EEG functional connectivity and ApoE genotype in Alzheimer's disease and controls

Objective: We examined the relation between Apolipoprotein E A allele (ApoE A) genotype and functional connectivity measured by Electroencephalography (EEG) in patients with Alzheimer's disease (AD) and patients with Subjective complaints (SC). Methods: We included 43 patients with AD (age (SD) = 74.2 (4.0), m/f = 22/21: 30 of ApoE epsilon 4 carriers) and 21 patients with SC (age (SD) = 73.2 (5.2), m/f = 13/8: 7 ApoE epsilon 4 carriers) for this Study. Resting state EEGs were recorded in all subjects. Synchronisation likelihood (SL) between local cortical areas was compared in the alpha and beta band according to ApoE epsilon 4 status and diagnosis. Results: ApoE epsilon 4 carriers had higher SL values in lower and upper alpha band, in both diagnostic groups. In upper alpha band and beta band AD patients had lower SL than patients with SC, was irrespective of ApoE status. Conclusion: The effects of AD and ApoE epsilon 4 oil functional connectivity are opposite and independent. Significance: The observed increase in SL in both AD and patients with SC carrying ApoE epsilon 4 suggests a strong genetic impact of ApoE epsilon 4 on brain function. (c) 2008 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.