Abásolo Daniel, Hornero Roberto, Espino Pedro, Poza Jesús, Sánchez Clara I, de la Rosa Ramón
E.T.S. Ingenieros de Telecomunicación, University of Valladolid, Camino del Cementerio s/n, 47011 Valladolid, Spain.
Clin Neurophysiol. 2005 Aug;116(8):1826-34. doi: 10.1016/j.clinph.2005.04.001.
The aim of this study was to analyse the regularity of the EEG background activity of Alzheimer's disease (AD) patients to test the hypothesis that the irregularity of the AD patients' EEG is lower than that of age-matched controls.
We recorded the EEG from 19 scalp electrodes in 10 AD patients and 8 age-matched controls and estimated the Approximate Entropy (ApEn). ApEn is a non-linear statistic that can be used to quantify the irregularity of a time series. Larger values correspond to more complexity or irregularity. A spectral analysis was also performed.
ApEn was significantly lower in the AD patients at electrodes P3 and P4 (P < 0.01), indicating a decrease of irregularity. We obtained 70% sensitivity and 100% specificity at P3, and 80% sensitivity and 75% specificity at P4. Results seemed to be complementary to spectral analysis.
The decreased irregularity found in the EEG of AD patients in the parietal region leads us to think that EEG analysis with ApEn could be a useful tool to increase our insight into brain dysfunction in AD. However, caution should be applied due to the small sample size.
This article represents a first step in demonstrating the feasibility of ApEn for recognition of EEG changes in AD.
本研究旨在分析阿尔茨海默病（AD）患者脑电图背景活动的规律，以检验AD患者脑电图不规则性低于年龄匹配对照组这一假设。
我们记录了10例AD患者和8例年龄匹配对照组19个头皮电极的脑电图，并估计近似熵（ApEn）。ApEn是一种非线性统计量，可用于量化时间序列的不规则性。值越大，对应越复杂或不规则。还进行了频谱分析。
AD患者在电极P3和P4处的ApEn显著降低（P<0.01），表明不规则性降低。我们在P3处获得了70%的敏感性和100%的特异性，在P4处获得了80%的敏感性和75%的特异性。结果似乎与频谱分析互补。
在AD患者顶叶区域脑电图中发现的不规则性降低使我们认为，用ApEn进行脑电图分析可能是一种有用的工具，有助于加深我们对AD脑功能障碍的认识。然而，由于样本量小，应谨慎使用。
本文是证明ApEn用于识别AD脑电图变化可行性的第一步。
