title: Neurophysiological assessment of Alzheimer's disease individuals by a single electroencephalographic marker.
abstract: Here we presented a single electroencephalographic (EEG) marker for a neurophysiological assessment of Alzheimer's disease (AD) patients already diagnosed by current guidelines. The ability of the EEG marker to classify 127 AD individuals and 121 matched cognitively intact normal elderly (Nold) individuals was tested. Furthermore, its relationship to AD patients' cognitive status and structural brain integrity was examined. Low-resolution brain electromagnetic tomography (LORETA) freeware estimated cortical sources of resting state eyes-closed EEG rhythms. The EEG marker was defined as the ratio between the activity of parieto-occipital cortical sources of delta (2-4 Hz) and low-frequency alpha (8-10.5 Hz) rhythms. Results showed 77.2% of sensitivity in the recognition of the AD individuals; 65% of specificity in the recognition of the Nold individuals; and 0.75 of area under the receiver-operating characteristic curve. Compared to the AD subgroup with the EEG maker within one standard deviation of the Nold mean (EEG-), the AD subgroup with EEG+ showed lower global cognitive status, as revealed by Mini-Mental State Evaluation score, and more abnormal values of white-matter and cerebrospinal fluid normalized volumes, as revealed by structural magnetic resonance imaging. We posit that cognitive and functional status being equal, AD patients with EEG+ should receive special clinical attention due to a neurophysiological "frailty". EEG+ label can be also used in clinical trials (i) to form homogeneous groups of AD patients diagnosed by current guidelines and (ii) as end-point to evaluate intervention effects.
authors.affiliation: IRCCS San Raffaele Pisana, Rome, Italy.|Department of Physiology and Pharmacology, University of Rome "La Sapienza", Rome, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Lizio
authors.affiliation: IRCCS San Raffaele Pisana, Rome, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Del Percio
authors.affiliation: IRCCS SDN, Naples, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Marzano
authors.affiliation: IRCCS SDN, Naples, Italy.|Department of Studies of Institutions and Territorial Systems, University of Naples Parthenope, Naples, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Soricelli
authors.affiliation: Brain Dynamics, Cognition and Complex Systems Research Center, Istanbul Kültür University, Istanbul, Turkey.|Department of Neurosciences, Brain Dynamics Multidisciplinary Research Center, Department of Neurology, Dokuz Eylül University, Izmir, Turkey.
authors.forename: Görsev G
authors.initials: GG
authors.lastname: Yener
authors.affiliation: Brain Dynamics, Cognition and Complex Systems Research Center, Istanbul Kültür University, Istanbul, Turkey.
authors.forename: Erol
authors.initials: E
authors.lastname: Başar
authors.affiliation: Department of Neurology, Ospedali Riuniti, Foggia, Italy.
authors.forename: Ciro
authors.initials: C
authors.lastname: Mundi
authors.affiliation: Department of Neurology, Ospedali Riuniti, Foggia, Italy.
authors.forename: Salvatore
authors.initials: S
authors.lastname: De Rosa
authors.affiliation: Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy.
authors.forename: Antonio Ivano
authors.initials: AI
authors.lastname: Triggiani
authors.affiliation: IRCCS Oasi, Troina (Enna), Italy.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Ferri
authors.affiliation: Service of Clinical Neurophysiology (DiNOGMI; DipTeC), IRCCS AOU S Martino-IST, Genoa, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Arnaldi
authors.affiliation: Service of Clinical Neurophysiology (DiNOGMI; DipTeC), IRCCS AOU S Martino-IST, Genoa, Italy.
authors.forename: Flavio Mariano
authors.initials: FM
authors.lastname: Nobili
authors.affiliation: Department of Physiology and Pharmacology, University of Rome "La Sapienza", Rome, Italy.
authors.forename: Susanna
authors.initials: S
authors.lastname: Cordone
authors.affiliation: Department of Physiology and Pharmacology, University of Rome "La Sapienza", Rome, Italy.
authors.forename: Susanna
authors.initials: S
authors.lastname: Lopez
authors.affiliation: Department of Physiology and Pharmacology, University of Rome "La Sapienza", Rome, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Carducci
authors.affiliation: Department of Physiology and Pharmacology, University of Rome "La Sapienza", Rome, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Santi
authors.affiliation: Dipartimento Emergenza e Trapianti d'Organi (D.E.T.O), University of Bari, Bari, Italy.
authors.forename: Loreto
authors.initials: L
authors.lastname: Gesualdo
authors.affiliation: IRCCS San Raffaele Pisana, Rome, Italy.|Department of Geriatrics, Neuroscience & Orthopedics, Institute of Neurology, Catholic University, Rome, Italy.
authors.forename: Paolo M
authors.initials: PM
authors.lastname: Rossini
authors.affiliation: LENITEM (Laboratory of Epidemiology, Neuroimaging and Telemedicine), IRCCS Centro "S. Giovanni di Dio-F.B.F.", Brescia, Italy.
authors.forename: Enrica
authors.initials: E
authors.lastname: Cavedo
authors.affiliation: LENITEM (Laboratory of Epidemiology, Neuroimaging and Telemedicine), IRCCS Centro "S. Giovanni di Dio-F.B.F.", Brescia, Italy.|Memory Clinic and LANVIE - Laboratory of Neuroimaging of Aging, University Hospitals and University of Geneva, Geneva, Switzerland.
authors.forename: Margherita
authors.initials: M
authors.lastname: Mauri
authors.affiliation: LENITEM (Laboratory of Epidemiology, Neuroimaging and Telemedicine), IRCCS Centro "S. Giovanni di Dio-F.B.F.", Brescia, Italy.|Memory Clinic and LANVIE - Laboratory of Neuroimaging of Aging, University Hospitals and University of Geneva, Geneva, Switzerland.
authors.forename: Giovanni B
authors.initials: GB
authors.lastname: Frisoni
authors.affiliation: IRCCS San Raffaele Pisana, Rome, Italy.|Department of Physiology and Pharmacology, University of Rome "La Sapienza", Rome, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Babiloni
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000503:physiopathology*; D015415:Biomarkers; D001931:Brain Mapping; D016022:Case-Control Studies; D003072:Cognition Disorders / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007558:Italy; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009778:Occipital Lobe / Q000503:physiopathology*; D012372:ROC Curve; D012146:Rest; D014421:Turkey
chemical_list: D015415:Biomarkers
keywords: Alpha rhythms; Alzheimer’s disease; delta rhythms; electroencephalography; low resolution brain electromagnetic tomography (LORETA); neurophysiological assessment