Electrical vagus nerve stimulation (VNS) has been approved by FDA and is widely used in recent years for the treatment of epilepsy and possibly other medical conditions such as depression. The current success rate of VNS for epilepsy is about 50%, but there are complications, potential risks and cost concerns. One of the major limitations for this new therapy is that its antiseizure mechanisms are by no means clear. In particular, it is not known whether the therapeutic effect is vagal specific, what types of nerve fibers in the vagus nerve are contributing to the therapeutic effects, or what individual patients would benefit from the use of the expensive and invasive VNS implantation. There are controversies regarding how and where the VNS takes effect on epilepsy in the central nervous system. The poor understanding of VNS has inevitably limited the application and success of the therapy. The current review analyses the pros and cons of VNS for epilepsy in vis-à-vis other available therapies including Chinese medical methods, and explores the possible mechanisms in order to stimulate further improvement of this new technology.
