Preliminary evaluation of common experimental animal models for Alzheimer' s disease and mild cognitive impairment / 中国药理学通报

Alzheimer∗ s disease (AD) is a typical central nervous degenerative disease characterized by progressive cognitive impairment and behavioral damage, which is associated with the major pathological manifestations of extracellular amyloid deposition, intracellular neurofibrillary tangles, and neuron loss. Mild cognitive impairment ( MCI) is a kind of cognitive impairment status between normal cognition and AD, which is linked with a high risk of converting into AD. Previous studies mostly establish the animal models with clinical AD characteristics for mechanism research, drug screening, and new drug development. In recent years, researchers have attempted to establish animal models with clinical MCI characteristics, trying to intervene ear-ly at MCI stage to effectively prevent the occurrence of AD. There are many types of AD experimental animal models, and the MCI model should be distinguished from the AD model. Based on the systematic introduction of the characteristics of AD and MCI, this study aims to preliminarily evaluate the commonly used AD and MCI experimental animal models, providing sug-gestions for the research of AD and MCI.

Bioinformatics analysis of miRNAs in mild cognitive impairment due to Alzheimer's disease / 上海交通大学学报（医学版）

Objective: To analyze the expression profile of plasma microRNA (miRNA) in patients with mild cognitive impairment (MCI) due to Alzheimer's disease (AD) by bioinformatics method, and explore its pathogenesis at the level of genetic regulation. Methods: Five MCI patients due to AD and five control participants were recruited. The plasma miRNA expression profiles were analyzed by miRNA microarray sequencing. Target genes of significantly up-regulated miRNAs were detected by TargetScan 7.2 database. The miRNA-gene interaction network of significantly up-regulated miRNAs was established by Cytoscape software, and the key miRNAs of the network were analyzed. The target genes of key miRNAs were analyzed by Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genome (KEGG) pathway analysis using R packages. Results: There are 13 up-regulated miRNAs in the plasma of MCI patients due to AD, and 5 of them were key miRNAs in miRNA-gene interaction network. Target genes of these miRNAs were mainly involved in biological process such as synaptic plasticity reg-ulation, Wnt signaling pathway, synaptic vesicle transport and synaptic vesicle localization, as well as Ras signaling pathway, mitogen-activated protein kinase (MAPK) signaling pathway and glycolysis/gluconeogenesis pathway. Conclusion: Five up-regulated miRNAs in plasma of MCI due to AD may be the main regulators involved in the pathological mechanism of AD, which can be used as potential biomarkers for diagnosis of MCI due to AD.

Study of a screening system for mild cognitive impairment based on machine learning model / 上海交通大学学报（医学版）

Objective:To evaluate the reliability and validity of a computerized cognitive assessment system designed for screening mild cognitive impairment (MCI), and compare the screening accuracy among constructed different machine learning classification models. Methods:A group of random stratified samples of over 55 years old residents in the communities, nursing homes and memory-clinics from Shanghai and Henan were selected to assess their cognitive status using Montreal Cognitive Assessment (MoCA) by well-trained investigators. The reliability and validity were assessed by intrinsic consistency analysis and factor analysis, respectively. Taking the results of MoCA as standards, four machine learning classification algorithms, i.e., naïve Bayesian classification model, random forest classifier, Logistic regression classifier, and K-nearest neighbor classifier, were compared in accuracy and area under curve (AUC). Results:A total of 359 participants were included, the median age of whom was 63 years old. And 82.80% of them were secondary school graduates or below. According to the results of MoCA, 147 of them might be MCI. The Cronbach's α and KMO of this system were 0.84 and 0.78, respectively; Bartlett's sphericity test was significant (P<0.05); thirteen common factors could explain 75.10% of the system. The best classification model was naïve Bayesian classification model, and its accuracy and AUC were 88.05% and 0.941, respectively. Conclusion:The new designed computerized cognitive assessment system has been proved to be reliable and valid. The naïve Bayesian classification model has good classification accuracy.

