Mild cognitive impairment

McGill Center for Studies in Aging, Douglas Hospital, Montréal, Quebec, Canada.
The Lancet (Impact Factor: 45.22). 05/2006; 367(9518):1262-70. DOI: 10.1016/S0140-6736(06)68542-5
Source: PubMed


Mild cognitive impairment is a syndrome defined as cognitive decline greater than expected for an individual's age and education level but that does not interfere notably with activities of daily life. Prevalence in population-based epidemiological studies ranges from 3% to 19% in adults older than 65 years. Some people with mild cognitive impairment seem to remain stable or return to normal over time, but more than half progress to dementia within 5 years. Mild cognitive impairment can thus be regarded as a risk state for dementia, and its identification could lead to secondary prevention by controlling risk factors such as systolic hypertension. The amnestic subtype of mild cognitive impairment has a high risk of progression to Alzheimer's disease, and it could constitute a prodromal stage of this disorder. Other definitions and subtypes of mild cognitive impairment need to be studied as potential prodromes of Alzheimer's disease and other types of dementia.

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Available from: Harald J Hampel, Jul 25, 2014
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    • "Tel.: +34 92621532; Fax: +34 927256202; E-mail: education level, but which creates little to no interference with activities of daily life [1]. According to this definition, MCI has neither a specific outcome nor a specific etiology [2]. "
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    ABSTRACT: Background and objective: Current evidence shows that numerous classic vascular risk factors (VRF) contribute to mild cognitive impairment (MCI), but the effects of emerging VRFs are less well-known. Using a comprehensive approach, we assessed the frequency and strength of association between MCI and classic VRFs, subclinical markers of atherosclerosis (cystatin C, lipoprotein(a), high-sensitivity C-reactive protein, and intima-media thickness) and white matter hyperintensities (WMH). Methods: In this case-control study of consecutive MCI patients and cognitively normal controls, subjects underwent clinical and neuropsychological examinations, laboratory analyses, a carotid duplex scan, and a brain magnetic resonance imaging scan. Results: The study included 105 patients with amnestic MCI (aMCI): 24 with single domain amnestic MCI, 81 with multiple domain amnestic MCI, and 76 controls. Compared to controls, patients with aMCI were significantly older and had higher rates of arterial hypertension, atrial fibrillation, and depression. They also had a larger intima-media thickness and higher load of WMHs, both periventricular (WMHpv) and subcortical (WMHsc). In the adjusted analysis, all variables except WMHsc displayed a significant association with aMCI. Body mass index exerted a protective effect. Conclusions: Our findings suggest a direct association between aMCI and age, hypertension, atrial fibrillation depression, intima-media thickness, and WMHpv. Body mass index has a protective effect on this MCI subtype.
    Journal of Alzheimer's disease: JAD 10/2014; 44(2). DOI:10.3233/JAD-141770 · 4.15 Impact Factor
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    • "The objective of this review is to explore the utility of using transcranial ultrasound to diagnose AD, especially its preclinical or mild clinical stages of mild cognitive impairment (MCI). However, it is not clear whether MCI, and specifically its amnestic subtype, represents a translational stage of evolving dementia or is just an additional risk factor for AD [10]. We also discuss whether there is a special transcranial Doppler sonography (TCD) pattern of circulation impairment in AD and MCI compared with VaD and healthy control subjects. "
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    ABSTRACT: Alzheimer's disease (AD) is a progressive, neurodegenerative disease characterized by an increasing incidence. One of the pathologic processes that underlie this disorder is impairment of brain microvasculature. Transcranial ultrasound is a non-invasive examination of cerebral blood flow that can be employed as a simple and useful screening tool for assessing the vascular status of brain circulation in preclinical and clinical stages of AD. The objective of this review is to explore the utility of using a transcranial ultrasound to diagnose AD. With transcranial ultrasound, the most frequently studied parameters are cerebral blood flow velocities and pulsatility indices, cerebrovascular reserve capacity, and cerebral microembolization. On the basis of current knowledge, we recommend using as a transcranial Doppler sonography screening method of choice the assessment of cerebrovascular reserve capacity with breath-holding test.
    Journal of Alzheimer's disease: JAD 10/2014; 42. DOI:10.3233/JAD-141803 · 4.15 Impact Factor
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    • "Fifth, classifying individuals in provisional MCI status requires assessments that (a) differentiate normal aging decrements from those prodromal for dementia, (b) produce repeatable (stable) status over longitudinal time, (c) are sensitive to early transitions that emerge during the study period, or (d) are associated with eventual conversion to AD or a related disorder. Finally, MCI classification schemes can be characterized by the extent to which they fulfill these validityrelated process and outcome criteria (e.g., Gauthier et al., 2006; Dolcos et al., 2012). "
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    ABSTRACT: Objective: Research has reported associations among selected genetic susceptibility biomarkers and risk of (a) normal cognitive aging decrements, (b) established mild cognitive impairment (MCI), and (c) sporadic Alzheimer's disease (AD). In focusing on the transitional normal-to-early MCI phase, we examine associations among three theoretically relevant polymorphisms (APOE [rs429358, rs7412], BDNF [rs6265], COMT [rs4680]) and both baseline cognitive status (MCI vs. normal aging) and two-wave (four-year) longitudinal stability or change profiles. The latter included three profiles: (a) stable as normal aging, (b) stable or chronic impairment (MCI-to-MCI), and (c) emergence of impairment (normal-to-MCI). Method: Genotyped older adults (n = 237 at baseline; age range = 64–91; 62% women) from the Victoria Longitudinal Study were examined for (a) independent and interactive associations of three genetic polymorphisms with (b) two objectively classified cognitive status groups (not-impaired controls (NIC) and MCI) at (c) both baseline and across a two-wave (four-year) longitudinal interval. Results: First, logistic regression revealed that the presence of at least one APOE ε4 allele (the risk factor for AD) was linked to greater baseline risk of objective MCI. Second, multinomial logistic regression revealed that (a) the presence of an APOE ε4 allele was associated with an increased risk of 4-year MCI status stability (chronicity), and (b) the COMT homozygous risk genotype (G/G or Val/Val) was associated with an increased risk of both MCI-to-MCI stability (chronicity) and emerging NIC-to-MCI conversion. Discussion: Both chronicity and emergence of objectively classified early cognitive impairment may be genetically heterogeneous phenomena, with influences from a panel of both normal cognitive aging (COMT) and AD-related (APOE) polymorphisms.
    Frontiers in Aging Neuroscience 09/2014; 6:236. DOI:10.3389/fnagi.2014.00236 · 4.00 Impact Factor
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