Evaluation of High frequency oscillations as markers of epileptogenicity in intracranial EEG and their correlates on surface EEG

对于药物难治性癫痫患者，手术切除致痫组织是最有希望的治疗方法。致癫痫组织的识别是复杂的，即使是现代成像技术和颅内脑电图记录（iEEG）也不能可靠地预测术后结果。传统上，只有低于100 Hz的EEG频率用于临床目的，但技术进步现在允许我们记录采样率高达10000 Hz的更高频率。最近的研究表明，100 Hz以上的高频振荡（HFO）与致癫痫组织密切相关。然而，它们是在小的皮层区域上产生的，并且到目前为止仅用iEEG电极而不是表面EEG记录。此外，癫痫HFO的研究可能会受到生理HFO的混淆，这些HFO无法轻易与病理事件区分开来。本项目旨在研究以下关于80- 500 Hz之间HFO的假设：1）HFO是致痫性的可靠标志物。2)生理和病理HFO具有独立于频率的可区分的电生理模式3）在表面EEG上可以看到与癫痫棘波一起发生的HFO，从而允许用非侵入性EEG更好地描绘癫痫区域。

For patients with medically refractory epilepsy, surgical removal of epileptogenic tissue is the most promising treatment. The identification of epileptogenic tissue is complex; even modern imaging techniques and intracranial EEG recordings (iEEG) fail to reliably predict postsurgical outcome. Traditionally, only EEG frequencies below 100Hz are used for clinical purposes, but technical advancements now allow us to record higher frequencies with sampling rates up to 10000Hz. Recent studies have shown that high-frequency oscillations (HFOs) above 100 Hz are closely linked to epileptogenic tissue. They are however generated over small cortical areas and were until now only recorded with iEEG electrodes and not with surface EEG. Additionally, studies of epileptic HFOs may be confounded by physiological HFOs that cannot be easily distinguished from pathological events. This project aims to investigate the following hypotheses about HFOs between 80-500Hz: 1) HFOs are reliable markers of epileptogenicity. 2) Physiological and pathological HFOs have distinguishable electrophysiological patterns independent of frequency 3) HFOs occurring with epileptic spikes can be seen on surface EEG, allowing better delineation of epileptogenic areas with non-invasive EEG.