Characteristic of brain microbleeds in Alzheimer's disease / 上海交通大学学报（医学版）

Objective: To evaluate the differences of brain microbleeds among Alzheimer's disease (AD), amnesia mild cognitive impairment (aMCI) and normal control (NC). Methods: Eighteen AD patients, 28 aMCI patients and 30 age-matched NC were recruited in the study. The location and number of microbleeds was recorded in the brain according to the susceptibility-weighted images. The bilateral frontal lobe, parietal lobe, occipital lobe, temporal lobe, and thalamus were manually mapped on 3D-MR imaging. The number of cases with microbleeds and the number of microbleeds in each lobe were calculated and compared among three groups using the chi-square test and ANOVA. Results: Significant differences on case number with microbleeds were found between AD group and NC group in the frontal lobe (P=0.005), the temporal lobe (P=0.005) and whole brain (P=0.004), and between aMCI group and NC group in the frontal lobe (P=0.048). It also showed significant differences among three groups in the frontal lobe (P=0.006), the temporal lobe (P=0.006) and whole brain (P=0.016). For the microbleeds counts, significant differences were found between AD group and NC group in the frontal lobe (P=0.004) and the temporal lobe (P=0.049), and between AD group and NC group in the frontal lobe (P=0.044). It also had significant differences among three groups in the frontal lobe (P=0.016), the temporal lobe (P=0.038) and whole brain (P=0.048). Conclusion: The AD group has more significant microbleeds in frontal and parietal lobes in comparison to NC group. The quantization of cerebral microbleeds may be a potential biomarker for AD diagnosis.

Pattern Visual Evoked Potential (VEP) is Unaffected in the Early Stage of Mild Cognitive Impairment / Jurnal Sains Kesihatan Malaysia

The aim of this study was to determine whether pattern-reversal Visual Evoked Potential (PRVEP) is affected in mild cognitive impairment (MCI). Participants aged ≥ 60 years diagnosed as MCI were invited to participate in a study together with a group of controls. PRVEP was measured using A RETI-port/Scan 21 and stimuli of large and small checks sizes, 1° (60 min of arc) and 0.25° (15 min) respectively were used to obtain responses. The amplitude and implicit times of the MCI and control groups were then compared. A total of 18 MCI participants (age 65.7 ± 3.1 years) and 18 controls (65.1 ± 3.8 years) consented to participate in the study. The amplitude and implicit times for the MCI group using the target sizes of 60 min of arc were 9.80 ± 4.06 μV and 108.83 ± 7.63 ms and for 30 min of arc were 11.00 ± 7.44 μV and 123.96 ± 6.18 ms respectively. Consecutively for the control groups the amplitudes and implicit times were 8.96 ± 3.52μV, 105.85 ± 3.60 ms and 11.97± 6.11 μV, 122.57 ± 8.28 ms. PRVEP results did not reveal significant differences in P100-wave amplitude nor implicit time between the two groups under investigation. This study concluded that the visual pathway of MCI participants may be unaffected in the early part of the disease process.

Evolución de la categorización semántica en adultos mayores con diagnóstico de DCL-A y DTA y sin patología neurológica / Evolution of semantic categorization in older adults with and without neurological disease

Tradicionalmente la memoria semántica ha sido definida como un tesoro mental que almacena información sobre las palabras, su significado, como así también la relación entre ellas, los hechos y los conceptos. Una de las vías principales para explicar cómo se organiza la información en la memoria semántica (MS) es a través de categorías. La demencia tipo Alzheimer (DTA) suele estar caracterizada por un deterioro en la memoria episódica. Sin embargo, se debate en torno al deterioro de la misma, en qué momento aparece, a qué se debe y si hay una pérdida diferencial en distintos momentos de la enfermedad. El objetivo del trabajo que se informa fue analizar los procesos de categorización semántica en adultos mayores sanos comparándolos con dos grupos de personas con patologías neurológicas: uno con diagnóstico de deterioro cognitivo leve (DCL) y otro con demencia tipo Alzheimer (DTA), emparejados por edad, nivel educativo y género. Para ello, se utilizaron tareas tradicionales para evaluar la memoria semántica y también un método novedoso, el DISTSEM, que permite evaluar las estimaciones que realizan las personas de las distancias semánticas entre los conceptos. Los resultados mostraron que el grupo de personas sin patología tuvo un rendimiento superior en todas las tareas en comparación con los grupos de personas con patología neurológica. Por otro lado, el grupo con DTA mostró un deterioro semántico afectando en primer lugar a la categoría seres vivos. El DCL preservó la estructura categorial sólo con pequeñas intrusiones. El DISTSEM mostró ser un instrumento adecuado para la discriminación entre sujetos sanos y DTA.

