Vagus nerve stimulation (VNS) for Epilepsy

Overview
Approximately 20 percent of people with epilepsy cannot adequately control their seizures with antiepileptic drugs (AEDs). Other people experience serious side effects from AEDs that impact their quality of life. Some of these people may be candidates for surgery. For those with intractable epilepsy who are not eligible for surgery, vagus nerve stimulation (VNS) may be considered.

The vagus nerve extends from the brain through the neck to the chest and abdomen. VNS involves an implanted device that sends electrical signals through the vagus nerve to help control seizures. VNS is most often used in combination with medication.

Not everyone with intractable epilepsy is a good candidate for VNS. VNS may be more effective in treating focal seizures than other types of seizures. To be eligible for vagus nerve stimulation, you must have tried several different AEDs for significant periods of time. You must be 12 years or older. You must have ruled out surgery as a possible treatment for your epilepsy. Finally, you and your doctors must agree that the benefits you might gain by having the VNS device implanted outweigh the risks.

What does it involve?
VNS implantation involves a surgical procedure that takes one or two hours. You will be placed under general anesthesia. The surgeon will make a small incision in the chest near the collarbone or armpit and implant the VNS device. They will also make a small incision along the side of the neck and attach the wires of the device to the vagus nerve. The wires are threaded beneath the skin and are not visible.

You can expect to return home the same day after receiving a VNS device.

Over the next few days, the device will be programmed to emit electrical signals on a regular basis. You will also learn how to activate the signal yourself if you experience an aura or other warning of an impending seizure. You will continue taking AEDs after receiving a VNS device.

Intended Outcomes
VNS can help prevent seizures or reduce the intensity of seizures. Many people report that VNS improves quality of life in terms of better mood and improved alertness, memory, and energy levels. VNS can help reduce the amount of AED medication you need to take.

Results
Studies have shown that VNS can decrease seizure frequency by 20 to 30 percent in the short term and 40 to 50 percent in the long term.

Constraints
Any surgery carries risks including blood clots, blood loss, infection, breathing problems, reactions to medication, and heart attack or stroke during the surgery.

VNS may not be successful in reducing your seizures.

Links:

Vagus Nerve Stimulation (VNS) – Epilepsy Foundation
http://www.epilepsy.com/learn/treating-seizures...

VNS Therapy – Cyberonics
http://us.livanova.cyberonics.com/