Beyond mild cognitive impairment: vascular cognitive impairment, no dementia (VCIND)

Polysomnographic abnormalities in patients with vascular cognitive impairment-no dementia

OBJECTIVES

We aimed to investigate subjective sleep quality and polysomnographic sleep structure features in patients with vascular cognitive impairment-no dementia (VCIND).

METHODS

Fifty-six patients with VCIND, 48 patients with simple stroke (without cognitive impairment), and 48 control subjects were included. The Pittsburgh Sleep Quality Index (PSQI) and polysomnography (PSG) were used to analyze their sleep characteristics. The Montreal Cognitive Assessment (MoCA) was conducted to assess mental state.

RESULTS

Patients with VCIND had higher PSQI scores compared with control subjects and simple stroke patients (P<.01). PSG revealed that patients with VCIND or stroke were more likely to experience prolonged sleep latency (SL), decreased sleep efficiency (SE), increased arousal, and reduced deep sleep and rapid eye movement (REM) sleep than controls. Patients with VCIND had significantly longer SL, increased periodic leg movements in sleep (PLMS), decreased SE, and increased arousal and sleep fragmentation compared to patients with simple stroke (P<.05). In VCIND patients, a significant positive correlation was found between SE and MoCA scores (r=0.632; P<.001), though PSQI, SL, and arousal index were significantly negatively associated with MoCA scores (r=-0.787, -0.740, -0.772, respectively; P<.001 for all).

CONCLUSIONS

VCIND patients had different abnormal sleep features, including decreased SE, increased PLMS, and prolonged SL and sleep fragmentation. Abnormal sleep in VCIND may be associated with cognitive impairment.

Reliability, validity, and optimal cutoff score of the montreal cognitive assessment (changsha version) in ischemic cerebrovascular disease patients of hunan province, china

BACKGROUND/AIMS

The goal of this study was to examine the reliability and validity of the Changsha version of the Montreal Cognitive Assessment (MoCA-CS) in ischemic cerebrovascular disease patients of Hunan Province, China, and to explore the optimal cutoff score for detecting vascular cognitive impairment-no dementia (VCI-ND) and vascular dementia (VD).

METHODS

Three hundred and thirty-eight ischemic cerebrovascular disease patients (131 with normal cognition, 111 with VCI-ND, and 96 with VD) and 132 healthy controls were recruited. All participants accepted examination by the MoCA-CS, Mini-Mental State Examination (MMSE), and other related scales. A detailed neuropsychological battery was used for making a final cognitive diagnosis. SPSS 16.0 statistical software was used for reliability, validity examination, and optimal cutoff score detection.

RESULTS

Cronbach's α of the MoCA-CS was 0.884, and test-retest and interrater reliability of the MoCA-CS were 0.966 and 0.926, respectively. MoCA-CS scores were highly correlated with MMSE scores (r = 0.867) and simplified intelligence quotients (r = 0.822). The results indicate that 1 point should be added for subjects with less than 6 years of education, and that the optimal cutoff score for detecting VCI-ND is 26/27 (sensitivity 96.1%, specificity 75.6%), whereas the optimal cutoff score for detecting VD is 16/17 (sensitivity 92.7%, specificity 96.3%).

CONCLUSION

The MoCA-CS has good reliability and validity, and is a useful cognitive screening instrument for detecting VCI in the Chinese population.

Diagnosing Mild Cognitive Impairment (MCI) in clinical trials: a systematic review

OBJECTIVE

To describe how criteria for amnestic Mild Cognitive Impairment (aMCI) have been operationalised in randomised controlled clinical trials (RCTs).

DESIGN

Systematic review.

INFORMATION SOURCES

EMBASE, PubMed and PSYCHInfo were searched from their inception to February 2012. Electronic clinical trial registries were also searched (February 2012).

STUDY SELECTION

RCTs were included where participant selection was made using Petersen et al-defined aMCI. There was no restriction on intervention type or the outcome tested.

DATA EXTRACTION

For each trial, we extracted information on study design, demographics, exclusion criteria and the operationalisation strategy for the five aMCI diagnostic criteria including: (1) memory complaint, (2) normal general cognitive function, (3) memory impairment, (4) no functional impairment and (5) no dementia.

RESULTS

223 articles and 278 registered trials were reviewed, of which 22 met inclusion criteria. Various methods were applied for operationalising aMCI criteria resulting in variability in participant selection. Memory complaint and assessment of general cognitive function were the most consistently measured criteria. There was large heterogeneity in the neuropsychological methods used to determine memory impairment. It was not possible to assess the impact of these differences on case selection accuracy for dementia prediction. Further limitations include selective and unclear reporting of how each of the criteria was measured.