Traditionally, semantic memory has been defined as a mental trove that contains organized information about words and their meaning, as well as relationships between words, facts and concepts.There are different ways of explaining how the information in such memory system is represented and organized. One of the main ways of explaining this organization is through categories. Categorization starts the very moment that any sensorial perception is associated to an abstract category; it is the ability to organize information in equivalence classes, and it is very important because it allows us to summarize the information that we gather through our senses and thus facilitate its manipulation. Alzheimer's disease (AD) is the main cause of dementia among older adults, and it is one of the most pressing sanitary, social and cultural problems of the present times. The main risk factor for the illness is age, for its prevalence augments exponentially from 65 to 85 years old, and due to the rise in life expectancy it is considered that it might be transformed into a world-wide epidemic in the coming years. The start of the illness is insidious and slowly progressing, and it is characterized by a loss of episodic memory from its beginnings. With respect to the deterioration of semantic memory in AD, a debate has arisen about its mode of presentation, its causes, and whether there is a differential loss of categories (live or non-live beings) in different moments of the illness. During the 90s, Petersen proposed the concept of mild cognitive impairment (MCI) to label the subjects with a functional cognitive impairment insufficient to diagnose a dementia syndrome. The importance of this syndrome is that between 8 to 15% of those who suffer it evolve to AD annually, while in the general population this evolution is only from 1 to 2%. However, there is a great controversy about the validity and scope of the term MCI, for its etiology can be very varied and it is very difficult to predict its evolution. There are different sub-kinds of MCI, and the amnesic form is the more likely to evolve into AD, for its main characteristic is the subjective deterioration of memory corroborated by standardized test by reference to normative data for the same age and educational level of the subject. The other cognitive functions not present alterations. The main objective of this work was to analyze the semantic categorization processes in healthy older adults comparing them with two groups of people with neurological pathologies, one with diagnosis of MCI and the other with AD, matched by age, educational level and gender. To evaluate this categorization process, two traditional tasks were used together with a novel method, the DISTSEM, which allows the evaluation of the estimation made by people about the semantic distance among a set of given concepts. The results showed that the group of people without pathologies had a superior performance in all the tasks in comparison with the groups of people with neurological pathologies. On the other hand, the group with AD showed a semantic impairment which affected in the first place the category of live beings, which was evident in the all the tasks. The MCI preserved the categorical structure with only minor intrusions. The DISTSEM has shown itself to be a valuable instrument that allows the discrimination between healthy subjects and those with AD. It is expected that this work can provide empirical evidence relevant to the debate surrounding semantic memory, for studies in patients with brain injury offer key information to examine the organizing models of such memory.

Puntuaciones del MoCA y el MMSE en pacientes con deterioro cognitivo leve y demencia en una clínica de memoria en Bogotá / MoCA and MMSE scores in patients with mild cognitive impairment and dementia in a memory clinic in Bogotá

