by Neil Bauman, Ph.D.
October 24, 2016
A lady asked,
I have lower back pain from degenerative disk disease. I’m wondering if I can use a TENS unit on my back now that I have a cochlear implant?
If you are not familiar with TENS, TENS is not what comes after NINES and before ELEVENS! Rather it is an acronym that stands for “Transcutaneous Electrical Nerve Stimulation”.
Typically, TENS is used to help treat chronic pain. TENS units pass an electrical current through your skin (that’s what transcutaneous means) via two (or more) electrode pads taped to your skin near where the pain signals originate in order to stimulate the underlying nerves using electrical impulses.
The idea is that:
The body is capable of producing natural painkillers called endorphins and encephalins. It is thought that the impulses produced by the TENS machine help your body to produce these painkillers and so reduce pain.
The electrical impulses that are produced by the machine travel along the same nerve pathway as your pain. These impulses interfere with the pain message getting to the brain and override the pain sensation. (1)
Now, what does this have to do with cochlear implants (CIs)? Good question.
If you use a TENS unit too close to your cochlear implant, the current from the TENS unit can alter “the frequency of cochlear implants requiring them to be re-tuned”. (1) In other words, it can wipe out your cochlear implant’s maps. When this happens, you will need to have your cochlear implant reprogrammed. Until you do that, your cochlear implant won’t work and you’ll be left deaf.
Thus, when it comes to electrical equipment, it’s always better to be safe than sorry. So let’s look more deeply into this issue.
The cochlear implant manufacturers are well aware of TENS units and determine how close a TENS unit can be and yet not cause problems with the cochlear implant. Then they add additional distance for an extra margin of safety.
For example, the card that comes with CIs from Cochlear Ltd says not to use a TENS unit on the head or neck.
More specifically, according to otologist Dr. Thomas Haberkamp of the Cleveland Clinic Foundation, “TENS can be used but needs to be 20 cm from the implant: basically any treatment like that needs to be below the shoulder with any grounding below the shoulder.”
If you don’t know your metric conversions, 20 cm is 7.8 inches. Thus, just be sure that you keep any TENS electrodes at least 8” from your implant, and you will be ok. Note: both (all) electrodes need to be more than 8 inches from your implant, not just the “hot” one.
Since the 8” distance figure is already allowing for plenty of extra distance for safety, basically you can use TENS on your back below your neck and upper shoulders with safety.
In your case, since you are going to use it on the lumbar vertebrae in your lower back, you can use TENS without worrying that it may interfere with your cochlear implant in any way.
Does TENS work? Some swear it does and other say it doesn’t. Whether it works or not can also depend on the type of pain you have and where it is located.
However, if you have chronic pain, you can try it for yourself to see whether it works for you or not. It is non-invasive and does not have all the ototoxic and other negative side effects that painkiller drugs have so it can be a good initial treatment for pain management.
(1) Transcutaneous Electrical Nerve Stimulation (TENS). 2011. Nottingham University Hospitals. https://www.nuh.nhs.uk/.