For people with drug-resistant epilepsy, treatment options can be limited. Vagus nerve stimulation (VNS) offers another treatment option for some people with difficult-to-treat seizures.

Using a small device implanted under the skin of your upper chest, VNS delivers electrical impulses to help reduce seizures. Although it doesn’t cure epilepsy, VNS can improve seizure control and quality of life.

This article explains how VNS works, who it might be recommended for, and what the potential risks are.

What Is Vagus Nerve Stimulation, and How Does It Work?

VNS is an epilepsy treatment approved by the United States Food and Drug Administration (FDA). The therapy uses a small device that’s surgically implanted under the skin of the chest. A wire connects the device to the left vagus nerve in the neck.

The device sends electrical pulses through the vagus nerve to the brain and is usually programmed to cycle on and off automatically throughout the day. These pulses help reduce the abnormal brain activity that causes seizures.

Researchers don’t fully understand exactly how VNS prevents seizures. They believe it works by affecting brain areas involved in seizure activity and changing how brain cells communicate, making seizures less likely.

Before a seizure, some people experience an increase in heart rate. The VNS device can be programmed to detect this change and automatically deliver extra stimulation to stop or lessen the seizure.

People with VNS devices also receive a handheld magnet. Keeping the magnet with you lets you manually activate the device if you notice warning signs that a seizure may be starting. Some people wear it clipped to their belt or as a bracelet so it’s easy to reach.

Be sure to tell your close friends and family how to use the magnet if you have a seizure.

1. VNS Therapy Is Recommended for People With Drug-Resistant Epilepsy

VNS is FDA-approved to treat adults and children ages 4 and older who have drug-resistant epilepsy. This means their seizures haven’t been controlled with medication. To qualify for VNS, a person generally must have tried at least two anti-seizure medications without successfully controlling their seizures.

VNS is approved to treat focal seizures (also called partial seizures). It works for seizures caused by abnormal electrical activity in the brain, so it’s only used for people with epilepsy.

VNS may also help some people with Lennox-Gastaut syndrome (LGS), a severe type of epilepsy that’s often difficult to treat. For people with LGS, VNS is usually used along with anti-seizure medications.

VNS is also an option for people who aren’t candidates for epilepsy surgery or whose seizures continue after surgery. A neurologist can determine whether VNS is a good option.

It’s important to note that VNS isn’t a cure for epilepsy and isn’t used on its own to manage seizures. Most people using VNS continue taking anti-seizure medications.

2. VNS Therapy May Reduce Seizures by up to 75 Percent After 10 Years

VNS can’t cure epilepsy, but it can reduce how often seizures happen and how severe they are for some people.

One study published in 2011 followed 65 adults and children with VNS devices. After six months of treatment, participants had, on average, nearly 36 percent fewer seizures. After 10 years, seizures had decreased by an average of 75.5 percent.

VNS may also improve quality of life, shorten the recovery time after a seizure, and lower the risk of sudden unexpected death in epilepsy (SUDEP).

If the VNS device is working well, your neurologist may lower the dose or reduce the number of anti-seizure medications you take. This may help reduce side effects.

3. Different Devices Have Different Features

Common VNS devices for treating drug-resistant epilepsy include:

• AspireSR — Automatically delivers extra stimulation when it detects a rise in heart rate and can be activated with a handheld magnet
• SenTiva — Includes the same features as AspireSR, along with additional programming options that allow more customized treatment

The newer SenTiva model can also detect if a person is lying flat after a seizure, which may help caregivers recognize that a seizure has occurred.

You’ll work closely with your neurologist to decide which device is the best fit for your epilepsy and treatment goals.

4. VNS Devices Are Placed During Outpatient Surgery

The VNS device is implanted during a surgical procedure, which usually takes 60 to 90 minutes. You’ll receive general anesthesia, so you’ll be asleep during the procedure.

A neurosurgeon makes two small cuts to place the VNS system — one incision on the left side of the chest to place the pulse generator, and another on the lower left side of the neck to connect the wire from the generator to the vagus nerve.

VNS implantation is usually an outpatient procedure, which means most people go home the same day. Be sure to get plenty of rest after surgery.

Your care team may recommend sipping on fluids and soups the first day at home, especially if you feel nauseous after anesthesia. You can usually go back to your normal diet as you feel ready.

Most people can return to their usual daily activities when they feel comfortable. However, you’ll likely need to avoid heavy lifting and strenuous exercise for about two weeks. This includes activities like hauling groceries or shoveling snow.

Your neurosurgeon will let you know when it’s safe to return to work, sports, and other activities.

5. The VNS Device Is Adjusted During Follow-Up Appointments

About two to four weeks after VNS surgery, you’ll see your neurologist to activate the device. They’ll program it to deliver electrical pulses based on your individual needs and seizure pattern.

VNS devices are usually started at a low setting and increased as needed. The device typically delivers stimulation in regular cycles, with periods when it’s on and off.

You’ll continue following up with your neurologist to adjust the settings as needed. It may take several weeks or months to find the program that works best for you.

The battery in a VNS device typically lasts four to eight years, depending on the settings. When the battery needs to be replaced, a surgeon can usually do so through a small incision over the device in the chest.

6. VNS Devices Are Designed for Long-Term Use but Can Be Removed

VNS devices are designed to be a long-term treatment for epilepsy. Once they’re placed, they can remain in place for many years if they’re helping reduce seizures.

If VNS isn’t effective or causes bothersome side effects, the device can be turned off or removed. Your neurologist and neurosurgeon can help you decide whether removal is the right option.

Some VNS devices may affect whether you can safely have certain MRI scans. If you need an MRI or another imaging test, be sure to tell your healthcare team that you have a VNS device. They can determine whether any special precautions or adjustments are needed.

7. VNS Devices Are Generally Safe and Have Few Side Effects

Most people can’t feel the stimulator as it sends electrical pulses. If side effects do occur, they’re usually mild and often improve over time or after your neurologist adjusts the device settings. Let your neurologist know if you’re having side effects such as:

• Infection at the surgical site
• A hoarse voice
• Sore throat
• Coughing
• Tingling or discomfort in the throat or neck
• Headaches
• Muscle spasms in the throat or larynx (voice box)

Talk With Your Neurologist About Vagus Nerve Stimulation

If you want to learn more about VNS and whether it’s a potential treatment option for you or a loved one, talk with your neurologist. They can help determine if you’re a candidate for this type of therapy and how it may fit into your epilepsy treatment plan.

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