Introducción. Diferentes pruebas neuropsicológicas permiten explorar las funciones cognitivas del adulto mayor, en un tiempo corto. En Colombia se dispone de pocos estudios sobre puntuaciones y puntos de corte para el MMSE y para el MoCA en relación al diagnóstico de deterioro cognitivo. Objetivo. Describir la distribución de las puntuaciones del MMSE y el MoCA y los puntos de corte con mejor discriminación, para el diagnóstico de deterioro cognitivo leve y demencia, en una muestra de pacientes de Bogotá. Material y métodos. Se evaluaron 248 pacientes por un equipo multidisciplinario, que consultaron a la Clínica de Memoria del HIUSJ entre 2009-2012, siguiendo un protocolo establecido. Se identificaron las puntuaciones del MoCA y MMSE, que permitieron obtener el mayor porcentaje de pacientes correctamente clasificados. Resultados. En el 70% de los pacientes con DCL y en el 69 % de los sujetos normales, se encontraron puntuaciones del MMSE inferiores o iguales a 28. En 91% de pacientes con DCL y 84% de los sujetos normales, se presentaron puntuaciones del MoCA inferiores o iguales a 25. Los pacientes con cualquier tipo de demencia, presentaron puntuaciones del MMSE inferiores o iguales a 27 e inferiores o iguales a 24 en el MoCA. Conclusión. Según el presente estudio, el tamizaje de funciones cognitivas, utilizando el MoCA, clasifica de manera más acertada que el MMSE, a los sujetos con deterioro cognitivo. Creemos que en atención primaria, estos puntos de corte del MoCA, pueden ser considerados por ahora, cuando se trate especialmente de sujetos con alta escolaridad.

Introduction. Some cognitive tests allow the evaluation of cognitive functions on the elderly in a short period of time. There are few studies in Colombia about cut-off point for the MMSE and the MoCA test. Objectives. To describe the distribution on scores on MMSE and MoCA test and the cut-off point with a better discrimination criteria for the diagnosis of mild cognitive impairment and dementia, in a sample of patients from Bogotá. Materials and methods. Two hundred forty eight patients were included in this study, being evaluated by a multidisciplinary team that followed an established protocol, on patients who attended to the Memory Clinic of HIUSJ between 2009-2012. MoCA test and MMSE scores that allow higher percentages of correctly classified patients were identified. Results. Seventy percent of patients with mild cognitive impairment and 69% of normal individuals had scores on MMSE below or equal to 28. Ninety-one percent of patients with MCI and 89% of normal patients, had scores below or equal to 25. Patients with any type of dementia had scores on MMSE below or equal to 27 and below or equal to 24 in MoCA test. Conclusion. According to the study, the screening of cognitive functions, using MoCA test, is more accurate than MMSE in patients with cognitive decline. The cut-off points, identified in our study, can be considered useful until now in primary attention, in patients with a high level of education.

A Comparison of the Performances on the MMSE, HDS-R, and MoCA According to the CDR Sum of Boxes in Amnestic Mild Cognitive Impairment and Vascular Mild Cognitive Impairment

BACKGROUND: O'Bryant et al. (2008) argued that the CDR Sum of Boxes (CDR-SB) can be used to distinguish MCI from very early dementia in patients with CDR-GS of 0.5. They reported that the optimal CDR-SB cut-off score was 2.5. The present study was conducted to examine whether the subgroups classified with CDR-SB scores showed the corresponding group differences on the cognitive tests. METHODS: The subjects were 45 amnestic multi-domain MCI (amMCI) and 53 vascular MCI (VaMCI) with CDR-GS of 0.5. Each patient group was classified into "mild (0.5-2.0)" and "severe (2.5-4.0)" subgroups based on the CDR-SB. As the result, 4 groups were formed such as mild amMCI (n=23), severe amMCI (n=22), mild VaMCI (n=29), and severe VaMCI (n=24). The subjects were given the MMSE, HDS-R, and MoCA. The MANCOVA was conducted separately for each test with a Bonferroni correction for multiple comparisons. RESULTS: Severe groups of both amMCI and VaMCI showed significantly lower performances than two mild groups in MMSE, HDS-R, and MoCA. It was found that "serial 100-7" was a good item to discriminate between the mild and severe groups in both amMCI and VaMCI. Items measuring "orientation" or "naming" showed significant subgroup differences in the amMCI, whereas items related to "memory," "visuospatial construction," or "frontal/executive function" showed significant subgroup differences in the VaMCI. CONCLUSION: These results showed that there were significant differences in cognitive functions between the two subgroups with CDR-GS of 0.5. The results about the items discriminating between subgroups in amMCI and VaMCI were consistent with the previous findings about the progression of cognitive impairments in AD and VaD. Therefore, these results support the use of CDR-SB as a guideline for distinguishing MCI from early dementia.

