title: Cortical connectivity and memory performance in cognitive decline: A study via graph theory from EEG data.
abstract: Functional brain abnormalities including memory loss are found to be associated with pathological changes in connectivity and network neural structures. Alzheimer's disease (AD) interferes with memory formation from the molecular level, to synaptic functions and neural networks organization. Here, we determined whether brain connectivity of resting-state networks correlate with memory in patients affected by AD and in subjects with mild cognitive impairment (MCI). One hundred and forty-four subjects were recruited: 70 AD (MMSE Mini Mental State Evaluation 21.4), 50 MCI (MMSE 25.2) and 24 healthy subjects (MMSE 29.8). Undirected and weighted cortical brain network was built to evaluate graph core measures to obtain Small World parameters. eLORETA lagged linear connectivity as extracted by electroencephalogram (EEG) signals was used to weight the network. A high statistical correlation between Small World and memory performance was found. Namely, higher Small World characteristic in EEG gamma frequency band during the resting state, better performance in short-term memory as evaluated by the digit span tests. Such Small World pattern might represent a biomarker of working memory impairment in older people both in physiological and pathological conditions.
authors.affiliation: Brain Connectivity Laboratory, IRCCS San Raffaele Pisana, Rome, Italy. Electronic address: fabrizio.vecchio@uniroma1.it.
authors.forename: F
authors.initials: F
authors.lastname: Vecchio
authors.affiliation: Brain Connectivity Laboratory, IRCCS San Raffaele Pisana, Rome, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Miraglia
authors.affiliation: Institute of Neurology, Department of Geriatrics, Neuroscience & Orthopedics, Catholic University, Policlinic A. Gemelli, Rome, Italy; Neuropsychological Center, Catholic University, Rome, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Quaranta
authors.affiliation: Brain Connectivity Laboratory, IRCCS San Raffaele Pisana, Rome, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Granata
authors.affiliation: Brain Connectivity Laboratory, IRCCS San Raffaele Pisana, Rome, Italy.
authors.forename: R
authors.initials: R
authors.lastname: Romanello
authors.affiliation: Institute of Neurology, Department of Geriatrics, Neuroscience & Orthopedics, Catholic University, Policlinic A. Gemelli, Rome, Italy; Neuropsychological Center, Catholic University, Rome, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Marra
authors.affiliation: IRCCS Centro Neurolesi Bonino-Pulejo, Messina, Italy.
authors.forename: P
authors.initials: P
authors.lastname: Bramanti
authors.affiliation: Brain Connectivity Laboratory, IRCCS San Raffaele Pisana, Rome, Italy; Institute of Neurology, Department of Geriatrics, Neuroscience & Orthopedics, Catholic University, Policlinic A. Gemelli, Rome, Italy.
authors.forename: P M
authors.initials: PM
authors.lastname: Rossini
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000150:complications*; D000704:Analysis of Variance; D001931:Brain Mapping; D058256:Brain Waves / Q000502:physiology*; D002540:Cerebral Cortex / Q000473:pathology / Q000503:physiopathology*; D060825:Cognitive Dysfunction / Q000150:complications*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008569:Memory Disorders / Q000209:etiology* / Q000473:pathology*; D008609:Mental Status Schedule; D009415:Nerve Net / Q000473:pathology / Q000503:physiopathology; D009483:Neuropsychological Tests; D014706:Verbal Learning
keywords: Alzheimer and MCI; EEG and alpha band; eLORETA; functional connectivity; graph theory; memory