Vagus Nerve Stimulation (VNS)

This leaflet will provide you with information about Vagus Nerve Stimulation (VNS) therapy.

What is Vagus Nerve Stimulation (VNS) therapy?

VNS therapy involves a small electrical device, like a pacemaker, which is implanted under the skin of your child chest. The device sends electrical impulses to your child brain through a nerve in your child neck called the vagus nerve.

How does VNS therapy work?

 VNS therapy uses the VNS system, which is made up of 3 parts:

  1. A small pacemaker like device called a generator
  2. A thin and flexible wire called a lead
  3. A hand-held magnet
VNS
  • The vagus nerve sends messages between the brain and other parts of the body.
  • In VNS therapy, a generator is connected to the vagus nerve by a lead. The generator is programmed to send electrical impulses to the vagus nerve at regular intervals all day, every day.
  • These impulses are then carried by the vagus nerve to the brain.
  • This regular stimulation can help to reduce the number of seizures your child have and make them less severe.
  • Your child can also sweep the hand-held magnet over the generator to send more impulses to the vagus nerve. This could be if your child has an aura (warning) before a seizure
  • If your child feels a seizure starting, or when your child is having a seizure. Some people find that using the magnet stops a seizure happening, shortens the seizure or makes the seizure less severe.
  • A carer or family member can also use the magnet, if they see your child having a seizure.
  • New models of the VNS generator can also detect increases in heart rate.
  • In some people with epilepsy, an increase in heart rate can be a sign that they are having a seizure.
  • When the generator detects an increase in heart rate, it automatically sends more impulses to the vagus nerve. This may help to stop a seizure happening or make it less severe.

Who is eligible for VNS therapy?

  • If your child is still having seizures despite trying a number of different epilepsy medicines
  • If your child epilepsy medicine causes too many side effects.
  • If your child’s case is unsuitable for epilepsy brain surgery, or your child have had brain surgery but still having seizures.

What does VNS surgery involve?

  • Surgery to implant the VNS system is carried out under general anesthetic.
  • Your child’s surgeon will give more information before the operation takes place.
  • The operation takes between 1 and 2 hours and your child usually go home the next day and few cases can be at the same day.
  • The neurosurgeon makes 2 small cuts, 1 in a natural crease on the left of your child’s neck, and 1 in the left-hand side of your child’s chest, below your child collarbone.
  • The generator is placed under the skin in your child’s chest. A lead is inserted under the skin to connect the generator to the left vagus nerve in the neck.
  • Your child might have some pain for a while from the area of the implant after VNS surgery.
  • Your child’s doctor can prescribe something for the pain.

What happens after VNS surgery?

  • The generator is usually left switched off for two weeks after surgery. This is to help your child’s body to heal.
  • After that, it is usually switched on by a specialist doctor or nurse in a clinic.
  • They will gradually increase the settings over a number of weeks. This gives your child a chance to get used to the stimulation over time.

Will my child still need to take epilepsy medicine after the VNS has been implanted?

VNS is designed to be used in addition to epilepsy medicine, not to replace it. Most people need to keep taking epilepsy medicine after they have had a VNS system fitted. Some people are able to reduce the amount of epilepsy medicine they take over time. You will be able to talk to your child epilepsy specialist about any possible changes to your child medicine.

How long does the generator last?

  • At some point, the generator will need replacing when the battery runs low.
  • The generator battery can last between 3 and 8 years, depending on the model and settings used.
  • Your child’s doctor or nurse can tell when the battery is running down during your child’s follow up appointments.
  • They will then arrange for a new generator to be fitted. This involves a small operation, which lasts less than an hour.

What are the benefits of VNS?

The benefits of VNS can include the following:

  • Having fewer seizures
  • Having less severe seizures or shorter seizures
  • Possibly less epilepsy medicine
  • Having improved quality of life

What are the side effects from VNS?

Some of the side effects and health problems associated with implanted VNS can include:

  • Hoarseness
  • Tickling in the throat
  • Shortness of breath
  • Cough

The side effects of VNS usually happen during stimulation periods, and may improve over time. If you find the side effects uncomfortable, talk to your child’s doctor. They may be able to help by altering the level of stimulation. Also, it is possible to turn the VNS off for a short while using the magnet. If it causes major problems, it can be removed.

Safety Precautions:

MRI scans

If an MRI is recommended for your child, it’s important that all health care providers involved in the scan know about your child’s VNS system. They may need to take precautions to carry out the scan safely. You should inform your child’s doctor if MRI is requested.

Sidra Medicine cares about your health. The information in this leaflet should not be used as a substitute for the medical care and the advice of your doctor. Ask your healthcare provider about this information if you have questions. You can find us on www.sidra.org