Meta analysis on the levels of total Tau protein and β-amyloid42 in cerebrospinal fluid in mild cognitive impairment patients / 中国神经精神疾病杂志

Objective To evaluate the changes of the level of cerebrospinal fluid T-tau protein andβ-amyloid 42 in mild cognitive impairment (MCI) patients. Methods Computer retrieval was preformed for cerebrospinal fluid (CSF) to-tal tau protein (T-tau) and β-amyloid 42 (Aβ 42) levels among MCI and healthy people in Pubmed, Cochrane Library, Ovid, CNKI, VIP Data and Wangfang Data. Meta-analyses were conducted on the T-tau and Aβ42 levels using Review Manager 5.2 software. Results Seventeen studies met inclusion criteria. Meta-analysis results showed that, CSF T-tau protein levels were significantly higher (MD:113.10;95%CI:87.93-138.26) and Aβ42 levels were significantly lower in the patients with MCI, (MD=-146.50;95%CI=-178.70- -114.29) compared with the control group (P<0.01). Conclu-sions T-tau significantly increases while Aβ42 significantly decreases in the CSF in patients with MCI.

The Impact of Choline Acetyltransferase Polymorphism on the Expression of Mild Cognitive Impairment

OBJECTIVES: The potential association between choline acetyltransferase(CHAT) polymorphism and the risk of mild cognitive impairment(MCI) has not been investigated in Korea. We examined the main effect of CHAT polymorphism and its interaction with apolipoprotein E(APOE) polymorphism in the development of MCI in elderly Korean sample. METHODS: We analyzed CHAT 2384G > A polymorphism and APOE polymorphism among 149 MCI subjects with MCI and 298 normal controls. We tested the association between MCI and CHAT A allele status using a logistic regression model. In addition, we employed generalized multifactor dimensionality reduction(GMDR) to investigate the interaction between CHAT and APOE with regard to the risk of MCI. RESULTS: The CHAT A allele was associated with AD risk(OR = 1.59, 95% CI = 1.02-2.48, p = 0.042). No significant gene-gene interaction between CHAT and APOE was found in GMDR method(testing balanced accuracy = 0.540, p = 0.055). CONCLUSION: The CHAT A allele was associated with MCI risk in the Korean elderly. Its interaction with the APOE epsilon4 allele was not significant with regard to the development of MCI.

Neuropsychiatric Symptoms in Patients with Amnestic Mild Cognitive Impairment / 신경정신의학

OBJECTIVES : To define the neuropsychiatric features of amnestic-type Mild Cognitive Impairment (aMCI) and compare them with those of mild Alzheimer's disease (AD). METHODS : The study participants included 353 aMCI and 500 mild AD patients. The Neuropsychiatric Inventory (NPI) was used to assess the neuropsychiatric symptoms in two groups. RESULTS : 65.4% of aMCI and 85.4% of mild AD patients exhibited neuropsychiatric symptoms. The most common symptoms in the aMCI group were depression (33.7%), irritability (29.5%), sleep/ night-time behavior (23.2%), apathy (21.5%), and anxiety (21.2). The most common features in the mild AD group were depression (52.4%), apathy (52%), irritability (41.6%), and anxiety (41%). There were significant differences between the aMCI and mild AD groups in 11 NPI symptoms except sleep/night-time behavior. CONCLUSION : A high prevalence of neuropsychiatric symptoms were associated with aMCI, especially mood disturbances and apathy. In contrast, psychotic symptoms were rare. The neuropsychiatric symptoms observed in aMCI were similar to those of mild AD.

Neuropsychiatric Symptoms in Patients with Amnestic Mild Cognitive Impairment / 신경정신의학

OBJECTIVES : To define the neuropsychiatric features of amnestic-type Mild Cognitive Impairment (aMCI) and compare them with those of mild Alzheimer's disease (AD). METHODS : The study participants included 353 aMCI and 500 mild AD patients. The Neuropsychiatric Inventory (NPI) was used to assess the neuropsychiatric symptoms in two groups. RESULTS : 65.4% of aMCI and 85.4% of mild AD patients exhibited neuropsychiatric symptoms. The most common symptoms in the aMCI group were depression (33.7%), irritability (29.5%), sleep/ night-time behavior (23.2%), apathy (21.5%), and anxiety (21.2). The most common features in the mild AD group were depression (52.4%), apathy (52%), irritability (41.6%), and anxiety (41%). There were significant differences between the aMCI and mild AD groups in 11 NPI symptoms except sleep/night-time behavior. CONCLUSION : A high prevalence of neuropsychiatric symptoms were associated with aMCI, especially mood disturbances and apathy. In contrast, psychotic symptoms were rare. The neuropsychiatric symptoms observed in aMCI were similar to those of mild AD.

