PDF(Pubmed)
Abstract：
Inter-ictal spikes aid in the diagnosis of epilepsy and in planning surgery of medication-resistant epilepsy. However, the localizing information from spikes can be unreliable because spikes can propagate, and the burden of spikes, often assessed as a rate, does not always correlate with the seizure onset zone or seizure outcome. Recent work indicates identifying where spikes regularly emerge and spread could localize the seizure network. Thus, the current study sought to better understand where and how rates of single and coupled spikes, and especially brain regions with high-rate and leading spike of a propagating sequence, informs the extent of the seizure network. In 37 patients with medication-resistant temporal lobe seizures, who had surgery to treat their seizure disorder, an algorithm detected spikes in the pre-surgical depth inter-ictal EEG. A separate algorithm detected spike propagation sequences and identified the location of leading and downstream spikes in each sequence. We analysed the rate and power of single spikes on each electrode and coupled spikes between pairs of electrodes, and the proportion of sites with high-rate, leading spikes in relation to the seizure onset zone of patients seizure free (n = 19) and those with continuing seizures (n = 18). We found increased rates of single spikes in mesial temporal seizure onset zone (ANOVA, P < 0.001, η2 = 0.138), and increased rates of coupled spikes within, but not between, mesial-, lateral- and extra-temporal seizure onset zone of patients with continuing seizures (P < 0.001; η2 = 0.195, 0.113 and 0.102, respectively). In these same patients, there was a higher proportion of brain regions with high-rate leaders, and each sequence contained a greater number of spikes that propagated with a higher efficiency over a longer distance outside the seizure onset zone than patients seizure free (Wilcoxon, P = 0.0172). The proportion of high-rate leaders in and outside the seizure onset zone could predict seizure outcome with area under curve = 0.699, but not rates of single or coupled spikes (0.514 and 0.566). Rates of coupled spikes to a greater extent than single spikes localize the seizure onset zone and provide evidence for inter-ictal functional segregation, which could be an adaptation to avert seizures. Spike rates, however, have little value in predicting seizure outcome. High-rate spike sites leading propagation could represent sources of spikes that are important components of an efficient seizure network beyond the clinical seizure onset zone, and like the seizure onset zone these, too, need to be removed, disconnected or stimulated to increase the likelihood for seizure control.
摘要：
发作间尖峰有助于癫痫的诊断和耐药性癫痫的计划手术。然而,从尖峰定位信息可能是不可靠的，因为尖峰可以传播，和尖峰的负担，通常被评估为一个比率，并不总是与癫痫发作发作区或癫痫发作结果相关。最近的工作表明，确定峰值经常出现和传播的地方可以定位癫痫发作网络。因此，当前的研究试图更好地了解单尖峰和耦合尖峰的速率在哪里以及如何，尤其是具有高速率和传播序列的前导尖峰的大脑区域，通知缉获网络的范围。在37例耐药颞叶癫痫患者中，他们接受了治疗癫痫的手术，一种算法在手术前深度发作间脑电图中检测到尖峰。单独的算法检测尖峰传播序列并识别每个序列中的前导和下游尖峰的位置。我们分析了每个电极上单个尖峰的速率和功率以及电极对之间的耦合尖峰，以及高利率网站的比例，与无癫痫发作患者(n=19)和持续癫痫发作患者(n=18)的癫痫发作区相关的主要峰值。我们发现内侧颞部癫痫发作区单个尖峰的发生率增加(方差分析，P<0.001，η2=0.138），内部耦合尖峰的比率增加，但不是之间，mesial-,持续癫痫发作患者的外侧和颞外癫痫发作区（P<0.001；η2分别=0.195、0.113和0.102）。在这些患者中，高速率领导者的大脑区域比例更高，并且每个序列包含更多数量的尖峰，这些尖峰在癫痫发作区以外的较长距离上以更高的效率传播，而不是没有癫痫发作的患者（Wilcoxon，P=0.0172)。癫痫发作区内外的高利率领导者比例可以预测癫痫发作结果，曲线下面积=0.699，但不能预测单一或耦合尖峰的发生率（0.514和0.566）。耦合尖峰的比率比单个尖峰更大程度地定位了癫痫发作的发作区域，并为发作间功能隔离提供了证据。这可能是避免癫痫发作的一种适应。尖峰率，然而,在预测癫痫发作结果方面价值不大。导致传播的高速率尖峰位点可能代表尖峰的来源，这些尖峰是超出临床癫痫发作区的有效癫痫发作网络的重要组成部分。就像癫痫发作区一样，也是,需要删除，断开或刺激以增加癫痫发作控制的可能性。
