title: Alpha-band hypersynchronization in progressive mild cognitive impairment: a magnetoencephalography study.
abstract: People with mild cognitive impairment (MCI) show a high risk to develop Alzheimer's disease (AD; Petersen et al., 2001). Nonetheless, there is a lack of studies about how functional connectivity patterns may distinguish between progressive (pMCI) and stable (sMCI) MCI patients. To examine whether there were differences in functional connectivity between groups, MEG eyes-closed recordings from 30 sMCI and 19 pMCI subjects were compared. The average conversion time of pMCI was 1 year, so they were considered as fast converters. To this end, functional connectivity in different frequency bands was assessed with phase locking value in source space. Then the significant differences between both groups were correlated with neuropsychological scores and entorhinal, parahippocampal, and hippocampal volumes. Both groups did not differ in age, gender, or educational level. pMCI patients obtained lower scores in episodic and semantic memory and also in executive functioning. At the structural level, there were no differences in hippocampal volume, although some were found in left entorhinal volume between both groups. Additionally, pMCI patients exhibit a higher synchronization in the alpha band between the right anterior cingulate and temporo-occipital regions than sMCI subjects. This hypersynchronization was inversely correlated with cognitive performance, both hippocampal volumes, and left entorhinal volume. The increase in phase synchronization between the right anterior cingulate and temporo-occipital areas may be predictive of conversion from MCI to AD.
authors.affiliation: Laboratories of Cognitive and Computational Neuroscience (Complutense University of Madrid-Universidad Politécnica of Madrid) and Department of Basic Psychology II, Complutense University of Madrid (UCM), 28040 Madrid, Spain, meugenia.lopez@ctb.upm.es.
authors.forename: María Eugenía
authors.initials: ME
authors.lastname: López
authors.affiliation: Laboratories of Cognitive and Computational Neuroscience (Complutense University of Madrid-Universidad Politécnica of Madrid) and.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Bruña
authors.affiliation: Laboratories of Cognitive and Computational Neuroscience (Complutense University of Madrid-Universidad Politécnica of Madrid) and Department of Basic Psychology II, Complutense University of Madrid (UCM), 28040 Madrid, Spain.
authors.forename: Sara
authors.initials: S
authors.lastname: Aurtenetxe
authors.affiliation: Laboratories of Cognitive and Computational Neuroscience (Complutense University of Madrid-Universidad Politécnica of Madrid) and Laboratory of Neuroimaging (Universidad Politécnica de Madrid) (National Pedagogic University), Centre for Biomedical Technology (CTB), 28223 Madrid, Spain.
authors.forename: José Ángel
authors.initials: JÁ
authors.lastname: Pineda-Pardo
authors.affiliation: Departments of Neurology and.
authors.forename: Alberto
authors.initials: A
authors.lastname: Marcos
authors.affiliation: Radiology, San Carlos University Hospital, 28040 Madrid, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Arrazola
authors.affiliation: Centre for Prevention of Cognitive Impairment, Madrid Health, 28006, Madrid, Spain, and.
authors.forename: Ana Isabel
authors.initials: AI
authors.lastname: Reinoso
authors.affiliation: Centre for Prevention of Cognitive Impairment, Madrid Health, 28006, Madrid, Spain, and.
authors.forename: Pedro
authors.initials: P
authors.lastname: Montejo
authors.affiliation: Laboratories of Cognitive and Computational Neuroscience (Complutense University of Madrid-Universidad Politécnica of Madrid) and Department of Mathematics, International University of La Rioja (UNIR), 26006 Logroño, Spain.
authors.forename: Ricardo
authors.identifier: http://orcid.org/0000-0003-0646-2962
authors.initials: R
authors.lastname: Bajo
authors.affiliation: Laboratories of Cognitive and Computational Neuroscience (Complutense University of Madrid-Universidad Politécnica of Madrid) and Department of Basic Psychology II, Complutense University of Madrid (UCM), 28040 Madrid, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Maestú
mesh_terms: D000368:Aged; D000513:Alpha Rhythm / Q000502:physiology*; D002540:Cerebral Cortex / Q000503:physiopathology*; D060825:Cognitive Dysfunction / Q000503:physiopathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D009483:Neuropsychological Tests
keywords: MEG; alpha band; anterior cingulate; functional connectivity; mild cognitive impairment; phase locking value