A small device can make a big difference

An introduction to VNS Therapy

What are the components?


How does it work?

VNS Therapy works 24 hours a day, every day, for many years. VNS Therapy uses a small medical device (the generator) that will send small electrical pulses to the left vagus nerve in the neck. The vagus nerve is a major communication link between the body and the brain. It delivers these electrical impulses to the brain where seizures are believed to start.

What does VNS Therapy involve?

STEP 1: Implanting the VNS Therapy generator and lead

VNS Therapy is not brain surgery. Implanting the device requires a simple surgical procedure, which will involve just a short stay in the hospital.
Stimulation is provided by the generator sitting under the skin just below the left collar bone or close to the armpit. A small incision is made in the neck to attach two tiny wires (electrodes) to the left vagus nerve. The wires are threaded beneath the skin from the generator to the vagus nerve in the neck.
Aside from small scars (which usually fade with time and blend in with the natural fold of your neck) and a slight bulge in your chest, the device should be barely noticeable.


Step 2: Adjusting the parameters of electrostimulation

Your doctor will gradually adjust the parameters to find a dose that is effective and comfortable for you. The dose adjustment is typically a painless procedure, the doctor can adjust the dose to a comfortable setting without taking off clothes.
Your doctor programs the generator to automatically deliver the appropriate dose of stimulation for you on a daily and all day long basis. Once the dose is adjusted, stimulation is regular and automatic. At first, you may be required to see your doctor or nurse once every 2 weeks until they determine the best settings for you. Later, you may just need to visit your doctor every few months.

What is the function of the VNS Therapy magnet?

It is not necessary to use it for your regular stimulation.
By swiping the VNS Therapy magnet over the generator, either you or your caregiver will immediately activate therapy, which can be done either when you feel a seizure coming on or during a seizure. Using the magnet could potentially stop the seizure, shorten the seizure or decrease the intensity of the seizure. Furthermore, it might also improve the recovery period following the seizure.
You can also fix or hold the magnet over your VNS Therapy device to temporarily stop stimulation during times (for example while undertaking certain activities) when even mild side effects could be inconvenient.

What results can you expect?

VNS Therapy may bring you seizure relief
Successful VNS Therapy most often decreases seizure rate. The extent of the seizure reduction is variable for each person. And whilst the effects of VNS Therapy may take between a few months to one or two years to reach their optimum level, the positive effects typically will not decline; on the contrary, they could potentially further improve over time.

Improving the quality of life

VNS Therapy has been proven to reduce the number and intensity of seizures for people with drug-resistant epilepsy. Many people using VNS Therapy have also reported improvements in mood, alertness and memory. Furthermore, physicians have confirmed that some patients have been able to reduce the quantity and/or doses of medications over time. And many patients using VNS Therapy no longer have to make as many visits to the hospital.

The most common side effects of VNS Therapy include: a feeling of hoarseness or changes in voice tone, coughing, a tickling sensation in the throat and a feeling of shortness of breath. These side effects generally occur only when the generator is on and usually decrease over time.

Are there potential side effects?

Frequently Asked Questions

Will electrical and electronic equipment affect the VNS Therapy device?

Neither household appliances, such as microwave ovens, toasters, hair dryers, and cell phones will affect the device, nor the VNS Therapy device will affect electrical and electronic equipment.

Will metal detectors, for instance, such as airport security, affect the VNS Therapy device?

Such devices should not affect the VNS Therapy device or be affected by it. As a precaution, however, move through a metal detector at a steady pace; do not linger in the area.

Is VNS Therapy safe for pregnant women?

The safety and effectiveness of VNS Therapy have not been specifically studied in pregnant women. If you want to become pregnant or you are pregnant, please contact your doctor.

Can a patient be active in sports?

Patients should consult with a physician before engaging in unsupervised activities, such as driving, swimming, and in strenuous sports that could harm them or others.

What will happen if VNS Therapy doesn’t work for me?

If VNS Therapy has not helped you after one or two years, or you and your doctor consider VNS Therapy ineffective in any way, there are several options. The device can be turned off and remain implanted for an indefinite period of time. It may also be removed if you prefer or your doctor recommends it. Removal of the generator will involve a minor procedure and the lead will most likely remain in place. It is important to know that if you have VNS Therapy, you are still a candidate for any new treatment that could emerge in the future, for example, new surgical procedures or new drugs.

Intended use in EU

The VNS Therapy system is indicated for use as an adjunctive therapy in reducing the frequency of seizures in patients whose epileptic disorder is dominated by partial seizures (with or without secondary generalization) or generalized seizures that are refractory to seizure medications.


The VNS Therapy system cannot be used in patients after a bilateral or left cervical vagotomy. Do not use shortwave diathermy, microwave diathermy, or therapeutic ultrasound diathermy on patients implanted with the VNS Therapy system. Diagnostic ultrasound is not included in this contraindication.


Physicians should inform patients about all potential risks and adverse events discussed in the VNS Therapy Physician Manuals, including information that VNS Therapy may not be a cure for epilepsy. Since seizures may occur unexpectedly, patients should consult with a physician before engaging in unsupervised activities, such as driving, swimming, and bathing, or in strenuous sports that could harm them or others. Patients who have pre-existing swallowing, cardiac, or respiratory difficulties (including, but not limited to, obstructive sleep apnea and chronic pulmonary disease) should discuss with their physicians whether VNS Therapy is appropriate for them since there is the possibility that stimulation might worsen their condition.

The VNS Therapy System may affect the operation of other medical devices the same as other medical devices may affect the operation of the VNS Therapy System, MRI can be safely performed; however, special equipment and procedures must be used.

Adverse Events

The most commonly reported side effects from stimulation include hoarseness (voice alteration), paresthesia (prickling feeling in the skin), dyspnea (shortness of breath), sore throat and increased coughing. The most commonly reported side effect from the implant procedure is infection.