Responsive neurostimulation (RNS) is a treatment option for patients with refractory epilepsy when surgical resection is not possible due to overlap of the irritative zone and eloquent cortex. Presurgical evaluations for RNS placement typically rely on invasive methods. This study investigated the potential of transcranial magnetic stimulation (TMS) and magnetoencephalography (MEG) to provide key presurgical information non-invasively. We hypothesized that these non-invasive methods may assist in optimizing RNS placement by providing useful information for seizure localization by MEG and eloquent cortex mapping by TMS. A retrospective chart review identified nine patients who underwent RNS placement (mean age = 20.4 years [ = 5.6], two-thirds were female). Characterization of the irritative zone using MEG was successful in eight of nine patients. Non-invasive mapping of relevant eloquent cortex was attempted in all patients. TMS was successful in eight of nine patients, and MEG was successful in two of six patients. Importantly, patients mapped with non-invasive modalities experienced an average seizure reduction of 77 % at their most recent clinic visit, compared to 75 % seizure reduction in those with invasive evaluations, indicating appropriate RNS placement. These data demonstrate that TMS and MEG can provide key information for RNS and may be feasible alternatives to invasive methods for assisting in decision making regarding RNS placement. Non-invasive methods for determining RNS placement have a high rate of success when data from multiple non-invasive modalities converge and can inform more accurate placement of intracranial electrodes prior to RNS placement or mitigate their need.

中文翻译：

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经颅磁刺激和脑磁图是优化响应性神经刺激装置放置的侵入性方法的可行替代方案


当由于刺激区和口语皮质重叠而无法进行手术切除时，反应性神经刺激（RNS）是难治性癫痫患者的一种治疗选择。 RNS 放置的术前评估通常依赖于侵入性方法。这项研究调查了经颅磁刺激 (TMS) 和脑磁图 (MEG) 以无创方式提供关键术前信息的潜力。我们假设这些非侵入性方法可能通过为 MEG 癫痫定位和 TMS 雄辩皮层映射提供有用信息来帮助优化 RNS 放置。回顾性图表审查确定了 9 名接受 RNS 植入的患者（平均年龄 = 20.4 岁 [= 5.6]，三分之二是女性）。使用 MEG 对 9 名患者中的 8 名刺激区域进行了成功表征。对所有患者都尝试了相关口才皮层的非侵入性绘图。 TMS 在 9 名患者中的 8 名中取得了成功，MEG 在 6 名患者中的 2 名中取得了成功。重要的是，接受非侵入性评估的患者在最近一次就诊时癫痫发作平均减少了 77%，而接受侵入性评估的患者癫痫发作减少了 75%，这表明 RNS 放置适当。这些数据表明，TMS 和 MEG 可以为 RNS 提供关键信息，并且可能是侵入性方法的可行替代方案，用于协助有关 RNS 放置的决策。当来自多种非侵入性方式的数据汇聚时，用于确定 RNS 放置的非侵入性方法具有很高的成功率，并且可以在 RNS 放置之前告知更准确的颅内电极放置或减轻其需求。