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IC‐P‐201: Fractional anisotropy differences in attention and default‐mode network areas between healthy aging and Alzheimer's disease
Author(s) -
Luedke Angela,
FernandezRuiz Juan,
Tam Angela,
Garcia Angeles
Publication year - 2013
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.2013.05.200
Subject(s) - fractional anisotropy , precuneus , default mode network , diffusion mri , white matter , posterior cingulate , psychology , region of interest , neuroscience , medicine , audiology , cardiology , cortex (anatomy) , functional magnetic resonance imaging , magnetic resonance imaging , radiology
assessments andMRI scan. The intrinsic connectivity of bilateral hippocampus (seed regions) was measured by the R-fMRI approach at a 3.0 T GE scanner. The correlation coefficient maps of individual participant were generated by cross-correlating each voxel timecourse with the average time course of seed regions. Fisher’s Z-transformation was then performed in the resulting datasets, and data normalized to a standard Talairach space. Voxelwise 2 3 2 ANCOVA analysis was used to examine the main effects and interactive effects of LLD and MCI on the HFC networks in the four groups, after controlling for age, gender, education and gray matter volumes. Results: The main effects of depression on the bilateral HFC was seen in the regions previously implicated in mood regulation, including bilateral dorsolateral prefrontal cortex (DLPFC), dorsomedial prefrontal cortex (DMPFC), thalamus, and dorsal striatum; main effects of MCI on the bilateral HFCs were seen in the default mode, executive control and salience network-related regions (Fig 1a representing right HFC); The interactive effects of depression andMCI on the right HFC network were identified in the bilateral ventromedial PFC, dorsal anterior cingulate cortex, right DLPFC and middle occipital gyrus (Fig 1b). Conclusions: Divergent hippocampal network abnormalities were associated with LLD and MCI, whereas shared and interactive effects of these disorders were also identified. The presence of specific medial temporal lobe-based network dysfunction may increase the vulnerability of individuals with LLD and/or MCI to progress to AD.