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Structural Connectivity Changes Underlying Altered Working Memory Networks in Mild Cognitive Impairment: A Three-Way Image Fusion Analysis
- Source :
- Journal of neuroimaging 25(4), 634-642 (2014). doi:10.1111/jon.12178
- Publication Year :
- 2014
-
Abstract
- Working memory impairment is among the earliest signs of cognitive decline in Alzheimer's disease (AD) and mild cognitive impairment (MCI). We aimed to study the functional and structural substrate of working memory impairment in early AD dementia and MCI.We studied a group of 12 MCI and AD subjects compared to 12 age- and gender-matched healthy elderly controls using diffusion tensor imaging (DTI), and functional magnetic resonance imaging (fMRI) during a 2-back versus 1-back letter recognition task. We performed a three-way image fusion analysis with joint independent component analysis of cortical activation during working memory, and DTI derived measures of fractional anisotropy (FA) and the mode of anisotropy.We found significant hypoactivation in posterior brain areas and relative hyperactivation in anterior brain areas during working memory in AD/MCI subjects compared to controls. Corresponding independent components from DTI data revealed reduced FA and reduced mode of anisotropy in intracortical projecting fiber tracts with posterior predominance and increased FA and increased mode along the corticospinal tract in AD/MCI compared to controls.Our findings suggest that impairments of structural fiber tract integrity accompany breakdown of posterior and relatively preserved anterior cortical activation during working memory performance in MCI/AD subjects.
- Subjects :
- Male
physiopathology [Cognitive Dysfunction]
pathology [Cognitive Dysfunction]
pathology [Nerve Net]
Multimodal Imaging
methods [Diffusion Tensor Imaging]
methods [Connectome]
methods [Magnetic Resonance Imaging]
physiopathology [Nerve Net]
Connectome
physiopathology [Memory Disorders]
Humans
pathology [Memory Disorders]
Cognitive Dysfunction
ddc:610
physiology [White Matter]
Aged
Aged, 80 and over
Memory Disorders
methods [Multimodal Imaging]
Magnetic Resonance Imaging
White Matter
etiology [Memory Disorders]
Diffusion Tensor Imaging
Memory, Short-Term
Female
Nerve Net
complications [Cognitive Dysfunction]
Subjects
Details
- ISSN :
- 15526569
- Volume :
- 25
- Issue :
- 4
- Database :
- OpenAIRE
- Journal :
- Journal of neuroimaging : official journal of the American Society of Neuroimaging
- Accession number :
- edsair.pmid.dedup....8b191f72fe9c9fe79b94dbbe6ad2d23f