Article

Criteria for the clinical diagnosis of Alzheimer's disease (AD) were
established in 1984, and they needed to be updated and revised, in vue of the
scientific knowledge acquired over the last decades. METHODS: The National
Institute on Aging (NIA) and the Alzheimer's Association (AA) sponsored a series
of advisory round table meetings to establish a revision of diagnostic and
research criteria for AD. The workgroups reviewed the biomarker, epidemiological,
and neuropsychological evidence, and proposed conceptual frameworks as well as
operational research criteria based on the prevailing scientific evidence to
date. RESULTS: Three preclinical stages of AD were proposed: asymptomatic
amyloidosis, asymptomatic amyloidosis+neurodegeneration,
amyloidosis+neurodegeneration+subtle cognitive decline. The preclinical workgroup
developed recommendations to determine the factors, which best predict the risk
of progression from normal cognition to mild cognitive impairment (MCI) and AD
dementia. It is necessary to refine these models with longitudinal clinical
research studies. The workgroups on MCI and AD dementia sought to ensure that the
revised criteria would be flexible enough to be used by both general healthcare
providers without access to neuropsychological testing, advanced imaging, and
cerebrospinal fluid measures, and specialized investigators involved in research
or in clinical trial studies who would have these tools available. The
symptomatic predementia phase of AD was referred to as MCI due to AD. Core
clinical and cognitive criteria of MCI were proposed, the final set of criteria
for MCI due to AD has four levels of certainty, depending on the presence and
nature of the biomarker findings. Criteria for all-cause dementia and for AD
dementia were presented. Dementia caused by AD were classified in: probable AD
dementia, possible AD dementia, and probable or possible AD dementia with
evidence of the AD pathophysiological process, for use in research settings. The
core clinical criteria for AD dementia will continue to be the cornerstone of the
diagnosis in clinical practice, but biomarker evidence is expected to enhance the
pathophysiological specificity of the diagnosis. CONCLUSIONS: In the revised
criteria, a conceptual distinction is made between AD pathophysiological
processes and clinically observable syndromes. The core clinical criteria of the
recommendations regarding MCI due to AD and AD dementia are intended to guide
diagnosis in the clinical setting whereas the recommendations of the preclinical
AD workgroup are intended purely for research purposes and do not have any
clinical implications. Considerable work is needed to validate the criteria that
use biomarkers and to standardize biomarker analysis for use in community
settings.
CI - Copyright (c) 2012 Elsevier Masson SAS. All rights reserved.

Langue : FRANCAIS