Woodbury D M, Woodbury J W
Department of Physiology, University of Utah School of Medicine, Salt Lake City 84108.
Epilepsia. 1990;31 Suppl 2:S7-19. doi: 10.1111/j.1528-1157.1990.tb05852.x.
Repetitive stimulation of the vagus nerve inhibits chemically induced seizures in dogs. We report here the results and conclusions from studies designed to answer some of the immediate questions raised by this finding. (1) Maximal stimulation of vagal C fibers at frequencies greater than 4 Hz prevents or reduces chemically and electrically induced seizures in young male rats. (2) Antiepileptic potency is directly related to the fraction of vagal C fibers stimulated. (3) Vagal stimulation shortens but does not shut down a chemical seizure once it has begun. (4) In rats, optimal stimulus frequency is approximately 10-20 Hz; duration of stimulus, 0.5-1 ms; and stimulus strength, 0.2-0.5 mA/mm2 of nerve cross-section. These results, when taken together with similar results obtained from dogs, monkeys, and humans, strongly suggest that periodic stimulation of the vagus nerve using appropriate stimulation parameters is a powerful method for preventing seizures. The data from the literature suggest that the antiepileptic actions of vagal stimulation are largely mediated by widespread release of GABA and glycine in the brainstem and cerebral cortex. The probable pathway is via projections from the nucleus of the solitary tract to the reticular formation and thence by diffuse projections to the cortex and other areas. Intermittent vagal stimulation has the potentiality of reducing the number and/or the intensity of seizures in patients with intractable epilepsy. These results indicate that feasibility studies in humans should be continued and expanded.
反复刺激迷走神经可抑制犬类化学诱导的癫痫发作。我们在此报告旨在回答这一发现所引发的一些紧迫问题的研究结果和结论。（1）以大于4 Hz的频率对迷走神经C纤维进行最大刺激可预防或减少年轻雄性大鼠的化学诱导和电诱导癫痫发作。（2）抗癫痫效力与受刺激的迷走神经C纤维比例直接相关。（3）迷走神经刺激可缩短化学性癫痫发作的持续时间，但一旦发作开始则无法终止。（4）在大鼠中，最佳刺激频率约为10 - 20 Hz；刺激持续时间为0.5 - 1毫秒；刺激强度为0.2 - 0.5 mA/mm²神经横截面积。这些结果与从犬、猴和人类获得的类似结果相结合，强烈表明使用适当的刺激参数定期刺激迷走神经是预防癫痫发作的有效方法。文献数据表明，迷走神经刺激的抗癫痫作用在很大程度上是由脑干和大脑皮层中广泛释放的GABA和甘氨酸介导的。可能的途径是从孤束核投射到网状结构，然后通过弥散投射到皮层和其他区域。间歇性迷走神经刺激有可能减少难治性癫痫患者的癫痫发作次数和/或发作强度。这些结果表明，应继续并扩大在人类中的可行性研究。
