Vagus nerve stimulation (VNS)

What is VNS used for?

Vagus nerve stimulator (VNS) is used as a treatment option for people who experience epilepsy that is poorly controlled with anti-epileptic medicines. The aim of VNS is to reduce the amount and length of seizures that your child has.

It aims to prevent the irregular electrical signals in the brain that cause seizures. This is done by the medical device delivering an electrical signal along wires to your child’s vagus nerve and then onto their brain. This is done by using an external magnet.

What is VNS?

A vagus nerve stimulator (VNS) is a medical device around 0.5cm thick and 5 cm across, with a plastic cover. It contains a battery and has wires that connect to the vagus nerve in the neck. The medical device sends an electrical signal along the wire to the vagal nerve. The setting of the device is managed by the epilepsy team.

The implant is not affected by any household appliances such as microwaves, mobile phones and so on. It will also not affect or be affected by security systems, such as metal detectors in shop doors and airports. However if your child needs an MRI scan, you must inform the medical team so they can take special precautions.

How is it inserted?

To have a VNS put in place, your child will need an operation by our paediatric neurosurgical team, is needed. Your child will be asleep under general anaesthetic, through out the procedure.

During the operation a small opening will be made to the left side of your child’s chest where the medical device will be placed inside. Another small opening will be made for the wires to be attached to the vagus nerve. The wire travels under the skin up the left side of the neck and is connected to both the medical device and the vagus nerve.

The wounds will be closed with dissolvable stitches. Pain relief will be given to your child during the operation.

What happens after the operation?

After the operation and once awake, your child will be transferred back to the ward. Initially your child may feel some discomfort where the VNS has been put inside their body. The nurses will monitor this and give your child pain relief.

If your child has a good recovery, they can go home the day after the operation. Stitches are usually dissolvable and so will not need taking out.

If pain relief is still needed this can be given to take home. There may be some swelling around the device this should settle as your child recovers and returns to normal activities.

How do we care for the wounds?

After the operation your child can bathe or shower, but the wound needs to be kept dry for 5 days after the operation. This is to stop the stitches from dissolving too quickly.

Keep a close eye on the wounds to make sure they should continue to heal and improve. Try to stop your child from touching or rubbing their wound. If the wound shows any signs of redness, pain or discharge please contact us immediately.

When can my child return to school?

It takes a different amount of time for children to recover from a general anaesthetic and an operation. In most cases children have returned to their normal activities by a week after the operation.

What aftercare will my child have?

Once your child has the VNS your neurology team (the Ryegate epilepsy team) will decide on an appropriate amount of electrical signals to be sent to your child’s brain by the VNS. After the procedure the VNS will be on its lowest setting.

Your child will need to come to follow-up appointments, so that the neurology team can change the electrical signal settings by using a wand and computer to meet your child’s needs. This does not hurt. These appointments will be quite regular at first, so your child can be monitored closely.

Your neurology team will explain how to use the magnet so please take it along to all your appointments. The aim of the magnet is to prevent a seizure or to help reduce the intensity or length. In certain situations the magnet can also be used to temporarily stop the stimulator for relief of the side effects, such as during exercise.

Your child will also have a follow-up appointment with the neurosurgical team to check on their wounds and recovery after surgery.

Are there any problems that can happen?

As with all operations and medical devices there is a risk of infection. If this happens your child will need treatment.

The device has a battery built into it however over time this will become less efficient and will need replacing. How much the device is used will determine when the battery needs to be replaced. Battery replacement is done by the same team, in a similar operation, however only the medical device needs to be changed and not the wires.

Should my child continue with epilepsy medication?

It is important to follow your neurology team’s advice on what medicines to use after surgery. Even though your child has their VNS, the neurology team may ask you to continue giving your child’s medicine, as VNS is not a replacement for medicine. VNS is an additional treatment.

Does VNS work?

Some patients report a big decrease in seizures, some have reported a smaller decrease and unfortunately some have reported no benefit after VNS treatment. However, following your child’s operation, it can take some time to see the results but this does not necessarily mean the VNS will not work.

Are there side effects to VNS?

There are some side effect from VNS including:

• a temporary hoarseness or change in your child’s tone of voice
• a tickling sensation, which may make your child cough
• some shortness of breath

These side effects can often re-occur when the electrical settings are changed but usually lessen over time.