Could Vagus Nerve Stimulation (VNS) Stop Your Seizures?

A small device (sometimes called a ‘pulse generator’ or ‘stimulator’) is fitted under your skin near your collar bone. After approx. two weeks this is switched on. At regular intervals this sends short electrical pulses intermittently through your vagus nerve to your brain. This doesn’t hurt or cause any discomfort though it can make your voice squeak or make you cough at first, it should settle down after a while. Instead the small electric pulses help to calm the brain and the activity that usually causes seizures.  

The VNS will be pre-programmed for a 24-hour clock, allowing for ‘on time’ and ‘off time’ day and night. This timing can be adjusted by your epilepsy doctor. Here’s the really interesting bit – the device will be set at a stimulation amplitude (that’s electrical stimulation of sensory neurons) of 1.0 to 3.0 mA (milliamperes), a stimulation frequency of 20-30Hz (hertz) and a pulse width of 130 to 500 microseconds. Adjusting these settings to suit you can help you control your seizures and reduce pain and side-effects. Simulators can detect an increase in heart rate and measure your pulse, so if a spike in your heart rate is a seizure-trigger if will give you advance warning. As well as the stimulator, you’ll be given a hand-held magnet so you can activate the device. Fascinating isn’t it?

If you have auras or if your body sends a warning with seizure-like symptoms you can manually send an electric pulse to your brain. Simply swipe the magnet over the device for a second. Alternatively, if you’re having a seizure, someone close to you nearby can use the magnet to swipe for you. This can reduce the severity of your seizure. If your seizure continues, swipe again. There’s no limit to the number of times you can swipe – it won’t cause any side effects, but obviously the more you use it the faster the battery will run down – but don’t let this stop you swiping when you need to.

It may take some time for your body to adjust to VNS. You should start to see improvements in seizure control within 6-12 months. Within 18 months you should see a marked improvement.

This involves an operation (50-90 mins) under general anaesthetic. Chances are you’ll be able to go home the same day or, in some cases, after an overnight stay. Your brain will not be operated on – this procedure will just involve your neck and you may be left with a small scar. A tiny cut will be made on the lower left side of your neck, along a crease of skin. The device is implanted under the skin and a connecting wire is then wound along the vagus nerve from the stimulator. The implant is round and flat, about 4cm in diameter. If you have any queries before your operation, your epilepsy team will be available to chat through the surgery in more detail.

Side effects of VNS are usually minor and occasional such as coughing, feeling hoarse, sore throat and discomfort, swallowing difficulties and itching scars. The vagus nerve is responsible for your vocal cords and swallowing (among other things). So, stimulation of it can have side effects in these areas, for example, some people notice a change in their voice. These can almost always be reduced by adjusting the stimulation current in the device’s settings. Experiencing these side effects doesn’t mean that your VNS device will need to be removed, they will settle down over time. If you have any concerns though, chat to your epilepsy doctor about your side-effects.

On the plus side, you may notice that VNS helps improve your mood and wellbeing. It’s sometimes used to help people with depression so you may feel a boost emotionally, whether you need it or not.

Your battery should last between five and ten years depending on the make and model of the device. A small operation will be needed to replace the battery – this can be done under a local or general anaesthetic as a day patient. Your epilepsy doctor will know when it’s time to change the battery but do contact them if you think it’s time.

If you think VNS sounds good for you, have a chat to your epilepsy team about your options.