Scholly Julia, Pizzo Francesca, Timofeev Alexander, Valenti-Hirsch Maria Paola, Ollivier Irène, Proust François, Roehri Nicolas, Bénar Christian-George, Hirsch Edouard, Bartolomei Fabrice
University of Strasbourg, Epilepsy Unit, Hautepierre Hospital, Strasbourg, France; Aix Marseille University, Service de Neurophysiologie Clinique, Hôpital Timone, Marseille, France.
Aix Marseille University, Institut de Neurosciences des Systèmes, Inserm, U1106, Marseille, France; Aix Marseille University, Service de Neurophysiologie Clinique, Hôpital Timone, Marseille, France.
Epilepsy Res. 2019 Feb;150:27-31. doi: 10.1016/j.eplepsyres.2018.12.006. Epub 2018 Dec 15.
Epilepsy associated with periventricular nodular heterotopia (PNH) is characterized by complex relationships between the heterotopic and the normotopic cortex during the interictal state and at seizure onset. High-frequency oscillations (HFO) have been proposed as a marker of epileptogenicity that might reflect disease activity. The effects of thermocoagulations on epileptogenicity in this context remain unknown. We aimed to investigate the interictal HFO- and spike profiles of different cortical structures before and after two consecutive SEEG-guided thermocoagulations, in correlation with seizure outcome, in a patient with PNH-related drug-resistant epilepsy.
The epileptogenic zone (EZ) was defined by SEEG analysis based on the Epileptogenicity Index. Interictal spikes, ripples (80-250 Hz) and fast ripples (FR, 250-330 Hz) were analyzed within the heterotopia, the temporal neocortex and the hippocampus.
The SEEG recordings revealed a distributed EZ involving the heterotopia and the posterior temporal neocortex. Both structures were targeted by thermocoagulations. Background spikes, ripples and FR-rates were significantly higher in PNH compared to the normotopic cortex. A drastic reduction of spikes (by over 80%) and absence of FR were demonstrated both in the PNH and in the neocortex during the second SEEG exploration 6 months after the first thermocoagulation, whereas no significant difference was observed in the posterior hippocampus. Ripples were significantly reduced by the first and suppressed by the second thermocoagulation within the three structures. Seizures relapsed after two months but decreased in frequency after the first thermocoagulation. Sustained seizure-freedom was achieved only after the second procedure.
Our data demonstrate the running down of interictal HFO and spikes within the epileptogenic network following thermocoagulations of heterotopic and normotopic sites involved at seizure onset. This dynamics was in good correlation with significantly improved seizure control.
Combination of ictal and different interictal markers of epileptogenicity, including HFO and spike analysis, is important to get the full picture of the epileptogenic zone and could help to evaluate the disease activity.
与脑室周围结节性异位（PNH）相关的癫痫，其特征在于发作间期和发作起始时异位皮质与正常皮质之间存在复杂关系。高频振荡（HFO）已被提议作为癫痫源性的标志物，可能反映疾病活动。在此背景下，热凝对癫痫源性的影响尚不清楚。我们旨在研究在连续两次立体定向脑电图（SEEG）引导下热凝前后，一名与PNH相关的药物难治性癫痫患者不同皮质结构的发作间期HFO和棘波特征，并与癫痫发作结果相关联。
基于癫痫源性指数，通过SEEG分析确定癫痫发作起始区（EZ）。在异位结节、颞叶新皮质和海马体内分析发作间期棘波、涟漪（80 - 250Hz）和快涟漪（FR，250 - 330Hz）。
SEEG记录显示一个分布性的EZ，涉及异位结节和颞叶后部新皮质。两个结构均接受了热凝治疗。与正常皮质相比，PNH中的背景棘波、涟漪和FR频率显著更高。在第一次热凝治疗6个月后的第二次SEEG检查中，PNH和新皮质中的棘波均大幅减少（超过80%）且未观察到FR，而后海马体中未观察到显著差异。三个结构中的涟漪在第一次热凝时显著减少，在第二次热凝时受到抑制。癫痫发作在两个月后复发，但在第一次热凝后频率降低。仅在第二次手术后实现了持续无癫痫发作。
我们的数据表明，对发作起始时涉及的异位和正常部位进行热凝后，癫痫发作间期网络内的HFO和棘波减少。这种动态变化与癫痫发作控制的显著改善密切相关。
结合发作期和不同的发作间期癫痫源性标志物，包括HFO和棘波分析，对于全面了解癫痫发作起始区很重要，并且有助于评估疾病活动。
