poor performance) was associated with distinct brain volume reductions between CHI and MCI. The covariance analysis showed cortical regions involving the default mode network in CHI and bilateral cerebellar regions in MCI. CONCLUSIONS:GM networks associated with the TUG vary between CHI and MCI, suggesting distinct brain control for locomotion between CHI and MCI patients.

背景与目标：

BACKGROUND & AIMS: OBJECTIVES:To use a Machine Learning (ML) approach to compare Neuropsychiatric Symptoms (NPS) in participants of a longitudinal study who developed dementia and those who did not. DESIGN:Mann-Whitney U and ML analysis. Nine ML algorithms were evaluated using a 10-fold stratified validation procedure. Performance metrics (accuracy, recall, F-1 score, and Cohen's kappa) were computed for each algorithm, and graphic metrics (ROC and precision-recall curves) and features analysis were computed for the best-performing algorithm. SETTING:Primary care health centers. PARTICIPANTS:128 participants: 78 cognitively unimpaired and 50 with MCI. MEASUREMENTS:Diagnosis at baseline, months from the baseline assessment until the 3rd follow-up or development of dementia, gender, age, Charlson Comorbidity Index, Neuropsychiatric Inventory-Questionnaire (NPI-Q) individual items, NPI-Q total severity, and total stress score and Geriatric Depression Scale-15 items (GDS-15) total score. RESULTS:30 participants developed dementia, while 98 did not. Most of the participants who developed dementia were diagnosed at baseline with amnestic multidomain MCI. The Random Forest Plot model provided the metrics that best predicted conversion to dementia (e.g. accuracy=.88, F1=.67, and Cohen's kappa=.63). The algorithm indicated the importance of the metrics, in the following (decreasing) order: months from first assessment, age, the diagnostic group at baseline, total NPI-Q severity score, total NPI-Q stress score, and GDS-15 total score. CONCLUSIONS:ML is a valuable technique for detecting the risk of conversion to dementia in MCI patients. Some NPS proxies, including NPI-Q total severity score, NPI-Q total stress score, and GDS-15 total score, were deemed as the most important variables for predicting conversion, adding further support to the hypothesis that some NPS are associated with a higher risk of dementia in MCI.

背景与目标：

BACKGROUND & AIMS: OBJECTIVE:Although visual memory has been shown to be impaired in amnestic mild cognitive impairment (aMCI), the differences between MCI subtypes are not well defined. The current study attempted to investigate visual memory profiles in different MCI subtypes. METHODS:One hundred and seventy volunteers aged older than 50 years performed several visual memory tests included in the CANTAB battery. Participants were classified into four groups: (1) multiple domain aMCI (mda-MCI) (32 subjects); (2) single domain aMCI (sda-MCI)(57 subjects); (3) multiple domain non amnestic MCI (mdna-MCI) (32 subjects); and (4) controls (54 healthy individuals without cognitive impairment). Parametric and non parametric analyses were performed to compare the groups and to obtain their corresponding memory profiles. RESULTS:The mda-MCI group exhibited impairments in both dimensions of episodic memory (recognition and recollection/recall), and also in learning and working memory, whereas the sda-MCI only showed impairment in recollection-delayed recall and learning. The mdna-MCI group displayed impairment in working memory but good preservation of learning and episodic memory. CONCLUSION:The CANTAB visual memory profiles may contribute to better cognitive characterization of patients with different MCI subtypes, allowing comparison across several processes involved in visual memory such as attention, recognition, recollection and working memory.

