An accurate identification of the epileptogenic zone is essential for patients with intractable epilepsy who are candidates to neurosurgery. EEG recordings can provide predictive biomarkers of the epileptogenic zone. Wide-band EEG makes it possible to record from infraslow (including DC shifts) to high frequency (HFO, over 300 Hz) oscillations for diagnostic purposes in patients with epilepsy. Although the presence of HFOs have been proposed to sign the epileptogenic zone, DC-like recordings demonstrate that DC shifts precede HFOs at seizure onset. This led to the proposal that "ictal active DC shifts" are causally related to seizure onset as opposed to "ictal passive DC shifts". Thus, active DC shifts may constitute predictive biomarkers of the epileptogenic zone in epilepsy. Since DC shift is commonly associated to a rise in extracellular potassium, potassium homeostasis regulated by Kir4.1 channels in astrocytes may play an key role at seizure onset. In addition, we hypothesize that, during the interictal period, the co-occurrence of slow events and interictal HFOs, so-called "Red slow", may also delineate an epileptogenic zone, even if a seizure would not be actually recorded.

中文翻译：

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有源直流 (DC) 转移和“红慢”：癫痫发作机制和致痫区识别的两个新概念

准确识别致痫区对于适合接受神经外科手术的顽固性癫痫患者至关重要。脑电图记录可以提供癫痫发生区的预测性生物标志物。宽带脑电图可以记录从超低速（包括直流偏移）到高频（HFO，超过 300 Hz）的振荡，以用于癫痫患者的诊断目的。尽管已提出 HFO 的存在标志着致癫痫区，但类似 ​​DC 的记录表明，在癫痫发作时 DC 转移先于 HFO。这导致提出“发作性主动 DC 转变”与癫痫发作有因果关系，而不是“发作性被动 DC 转变”。因此，活跃的 DC 转移可能构成癫痫致癫痫区的预测性生物标志物。由于 DC 转移通常与细胞外钾的升高有关，星形胶质细胞中由 Kir4.1 通道调节的钾稳态可能在癫痫发作时起关键作用。此外，我们假设，在发作间期，缓慢事件和发作间期 HFO 的同时发生，即所谓的“红色缓慢”，也可能描绘出致癫痫区，即使实际上不会记录癫痫发作。