Overview of VNS and Magnet Use
VNS Therapy™ helps control seizures by providing electrical stimulation to the vagus nerve, which then stimulates the brain. If you have a VNS implanted, you will return to see the doctor or nurse to program the device during office visits. During these visits, the generator is programmed to deliver intermittent stimulation, usually every 5 minutes but it can be more frequently. The device can also be programmed to deliver stimulation when it’s activated by a magnet. This allows the user to trigger an extra burst of stimulation when a magnet is swiped over the generator. The magnet settings may be set a little higher than the usual settings to provide more stimulation at the time of a seizure. The stimulation may last 30 or 60 seconds at a time, depending on how it works for you.
How does the VNS Magnet work?
Inside the VNS generator is a switch that opens and closes when the magnet is passed over it. The movement of this switch sends the burst of stimulation to the vagus nerve – when the magnet is held over the generator, the switch is closed and no stimulation is given. When the magnet is removed, the switch opens and the device is turned on. The location of the switch is key to knowing where to place the magnet on the generator. The placement of the switch varies slightly in the different models.
- Make sure that you read the VNS Therapy Patient Manual to find the location of the switch in the model of VNS that you have and how to swipe the magnet over the generator.
- When you see the VNS programmer (doctor or nurse), ask them to check the device history of your VNS. They can tell if the magnet mode has been activated and when. This information may help you know if you are using the magnet correctly. If you are using the magnet more frequently than is being recorded by the device, you may be swiping the magnet in the wrong place.
How helpful is the magnet?
Some people find that stimulation at the time of a seizure can help stop the seizure, shorten the event, make it less intense, or help the person recover quicker than usual. Not everyone finds the magnet helpful, but when it does work, it should be used as part of seizure first aid.
When should the magnet be used?
The magnet can be used anytime during a seizure, but it is most likely to work when it is used towards the beginning of a seizure. Use the magnet if…
- You feel a warning or sense that a seizure may be coming.
- At the start of a seizure.
- When someone notices that you are having seizure activity or anytime during a seizure.
How do I use the magnet when a seizure occurs?
- The magnet can be used by the person with seizures or by another person.
- Swipe the magnet across the generator under the skin (usually on the left side of the chest) for one second – start in the middle of the chest and swipe across the generator, counting ‘one, one thousand’.
- Wait 1 to 2 minutes (depending on how long the magnet is programmed to deliver stimulation) and if the seizure is still going on, swipe the magnet across the generator again.
- Don’t hold the magnet over the generator – the magnet will turn the generator off as long as it is held over the device for at least 6 seconds. Removing the magnet will cause the device to go back to its programmed stimulation cycles.
- Avoid overstimulation- if more than 4 hours of constant stimulation occurs, damage to the vagus nerve could occur.
What should I teach others about using the magnet?
- People who have the VNS implanted should teach others how and when to use the magnet as part of seizure first aid.
- Make sure other people know what your seizures look like and will recognize when you are having a seizure.
- Ask others to still provide basic care and comfort seizure first aid and make sure you are safe during a seizure.
- Show them how to use the magnet and let them practice when you aren’t having a seizure.
- Make sure they know when to use the magnet or if they notice you having a seizure.
- If the magnet doesn’t work or seizures continue, make sure others know when to call for emergency help. The VNS magnet is NOT an emergency treatment for seizures.
When can the VNS be turned off?
The VNS magnet can also be used to temporarily turn off stimulation. People may want to do this for different reasons. For example, people who have occasional hoarseness as a side effect of the VNS may want to stop the stimulation when they are singing or speaking in public. If a sensation of breathlessness occurs during stimulation, you may want to temporarily turn it off during intense exercise. Those with swallowing troubles may want to stop stimulation while eating or swallowing pills.
Talk to your doctor or nurse about when to turn off stimulation temporarily, for example:
- If stimulation interferes with certain activities.
- If stimulation becomes uncomfortable or painful.
How does the VNS magnet work to turn off stimulation?
When the magnet is held directly over the generator, the switch inside the generator is closed and stimulation will not be delivered. When the magnet is removed, the switch opens and the device is able to deliver stimulation.
Make sure that you read the VNS Therapy Patient Manual to find the location of the switch in the model of VNS that you have and how to hold the magnet over the pulse generator.
How do I use the magnet to turn off stimulation?
- Hold the magnet over the generator for at least 6 seconds. As long as the magnet is held over the generator, stimulation will not occur.
- If the magnet is removed in less than 65 seconds, a burst of stimulation will occur from the magnet mode then it will return to its normal cycle of stimulation.
- If the magnet is held over the generator for more than 65 seconds, when you remove the magnet, the generator will return to its usual cycle of stimulation.
- To hold the magnet over the generator for a period of time, tape the magnet in place. You can also wear a jogbra or something tight around the chest to keep it secure.
Anything that could be affected by strong magnetic fields could be damaged by the VNS magnet if it is kept too close to it. Keep the VNS magnet at least 10 inches from these items, for example, bank cards, credit cards, watches, computer discs or hard drives, televisions, or other items that may be affected by magnets.
A few safety tips
- Keep your magnet in a different pocket or on your belt buckle, away from your wallet.
- Create a metal lining for your wallet.
- If you use a computer frequently, don’t wear the magnet on your wrist – it may get too close to the computer. Wear it on your belt buckle or put it on the floor when you are working at the computer.
- Don’t put magnets on top of a television, stereo, or other electronic device.
- Don’t enter rooms or places that have strong electronic or magnetic fields or that have warnings for people with pacemakers or other implanted devices.
- Ask your doctor or nurse to write a letter to use while traveling that explains the VNS device and magnets. Wands used during security checks could affect the VNS device or the magnet could trigger a security alarm.
- Refer to the VNS Therapy Patient Manual and talk to your doctor for details about safety concerns with VNS Therapy and magnet use.