Anninos P A, Anogianakis G, Lehnertz K, Pantev C, Hoke M
Department of Neurology, Medical School, University of Thraki, Alexandroupolis, Greece.
Int J Neurosci. 1987 Dec;37(3-4):149-68. doi: 10.3109/00207458708987144.
Systematic studies of the magnetoencephalogram (MEG) in normal and pathological subjects (mainly with focal epilepsies) showed that the MEG may evidence significant brain activities even if they are not present in the electroencephalogram (EEG). They also showed that the MEG has a considerably higher spatial resolution than the EEG. A novel mapping technique was introduced to get such a representation of the data that would enable the investigator to draw his conclusions mainly from inspecting the plots. This technique is characterized by an isospectral amplitude (iso-SA) mapping of the scalp distribution of specified spectral components or frequency bands of the MEG power spectrum. With the above method we were able to localize an epileptiform focus using a noninvasive technique without applying an eliciting stimulus. Furthermore using SQUID measurements we were able to describe the behavior of the MEG when the brains of different subjects were subjected to low frequency sinusoidal binaural stimuli. Under these conditions it has been shown that the MEG tends to organize around discrete frequencies that depend on the interference pattern (beat) between the two inputs.
对正常受试者和病理受试者（主要是局灶性癫痫患者）的脑磁图（MEG）进行的系统研究表明，即使脑电图（EEG）未显示明显的脑活动，MEG也可能显示出显著的脑活动。研究还表明，MEG的空间分辨率比EEG高得多。引入了一种新颖的映射技术，以获得能够使研究人员主要通过检查图表得出结论的数据表示形式。该技术的特点是对MEG功率谱的特定频谱成分或频段的头皮分布进行等谱幅度（iso-SA）映射。使用上述方法，我们能够在不施加诱发刺激的情况下，采用非侵入性技术定位癫痫样病灶。此外，通过超导量子干涉仪（SQUID）测量，我们能够描述不同受试者的大脑在受到低频正弦双耳刺激时MEG的表现。在这些条件下，研究表明MEG倾向于围绕离散频率进行组织，这些频率取决于两个输入之间的干涉图样（拍频）。
