Epilepsy

Vagus nerve stimulation (VNS) therapy

Anti-epileptic drugs control seizures in most people with epilepsy, but for those people for whom drugs do not work, such as with drug resistant epilepsy, there are other forms of treatment, such as neurosurgery.

For people who are not able to have epilepsy brain surgery, another form of treatment that may be available is Vagus Nerve Stimulation (VNS) therapy. 

What is VNS therapy?

VNS therapy involves surgically implanting a small electrical device (called a generator), similar to a pacemaker, under the skin of the chest, near the collarbone. The aim with VNS therapy is to reduce the number, duration, and severity of seizures.

The device has a wire that is wrapped around the vagus nerve. The vagus nerve is one of many nerves which carry messages to and from the brain and is found on the side of your neck.

The device passes a regular dose of mild electricity pulses to the nerve to stimulate it, and the vagus nerve carries these electrical pulses to the brain. This stimulation can help reduce or lessen the severity of seizures by altering irregular electrical brain activity that causes seizures.

The battery for the VNS device can last between 1 to 16 years depending on the model and settings used, after which time a further procedure will be needed to replace it.

How does VNS therapy work?

VNS can reduce the frequency and intensity of seizures, but very few people become totally seizure free, and most people continue to take anti-epileptic medication alongside VNS therapy.

How and why VNS works is not fully understood, but it is thought that stimulating the vagus nerve alters the chemical transmissions in the brain and changes patterns of electrical activity in the brain that cause the seizures.

If a consultant believes that VNS might be an option, certain criteria must be met before they can be considered for treatment with a VNS.

The National Institute for Health and Care (NICE)'s guidelines state that VNS therapy may be suitable in cases where a person has drug-resistant epilepsy (epilepsy that is not controlled after taking 2 or more anti-epileptic drugs) and epilepsy brain surgery is not an option.

VNS therapy is designed to be used as an add-on treatment to have alongside epilepsy medication, though it may work well enough to reduce medication over time.

The full effects of VNS may take up to a year to develop. 

After the VNS therapy device is installed

Most people experience mild side effects when the system is first installed and when the vagus nerve is actually being stimulated.

One woman, who had a VNS implanted in 2001, recalled how she felt after the procedure.

Tells how she felt after the operation and how things went after that.

View full profile

Age at interview: 52

Sex: Female

Age at diagnosis: 30

See full profile

SHOW TEXT VERSION

PRINT TRANSCRIPT

So I was knocked out and came to and it was done. Bit of pain and also the fact that I felt, and I was, it was almost kept me to one side, the left side kept sort of, I couldn't move it at all. I came back here. Nothing, they didn't do anything more than put it in and I went back about a month and a little later, about a month and a half later for them to actually get it activated. They did all the necessary business with the removing of the stitches because I've got little stitches where they'd put the vagal nerve stimulator in, and then three little lines coming up, I have a few more stitches there. But I went up I would say for them to get it activated the first time, but it was put in extremely low, almost as if I wouldn't feel anything. I did feel something but obviously after having had it done the first time, it was obvious that the, say the first fortnight, three weeks that you know, something had been done. And then just gone, you wouldn't even know it was there. And regular visits while they've had a look at it, seen whether it's necessary, asked me questions [um] 'How was I feeling?', 'Did I feel any better?'. 'How many seizures was I getting?' Each time that I have gone up they've been able to put it up a little bit higher from what has come from my mouth, 'Yes, it's better'.

Reported side effects include pain or discomfort in the face or neck, a tickly throat and/or cough, headache, and alteration of the voice.

As the person gets used to the device, the side effects may lessen. Adjusting the intensity, frequency or duration of the stimulation may also help.

The person can use the hand-held magnet to deactivate the generator or to increase the stimulation.

One woman explained how she got used to having the VNS despite a few side effects.

A carer, who told us about her 15-year-old daughter, reported experiencing problems with the magnet.

Explains that she got used to having the VNS despite a few side effects.

View full profile

Age at interview: 52

Sex: Female

Age at diagnosis: 30

See full profile

SHOW TEXT VERSION

PRINT TRANSCRIPT

I've got very, very used to it, extremely used to it now with the business of the magnet which is round my wrist, which if I feel any problems I can just whack it straight across where the operation in my chest has been done and that gives me a boost. In normal circumstances, providing everything is operating accordingly, it will do it by itself every 5 minutes. And it's quite interesting when people look at you and say 'Are you all right? You know, you're suddenly talking a little bit differently'. And that's fine because that means I don't have to do what they have asked me to do every morning, just test it by using your magnet across where the little operation has been done. This is what they're asking you to do but as things have gone on and I have been put up a little bit higher, a little bit higher, it's now become if anything a tiny bit painful in my neck area, in the jaw I would say. I know things are going on there. You, you do actually know 'Yes, it's working. It's doing it's business'.

