Does resting state functional connectivity differ between mild cognitive impairment and early Alzheimer's dementia?
| Autor: | Ramshekhar N. Menon, Sheelakumari Raghavan, Nandini Mohanan, Bejoy Thomas, Shania M. Soman, Chandrsekharan Kesavadas, P.G. Rajesh |
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| Rok vydání: | 2020 |
| Předmět: |
medicine.medical_specialty
Neuropsychological Tests Audiology Correlation 03 medical and health sciences 0302 clinical medicine Alzheimer Disease mental disorders Humans Medicine Dementia Cognitive Dysfunction 030212 general & internal medicine Cognitive impairment Default mode network General linear model Resting state fMRI Recall business.industry Functional connectivity Brain medicine.disease Magnetic Resonance Imaging Cross-Sectional Studies Neurology Neurology (clinical) Nerve Net business human activities 030217 neurology & neurosurgery |
| Zdroj: | Journal of the Neurological Sciences. 418:117093 |
| ISSN: | 0022-510X |
| DOI: | 10.1016/j.jns.2020.117093 |
| Popis: | Purpose This study aimed to investigate differences in functional connectivity (FC) among different resting state networks (RSN) in clinically non-progressive mild cognitive impairment (MCI) and Alzheimer's disease (AD). Methods Using 3T MRI acquired resting-state functional MRI (rs-fMRI), we attempted identification of different RSN using independent component analysis (ICA) in amnestic-MCI, convertors to early AD and age-matched cognitively normal healthy controls. Regions of interest (ROI) that showed significant differences in connectivity on group ICA were selected as seeds for seed-voxel analysis. Group differences in FC for each network-connectivity map were entered into a general linear model with age, gender and total intra-cranial volume (TIV) as covariates. Results In this cross-sectional design 31 HC, 30 MCI and 30 MCI-convertors to early AD were evaluated. Seed-based analysis between AD and controls revealed reduced posterior connectivity within the default mode (DMN), dorsal attention (DAN) and antero-posterior connectivity with sensori-motor (SMN) networks. Reduced cerebellar connectivity of DMN and posterior connectivity within the frontal parietal network (FPN) separated AD from MCI. MCI-control comparisons revealed differences only on ICA. Positive correlation was observed between FC in DMN network clusters with verbal list-learning (r = 0.50) and recall scores (r = 0.51) in AD, the latter additionally demonstrating correlation with SMN clusters (r = 0.50). Conclusions Widespread network hypo-connectivity is apparent in AD as opposed to MCI non-convertors in comparison to controls, along with positive correlation with memory scores. Reduced connectivity involving DMN and FPN helps to differentiate between AD and MCI-nonconvertors to dementia. Longitudinal studies are required into utility of these measures. |
| Databáze: | OpenAIRE |
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