Vagus Nerve Stimulation (VNS) Therapy
The goal of the therapy is fewer seizures, shorter seizures and faster recovery times afterwards, however individual results vary. Vagus Nerve Stimulation (VNS) Therapy is delivered through an implanted device that sends mild pulses through the vagus nerve to areas of the brain known to be associated with seizures.
What is the vagus nerve and what does it do?
The vagus nerve is a cranial nerve, meaning it is connected to the brain. There’s one of these nerves on each side of the body, which runs from the base of the brain, down the neck to the chest and abdomen. These nerves control muscles responsible for coughing, swallowing and voice sounds and sends feedback to the brain from the heart, lungs, stomach and upper bowel. The left vagus nerve mostly receives this input, with few connections to the heart, which is why it is the most suitable for VNS therapy.
How does it work?
The system, which is implanted within the body, comprises a lead, placed on the left vagus nerve in the neck, and a pulse generator, placed in the upper chest area similar to a cardiac pacemaker. Pulses from the generator are sent to the vagus nerve via the lead. The generator, which is programmed from outside the body, delivers stimulation pulses, as programmed by your physician, 24 hours a day regardless of your seizure activity or whether you are awake or asleep. You can deliver additional stimulation if you can feel the onset of a seizure by placing a magnet over the generator for a short time. A colleague or carer may also do this for you if a seizure has already commenced.
It is not fully understood how VNS works, but it is thought to alter the nerve pathways involved in seizures over time. VNS differs from anti-epileptic medications or dietary therapy. It is not a substitute for your medications and does not stop a person from trying new ones.
ALWAYS follow your doctor’s advice about medications.
Is it safe and effective?
Many people experience long-lasting seizure control with VNS. The therapy is safe and effective with benefits that have been shown to improve with time. Some people may experience side effects.
The most common include:
- hoarseness or changes in voice tone
- a prickling feeling in the skin
- shortness of breath
- sore throat
These side effects generally only occur during stimulation and usually decrease over time.
Vagus nerve stimulation has been approved for patient use in Australia by the Therapeutic Goods Administration.
The operation to implant the system is carried out under general anesthesia in a hospital setting. The procedure usually only takes an hour. An incision for the lead is made on the left side of the neck through which the vagus nerve is exposed and the lead placed around it. The other end of the lead is taken under the skin to the second incision in the left upper chest area below the collarbone and connected to the pulse generator. The system will not be switched on until several weeks after the operation.
Who is a candidate for VNS?
You may be a candidate for VNS therapy if you have epilepsy that is resistant to anti-epileptic medications, poor seizure control and are not a candidate for surgery. Children as young as 18 months have received this treatment and patients over 60 years have also been implanted. It is best to discuss your suitability with your medical specialist.
The text appearing here is abstracted from LivaNova where you can access further information.