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IC‐P1‐038: Neuroimaging studies on Mild Cognitive Impairment and dementia in a community—implications for clinical practice: The Osaki‐Tajiri Project (1)
Author(s) -
Meguro Kenichi
Publication year - 2008
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2008.05.049
Subject(s) - neuroimaging , dementia , donepezil , cerebral blood flow , medicine , vascular dementia , nuclear medicine , positron emission tomography , psychology , psychiatry , disease
changes in extra-temporal circuitry in amnestic MCI (aMCI), with growing evidence for disruption in parietal and frontal functionality. The concept of MCI has recently evolved to include non-amnestic syndromes (naMCI) so very little is known about functional changes in these subjects. Our objective was to compare fMRI activation in cognitively normal elderly (CN), aMCI, and naMCI subjects. Methods: Twenty-nine CN, 19 aMCI, and 12 naMCI subjects completed a blockdesign recognition memory paradigm at 3.0T. Subjects were instructed to respond to color photographs they recognized from a previous encoding task completed earlier in the same scanning session. The threshold for significance was set at p .001 (uncorrected) for within group analysis of fMRI activation using SPM2. Results: CN subjects activated a network that included the medial and lateral frontal lobes, anterior cingulate, thalamus, posterior hippocampus, fusiform gyrus, posterior cingulate, and lateral temporal-parietal-occipital lobes in a bilaterally symmetric manner (figure). Amnestic MCI subjects activated the same regions (except the thalamus) but with less magnitude. Nonamnestic MCI subjects activated the same regions as CN and aMCI (except the thalamus and posterior cingulate) but with less magnitude still than either CN or aMCI. There were no areas in which the naMCI group showed increased activation compared to aMCI. There were also no areas in which the aMCI and naMCI groups had more activation than CN. Conclusions: The network activated by a recognition memory paradigm is largely similar among CN, aMCI, and naMCI. However, the strength of activation is ordered CN aMCI naMCI. We interpret the decreased activation observed in naMCI on what is nominally a “memory” task to represent non-memory components of the task in the domains of attentional and visuospatial function. IC-P1-038 NEUROIMAGING STUDIES ON MILD COGNITIVE IMPAIRMENT AND DEMENTIA IN A COMMUNITY—IMPLICATIONS FOR CLINICAL PRACTICE: THE OSAKI-TAJIRI PROJECT (1)