Alzheimer's disease qEEG: spectral analysis versus coherence. Which is the best measurement?
There is evidence in electroencephalography that alpha, theta and delta band oscillations reflect cognitive and memory performances and that quantitative techniques can improve the electroencephalogram (EEG) sensitivity. This paper presents the results of comparative analysis of qEEG variables as reliable markers for Alzheimer's disease (AD). We compared the sensitivity and specificity between spectral analysis (spectA) and coherence (Coh) within the same group of AD patients. SpectA and Coh were calculated from EEGs of 40 patients with mild to moderate AD and 40 healthy elderly controls. The peak of spectA was smaller in the AD group than in controls. AD group showed predominance of slow spectA in theta and delta bands and a significant reduction of inter-hemispheric Coh for occipital alpha 2 and beta 1 and for frontal delta sub-band. ROC curve supported that alpha band spectA was more sensitive than coherence to differentiate controls from AD.
Department of Neurology, School of Medicine, University of São Paulo, Brazil. anghinah@usp.br
Renato
R
Anghinah
Paulo Afonso Medeiros
PA
Kanda
Helder Frederico
HF
Lopes
Luis Fernando Hindi
LF
Basile
Sérgio
S
Machado
Pedro
P
Ribeiro
Bruna
B
Velasques
Koichi
K
Sameshima
Daniel Yasumasa
DY
Takahashi
Lécio Figueira
LF
Pinto
Paulo
P
Caramelli
Ricardo
R
Nitrini
D000368:Aged; D000369:Aged, 80 and over; D000513:Alpha Rhythm / Q000502:physiology; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000503:physiopathology; D001611:Beta Rhythm / Q000502:physiology; D016022:Case-Control Studies; D004569:Electroencephalography / Q000379:methods*; D006801:Humans; D008875:Middle Aged; D012372:ROC Curve; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index