MRI patterns of atrophy associated with progression to AD in amnestic mild cognitive impairment

Department of Radiology, Mayo Clinic, 200 1st St SW, Rochester, MN 55905, USA.
Neurology (Impact Factor: 8.3). 03/2008; 70(7):512-20. DOI: 10.1212/01.wnl.0000280575.77437.a2
Source: PubMed

ABSTRACT To compare the patterns of gray matter loss in subjects with amnestic mild cognitive impairment (aMCI) who progress to Alzheimer disease (AD) within a fixed clinical follow-up time vs those who remain stable.
Twenty-one subjects with aMCI were identified from the Mayo Clinic Alzheimer's research program who remained clinically stable for their entire observed clinical course (aMCI-S), where the minimum required follow-up time from MRI to last follow-up assessment was 3 years. These subjects were age- and gender-matched to 42 aMCI subjects who progressed to AD within 18 months of the MRI (aMCI-P). Each subject was then age- and gender-matched to a control subject. Voxel-based morphometry (VBM) was used to assess patterns of gray matter atrophy in the aMCI-P and aMCI-S groups compared to the control group, and compared to each other.
The aMCI-P group showed bilateral loss affecting the medial and inferior temporal lobe, temporoparietal association neocortex, and frontal lobes, compared to controls. The aMCI-S group showed no regions of gray matter loss when compared to controls. When the aMCI-P and aMCI-S groups were compared directly, the aMCI-P group showed greater loss in the medial and inferior temporal lobes, the temporoparietal neocortex, posterior cingulate, precuneus, anterior cingulate, and frontal lobes than the aMCI-S group.
The regions of loss observed in subjects with amnestic mild cognitive impairment (aMCI) who progressed to Alzheimer disease (AD) within 18 months of the MRI are typical of subjects with AD. The lack of gray matter loss in subjects with aMCI who remained clinically stable for their entire observed clinical course is consistent with the notion that patterns of atrophy on MRI at baseline map well onto the subsequent clinical course.

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Available from: Maria Shiung, Aug 26, 2015
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    • "Advanced automated segmentation techniques, such as voxel based morphometry, allow quantification of grey and white matter volumes using magnetic resonance imaging (MRI) [26]. Grey matter loss is related to progressive mild cognitive impairment (MCI) and conversion to dementia in the MCI group [9] [17] [27]. Global and regional grey matter volume measurements are now crucial biomarkers in detecting neuronal loss and progression of cognitive decline. "
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    • "Medial temporal regions including the entorhinal cortex and amygdala are also decreased in volume in MCI patients who later develop AD. Similarly, atrophy of the temporal and frontal lobes, the temporoparietal cortices, anterior and posterior cingulate gyrus, and precuneus are associated with a 3-year progression from MCI to AD [34]. Among AD patients, hippocampal atrophy occurs first, followed by atrophy of the cingulum bundle and the uncinate fasciculus [35]. "
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