Restriction of Instrumental Activities of Daily Living in MCI / 신경정신의학

OBJECTIVES: Mild cognitive impairment (MCI) is distinguished from mild dementia by an absence of global intellectual deterioration and the preservation of activities of daily living (ADL). Recently, however, it became apparent that impairment of instrumental activities of daily living (IADL) is present before the threshold of dementia is reached. Thus, we want to examine whether IADL are impaired in patients with MCI, and which items of IADL are particularly involved. We divided the MCI group into amnestic (aMCI) and non-amnestic MCI (naMCI), and compared to the cognitively normal controls. In this study, we focused on the instrumental activities of daily living (IADL). METHODS: The sample consisted of 69 community-dwelling older adults from a welfare center for the aged in Korea. The subjects were divided into three diagnostic groups; aMCI [N=19, memory domains below -1.5 standard deviation (SD)], naMCI (N=19, other cognitive domains below -1.5 SD, except memory domains) and cognitive normal controls (N=31). Subjects were assessed both on IADL and the cognitive function. In order to assess the IADL, we used the Seoul -Instrumental Activities of Daily Living (S-IADL). Included measures of cognitive tests are as follows; Seoul Verbal Learning Test (SVLT), Rey Complex Figure Test (RCFT), Korean-Boston Naming Test (K-BNT), Stroop test, and Korean-Mini Mental Status Examination (K-MMSE). Groups were compared on the S-IADL and the cognitive tests. RESULTS: The three groups did not differ in the mean age, gender distribution and years of education. S-IADL were shown to be different between the groups in this study. Subjects with aMCI were significantly more impaired in S-IADL in comparison to the controls [F(2,50)= 4.251, p=0.020]. And on four items of S-IADL (shopping, transportation, medication and talking about recent events), subjects with aMCI showed higher impairment compared to the controls. However, the S-IADL did not differ between the subjects with naMCI and controls. CONCLUSION: In this study, impairment of S-IADL was shown in subjects with aMCI. And S-IADL of naMCI was not significantly differed from aMCI and controls. The results suggest that naMCI would be distinguished from aMCI in characteristics and prognosis.

Study of word naming reaction time of reading Chinese in patients with mild Alzheimer disease and mild cognitive impairment / 中国康复理论与实践

@#ObjectiveTo explore the pattern and the time course changes of semantic and phonological processing during Chinese language cognition study in patients with mild Alzheimer's disease(AD) and mild cognitive impairment (MCI).MethodsPatients with mild AD and MCI and normal controls matched with age, gender, level of education were enrolled in the single-character words naming task, which applied short and long stimulus onset asynchrony (SOA). Semantic, homophonic, semihomophonic and unrelated primes preceded the words as well as nonwords targets. Subjects were asked to read the targets aloud. Semantic and phonological priming effects were analyzed by comparing reaction time of semantic, homophonic or semihomophonic related targets to unrelated targets. The reaction time and accuracy for each response were recorded.ResultsThe mean reaction time of mild AD and MCI patients were prolonged for all types of priming in contrast with normal controls. Responses of the normal controls were faster during the long SOA comparing to short SOA, whereas the mild AD group's reaction time was longer for long SOA than for short SOA. Normal controls exhibited homophonic priming, whereas mild AD and MCI groups exhibited tonal inhibition effects.ConclusionThe speed of Chinese language cognitive processing decreased in mild AD and MCI patients. The phonological encoding and accessing ability may be impaired in mild AD and MCI.