CONCLUSIONS

The results highlight the urgent need for a standardised approach to map aMCI. Lack of uniformity in clinical diagnosis, however, is not exclusively a problem for MCI but also for other clinical states such as dementia including Alzheimer's disease, Lewy Body, frontotemporal or vascular dementia. Defining a uniform approach to MCI classification, or indeed for any classification concept within the field of dementia, should be a priority if further trials are to be undertaken in the older aged population based on these concepts.

Effect of Western medicine therapy assisted by Ginkgo biloba tablet on vascular cognitive impairment of none dementia

OBJECTIVE

To discuss the clinical effects of Western medicine therapy assisted by Ginkgo biloba tablet (GBT) on patients with vascular cognitive impairment of none dementia (VCIND).

METHODS

A total of 80 patients with VCIND were divided into two groups randomly: Conventional treatment group (control group) and combined treatment group. Conventional treatment group was given conventional treatment with anti-platelet aggregation. In this group, 75 mg aspirin was given three times a day for 3 months. While in combined treatment group, 19.2 mg GBT was given three times a day for 3 months together with conventional treatment (anti-platelet aggregation drugs). Montreal cognitive assessment (MoCA) and transcranial Doppler (TCD) were used to observe changes of cognitive ability and cerebral blood flow in VCIND patients before and after treatment in both groups. Then the clinical data were analyzed so as to compare the efficacy in two groups.

RESULTS

After 3 month-treatment in combined treatment group, the scores of executive ability, attention, abstract, delayed memory, orientation in the MoCA were significantly increased compared with those before treatment and those in control group after treatment. Besides, blood flow velocity of anterior cerebral artery increased significantly than that before treatment and that in control group after treatment.

CONCLUSIONS

GBT tablet can improve the therapeutic efficacy as well improve cognitive ability and cerebral blood flow supply of patients with VCIND.

Plasma microRNA biomarkers for detection of mild cognitive impairment

Early stages of many neurodegenerative diseases, such as Alzheimer's disease, vascular and frontotemporal dementia, and Parkinson's disease, are frequently associated with Mild Cognitive Impairment (MCI). A minimally invasive screening test for early detection of MCI may be used to select optimal patient groups in clinical trials, to monitor disease progression and response to treatment, and to better plan patient clinical care. Here, we examined the feasibility of using pairs of brain-enriched plasma microRNA (miRNA), at least one of which is enriched in synapses and neurites, as biomarkers that could differentiate patients with MCI from age-matched controls. The identified biomarker pairs fall into two sets: the "miR-132 family" (miR-128/miR-491-5p, miR-132/miR-491-5p and mir-874/miR-491-5p) and the "miR-134 family" (miR-134/miR-370, miR-323-3p/miR-370 and miR-382/miR-370). The area under the Receiver-Operating Characteristic curve for the differentiation of MCI from controls using these biomarker pairs is 0.91-0.95, with sensitivity and specificity at 79%-100% (miR-132 family) and 79%-95% (miR-134 family), and p〈0.001. In a separate longitudinal study, the identified miRNA biomarker pairs successfully detected MCI in majority of patients at asymptomatic stage 1-5 years prior to clinical diagnosis. The reported biomarker pairs also appear useful for detecting age-related brain changes. Further testing in a larger study is necessary for validation of these results.

Diagnosis of vascular cognitive impairment and its main categories

OBJECTIVE

A review of current criteria for the diagnosis of categories related with vascular cognitive impairment, in particular the nomenclature, diagnostic criteria, and differential clinical-radiological findings.

DEVELOPMENT

The criteria for the diagnosis of vascular cognitive impairment have evolved, but available criteria were designed basically for differentiating between vascular dementia and dementia due to Alzheimer disease, and for research purposes. Nevertheless, in clinical practice precise elements are required for: 1) Clinical diagnosis of dementia and mild cognitive impairment; 2) Clinical and neuroimaging criteria for identification of the various cerebrovascular lesions associated with cognitive dysfunction, and 3) A formulation of the aetiogenic-pathogenic relationship between cognitive impairment and cerebrovascular lesions. For this reason, a review was carried out on the diagnostic elements of vascular cognitive impairment categories, classification, and their most relevant characteristics. It highlights the characteristic for the diagnosis of multi-infarction dementia, strategic single infarct dementia, small vessel disease with dementia, mixed dementia, and vascular mild cognitive impairment.

CONCLUSIONS

Standardisation is required, by a multidisciplinary expert team, as regards nomenclature and criteria for the diagnosis of the full spectrum associated with vascular cognitive impairment and especially for vascular dementia and its categories.

