title: EEG Spectral Features Discriminate between Alzheimer's and Vascular Dementia.
abstract: Alzheimer's disease (AD) and vascular dementia (VaD) present with similar clinical symptoms of cognitive decline, but the underlying pathophysiological mechanisms differ. To determine whether clinical electroencephalography (EEG) can provide information relevant to discriminate between these diagnoses, we used quantitative EEG analysis to compare the spectra between non-medicated patients with AD (n = 77) and VaD (n = 77) and healthy elderly normal controls (NC) (n = 77). We use curve-fitting with a combination of a power loss and Gaussian function to model the averaged resting-state spectra of each EEG channel extracting six parameters. We assessed the performance of our model and tested the extracted parameters for group differentiation. We performed regression analysis in a multivariate analysis of covariance with group, age, gender, and number of epochs as predictors and further explored the topographical group differences with pair-wise contrasts. Significant topographical differences between the groups were found in several of the extracted features. Both AD and VaD groups showed increased delta power when compared to NC, whereas the AD patients showed a decrease in alpha power for occipital and temporal regions when compared with NC. The VaD patients had higher alpha power than NC and AD. The AD and VaD groups showed slowing of the alpha rhythm. Variability of the alpha frequency was wider for both AD and VaD groups. There was a general decrease in beta power for both AD and VaD. The proposed model is useful to parameterize spectra, which allowed extracting relevant clinical EEG key features that move toward simple and interpretable diagnostic criteria.
authors.affiliation: Institute of Biological and Medical Psychology, University of Bergen , Bergen , Norway ; Section for Clinical Neurophysiology, Haukeland University Hospital , Bergen , Norway.
authors.forename: Emanuel
authors.initials: E
authors.lastname: Neto
authors.affiliation: Institute of Biological and Medical Psychology, University of Bergen , Bergen , Norway ; K. G. Jebsen Center for Research on Neuropsychiatric Disorders , Bergen , Norway ; The Mind Research Network , Albuquerque, NM , USA.
authors.forename: Elena A
authors.initials: EA
authors.lastname: Allen
authors.affiliation: Section for Clinical Neurophysiology, Haukeland University Hospital , Bergen , Norway.
authors.forename: Harald
authors.initials: H
authors.lastname: Aurlien
authors.affiliation: Institute of Biological and Medical Psychology, University of Bergen , Bergen , Norway.
authors.forename: Helge
authors.initials: H
authors.lastname: Nordby
authors.affiliation: Institute of Biological and Medical Psychology, University of Bergen , Bergen , Norway ; Section for Clinical Neurophysiology, Haukeland University Hospital , Bergen , Norway ; K. G. Jebsen Center for Research on Neuropsychiatric Disorders , Bergen , Norway.
authors.forename: Tom
authors.initials: T
authors.lastname: Eichele
keywords: Alzheimer’s disease; electroencephalogram; qEEG; quantitative analysis; vascular dementia