1. Disruption of Semantic Network in Mild Alzheimer’s Disease Revealed by Resting-State fMRI
- Author
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Laura Serra, Mauro DiNuzzo, Silvia Mangia, Marco Bozzali, Bruno Maraviglia, Daniele Mascali, and Federico Giove
- Subjects
Male ,posterior middle temporal gyrus ,Rest ,Middle temporal gyrus ,voxel-wise functional connectivity ,Inferior frontal gyrus ,Neuropsychological Tests ,Biology ,Semantics ,Severity of Illness Index ,Brain mapping ,Article ,semantic control network ,050105 experimental psychology ,Semantic network ,03 medical and health sciences ,0302 clinical medicine ,inferior frontal gyrus ,Alzheimer Disease ,Neural Pathways ,medicine ,Humans ,0501 psychology and cognitive sciences ,Aged ,Brain Mapping ,medicine.diagnostic_test ,Resting state fMRI ,General Neuroscience ,05 social sciences ,Brain ,medicine.disease ,Magnetic Resonance Imaging ,Oxygen ,RC0346 ,Cerebrovascular Circulation ,Female ,Alzheimer's disease ,Functional magnetic resonance imaging ,Alzheimer’s disease ,Neuroscience ,resting-state fMRI ,030217 neurology & neurosurgery - Abstract
Subtle semantic deficits can be observed in Alzheimer's disease (AD) patients even in the early stages of the illness. In this work, we tested the hypothesis that the semantic control network is deregulated in mild AD patients. We assessed the integrity of the semantic control system using resting-state functional magnetic resonance imaging in a cohort of patients with mild AD (n = 38; mean mini-mental state examination = 20.5) and in a group of age-matched healthy controls (n = 19). Voxel-wise analysis spatially constrained in the left fronto-temporal semantic control network identified two regions with altered functional connectivity (FC) in AD patients, specifically in the pars opercularis (POp, BA44) and in the posterior middle temporal gyrus (pMTG, BA21). Using whole-brain seed-based analysis, we demonstrated that these two regions have altered FC even beyond the semantic control network. In particular, the pMTG displayed a wide-distributed pattern of lower connectivity to several brain regions involved in language-semantic processing, along with a possibly compensatory higher connectivity to the Wernicke's area. We conclude that in mild AD brain regions belonging to the semantic control network are abnormally connected not only within the network, but also to other areas known to be critical for language processing.
- Published
- 2018