title: Brain neural synchronization and functional coupling in Alzheimer's disease as revealed by resting state EEG rhythms.
abstract: Alzheimer's disease (AD) is the most common type of neurodegenerative disorder, typically causing dementia along aging. AD is mainly characterized by a pathological extracellular accumulation of amyloid-beta peptides that affects excitatory and inhibitory synaptic transmission, inducing aberrant patterns in neuronal circuits. Growing evidence shows that AD targets cortical neuronal networks related to cognitive functions including episodic memory and visuospatial attention. This is partially reflected by the abnormal mechanisms of cortical neural synchronization and coupling that generate resting state electroencephalographic (EEG) rhythms. The cortical neural synchronization is typically indexed by EEG power density. The EEG coupling between electrode pairs probes functional (inter-relatedness of EEG signals) and effective (casual effect from one over the other electrode) connectivity. The former is typically indexed by synchronization likelihood (linear and nonlinear) or spectral coherence (linear), the latter by granger causality or information theory indexes. Here we reviewed literature concerning EEG studies in condition of resting state in AD and mild cognitive impairment (MCI) subjects as a window on abnormalities of the cortical neural synchronization and functional and effective connectivity. Results showed abnormalities of the EEG power density at specific frequency bands (<12Hz) in the MCI and AD populations, associated with an altered functional and effective EEG connectivity among long range cortical networks (i.e. fronto-parietal and fronto-temporal). These results suggest that resting state EEG rhythms reflect the abnormal cortical neural synchronization and coupling in the brain of prodromal and overt AD subjects, possibly reflecting dysfunctional neuroplasticity of the neural transmission in long range cortical networks.
authors: Department of Physiology and Pharmacology, University of Rome "La Sapienza", Rome, Italy; Department of Neuroscience, IRCCS San Raffaele Pisana, Rome, Italy. Electronic address: claudio.babiloni@uniroma1.it.
authors: Claudio
authors: C
authors: Babiloni
authors: Department of Neuroscience, IRCCS San Raffaele Pisana, Rome, Italy.
authors: Roberta
authors: R
authors: Lizio
authors: IRCCS "SDN", Naples, Italy.
authors: Nicola
authors: N
authors: Marzano
authors: Department of Neuroscience and Imaging, University G. D'Annunzio, Chieti, Italy.
authors: Paolo
authors: P
authors: Capotosto
authors: IRCCS "SDN", Naples, Italy; Department of Studies of Institutions and Territorial Systems, University of Naples Parthenope, Naples, Italy.
authors: Andrea
authors: A
authors: Soricelli
authors: Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy.
authors: Antonio Ivano
authors: AI
authors: Triggiani
authors: Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy.
authors: Susanna
authors: S
authors: Cordone
authors: Department of Emergency and Transplantation of Organs, University of Bari, Bari, Italy.
authors: Loreto
authors: L
authors: Gesualdo
authors: Department of Neuroscience, IRCCS San Raffaele Pisana, Rome, Italy.
authors: Claudio
authors: C
authors: Del Percio
mesh_terms: D000544:Alzheimer Disease / Q000473:pathology*; D002540:Cerebral Cortex / Q000503:physiopathology*; D060825:Cognitive Dysfunction / Q000473:pathology; D003344:Cortical Synchronization / Q000502:physiology*; D004569:Electroencephalography; D006801:Humans; D012146:Rest
keywords: Alzheimer's disease; Drug treatments; Electroencephalography (EEG)