Epilepsy: Vagus Nerve Stimulation (VNS)
How Does VNS Work?
It is not known exactly how VNS works. It is known, however, that the vagus nerve is an important pathway to the brain. It is thought that by stimulating the vagus nerve, electrical energy is discharged upward into a wide area of the brain, disrupting the abnormal brain activity responsible for seizures. Another theory suggests that stimulating the vagus nerve causes the release of special brain chemicals that decrease seizure activity.
What Are the Risks of VNS?
The risks of VNS include injury to the vagus nerve or nearby blood vessels, including the carotid artery and jugular vein. In addition, there are risks associated with any surgical procedure, such as infection, bleeding and an allergic reaction to the anesthesia.
What Are the Benefits of VNS?
VNS is not a cure, and the total elimination of seizures is rare. However, many people who undergo VNS experience a significant (more than 50%) reduction in the frequency of seizures, as well as a decrease in seizure severity. This can greatly improve the quality of life for people with epilepsy.
What Side Effects Are Associated With VNS?
The most common side effects of VNS include hoarseness, coughing, tingling in the neck and problems swallowing. These usually occur only when the nerve is being stimulated. These side effects generally are mild and tend to go away over time.