Ben-Menachem E
Department of Clinical Neuroscience, University of Götborg, Sahlgrenska Hospital, Sweden.
Baillieres Clin Neurol. 1996 Dec;5(4):841-8.
Vagus nerve stimulation (VNS) was first tried as a treatment for seizure patients in 1988. The idea to stimulate the vagus nerve and disrupt or prevent seizures was proposed by Jacob Zabarra. He observed a consistent finding among several animal studies which indicated that stimulation of the vagus nerve could alter the brain wave patterns of the animals under study. His hypothesis formed the basis for the development of the vagus nerve stimulator, an implantable device similar to a pacemaker, which is implanted in the left chest and attached to the left vagus nerve via a stimulating lead. Once implanted, the stimulator is programmed by a physician to deliver regular stimulation 24 hours a day regardless of seizure activity. Patients can also activate extra 'on-demand' stimulation with a handheld magnet. Clinical studies have demonstrated VNS therapy to be a safe and effective mode of treatment when added to the existing regimen of severe, refractory patients with epilepsy. Efficacy ranges from seizure free to no response with the majority of patients (> 50%) reporting at least a 50% improvement in number of seizures after 1.5 years of treatment. The side-effect profile is unique and mostly includes stimulation-related sensations in the neck and throat. The mechanism of action for VNS is not clearly understood although two theories have emerged. First, the direct connection theory hypothesizes that the anticonvulsant action of VNS is caused by a threshold raising effect of the connections to the nucleus of the solitary tract and on to other structures. The second is the concept that chronic stimulation of the vagus nerve increases the amount of inhibitory neurotransmitters and decreases the amount of excitatory neurotransmitters. Additional research into the optimal use of VNS is ongoing. Animal and clinical research have produced some interesting new data suggesting there are numerous ways to improve the clinical performance of vagus nerve stimulation as a treatment for refractory patients.
1988年，迷走神经刺激术（VNS）首次被尝试用于治疗癫痫患者。刺激迷走神经以扰乱或预防癫痫发作的想法是由雅各布·扎巴拉提出的。他在多项动物研究中观察到一个一致的发现，即刺激迷走神经可以改变受试动物的脑电波模式。他的假设为迷走神经刺激器的开发奠定了基础，这是一种类似于起搏器的可植入设备，植入左胸并通过刺激导线连接到左迷走神经。一旦植入，刺激器由医生进行编程，无论癫痫发作活动如何，每天24小时进行定期刺激。患者还可以用手持磁铁激活额外的“按需”刺激。临床研究表明，对于严重的难治性癫痫患者，在现有治疗方案基础上添加VNS疗法是一种安全有效的治疗方式。疗效范围从无癫痫发作到无反应，大多数患者（>50%）报告在治疗1.5年后癫痫发作次数至少减少50%。副作用情况独特，主要包括颈部和喉咙的刺激相关感觉。虽然出现了两种理论，但VNS的作用机制尚不清楚。第一种，直接连接理论假设VNS的抗惊厥作用是由与孤束核及其他结构的连接的阈值升高效应引起的。第二种是长期刺激迷走神经会增加抑制性神经递质的量并减少兴奋性神经递质的量这一概念。关于VNS最佳使用方法的进一步研究正在进行中。动物和临床研究已经产生了一些有趣的新数据，表明有多种方法可以改善迷走神经刺激术作为难治性患者治疗方法的临床性能。
