Harmony T, Fernández-Bouzas A, Marosi E, Fernández T, Bernal J, Rodríguez M, Reyes A, Silva J, Alonso M, Casian G
ENEP Iztacala, Universidad Nacional Autónoma de México, Mexico.
Electroencephalogr Clin Neurophysiol. 1993 Oct;87(4):196-205. doi: 10.1016/0013-4694(93)90019-r.
In a group of patients with space-occupying brain lesions, CT measurements were correlated with absolute power (AP) and relative power (RP) of the delta, theta, alpha and beta EEG bands, calculated from the raw EEG potentials (EEGp) and from the Laplacian estimates also called "current source densities" (CSD). Rank correlations were calculated between the number of abnormal values in each band and the following CT measures: volume of the lesion and of the edema, density of the edema, percentage of ventricular collapse and midline shift. Abnormal spectral values are those which are significantly higher than the norm for the same age, in the delta and theta bands, and significantly lower in the alpha and beta bands. Spectral parameters obtained from the CSD showed higher correlations with CT measures than those calculated from the EEGp. In the Laplacian, all CT measures had a significant correlation with delta AP. Theta AP was significantly correlated with the volume and density of the edema, as well as with midline shift. Significant correlations were also observed with delta and alpha RP. However, changes in RP were considered to be a consequence of the increase in delta AP. Canonical correlation analyses between AP and RP calculated from EEGp or CSD and the first 3 CT measures showed that the volume of the lesion was only correlated with delta AP and RP. The volume and density of the edema showed a significant correlation with delta, theta and alpha AP calculated from EEGp and only with theta and alpha AP in the Laplacian. Since the EEGp tends to produce a more extensive and diffuse picture of abnormality, whereas the Laplacian acts as a spatial filter emphasizing local sources over distant sources, we concluded that edema is related not to delta activity, but to the theta and alpha power.
在一组患有脑占位性病变的患者中，CT测量值与δ、θ、α和β脑电频段的绝对功率（AP）和相对功率（RP）相关，这些功率由原始脑电电位（EEGp）以及拉普拉斯估计值（也称为“电流源密度”，CSD）计算得出。计算了每个频段异常值的数量与以下CT测量值之间的等级相关性：病变体积、水肿体积、水肿密度、脑室塌陷百分比和中线移位。异常频谱值是指在δ和θ频段中显著高于同年龄正常水平，而在α和β频段中显著低于正常水平的值。从CSD获得的频谱参数与CT测量值的相关性高于从EEGp计算得出的参数。在拉普拉斯估计值中，所有CT测量值与δ AP均有显著相关性。θ AP与水肿的体积和密度以及中线移位显著相关。在δ和α RP方面也观察到显著相关性。然而，RP的变化被认为是δ AP增加的结果。对由EEGp或CSD计算得出的AP和RP与前3项CT测量值进行典型相关性分析，结果表明病变体积仅与δ AP和RP相关。水肿的体积和密度与从EEGp计算得出的δ、θ和α AP显著相关，而在拉普拉斯估计值中仅与θ和α AP相关。由于EEGp往往会产生更广泛和弥散的异常图像，而拉普拉斯估计值起到空间滤波器的作用，强调局部源而非远处源，因此我们得出结论，水肿与δ活动无关，而是与θ和α功率有关。
