期刊名称：Psychologie & NeuroPsychiatrie du vieillissement
印刷版ISSN：1760-1703
电子版ISSN：1950-6988
出版年度：2007
卷号：5
期号：4
页码：269-279
DOI：10.1684/pnv.2007.0087
出版社：John Libbey Eurotext
摘要：Alzheimer’s disease (AD) is characterised by macroscopic cerebral damages which can be studied in vivo with neuroimaging techniques, even at the earliest stage. Studies were conducted in patients with amnestic Mild Cognitive Impairment (MCI) who best represent incipient AD. Right temporo-parietal hypometabolism, assessed by resting-state 18FDG-PET, distinguishes patients who further develop AD from those who remain stable. From the pre-dementia stage of MCI, atrophy of the hippocampal region detected with structural MRI contrasts with functional alteration of the posterior cingulate gyrus measured with 18FDG-PET and SPECT. Results from resting-state fMRI confirm this pattern of functional abnormalities and highlight changes in the hippocampal region functional connectivity, decreased with the posterior cingulate region, and increased with some frontal areas. Altogether with a structural connectivity impairment highlighted by DTI, those results support the hypothesis of a dysconnexion between the hippocampal and the posterior cingulate regions. Finally, activation fMRI data support the hypothesis of a functional compensation involving not only the frontal cortex but also, at the pre-dementia stage, the hippocampal region. Thus, this synthesis focuses on the hypotheses of dysconnexion and functional compensation, suggested to explain the discrepancies between the structural and functional alteration patterns, as well as on relevant results from resting-state fMRI, DTI and activation fMRI studies. Furthermore, this synthesis emphasizes the relevance of neuroimaging for the early detection of AD.
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