MEG MEASUREMENT OF EPILEPSY IN THE CORTEX

脑磁图（MEG）是近年来发展起来的一种脑磁图检查方法。 非侵入性定位和研究细胞内电流总和 癫痫发作的动物和人通过映射颅外 它们产生的磁场。 这个项目的长期目标是 是利用动物大脑皮层的癫痫模型， 人类癫痫样磁场神经发生的基础，以及 联合收割机结合脑磁图和详细的电记录来获取信息 关于兴奋性产生的细胞内和细胞外电流 体内癫痫新皮层的变化。 本项目将研究一个更复杂的钴焦点， 小型猪的真实脑回皮质。 我们的目标是减少 的模糊性，并增加现实主义的分析解决方案， 非侵入性记录癫痫数据的生理建模。 我们 将从三个方面解决这个问题。首先，我们将联合收割机 在所有建模中，来自MEG和EEG的信息 程序. 第二，不是简单地比较建模的结果， 我们会将信息整合到 脑回和脑沟的位置和形状 直接解决。 最后，我们将有选择地过滤这两种模式中的数据。 空间和时间来隔离对总系统方差的贡献， 尖波与慢波活动，以及局灶性与区域性活动 分别 我们将评估和提高这些的准确性， 通过将解决方案与详细的定量信息进行比较， 关于细胞电流的颅内分布， 只能从动物制剂中侵入性地获得。 这项工作的结果不仅将提供深入了解膜 兴奋性的变化，导致癫痫发作，但也将 与颅外磁场的解释直接相关 从正常人和癫痫病人的新皮层中测量。

The magnetoencephalogram (MEG) is a recently developed method of noninvasively localizing and studying the summed intracellular currents of epileptic paroxysms in animal and man by mapping the extracranial magnetic fields that they produce. The long-term goal of this project is to use models of epilepsy in animal cortex to establish an empirical basis for the neurogenesis of epileptiform magnetic fields in man, and to combine MEG with detailed electrical recording to obtain information about the intra and extracellular currents produced by excitability changes in the in vivo epileptic neocortex. The present project will study a more complex cobalt focus in the more realistic gyrencephalic cortex of miniature swine. Our goal is to reduce the ambiguity and increase the realism of analytical solutions derived from physiological modeling of noninvasively recorded epilepsy data. We will approach this problem in three ways. First, we will combine information from both MEG and electroencephalogram (EEG) in all modeling procedures. Second, instead of simply comparing the results of modeling to the geometry of underlying anatomy, we will incorporate information about the location and shape of gyri and sulci into the modeling solutions directly. Finally, we will selectively filter data in both space and time to isolate contributions to the total system variance from sharp versus slow wave activity, and from focal versus regional activity respectively. We will evaluate and improve the accuracy of these modeling solutions by comparing them to detailed quantitative information about the intracranial distribution of cellular currents, information obtainable only invasively from an animal preparation. The results of this work will not only provide insights into membrane excitability changes that result in epileptic seizures, but will also be directly relevant to the interpretation of extracranial magnetic fields measured from normal and epileptic human neocortex.