背景与目标：

BACKGROUND & AIMS: OBJECTIVE:The multicenter prospective cohort study (Japan Cooperative SPECT Study on Assessment of Mild Impairment of Cognitive Function: J-COSMIC) aimed to examine the value of (123)I-N-isopropyl-4-iodoamphetamine cerebral blood flow (IMP-CBF) SPECT in regards to early diagnosis of Alzheimer's disease (AD) in patients with mild cognitive impairment (MCI). METHODS:Three hundred and nineteen patients with amnestic MCI at 41 participating institutions each underwent clinical and neuropsychological examinations and (123)I-IMP-CBF SPECT at baseline. Subjects were followed up periodically for 3 years, and progression to dementia was evaluated. SPECT images were classified as AD/DLB (dementia with Lewy bodies) pattern and non-AD/DLB pattern by central image interpretation and automated region of interest (ROI) analysis, respectively. Logistic regression analyses were used to assess whether baseline (123)I-IMP-CBF SPECT was predictive of longitudinal clinical outcome. RESULTS:Ninety-nine of 216 amnestic MCI patients (excluding 3 cases with epilepsy (n = 2) or hydrocephalus (n = 1) and 100 cases with incomplete follow-up) converted to AD within the observation period. Central image interpretation and automated ROI analysis predicted conversion to AD with 56 and 58 % overall diagnostic accuracy (sensitivity, 76 and 81 %; specificity, 39 and 37 %), respectively. Multivariate logistic regression analysis identified SPECT as a predictor, which distinguished AD converters from non-converters. The odds ratio for a positive SPECT to predict conversion to AD with automated ROI analysis was 2.5 and combining SPECT data with gender and mini-mental state examination (MMSE) further improved classification (joint odds ratio 20.08). CONCLUSIONS:(123)I-IMP-CBF SPECT with both automated ROI analysis and central image interpretation was sensitive but relatively nonspecific for prediction of clinical outcome during the 3-year follow-up in individual amnestic MCI patients. A combination of statistically significant predictors, both SPECT with automated ROI analysis and neuropsychological evaluation, may increase predictive utility.

背景与目标：

BACKGROUND & AIMS: OBJECTIVE:Cognitive impairment is prevalent among individuals with Parkinson's disease (PD). Effort has been made to identify individuals at risk for cognitive decline and dementia. Objectively-defined subtle cognitive decline (Obj-SCD) is a novel classification that may identify individuals at risk for cognitive decline prior to a diagnosis of mild cognitive impairment (MCI). We examined the utility of Obj-SCD criteria to predict future cognitive decline and difficulties with activities of daily living (ADLs) among individuals with PD. METHOD:The sample included 483 individuals newly diagnosed with PD. Participants were followed for a five-year span with yearly visits where they completed neuropsychological tests. Participants were categorized as cognitively normal (CN), the newly proposed Obj-SCD, PD-MCI or Parkinson's disease dementia (PDD). Analyses determined if utilization of Obj-SCD criteria predicted subsequent cognitive impairment and difficulties with ADLs. RESULTS:At baseline, 372 (77%) participants were classified as CN, 40 (8.3%) classified as Obj-SCD, and 71 (14.7%) classified as PD-MCI. Analyses revealed that relative to the CN group, participants classified as Obj-SCD at baseline, were more likely to develop PD-MCI or PDD within 5 years (odds ratio 2.413; 95% confidence interval 1.215-4.792). Furthermore, the Obj-SCD represented an intermediate level of impairment, relative to the CN and PD-MCI groups, on an independent measure of cognition (Montreal Cognitive Assessment) and ADL. CONCLUSIONS:Findings provide evidence that Obj-SCD criteria can identify individuals at risk for cognitive decline and impairments in ADL. Obj-SCD criteria may identify individuals at risk for cognitive impairment who are not detected by PD-MCI criteria.

背景与目标：

BACKGROUND & AIMS: :Limited research has investigated the effects of executive dysfunction on semantic memory deterioration among patients with amnestic mild cognitive impairment (aMCI). This study examined the cognitive performance of 181 participants from various MCI subgroups, a group of mildly impaired individuals with dementia of the Alzheimer type (DAT) and a group of individuals with subjective memory impairment on various semantic memory tasks. The aMCI-single domain (aMCI-sd) group displayed poor performance on a semantic memory task requiring relatively higher degrees of effortful retrieval, and participants in the aMCI-multiple domain (aMCI-md) group, who also suffered with mild executive dysfunction displayed poor performance on all semantic memory tasks, similar to the DAT group. The nonamnestic MCI (non-a-MCI)-single domain group displayed normal performance across all semantic tasks, whereas the non-a-MCI-multiple domain group displayed a pattern similar to that of the aMCI-sd group. aMCI-sd patients who displayed poor performance on the semantic memory task had higher risk of conversion to DAT, whereas poor performance on tasks requiring relatively less effortful retrieval was associated with higher risk of conversion in the aMCI-md group. Thus, executive function may relate to deterioration of semantic memory retrieval processes. Such patterns of semantic memory impairment could be valuable for characterization of cognitive differences among MCI patients.

