Title :
Spectral and Nonlinear Analyses of MEG Background Activity in Patients With Alzheimer's Disease
Author :
Hornero, Roberto ; Escudero, Javier ; Fernandez, Alicia ; Poza, Jesús ; Gomez, Christopher
Author_Institution :
Dept. of Signal Theor. & Commun., Valladolid Univ., Valladolid
fDate :
6/1/2008 12:00:00 AM
Abstract :
The aim of the present study is to analyze the magnetoencephalogram (MEG) background activity from patients with Alzheimer´s disease (AD) and elderly control subjects. MEG recordings from 20 AD patients and 21 controls were analyzed by means of two spectral [median frequency (MF) and spectral entropy (SpecEn)] and two nonlinear parameters [approximate entropy (ApEn) and Lempel-Ziv complexity (LZC)]. In the AD diagnosis, the highest accuracy of 75.6% (80% sensitivity, 71.4% specificity) was obtained with the MF according to a linear discriminant analysis (LDA) with a leave-one-out cross-validation procedure. Moreover, we wanted to assess whether these spectral and nonlinear analyses could provide complementary information to improve the AD diagnosis. After a forward stepwise LDA with a leave-one-out cross-validation procedure, one spectral (MF) and one nonlinear parameter (ApEn) were automatically selected. In this model, an accuracy of 80.5% (80.0% sensitivity, 81.0% specificity) was achieved. We conclude that spectral and nonlinear analyses from spontaneous MEG activity could be complementary methods to help in AD detection.
Keywords :
diseases; magnetoencephalography; patient diagnosis; patient monitoring; Alzheimers disease; Lempel-Ziv complexity; MEG background activity; magnetoencephalogram; median frequency; spectral entropy; Aging; Alzheimer´s disease; Dementia; Electroencephalography; Entropy; Frequency; Linear discriminant analysis; Magnetic analysis; Neurons; Spectral analysis; Superconducting magnets; Alzheimer's disease (AD); Alzheimer´s Disease; Lempel–Ziv complexity (LZC); Lempel-Ziv complexity; approximate entropy; approximate entropy (ApEn); magnetoencephalogram; magnetoencephalogram (MEG); median frequency; median frequency (MF); spectral entropy; spectral entropy (SpecEn);
Journal_Title :
Biomedical Engineering, IEEE Transactions on
DOI :
10.1109/TBME.2008.919872