Schevernels Hanne, van Bochove Marlies E, De Taeye Leen, Bombeke Klaas, Vonck Kristl, Van Roost Dirk, De Herdt Veerle, Santens Patrick, Raedt Robrecht, Boehler C Nico
Department of Experimental Psychology, Ghent University, 9000 Ghent, Belgium.
Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, 6525 HR Nijmegen, The Netherlands.
Epilepsy Behav. 2016 Nov;64(Pt A):171-179. doi: 10.1016/j.yebeh.2016.09.014. Epub 2016 Oct 12.
In the current study, we explored whether vagus nerve stimulation (VNS) in patients with epilepsy, which is believed to increase norepinephrine (NE) levels via activation of the locus coeruleus, would positively affect response inhibition. Moreover, we tried to identify the dynamics of the underlying neural processes by investigating event-related potentials (ERPs) and pupil size. Patients performed a stop-signal task once when stimulation was switched on and once when it was switched off. We found a correlational pattern suggesting that patients who clinically benefit more from VNS treatment also show a larger behavioral advantage, in terms of faster response inhibition, when the vagus nerve is being stimulated. Event-related potential (ERP) results suggested more pronounced reactive inhibition when stimulation was switched on, independent of the individual amount of seizure reduction. Transient go-locked pupil size was increased from go trials to successful stop trials to unsuccessful stop trials but without displaying a clear VNS effect, which however, might relate to limited sensitivity. We conclude that VNS likely has a positive effect on response inhibition, at least in patients with epilepsy that benefit clinically from the treatment, presumably relating to enhancements of response-inhibition mechanisms and, therefore, identify enhanced response inhibition as a possible cognitive benefit of VNS.
在本研究中，我们探讨了癫痫患者的迷走神经刺激（VNS）是否会对反应抑制产生积极影响。VNS被认为可通过激活蓝斑来提高去甲肾上腺素（NE）水平。此外，我们试图通过研究事件相关电位（ERP）和瞳孔大小来确定潜在神经过程的动态变化。患者在刺激开启时和关闭时各执行一次停止信号任务。我们发现了一种相关模式，表明在迷走神经受到刺激时，从VNS治疗中临床获益更多的患者在反应抑制更快方面也表现出更大的行为优势。事件相关电位（ERP）结果表明，刺激开启时反应性抑制更明显，与个体癫痫发作减少量无关。从执行试验到成功停止试验再到未成功停止试验，瞬态的与执行相关的瞳孔大小增加，但未显示出明显的VNS效应，不过这可能与敏感性有限有关。我们得出结论，VNS可能对反应抑制有积极影响，至少在临床上从该治疗中获益的癫痫患者中如此，这大概与反应抑制机制的增强有关，因此，确定增强的反应抑制是VNS可能带来的一种认知益处。
