Kobayashi K, James C J, Yoshinaga H, Ohtsuka Y, Gotman J
Montreal Neurological Institute and Hospital, Quebec, Canada.
Clin Neurophysiol. 2000 Jan;111(1):134-49. doi: 10.1016/s1388-2457(99)00202-3.
We developed a novel non-invasive analysis to localize the source and visualize the time course of electrical activity generated inside the brain but unclear from the scalp. This analysis applies to signals with unique waveform characteristics, such as seizures.
The method extracts activity from an EEG data matrix as a spatiotemporal component having waveforms uncorrelated to the other concurrent activities. The method also provides the location and orientation of the dipole generating this activity. We applied this method to ten scalp seizures in three patients with temporal lobe epilepsy and single-focus seizures confirmed by intracerebral recordings. A realistic head model based on MRI was used for computation of field distributions.
When seizure activity was still not visually identifiable on the scalp, the method demonstrated in all scalp seizures a source in the temporal neocortex corresponding clearly to the region of seizure activity in intracerebral recordings. Frequency characteristics of the estimated activities also resembled those of the intracerebral seizures.
This method enables estimation of focal brain activity when its effect on scalp EEG is unclear to visual examination. It works in situations where currently available source analyses methods, which require noiseless definite activity, are not applicable.
我们开发了一种新型无创分析方法，用于定位脑内产生但从头皮上不明确的电活动源并可视化其时间进程。该分析适用于具有独特波形特征的信号，如癫痫发作。
该方法从脑电图数据矩阵中提取活动，作为一种时空成分，其波形与其他同时发生的活动不相关。该方法还提供产生这种活动的偶极子的位置和方向。我们将此方法应用于3例颞叶癫痫患者的10次头皮癫痫发作以及经脑内记录证实的单灶性癫痫发作。基于磁共振成像（MRI）的逼真头部模型用于计算场分布。
当头皮上仍无法通过视觉识别癫痫活动时，该方法在所有头皮癫痫发作中均显示颞叶新皮质有一个源，与脑内记录中的癫痫活动区域明显对应。估计活动的频率特征也与脑内癫痫发作的特征相似。
当局灶性脑活动对头皮脑电图的影响在视觉检查中不明确时，该方法能够对其进行估计。它适用于当前可用的源分析方法（这些方法需要无噪声的明确活动）不适用的情况。
