Epilepsy Talk

Vagus Nerve Stimulation…Is it for YOU? | September 12, 2021

Having a Vagus Nerve Stimulator implanted can be a tough decision.  Is it right for you? Will it work? What are the side effects and consequences?

I did some research and got the low-down on what it is, how it works and some interesting statistics.  (If you are already acquainted with the VNS and are on the fence, you might want to just skip down to risks and benefits sections.)

How it works

Vagus Nerve Stimulation (VNS) has been used to treat more than 30,000 epilepsy patients worldwide. It’s designed to prevent or interrupt seizures or electrical disturbances in the brain for people with hard to control seizures. Used in conjunction with anti-seizure medications, the VNS uses electrical pulses that are delivered to the vagus nerve in the neck and travel up into the brain.

The good news is that the vagus nerve has very few pain fibers, so it’s an excellent pathway to deliver signals to the brain without the need for direct brain stimulation.

It’s sometimes referred to as a “pacemaker for the brain,” because it’s part of the autonomic nervous system, which controls functions of the body that are not under voluntary control, such as the heart rate.

What is the surgery like?

The surgeon first makes an incision along the outer side of the chest on the left side, and the device is implanted under the skin. Then a second incision is made horizontally in the lower neck, along a crease of skin, and the wire from the stimulator is wound around the vagus nerve in the left side of the neck. The brain itself is not involved in the surgery.

The device (also called an implant) is a flat, round battery, about the size of a silver dollar, about an inch and a half across — and half an inch thick.

The procedure usually lasts about 50 to 90 minutes while you are under general anesthesia. Sometimes a hospital stay of one night is required. Some surgeons have performed the procedure with local anesthesia and the patient has been discharged the same day.

The VNS device is usually set at a low frequency, then progressively raised over several weeks, until the perfect setting is achieved individually for you. Initially, the electrical stimulation is set for 30 seconds every five minutes. Your doctor will then adjust the timing based on your tolerance and seizure response on follow-up visits.

Meanwhile, you also have some control over the VNS. You’ll receive a magnet that activates the device. When you “swipe” over the device with the magnet, the VNS turns “on” and delivers a stimulus. This actually creates an aura to warn you of an oncoming seizure…

The Vagus Nerve Stimulation doesn’t guarantee that you will be seizure free. But it’s scientifically proven to reduce the frequency and length of your seizures. If you do have a seizure, additional current can be given via a magnet, in the area of the vagus nerve and you will often snap out of the seizure within seconds.

An added bonus can be the improvement of mood swings and memory. And some people can eventually discontinue seizure medications. Doctors are also using the VNS surgery to help some people with depression.

The Vagus Nerve Stimulator is approved by the FDA for use in those with refractory partial epilepsy, those with refractory depression and in people with primary generalized epilepsy, Lennox-Gastaut syndrome, Landau-Kleffner syndrome, and other seizure disorders.

Risks and side-effects

The risks of VNS implantation are low and mostly include the minor surgical risks of bleeding or infection (about 1-2%). At first, you may notice a tingling in your neck during the 30 or so seconds that the stimulator is “on.” In addition, when the Vagus Nerve is stimulated, about one third of people experience some degree of hoarseness which you can reverse by reducing the amount of stimulation. Even without any change in the level of stimulation, the hoarseness and any changes in voice quality tend to diminish and resolve themselves over several weeks or months. Rare side effects include change in swallowing, coughing or shortness of breath.

One thing you need to know after having the device installed: you should contact your doctor before having any new medical treatment, like X-rays, dental work or any type of surgery.  

(Who knows what airport screening machines will do!!!)

Benefits

Studies have shown that about:

1/3 of people have up to a 50% reduction in seizure frequency…

1/2 had a 75% reduction in hospital admission days…

1/3 have had no worthwhile benefit…

Case Study

13-year old female experienced intractable seizures, developmental delay and multiple seizure types. The seizures were both nocturnal and included drop attacks and daily absence seizures.

An MRI of the brain showed shrinkage of the left temporal lobe. A positron emission tomography (PET) scan did not show focal cortical abnormalities. But she had failed multiple trials of anticonvulsants because of allergic reactions or lack of efficacy.

Vagus Nerve Stimulation was recommended and the device was implanted without any complications.

One month after her VNS implant, she continued her anti-epileptic medications but was much brighter and interactive. Six months later, she had over a 90% reduction in the frequency and intensity of her seizures, with great improvement in the quality of her life.

As one person says: “I had a VNS implant in April 2010.  My seizures are 80% improved at this point, no more clusters of grand mal seizures and hitting my head on the floor.  Now I just have small seizures (usually absence) and recover very quickly, instead of sleeping for hours afterward.  The VNS works for some people, not all, I think it’s like a 60% chance of success.  I would say it depends if you’re willing to take the risk that it may not be effective for you.  It does take time to adjust and to see seizure control improve.”

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Resources:

https://www.mayoclinic.org/tests-procedures/vagus-nerve-stimulation/about/pac-20384565

https://www.epilepsy.com/learn/treating-seizures-and-epilepsy/devices/vagus-nerve-stimulation/placement-programming-and-safety-vagus-nerve-stimulation-vns

https://www.aans.org/en/Patients/Neurosurgical-Conditions-and-Treatments/Vagus-Nerve-Stimulation

https://www.webmd.com/epilepsy/guide/vagus-nerve-stimulation-vns

https://epilepsysociety.org.uk/about-epilepsy/treatment/vagus-nerve-stimulation

https://my.clevelandclinic.org/health/treatments/17598-vagus-nerve-stimulation

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