Facilitation of epileptic activity during sleep is mediated by high amplitude slow waves.
Facilitation of epileptic activity during sleep is mediated by high amplitude slow waves.
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DOI：
10.1093/brain/awv073
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发表时间：
2015-06
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影响因子：
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通讯作者：
Gotman J
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文献类型：
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作者：
Frauscher B;von Ellenrieder N;Ferrari-Marinho T;Avoli M;Dubeau F;Gotman J
癫痫放电在非快速眼动睡眠期间增加。通过研究局灶性癫痫患者的睡眠脑电图，Frauscher等人表明，这种增加与高振幅慢波特别相关。与生理活动相反，它发生在从激活状态到失活状态的过渡，这是一个高度同步的时期。癫痫放电在非快速眼动睡眠期间增加。通过研究局灶性癫痫患者的睡眠脑电图，Frauscher等人表明，这种增加与高振幅慢波特别相关。与生理活动相反，它发生在从激活状态到失活状态的过渡，这是一个高度同步的时期。局灶性癫痫的癫痫放电在非快速眼动睡眠期间经常被激活。睡眠慢波存在于这个阶段，并且已经被证明包括去激活状态（“向下”，超极化）和激活状态（“向上”，去极化）。“向上”状态增强了生理节律，我们假设睡眠慢波，特别是“向上”状态是介导癫痫活动激活的非快速眼动睡眠的特定组成部分。我们调查了8例药物耐药的局灶性癫痫患者，他们接受了头皮-脑内脑电图联合检查以进行诊断评估。我们分析了259个额叶脑电图通道，并手动标记442个癫痫棘波和8487个高振幅广泛慢波期间的高频振荡，并在匹配的控制段与低振幅广泛慢波，非广泛慢波或无慢波选择在相同的睡眠阶段（慢波和控制段的总持续时间：49分钟）。在慢波期间，棘波和高频振荡比对照段更频繁（慢波期间79%的棘波和65%的高频振荡，均P <0.05）。高振幅慢波的棘波和高频振荡密度也增加。我们比较了尖峰的密度和高频振荡之间的“向上”和“向下”的状态。尖峰和高频振荡密度是最高的过渡期间，从“向上”到“向下”的状态。有趣的是，正常活动的通道中的高频振荡在从“向下”到“向上”状态的过渡处表达了不同的峰。这些结果表明，由非快速眼动睡眠引起的癫痫放电的明显激活不是一种状态依赖性现象，而是主要与特定事件相关，即在这种睡眠状态下频繁但不连续的高振幅广泛慢波。癫痫棘波和高频振荡都不像生理活动那样在"上“状态期间占主导地位，而是在慢波从”上“状态过渡到”下“状态期间占主导地位，这是一个高度同步的时期。因此，癫痫放电似乎与同步性比与兴奋性更相关。此外，没有癫痫活动的通道中的高频振荡在慢波周期期间与具有癫痫活动的通道中的高频振荡峰值不同。这种特性可以区分生理性和病理性的高频振荡，这是一个至今尚未解决的问题。
Epileptic discharges are increased during non-REM sleep. By studying the sleep EEG in patients with focal epilepsies, Frauscher et al. show that the increase is specifically associated with high-amplitude slow waves. In contrast to physiological activity, it occurs at transitions from activation to deactivation states, a period of high synchronization. Epileptic discharges are increased during non-REM sleep. By studying the sleep EEG in patients with focal epilepsies, Frauscher et al. show that the increase is specifically associated with high-amplitude slow waves. In contrast to physiological activity, it occurs at transitions from activation to deactivation states, a period of high synchronization. Epileptic discharges in focal epilepsy are frequently activated during non-rapid eye movement sleep. Sleep slow waves are present during this stage and have been shown to include a deactivated (‘down’, hyperpolarized) and an activated state (‘up’, depolarized). The ‘up’ state enhances physiological rhythms, and we hypothesize that sleep slow waves and particularly the ‘up’ state are the specific components of non-rapid eye movement sleep that mediate the activation of epileptic activity. We investigated eight patients with pharmaco-resistant focal epilepsies who underwent combined scalp-intracerebral electroencephalography for diagnostic evaluation. We analysed 259 frontal electroencephalographic channels, and manually marked 442 epileptic spikes and 8487 high frequency oscillations during high amplitude widespread slow waves, and during matched control segments with low amplitude widespread slow waves, non-widespread slow waves or no slow waves selected during the same sleep stages (total duration of slow wave and control segments: 49 min each). During the slow waves, spikes and high frequency oscillations were more frequent than during control segments (79% of spikes during slow waves and 65% of high frequency oscillations, both P ∼ 0). The spike and high frequency oscillation density also increased for higher amplitude slow waves. We compared the density of spikes and high frequency oscillations between the ‘up’ and ‘down’ states. Spike and high frequency oscillation density was highest during the transition from the ‘up’ to the ‘down’ state. Interestingly, high frequency oscillations in channels with normal activity expressed a different peak at the transition from the ‘down’ to the ‘up’ state. These results show that the apparent activation of epileptic discharges by non-rapid eye movement sleep is not a state-dependent phenomenon but is predominantly associated with specific events, the high amplitude widespread slow waves that are frequent, but not continuous, during this state of sleep. Both epileptic spikes and high frequency oscillations do not predominate, like physiological activity, during the ‘up’ state but during the transition from the ‘up’ to the ‘down’ state of the slow wave, a period of high synchronization. Epileptic discharges appear therefore more associated with synchronization than with excitability. Furthermore, high frequency oscillations in channels devoid of epileptic activity peak differently during the slow wave cycle from those in channels with epileptic activity. This property may allow differentiating physiological from pathological high frequency oscillations, a problem that is unresolved until now.