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S5‐02‐04: Disruption of functional connectivity in clinically normal older adults harboring amyloid burden
Author(s) -
Hedden Trey
Publication year - 2010
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.2010.05.525
Subject(s) - dementia , posterior cingulate , clinical dementia rating , pittsburgh compound b , magnetic resonance imaging , neuroimaging , functional magnetic resonance imaging , neuroscience , medicine , amyloid (mycology) , voxel , psychology , pathology , radiology , disease
reflect the regionally distributed effects of healthy aging from MCI and AD. Methods: Applications of multivariate network analyses using the Scaled Subprofile Model (SSM; Moeller et al., 1987) with MRI voxelbased morphometry (VBM) will be presented in studies of healthy aging, amnestic MCI, and AD. As a modified form of principal component analysis, the SSM produces regional patterns and corresponding subject scores that reflect an individual’s pattern expression. Bootstrap re-sampling is performed to determine robust regional contributions to the patterns. Results: SSM analyses with MRI VBM have identified regionally distributed patterns of brain changes associated with healthy aging that show reproducible regional features across samples, with regions in the prefrontal cortex appearing most consistently reduced. Application of this MRI multivariate network analysis method in young and old non-human primates further supports the preferential reduction of prefrontal cortex, in a model of healthy aging in which the full complement of AD pathology does not occur. The identified age-related SSM VBM patterns differ from the SSM pattern reflecting the continuum of clinical severity from normal to amnestic MCI to AD, in which medial and lateral temporal reductions are prominent. In addition, greater expression of this AD-related pattern was associated with the subsequent conversion to dementia in individuals with amnestic MCI. Conclusions: Together, these findings illustrate the potential for using multivariate analyses, like SSM, as a complement to univariate analysis methods to characterize regionally distributed brain changes associated with healthy and pathological aging. The use of this analytic approach may enhance early detection and has the potential to aid in the evaluation of treatments in human and non-human animal models of aging and AD.