Ultra Broad Band Neural Activity Portends Seizure Onset in a Rat Model of Epilepsy.
Ultra Broad Band Neural Activity Portends Seizure Onset in a Rat Model of Epilepsy.
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超宽带神经活动预示着癫痫大鼠模型的癫痫发作。
DOI：
10.1109/embc.2018.8512769
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Schiller,Yitzhak
中科院分区：
文献类型：
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作者：
Ehrens,Daniel;Assaf,Fadi;Cowan,NoahJ;Sarma,SrideviV;Schiller,Yitzhak
癫痫影响全球超过7000万人，30%的患者的癫痫发作无法用药物控制，这促使替代疗法如电刺激的发展。目前的刺激策略试图在癫痫发作开始后停止癫痫发作，但没有一个旨在完全预防癫痫发作。预防癫痫发作需要知道大脑何时进入发作前状态（即，接近癫痫发作）。在这里，我们表明，这种preictal活动可以检测到一个信息丰富的神经信号，逐步和单调变化的大脑接近癫痫发作事件。具体来说，我们使用局部场电位（LFP）从癫痫大鼠模型开发一个创新的措施，信号新奇相对于非癫痫活动，这表明在超宽带（4 Hz - 5 kHz）的进步神经动力学的存在。该措施是从功能的连接功能计算的LFP被用作一类支持向量机（SVM）的输入。SVM输出标量信号，该标量信号量化当前活动相对于基线（非癫痫发作）活动看起来有多新颖，并显示提前几分钟向癫痫发作发作的进展。在SVM中使用超宽带多变量特征产生了新奇信号，当与使用单个通道上的常规频带（4 - 500 Hz）中的功率作为SVM的输入特征相比时，该新颖信号在癫痫发作的进展中具有显著更高的斜率。功能连接与SVM结合是一种策略，它产生了一种新的新奇测量方法，可用于闭环系统的癫痫发作预测和预防。
Epilepsy affects over 70 million people worldwide and 30% of patients' seizures cannot be controlled with medications, motivating the development of alternative therapies such as electrical stimulation. Current stimulation strategies attempt to stop seizures after they start, but none aim to prevent seizures altogether. Preventing seizures requires knowing when the brain is entering a preictal state (i.e., approaching seizure onset). Here we show that such preictal activity can be detected by an informative neural signal that progressively and monotonically changes as the brain approaches a seizure event. Specifically, we use local field potentials (LFP) from a rat model of epilepsy to develop an innovative measure of signal novelty relative to nonseizure activity, that shows the presence of progressive neural dynamics in an ultra broad band (4 Hz - 5 kHz). The measure is extracted from functional connectivity features computed from the LFPs which are used as an input to a one-class Support Vector Machine (SVM). The SVM outputs a scalar signal which quantifies how novel the current activity looks relative to baseline (non-seizure) activity and shows a progression towards seizure onset minutes ahead of time. The use of ultra broad band multivariate features into the SVM results in a novelty signal that has a significantly higher slope in the progression to seizure onset when compared to using power in conventional frequency bands (4 - 500 Hz) on individual channels as input features to the SVM. Functional connectivity in conjunction with the SVM is a strategy that generates a new measurement of novelty that can be used by closed-loop systems for seizure forecasting and prevention.