Study of phonological encoding of Chinese disyllabic compound words in patients with mild cognitive impairment / 中国康复理论与实践

@#ObjectiveTo explore the characteristics of phonological encoding of Chinese disyllabic compound words in patients with mild cognition impairment(MCI). Methods10 patients with MCI and 10 normal controls who matched with the age, gender, level of education and handedness performed homophone judgment task. In this task, a picture with a disyllabic compound name was presented, after 100 ms of the presentation there would be a Chinese character below the picture. Subjects were asked to judge whether one of the morpheme in the picture name was homophonic to the character. The reaction time and error ratio were analyzed statistically. ResultsIn the normal controls, the reaction time for the second constituents was shorter than that for the first constituents, while there were no difference between the first and second constituents reaction time in MCI patients. The error ratio of the first and second constituents showed no difference in normal controls, but MCI patients made more error rate for the first constituents. ConclusionAs the heathy elderly,the MCI patients have same pattern in phonological coding of Chinese disyllabic compound words, but much slower in activation speed, indicating the impairment of semantic memory and phonological activation in patients with MCI.

Sustained attention for the patients with mild cognitive impairment and mild Alzheimer's disease / 中国康复理论与实践

@#ObjectiveTo deter mine the sustained attention function of the patients with mild Alzheimer's disease(AD) and mild cognitive impairment(MCI).Methods10 patients with MCI, 10 with mild AD and other 10 healthy elderly controls were tested with Continuous Performance Task(CPT) aimed to assess sustained attention. ResultsCompared with the normal controls, the mild AD patients reacted very more slowly(P<0.001), missed more targets(P<0.05), while that the MCI patients did was as well as the control group. ConclusionThe mild AD patients shows impairment in sustained attention function, but the MCI patients shows a preserved ability of sustained attention function.

Memory deficit for the patients with mild cognitive impairment:A functional magnetic resonance imaging study / 中国康复理论与实践

@#ObjectiveTo provide the early diagnosis of Alzheimer\'s disease(AD), the memory in the patients with mild cognitive impairment(MCI) was detected under the functional magnetic resonance imaging(fMRI), combined with the behavioral experiment.Methods9 patients with MCI and 9 controls matched for the age, gender, level of education and handedness performed encoding and retrieval of nonsense line drawings, presented visually while the MR machine was scanning. ResultsCompared with the controls, the patients manifested longer reaction time and lower correct ratio. The patients\' brain activation showed: the first episode of encoding of nonsense line drawings elicited distributed activation in bilateral dorsal lateral frontal lobes, left parahippocampus, bilateral temporal-occipital conjunction, parietal lobes and visual cortex in the control subjects. While these activations decreased in the second episode of encoding of the same stimuli, much stronger activation was found in most same areas during the retrieval phase except for the right parietal lobe, in which the patients showed stronger activation. Moreover, activation in the anterior cingulate cortex was observed only in the retrieval phase. The patients showed weaker and smaller activation in almost all activation areas during all tasks in the normal subjects. ConclusionThe patients with MCI have the deficit in memory. The examination of encoding and retrieval of nonsense line drawings by means of the behavioral experiment and fMRI test can offer a powerful reference for the early diagnosis of AD.

Calculation ability in mild cognitive impairment: A functional magnetic resonance imaging study / 中国康复理论与实践

@#ObjectiveTo explore the early diagnosis of Alzheimer's disease (AD),the arithmetic calculation ability in the patients with mild cognitive impairment (MCI) was detected under the functional magnetic resonance imaging (fMRI),combined with the neuropsychological test.Methods8 patients with MCI and 9 controls matched for the age, gender, level of education and handedness performed the subtraction of two digits presented visually while the MR machine was scanning. The raw data of the fMRI were processed with the software AFNI. The reaction time and correct ratio were analyzed with the statistical software Excel.ResultsCompared with the controls, the patients manifested longer reaction time and lower correct ratio. The patients' brain activation showed significant decrease in the inferior frontal lobe,temporal neocortex and inferior parietal area mainly in the left hemisphere. On the contrary, the activation intensity and extension in the right inferior frontal lobe were increased as compensation.ConclusionsThe patients with MCI have the deficit in calculation ability. The examination of the calculation by means of the cognitive neuropsychology and fMRI test can offer a powerful reference for the early diagnosis of AD.