Physics Department, Universidad de Buenos Aires, Buenos Aires, Argentina.
PLoS One. 2012;7(7):e41799. doi: 10.1371/journal.pone.0041799. Epub 2012 Jul 23.
Identification of critical areas in presurgical evaluations of patients with temporal lobe epilepsy is the most important step prior to resection. According to the "epileptic focus model", localization of seizure onset zones is the main task to be accomplished. Nevertheless, a significant minority of epileptic patients continue to experience seizures after surgery (even when the focus is correctly located), an observation that is difficult to explain under this approach. However, if attention is shifted from a specific cortical location toward the network properties themselves, then the epileptic network model does allow us to explain unsuccessful surgical outcomes.
The intraoperative electrocorticography records of 20 patients with temporal lobe epilepsy were analyzed in search of interictal synchronization clusters. Synchronization was analyzed, and the stability of highly synchronized areas was quantified. Surrogate data were constructed and used to statistically validate the results. Our results show the existence of highly localized and stable synchronization areas in both the lateral and the mesial areas of the temporal lobe ipsilateral to the clinical seizures. Synchronization areas seem to play a central role in the capacity of the epileptic network to generate clinical seizures. Resection of stable synchronization areas is associated with elimination of seizures; nonresection of synchronization clusters is associated with the persistence of seizures after surgery.
We suggest that synchronization clusters and their stability play a central role in the epileptic network, favoring seizure onset and propagation. We further speculate that the stability distribution of these synchronization areas would differentiate normal from pathologic cases.
在进行颞叶癫痫患者的术前评估时，识别关键区域是切除前最重要的步骤。根据“癫痫灶模型”，定位发作起始区是主要任务。然而，仍有少数癫痫患者在手术后继续发作（即使病灶定位正确），这种现象用这种方法很难解释。但是，如果注意力从特定的皮质位置转移到网络本身的特性上，那么癫痫网络模型确实可以帮助我们解释手术不成功的结果。
分析了 20 例颞叶癫痫患者的术中皮层脑电图记录，寻找发作间期同步集群。分析了同步性，并量化了高度同步区域的稳定性。构建了替代数据，并用于统计验证结果。我们的结果显示，在与临床发作同侧的颞叶外侧和内侧区域都存在高度局部化和稳定的同步区域。同步区域似乎在癫痫网络产生临床发作的能力中起着核心作用。切除稳定的同步区域与消除发作有关；非同步集群的切除与手术后发作的持续存在有关。
我们认为，同步集群及其稳定性在癫痫网络中起着核心作用，有利于发作的起始和传播。我们进一步推测，这些同步区域的稳定性分布将区分正常和病理情况。
