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.
After it is implanted in your body, the battery-powered device can
be programmed from outside your body by your doctor. You can also use a
handheld magnet to turn the device on if you feel a seizure about to start. And
turn it off if it is causing unpleasant side effects.
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
people over age 12 who have
partial seizures, who have not responded well to
antiepileptic medicines, and who are not candidates for epilepsy
surgery.
VNS is used in combination with medicine or surgery. While it does
not eliminate the need for medicine, 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 medicine and may make them less severe. It
is used along with antiepileptic medicines or epilepsy surgery to control
partial seizures.
It appears from initial research that the benefits of VNS increase
over time. In medical studies, about 3 out of 10 people had better control of
their seizures after 3 months. After 12 months of VNS, about 4 out of 10 people
had fewer seizures. After 18 months, about 3 out of 10 people had one-half the
seizures that they had before, and 2 out of 10 people had only one-fourth the
seizures they had before.1
For people who can sense when they are about to have a seizure,
turning on the VNS using their hand-held magnet can sometimes prevent the
seizure. It may also shorten a seizure already in progress.
Although the device has not yet been approved for use in children,
initial studies show that it may be as effective in children as in adults. VNS
also improved independence, mood, and learning in some children.2
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. It is most likely to be available
at an epilepsy center.
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.
Vagus nerve stimulation has not yet been approved for use in
children under age 12, but early studies suggest that it may significantly
benefit children with difficult-to-treat forms of epilepsy.
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