Ikeda Akio, Takeyama Hirofumi, Bernard Christophe, Nakatani Mitsuyoshi, Shimotake Akihiro, Daifu Masako, Matsuhashi Masao, Kikuchi Takayuki, Kunieda Takeharu, Matsumoto Riki, Kobayashi Tamaki, Sato Kazuaki
Department of Epilepsy, Movement Disorders and Physiology, Kyoto University, Japan.
Department of Respiratory Care and Sleep Control Medicine, Kyoto University, Japan.
Neurosci Res. 2020 Jul;156:95-101. doi: 10.1016/j.neures.2020.01.014. Epub 2020 Feb 8.
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.
对于适合接受神经外科手术的难治性癫痫患者，准确识别致痫区至关重要。脑电图记录可以提供致痫区的预测性生物标志物。宽带脑电图能够记录从超低频（包括直流偏移）到高频（高于300Hz的高频振荡）的振荡，用于癫痫患者的诊断。尽管有人提出高频振荡的存在标志着致痫区，但类似直流的记录表明，在癫痫发作开始时，直流偏移先于高频振荡出现。这导致有人提出，“发作期活跃性直流偏移”与癫痫发作起始存在因果关系，而与“发作期被动性直流偏移”相反。因此，活跃性直流偏移可能构成癫痫致痫区的预测性生物标志物。由于直流偏移通常与细胞外钾离子升高有关，星形胶质细胞中由Kir4.1通道调节的钾离子稳态可能在癫痫发作起始时起关键作用。此外，我们假设，在发作间期，慢波事件和发作间期高频振荡同时出现，即所谓的“红色慢波”，也可能勾勒出致痫区，即使实际上未记录到癫痫发作。