... And because it's at it's particular height on, you know, now I can in actual fact do exactly what they said, which I said it probably would never happen, I will cough. Perhaps when I'm laying down or if I've perhaps, how I would say over-used it, with the talking I'll suddenly, hmm, cough. Or if I've been over-working. You know doing a little bit more than I should have done. But that has been minimal, minimal.

Discusses some of the problems her daughter had with the magnet.

View full profile

Age at interview: 15

Sex: Female

Age at diagnosis: 7

See full profile

SHOW TEXT VERSION

PRINT TRANSCRIPT

She had one, and then we had a lot of problems at school with her because the magnet actually wipes computers and credit cards and discs, Cds, anything like that. It de-magnetizes, so they wouldn't let her do any computer lessons or, they stopped all that at school because they were terrified of this magnet and the thing that she had in.

Um, what else was it, on the train, she was sat on the train one day and she was too near some, some equipment and something started going funny. So we had to move her away from it. So there's one or two glitches with it to be careful of.

Effects of VNS therapy

One woman discussed how VNS improved her seizures and quality of life.

However, VNS therapy does not work for everyone and, if there is no improvement after 18-24 months, the person may choose to have the generator switched off or removed.

One woman explained that VNS therapy had not worked for her daughter. Her daughter had since had neurosurgery and the VNS device would soon be removed.

Another woman explained why she decided against having VNS but thought that the technique would improve with time.

Discusses the improvements to her life after having a VNS implanted.

View full profile

Age at interview: 52

Sex: Female

Age at diagnosis: 30

See full profile

SHOW TEXT VERSION

PRINT TRANSCRIPT

That is worth every, every minute that that has, you know, has been, and that's been in over a year now. That's been worth every, every minute that, since that's been put in. But I was warned then, when they put it in, that it, there was a good, good possibility that it wouldn't work for me. I may only get 20% if I was lucky. Yes, if I was lucky, I could get 20% from it because they really did think that there was nothing they could do, they had to put that in to, with, with the mere, mere possibility that it would help.

A 20% reduction?

Reduction from my seizures. I say to people that it's got up to 40%. People look at me and say 'No, Lesley'. People who know me, know me well, say 'No, that is easily 50%, probably not, if not 60%'. I don't know. When you live with something like this you, you're a little but unsure as to only how high you can put something like that up, but as I'm about to activate now I think to myself 'That's good, that's really good. It's there, it's doing its work and it's really, really helped me'.

I can go places now where I wasn't able to before. I can go to a theatre. We've got a little theatre very close which only is about every, it's a little theatre for three months of the year. I can go there now you know with friends. I can enjoy it, I can laugh, I can, it's marvellous.

Explains that VNS did not reduce her daughter's seizures and the generator would soon be removed.

View full profile

Age at interview: 15

Sex: Female

Age at diagnosis: 7

See full profile

SHOW TEXT VERSION

PRINT TRANSCRIPT

The vagal nerve stimulator didn't really do very much to be honest. It did help initially, again maybe that was because, I don't know it, it just never did seem to do very much at all.

And you say that they've decided that they're going to take the vagal nerve stimulator out?

Yes.

When is that going to be?

I don't know, I'm waiting for an appointment for that. I'm presuming its not going to be before Christmas now, I don't know.

And why have you decided to have that removed?

It was just, they said that six months after the operation [neurosurgery] it would come out, it was kind of um, they didn't want to upset things too much I don't think after having, her having the operation. So they'd leave it six months so it was actually due out in about September. But it's going to be some time.

Explains why she decided against having VNS.

View full profile

Age at interview: 53

Sex: Female

Age at diagnosis: 2

See full profile

SHOW TEXT VERSION

PRINT TRANSCRIPT

Now you mentioned the second surgery. Are you thinking about that or what, you know, what have the consultants talked to you about?

Well it was, where are we March 2001, so we're talking about eighteen months ago, I went to see him and I, it was a check, it was a case of having another lobotomy operation, major, or the VNS. Now I've read up a lot more about the VNS and various people had sent the details through and I'm sure its gonna be good, better in time but its not too good at the moment.

As I pointed out, I don't know if you know about, you have to have a magnet on you and so on. And I was sending them back light-hearted comments like 'If you went on the tube, on the Underground, you have to be so much ahead of everybody because it wipes all the credit cards, mobile phones, the lot out.'! (laughs).

So you're not going to consider that?

No, well as I say it's the two choices. There's that one or the more major one and I know it sounds silly, the major one is more successful, that was what I was more in line for, when we spoke, he and I could suss each other out and he realised it was gonna be better, and I virtually said you know - yes, the VNS isn't good enough at the moment for myself. It has been okay and passable for some.

Last reviewed: November 2025.
Last updated: November 2025.