Evolution of source EEG synchronization in early Alzheimer's disease.
Alzheimer's disease (AD) disrupts functional connectivity in distributed cortical networks. We analyzed changes in the S-estimator, a measure of multivariate intraregional synchronization, in electroencephalogram (EEG) source space in 15 mild AD patients versus 15 age-matched controls to evaluate its potential as a marker of AD progression. All participants underwent 2 clinical evaluations and 2 EEG recording sessions on diagnosis and after a year. The main effect of AD was hyposynchronization in the medial temporal and frontal regions and relative hypersynchronization in posterior cingulate, precuneus, cuneus, and parietotemporal cortices. However, the S-estimator did not change over time in either group. This result motivated an analysis of rapidly progressing AD versus slow-progressing patients. Rapidly progressing AD patients showed a significant reduction in synchronization with time, manifest in left frontotemporal cortex. Thus, the evolution of source EEG synchronization over time is correlated with the rate of disease progression and should be considered as a cost-effective AD biomarker.
LREN, Department of Clinical Neuroscience, Centre Hospitalier Universitaire Vaudois (CHUV), and University of Lausanne, Lausanne, Switzerland. Maria.Knyazeva@chuv.ch
Maria G
MG
Knyazeva
Cristian
C
Carmeli
Alireza
A
Khadivi
Joseph
J
Ghika
Reto
R
Meuli
Richard S
RS
Frackowiak
D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis / Q000503:physiopathology; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000503:physiopathology*; D003344:Cortical Synchronization; D018450:Disease Progression; D058407:Electroencephalography Phase Synchronization; D005260:Female; D005625:Frontal Lobe / Q000503:physiopathology; D006179:Gyrus Cinguli / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009778:Occipital Lobe / Q000503:physiopathology; D010296:Parietal Lobe / Q000503:physiopathology; D011379:Prognosis; D013702:Temporal Lobe / Q000503:physiopathology