Schönberger Jan, Huber Charlotte, Lachner-Piza Daniel, Klotz Kerstin Alexandra, Dümpelmann Matthias, Schulze-Bonhage Andreas, Jacobs Julia
Epilepsy Center, Medical Center, University of Freiburg, Freiburg, Germany.
Department of Neuropediatrics and Muscle Disorders, Medical Center, University of Freiburg, Freiburg, Germany.
Front Neurol. 2020 Sep 30;11:573975. doi: 10.3389/fneur.2020.573975. eCollection 2020.
Patients with dual pathology have two potentially epileptogenic lesions: One in the hippocampus and one in the neocortex. If epilepsy surgery is considered, stereotactic electroencephalography (SEEG) may reveal which of the lesions is seizure-generating, but frequently, some uncertainty remains. We aimed to investigate whether interictal high-frequency oscillations (HFOs), which are a promising biomarker of epileptogenicity, are associated with the primary focus. We retrospectively analyzed 16 patients with dual pathology. They were grouped according to their seizure-generating lesion, as suggested by ictal SEEG. An automated detector was applied to identify interictal epileptic spikes, ripples (80-250 Hz), ripples co-occurring with spikes (IES-ripples) and fast ripples (250-500 Hz). We computed a ratio R to obtain an indicator of whether rates were higher in the hippocampal lesion (R close to 1), higher in the neocortical lesion (R close to -1), or more or less similar (R close to 0). Spike and HFO rates were higher in the hippocampal than in the neocortical lesion ( < 0.001), particularly in seizure onset zone channels. Seizures originated exclusively in the hippocampus in 5 patients (group 1), in both lesions in 7 patients (group 2), and exclusively in the neocortex in 4 patients (group 3). We found a significant correlation between the patients' primary focus and the ratio R, i.e., the proportion of interictal fast ripples detected in this lesion ( < 0.05). No such correlation was observed for interictal epileptic spikes ( = 0.69), ripples ( = 0.60), and IES-ripples ( = 0.54). In retrospect, interictal fast ripples would have correctly "predicted" the primary focus in 69% of our patients ( < 0.01). We report a correlation between interictal fast ripple rate and the primary focus, which was not found for epileptic spikes. Fast ripple analysis could provide helpful information for generating a hypothesis on seizure-generating networks, especially in cases with few or no recorded seizures.
一个在海马体，一个在新皮质。如果考虑进行癫痫手术，立体定向脑电图（SEEG）可能会揭示哪个病灶是癫痫发作的起源，但通常仍会存在一些不确定性。我们旨在研究发作间期高频振荡（HFOs）这一有前景的致痫性生物标志物是否与主要病灶相关。我们回顾性分析了16例患有双重病理的患者。根据发作期SEEG提示的癫痫发作起源病灶对他们进行分组。应用自动探测器来识别发作间期癫痫棘波、涟漪（80 - 250Hz）、与棘波同时出现的涟漪（IES - 涟漪）和快速涟漪（250 - 500Hz）。我们计算了一个比率R，以获得一个指标，表明海马体病灶中的发生率是否更高（R接近1）、新皮质病灶中的发生率是否更高（R接近 - 1），或者两者是否大致相似（R接近0）。海马体病灶中的棘波和HFO发生率高于新皮质病灶（<0.001），尤其是在癫痫发作起始区通道。5例患者（第1组）的癫痫发作仅起源于海马体，7例患者（第2组）的癫痫发作起源于两个病灶，4例患者（第3组）的癫痫发作仅起源于新皮质。我们发现患者的主要病灶与比率R之间存在显著相关性，即该病灶中检测到的发作间期快速涟漪的比例（<0.05）。对于发作间期癫痫棘波（=0.69）、涟漪（=0.60）和IES - 涟漪（=0.54），未观察到这种相关性。回顾来看，发作间期快速涟漪能够正确“预测”69%患者的主要病灶（<0.01）。我们报告了发作间期快速涟漪发生率与主要病灶之间的相关性，而癫痫棘波未发现这种相关性。快速涟漪分析可为生成癫痫发作网络假说提供有用信息，尤其是在癫痫发作记录很少或没有记录的情况下。
