What is the "vagus nerve"?
With epilepsy, the vagus nerve is one of the 12 cranial nerves, it is Roman numeral 1. The vagus nerve has the longest extent, arising from the cranium (coming from the brain stem); it distributes through the neck, through the upper thorax, all the way down into the abdomen. The vagus nerve even gets into the stomach and maybe a little bit of the gut. The vagus nerve is involved in regulating our heartbeat, sensing when our stomach is upset, and also when our heart is beating too fast. So, it is part of our autonomic nervous system, and relays its information into the brain stem into a certain defined nucleus, called the solitary nucleus (mainly because it sits there all by itself). This nucleus has very vast projections to various autonomic centers of the brain that regulate heartbeat, thirst, hunger, mainly the hypothalamus, but also other limbic structures.