Risk and Determinants of Dementia in Patients with Mild Cognitive Impairment and Brain Subcortical Vascular Changes: A Study of Clinical, Neuroimaging, and Biological Markers-The VMCI-Tuscany Study: Rationale, Design, and Methodology

Dementia is one of the most disabling conditions. Alzheimer's disease and vascular dementia (VaD) are the most frequent causes. Subcortical VaD is consequent to deep-brain small vessel disease (SVD) and is the most frequent form of VaD. Its pathological hallmarks are ischemic white matter changes and lacunar infarcts. Degenerative and vascular changes often coexist, but mechanisms of interaction are incompletely understood. The term mild cognitive impairment defines a transitional state between normal ageing and dementia. Pre-dementia stages of VaD are also acknowledged (vascular mild cognitive impairment, VMCI). Progression relates mostly to the subcortical VaD type, but determinants of such transition are unknown. Variability of phenotypic expression is not fully explained by severity grade of lesions, as depicted by conventional MRI that is not sensitive to microstructural and metabolic alterations. Advanced neuroimaging techniques seem able to achieve this. Beside hypoperfusion, blood-brain-barrier dysfunction has been also demonstrated in subcortical VaD. The aim of the Vascular Mild Cognitive Impairment Tuscany Study is to expand knowledge about determinants of transition from mild cognitive impairment to dementia in patients with cerebral SVD. This paper summarizes the main aims and methodological aspects of this multicenter, ongoing, observational study enrolling patients affected by VMCI with SVD.

Vascular mild cognitive impairment: concept, definition, and directions for future studies

Vascular mild cognitive impairment (vascular MCI) describes an abnormal condition which is caused by vascular diseases and in which the patient presents with cognitive deficits not severe enough to fit the criteria for dementia (i.e., basic functional autonomy is not lost). As in neurodegenerative MCI, the clinical, neuroimaging, and natural history features of vascular MCI are currently under definition. It is particularly important to identify cognitive impairment of vascular origin during the early stages, as its progression may be slowed or halted by intervening with aggressive treatment of vascular risk factors and diseases. Longitudinal studies on the natural history of vascular MCI, with investigation of the factors responsible for the transition to dementia, are worthy of being planned and carried out.

Linking biological and cognitive aging: toward improving characterizations of developmental time

OBJECTIVES

Chronological age is the most frequently employed predictor in life-span developmental research, despite repeated assertions that it is best conceived as a proxy for true mechanistic changes that influence cognition across time. The present investigation explores the potential that selected functional biomarkers may contribute to the more effective conceptual and operational definitions of developmental time.

METHODS

We used data from the Victoria Longitudinal Study to explore both static and dynamic biological or physiological markers that arguably influence process-specific mechanisms underlying cognitive changes in late life. Multilevel models were fit to test the dynamic coupling between change in theoretically relevant biomarkers (e.g., grip strength, pulmonary function) and change in select cognitive measures (e.g., executive function, episodic and semantic memory).

RESULTS

Results showed that, independent of the passage of developmental time (indexed as years in study), significant time-varying covariation was observed linking corresponding declines for select cognitive outcomes and biological markers.

DISCUSSION

Our findings support the interpretation that cognitive decline is not due to chronological aging per se but rather reflects multiple causal factors from a broad range of biological and physical health domains that operate along the age continuum.

Risk of progression from mild memory impairment to clinically diagnosable Alzheimer's disease in a Japanese community (from the Nakayama Study)

BACKGROUND

Memory impairment has been proposed as the most common early sign of Alzheimer's disease (AD). The aims of this work were to evaluate the risk of progression from mild memory impairment/no dementia (MMI/ND) to clinically diagnosable AD in a community-based prospective cohort and to establish the risk factors for progression from MMI/ND to AD in the elderly.

METHODS

Elderly subjects aged over 65 years were selected from the participants in the first Nakayama study. MMI/ND was defined as memory deficit on objective memory assessment, without dementia, impairment of general cognitive function, or disability in activities of daily living. A total of 104 MMI/ND subjects selected from 1242 community-dwellers were followed longitudinally for five years.

RESULTS

During the five-year follow-up, 11 (10.6%) subjects were diagnosed with AD, five (4.8%) with vascular dementia (VaD), and six (5.8%) with dementia of other etiology. Logistic regression analysis revealed that diabetes mellitus (DM) and a family history of dementia (within third-degree relatives) were positively associated with progression to AD, while no factor was significantly associated with progression to VaD or all types of dementia.

CONCLUSIONS

DM and a family history of dementia were significant risk factors for progression from MMI/ND to clinically diagnosable AD in the elderly in a Japanese community.