Interictal high-frequency oscillations (100-500 Hz) in the intracerebral EEG of epileptic patients
Interictal high-frequency oscillations (100-500 Hz) in the intracerebral EEG of epileptic patients
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DOI：
10.1093/brain/awm149
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发表时间：
2007-09-01
期刊：
影响因子：
14.5
通讯作者：
Gotman, Jean
中科院分区：
文献类型：
--
作者：
Urrestarazu, Elena;Chander, Rahul;Gotman, Jean
据报道，在癫痫患者和实验大鼠模型中，从植入的微电极记录到的信号中，发作间期在100至500赫兹之间出现了快速振荡。250~500赫兹之间的振荡或快速波纹(FR)与癫痫灶有关，而波纹(80~200赫兹)与癫痫灶无关。我们报告了7例难治性局灶性癫痫患者在慢波睡眠期间用颅内大电极记录到的高频振荡。我们描述了快速振荡与癫痫灶的关系，并量化了它们与癫痫样瞬变的一致性，它们与癫痫样瞬变密切相关。之所以选择这些患者，是因为在发作起始区内外都发现了发作间期棘波。根据波纹和FRS与癫痫样棘波的关系，采用目视检查的方法对其进行识别和分类。用连续时间小波分析计算它们的能量。所有患者都存在涟漪，而7名患者中有5名患者存在FRS。大多数波纹和FRS与癫痫样瞬变同时发生。在7名患者中，有4名患者在发作起始区内的涟漪发生率高于发作区外。在5例FRS患者中，4例发作区内的FRS发生率明显高于发作区外(这4例中，发作区外几乎不存在FRS)。波纹和FRS的功率在电极中趋于较高，其比率也较高。这些结果表明，FRS更多地局限于癫痫发作起始区内的电极，尤其是海马区，而不是波纹。只有1例患者的FRS多出现在癫痫发作区域之外；该患者是唯一一例皮质发育不良且FRS发生率较高的电极位于病变内部。这项研究表明，患者的发作间期波纹和FRS可以用深度大电极记录到。大多数发生在癫痫样棘波出现时，但也有一些是孤立的。波纹在发作区和偏远区之间没有明显的区别，而FRS在发作区有更高的发生率和更高的功率。我们的结果还表明，异常的海马体具有产生FR的特殊能力，尽管它们也被记录在其他结构中。
Interictal fast oscillations between 100 and 500 Hz have been reported in signals recorded from implanted microelectrodes in epileptic patients and experimental rat models. Oscillations between 250 and 500 Hz, or fast ripples (FR), appeared related to the epileptic focus whereas ripples (80-200 Hz) were not. We report high-frequency oscillations recorded with intracranial macroelectrodes in seven patients with refractory focal epilepsy during slow-wave sleep. We characterize the relation of fast oscillations to the seizure focus and quantify their concordance with epileptiform transients, with which they are strongly associated. The patients were selected because interictal spikes were found within and outside the seizure onset zone. Visual inspection was used to identify and classify the ripples and FRs according to their relation to epileptiform spikes. Continuous-time wavelet analysis was used to compute their power. Ripples were present in all patients while FRs where found in five of the seven patients. Most ripples and FRs occurred at the same time as epileptiform transients. The rate of occurrence of ripples was higher within the seizure onset zone than outside in four of seven patients. The rate of FRs was much higher within the seizure onset zone than outside in four of the five patients with FRs ( in these four patients, FRs were almost inexistent outside the seizure onset zone). The power of ripples and FRs tended to be higher in the electrodes where their rate was also higher. These results indicate that FRs were more restricted to the electrodes located within the seizure onset zone, especially to the hippocampus, than ripples. In only one patient, FRs were more frequent outside the seizure onset zone; this patient was the only one with cortical dysplasia and the electrode with a high rate of FRs was inside the lesion. This study demonstrates that interictal ripples and FRs can be recorded with depth macroelectrodes in patients. Most occur at the time of epileptiform spikes but some are isolated. Ripples do not show a clear differentiation between the seizure onset zone and remote areas, whereas FRs have a higher rate and higher power in the seizure onset zone. Our results also suggest a special capacity of the abnormal hippocampus to generate FRs, although they were also recorded in other structures.