Souci Sabrine, Petton Mathilde, Jung Julien, Bourdillon Pierre, Bouet Romain, Richard-Mornas Aurélie, Streichenberger Nathalie, Catenoix Hélène, Montavont Alexandra, Isnard Jean, Guenot Marc, Kahane Philippe, Lachaux Jean-Philippe, Rheims Sylvain
Department of Functional Neurology and Epileptology, Hospices civils de Lyon, Lyon, France; Lyon 1 University, Lyon, France; Lyon's Neuroscience Research Center, INSERM U1028, CNRS UMR 5292, Lyon, France.
Lyon's Neuroscience Research Center, INSERM U1028, CNRS UMR 5292, Lyon, France.
Epilepsy Behav. 2018 Aug;85:76-84. doi: 10.1016/j.yebeh.2018.05.017. Epub 2018 Jun 14.
Few data are available about the functionality of type II focal cortical dysplasia (FCD). Identification of high-frequency activities (HFAs) induced by cognitive tasks has been proposed as an additional way to map cognitive functions in patients undergoing presurgical evaluation using stereoelectroencephalography (SEEG). However, the repetitive subcontinuous spiking pattern which characterizes type II FCD might limit the reliability of this approach, and its feasibility in these patients remains to be evaluated.
Seven patients whose magnetic resonance imaging (MRI) data, SEEG data, and/or pathological data were consistent with the diagnosis of type II FCD were included. All patients performed standardized cognitive tasks specifically designed to map task-induced increase of HFA (50 Hz to 150 Hz) at the recorded sites. Electrode contacts which showed an interictal SEEG pattern typical of type II FCD were considered to be localized within the FCD. A site was considered responsive if it was significantly different from baseline in at least one cognitive task.
Three of the seven patients (43%) had significant task-induced increase of HFA in the FCD for a total of 15 sites with an interictal SEEG pattern typical of type II FCD. These sites were always localized at the external border of the FCD whereas no HFA response was in the core of FCD. In three of the four other patients, a significant task-induced increase of HFA was observed in a cortical site immediately adjacent to the dysplastic cortex.
Detection of task-induced HFA remains feasible despite the repetitive subcontinuous spiking pattern which characterizes type II FCD. Depending on the localization of the FCD, some sites of the dysplastic cortex were included in large-scale functional networks. However, these sites were always those closest to the nondysplastic cortex suggesting that persistence of cortical functions might be restricted to a limited part of the FCD.
关于II型局灶性皮质发育不良（FCD）的功能，现有数据较少。有人提出，识别认知任务诱发的高频活动（HFAs）是在使用立体定向脑电图（SEEG）进行术前评估的患者中绘制认知功能的另一种方法。然而，II型FCD的特征性重复亚连续棘波模式可能会限制这种方法的可靠性，其在这些患者中的可行性仍有待评估。
纳入7例磁共振成像（MRI）数据、SEEG数据和/或病理数据与II型FCD诊断一致的患者。所有患者均执行标准化认知任务，这些任务专门设计用于在记录部位绘制任务诱发的HFA（50Hz至150Hz）增加情况。显示出II型FCD典型发作间期SEEG模式的电极触点被认为位于FCD内。如果一个部位在至少一项认知任务中与基线有显著差异，则认为该部位有反应。
7例患者中有3例（43%）在FCD中出现了显著的任务诱发HFA增加，共有15个部位具有II型FCD典型的发作间期SEEG模式。这些部位总是位于FCD的外缘，而FCD核心部位未出现HFA反应。在其他4例患者中的3例中，在紧邻发育异常皮质的皮质部位观察到了显著的任务诱发HFA增加。
尽管II型FCD具有特征性的重复亚连续棘波模式，但检测任务诱发的HFA仍然可行。根据FCD的定位，发育异常皮质的一些部位被纳入大规模功能网络。然而，这些部位总是最接近非发育异常皮质的部位，这表明皮质功能的持续存在可能仅限于FCD的有限部分。
