Functional cortical source connectivity of resting state electroencephalographic alpha rhythms shows similar abnormalities in patients with mild cognitive impairment due to Alzheimer's and Parkinson's diseases

WOS: 000427485900009 PubMed ID: 29448151 Objective: This study tested the hypothesis that markers of functional cortical source connectivity of resting state eyes-closed electroencephalographic (rsEEG) rhythms may be abnormal in subjects with mild cognitive impairment due to Alzheimer's (ADMCI) and Parkinson's (PDMCI) diseases compared to healthy elderly subjects (Nold). Methods: rsEEG data had been collected in ADMCI, PDMCI, and Nold subjects (N = 75 for any group). eLORETA freeware estimated functional lagged linear connectivity (LLC) from rsEEG cortical sources. Area under receiver operating characteristic (AUROC) curve indexed the accuracy in the classification of Nold and MCI individuals. Results: Posterior interhemispheric and widespread intrahemispheric alpha LLC solutions were abnormally lower in both MCI groups compared to the Nold group. At the individual level, AUROC curves of LLC solutions in posterior alpha sources exhibited moderate accuracies (0.70-0.72) in the discrimination of Nold vs. ADMCI-PDMCI individuals. No differences in the LLC solutions were found between the two MCI groups. Conclusions: These findings unveil similar abnormalities in functional cortical connectivity estimated in widespread alpha sources in ADMCI and PDMCI. This was true at both group and individual levels. Significance: The similar abnormality of alpha source connectivity in ADMCI and PDMCI subjects might reflect common cholinergic impairment. (C) 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved. H Marie S. Curie ITN-ETN project The present study was developed based on the data of the informal European Consortium PDWAVES and European Consortium of Dementia with Lewy Body. The members and institutional affiliations of the Consortia are reported in the cover page of this manuscript. Dr. Erol Basar passed away due to health problems on October 28th (November 18th 1938-October 28th 2017) in Istanbul, during the editorial processing of this manuscript. Until the end of his life, he had been working to the development of EEG science and its application in Clinical Neurophysiology. He leaves to all us an invaluable scientific legacy in the Science of Brain Rhythms and Human Cognition. He also leaves a permanent reminder of scientific passion, academic soul, and social responsibility to all fortunate people who met and knew him during his intense life. The research activities of the Unit of University of Rome "La Sapienza" were partially supported by the H2020 Marie S. Curie ITN-ETN project with the short title "BBDiag" (http://bbdiag-ITNetn.eu). We thank Mrs. Jessica Janson and Mrs. Marina Selivanova for their support to those activities in the framework of the BBDiag project.