背景与目标： : 有限的研究调查了执行功能障碍对遗忘型轻度认知障碍 (aMCI) 患者语义记忆恶化的影响。这项研究检查了来自各个MCI亚组的181名参与者的认知表现，一组轻度受损的阿尔茨海默氏痴呆症 (DAT) 个体和一组主观记忆障碍个体在各种语义记忆任务上的认知表现。aMCI-单域 (amci-sd) 组在需要相对较高程度的努力检索的语义记忆任务上表现不佳，而aMCI-多域 (amci-md) 组的参与者也患有轻度执行功能障碍在所有语义记忆任务上表现不佳，类似于DAT组。非遗忘MCI (non-a-MCI)-单域组在所有语义任务中显示正常性能，而非a-MCI-多域组显示的模式类似于amci-sd组。在语义记忆任务上表现不佳的amci-sd患者转换为DAT的风险较高，而在需要相对较少的努力检索的任务上表现不佳与amci-md组的转换风险较高相关。因此，执行功能可能与语义记忆检索过程的恶化有关。这种语义记忆障碍的模式对于表征MCI患者之间的认知差异可能很有价值。

BACKGROUND & AIMS: BACKGROUND:We explored the presence of both reserve and resilience in late-converter mild cognitive impairment due to Alzheimer's disease (MCI-AD) and in patients with slowly progressing amyloid-positive MCI by assessing the topography and extent of neurodegeneration with respect to both "aggressive" and typically progressing phenotypes and in the whole group of patients with MCI, grounding the stratification on education level. METHODS:We analyzed 94 patients with MCI-AD followed until conversion to dementia and 39 patients with MCI who had brain amyloidosis (AMY+ MCI), all with available baseline 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) results. Using a data-driven approach based on conversion time, patients with MCI-AD were divided into typical AD and late-converter subgroups. Similarly, on the basis of annual rate of Mini Mental State Examination score reduction, AMY+ MCI group was divided, obtaining smoldering (first tertile) and aggressive (third tertile) subgroups. Finally, we divided the whole group (MCI-AD and AMY+ MCI) according to years of schooling, obtaining four subgroups: poorly educated (Low-EDUC; first quartile), patients with average education (Average-EDUC; second quartile), highly educated (High-EDUC; third quartile), and exceptionally educated (Except-EDUC; fourth quartile). FDG-PET of typical AD, late converters, and aggressive and smoldering AMY+ MCI subgroups, as well as education level-based subgroups, were compared with healthy volunteer control subjects (CTR) and within each group using a two-samples t test design (SPM8; p < 0.05 family-wise error-corrected). RESULTS:Late converters were characterized by relatively preserved metabolism in the right middle temporal gyrus (Brodmann area [BA] 21) and in the left orbitofrontal cortex (BA 47) with respect to typical AD. When compared with CTR, the High-EDUC subgroup demonstrated a more extended bilateral hypometabolism in the posterior parietal cortex, posterior cingulate cortex, and precuneus than the Low- and Average-EDUC subgroups expressing the same level of cognitive impairment. The Except-EDUC subgroup showed a cluster of significant hypometabolism including only the left posterior parietal cortex (larger than the Low- and Average-EDUC subgroups but not further extended with respect to the High-EDUC subgroup). CONCLUSIONS:Middle and inferior temporal gyri may represent sites of resilience rather than a hallmark of a more aggressive pattern (when hypometabolic). These findings thus support the existence of a relatively homogeneous AD progression pattern of hypometabolism despite AD heterogeneity and interference of cognitive reserve. In fact, cortical regions whose "metabolic resistance" was associated with slower clinical progression had different localization with respect to the regions affected by education-related reserve.

背景与目标：