Vagus (Latin word for “wandering”) nerve stimulation (VNS) is a medical procedure used to treat epilepsy by implanting a pacemaker-like device that generates pulses of electricity to stimulate the vagus nerve – the longest one of the 12 cranial nerves attached to the undersurface of the brain and relay information to and from the brain.
The vagus nerve extends to many structures (including the larynx, lungs, heart and gastrointestinal tract) and brings information from the senses (like touch or sight) to the brain (sensory) and some control muscles (motor). Other cranial nerves, like the vagus, have both motor and sensory functions.
VNS is used in people who do not respond to anti-seizure medications and who are not considered good candidates for surgery.
During surgery, while the patient is asleep (general anesthesia), the stimulator device size of a silver dollar is placed under the skin in the upper part of the chest and an electrode connected with wire to a stimulator is attached to the vagus nerve through a small incision in the neck.
Then the stimulator is programmed using a computer to generate pulses of electricity at regular intervals, depending on the patient's tolerance but re-programming can be also done in the doctor’s office.
Also, after surgery, the patient will be given a hand-held magnet which can generate an immediate current of electricity to stop a seizure in progress or reduce the severity of the seizure when it is brought near the stimulator.
VNS cannot cure epilepsy and totally eliminate the seizures but many people who undergo VNS experience a significant reduction in the frequency of seizures, as well as a decrease in seizure severity and this greatly improves the quality of their life.
The risks of VNS include:
- Allergic reaction to the anesthesia
- Injury to the vagus nerve or nearby blood vessels
- Including the carotid artery and jugular vein
The most common side effects of VNS include:
- Tingling in the neck
- Problems swallowing
They usually occur only when the nerve is being stimulated; they are usually mild and tend to go away over time.