Vagus nerve stimulator for epilepsy
Treatment Overview
Similar to a pacemaker, a vagus nerve stimulator (VNS) is a small device implanted under the skin near your collarbone. A wire (lead) under the skin connects the device to the vagus nerve in your neck. The doctor programs the device to produce weak electrical signals that travel along the vagus nerve to your brain at regular intervals. These signals help prevent the electrical bursts in the brain that cause seizures.
Once implanted in your body, the battery-powered device can be programmed from outside your body by your doctor. You can also use a hand-held magnet to turn the device on if you feel a seizure about to start.
It takes approximately 2 hours to surgically implant the VNS device in the chest.
What To Expect After Treatment
The vagus nerve stimulator can begin working right after the surgery (as soon as the doctor programs it). You may notice a slight bulge in the area under your collarbone where the device is, and the surgery will leave small scars on the side of your neck where the wire lead was placed and on your chest where the device was implanted.
Why It Is Done
Vagus nerve stimulation has been approved for use in treating both children and adults with partial seizures who have not responded well to antiepileptic medications and are not candidates for epilepsy surgery.
VNS is used in combination with medication or surgery. While it does not eliminate the need for medication, it can help reduce the risk of complications from severe or repeated seizures.
How Well It Works
The vagus nerve stimulator reduces the frequency of partial seizures that don't respond well to medication and may make them less severe. It is used along with antiepileptic medications or epilepsy surgery to control partial seizures.
It appears from initial research that the benefits of VNS increase over time. After 3 months, 34% of people reported better control of seizures. After 12 months of VNS, 45% of people had fewer seizures—with 20% of those people reducing their seizure frequency by 75%.1
For people who can sense when they are about to have a seizure, turning on the VNS can sometimes prevent the seizure. It may also shorten a seizure already in progress.
Initial studies show that VNS may be as effective in children as in adults.2 Children treated with VNS also showed improved alertness, mood, and memory; better school performance; and improved verbal communication skills.3
Risks
The vagus nerve stimulator is considered safe. Mild side effects occur in some people when the device stimulates the nerve. The most common side effects include:
- Coughing.
- Throat pain.
- Hoarseness or slight voice changes.
- Shortness of breath.
In children, vagus nerve stimulation may cause increased hyperactivity.
What To Think About
Vagus nerve stimulation is not a cure for epilepsy, and it does not work for everyone. It does not replace the need for antiepileptic drugs.
Doctors are not exactly sure how or why the vagus nerve stimulator prevents seizures, and its long-term effects, if any, have not been studied. But, the vagus nerve stimulator has been approved by Health Canada, and this type of treatment is an area of ongoing research. It is becoming an accepted part of treatment for some types of epilepsy.
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| Author: | Douglas Dana Merrill Hayden | Last Updated: February 2, 2006 |
| Medical Review: | Adam Husney, MD - Family Medicine Tom Bailey, MD - Family Medicine Steven C. Schachter, MD - Neurology | |
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| Topic Contents | |
| Treatment Overview | |
| What To Expect After Treatment | |
| Why It Is Done | |
| How Well It Works | |
| Risks | |
| What To Think About | |
| References | |