Abnormalities of cortical neural synchronization mechanisms in patients with dementia due to Alzheimer's and Lewy body diseases: an EEG study

Publication date: July 2017
Source:Neurobiology of Aging, Volume 55
Author(s): Claudio Babiloni, Claudio Del Percio, Roberta Lizio, Giuseppe Noce, Susanna Cordone, Susanna Lopez, Andrea Soricelli, Raffaele Ferri, Maria Teresa Pascarelli, Flavio Nobili, Dario Arnaldi, Dag Aarsland, Francesco Orzi, Carla Buttinelli, Franco Giubilei, Marco Onofrj, Fabrizio Stocchi, Paola Stirpe, Peter Fuhr, Ute Gschwandtner, Gerhard Ransmayr, Georg Caravias, Heinrich Garn, Fabiola Sorpresi, Michela Pievani, Giovanni B. Frisoni, Fabrizia D'Antonio, Carlo De Lena, Bahar Güntekin, Lutfu Hanoğlu, Erol Başar, Görsev Yener, Derya Durusu Emek-Savaş, Antonio Ivano Triggiani, Raffaella Franciotti, Maria Francesca De Pandis, Laura Bonanni
The aim of this retrospective exploratory study was that resting state eyes-closed electroencephalographic (rsEEG) rhythms might reflect brain arousal in patients with dementia due to Alzheimer's disease dementia (ADD), Parkinson's disease dementia (PDD), and dementia with Lewy body (DLB). Clinical and rsEEG data of 42 ADD, 42 PDD, 34 DLB, and 40 healthy elderly (Nold) subjects were available in an international archive. Demography, education, and Mini–Mental State Evaluation score were not different between the patient groups. Individual alpha frequency peak (IAF) determined the delta, theta, alpha 1, alpha 2, and alpha 3 frequency bands. Fixed beta 1, beta 2, and gamma bands were also considered. rsEEG cortical sources were estimated by means of the exact low-resolution brain electromagnetic source tomography and were then classified across individuals, on the basis of the receiver operating characteristic curves. Compared to Nold, IAF showed marked slowing in PDD and DLB and moderate slowing in ADD. Furthermore, all patient groups showed lower posterior alpha 2 source activities. This effect was dramatic in ADD, marked in DLB, and moderate in PDD. These groups also showed higher occipital delta source activities, but this effect was dramatic in PDD, marked in DLB, and moderate in ADD. The posterior delta and alpha sources allowed good classification accuracy (approximately 0.85–0.90) between the Nold subjects and patients, and between ADD and PDD patients. In quiet wakefulness, delta and alpha sources unveiled different spatial and frequency features of the cortical neural synchronization underpinning brain arousal in ADD, PDD, and DLB patients. Future prospective cross-validation studies should test these rsEEG markers for clinical applications and drug discovery.



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