Mild cognitive impairment (part 1): clinical characteristics and predictors of dementia

Abstract

Objective: To critically review and evaluate existing knowledge on the conceptual limits and clinical usefulness of the diagnosis of mild cognitive impairment (MCI) and the neuropsychological assessment and short-and long-term prognosis thereof. Methods: We conducted a systematic search of the PubMed and Web of Science electronic databases, limited to articles published in English between 1999 and 2012. Based on the search terms mild cognitive impairment or MCI and epidemiology or diagnosis, we retrieved 1,698 articles, of which 248 were critically eligible (cross-sectional and longitudinal studies); the abstracts of the remaining 1,450 articles were also reviewed. Results: A critical review on the MCI construct is provided, including conceptual and diagnostic aspects; epidemiological relevance; clinical assessment; prognosis; and outcome. The distinct definitions of cognitive impairment, MCI included, yield clinically heterogeneous groups of individuals. Those who will eventually progress to dementia may present with symptoms consistent with the definition of MCI; conversely, individuals with MCI may remain stable or return to normal cognitive function. Conclusion: On clinical grounds, the cross-sectional diagnosis of MCI has limited prognostic relevance. The characterization of persistent and/or progressive cognitive deficits over time is a better approach for identification of cases at the pre-dementia stages, particularly if these cognitive abnormalities are consistent with the natural history of incipient Alzheimer's disease.

Automated tests for diagnosing and monitoring cognitive impairment: a diagnostic accuracy review

“…For example, guidelines suggest that the decision of whether or not to investigate for possible mild cognitive impairment or dementia is influenced by cognitive test scores (e.g. in the Mini-Mental State Examination, the threshold for mild Alzheimer's disease is a score of 21-26, whereas the threshold for moderate Alzheimer's disease is a score of [10][11][12][13][14][15][16][17][18][19][20].…”

“…[17][18][19][20] The diagnosis of MCI is complicated by the fact that complaints of memory loss in people over the age of 65 years are common. 21 Some of the indicators of dementia, such as a reduction in activities of daily living, decreased attention or ability to plan, are absent in people with MCI.…”

A Contribuição Da Avaliação Neuropsicológica Para O Diagnóstico De Comprometimento Cognitivo Leve (Ccl): Questões Metodológicas

“…Neste contexto, estudos recentes incluíram prejuízos em outros domínios cognitivos com inclinação para uma evolução à demência não-Alzheimer (Pa et al, 2009;Forlenza et al, 2013;Petersen et al, 2014 Pela carência de definição clínica e entendimento, para não cair no binário entre presença ou não de demência, estudos buscam estudar o processo (Petersen et al, 2014). Considerar apenas a dicotomia amnéstico e não-amnéstico pode provocar um total esquecimento dos outros déficits que não envolvam a memória (linguagem, função executiva e habilidades visuoespaciais, atenção, entre outras) e, assim, não capturar a heterogeneidade do CCL (Clark et al, 2013 (Kral 1962(Kral , 1966 …”

“…esquecimento benigno da senescência, comprometimento da memória associado à idade, declínio cognitivo associado à idade, comprometimento cognitivo sem demência chegando, finalmente, ao conceito de CCL (Charchat-Fichman, 2003;Crook et al, 2013;Forlenza et al, 2013;Petersen et al, 2014).…”

“…A avaliação neuropsicológica tem um papel fundamental no estabelecimento dos seus critérios diagnóstico. Apesar da importância da avaliação cognitiva, diferentes dificuldades metodológicas vêm sendo apresentadas na literatura conforme descrito na revisão recente de Petersen e colaboradores (2014 (Winblad et al, 2004;Yassuda et al, 2009;Petersen et al, 2009;Ladeira, Diniz, Nunes & Forlenza, 2009;Clark et al, 2013;Damin, 2011;Forlenza et al, 2013;O'Caoimh et al, 2013;de Paula et al, 2013;Petersen et al, 2014). …”