PENS Therapy: A Minimally Invasive Chronic Pain Management Solution
What is PENS Therapy?
PENS, or percutaneous electrical nerve stimulation, is a pain management technique that combines the benefits of acupuncture with electrotherapy. Sometimes referred to as electroacupuncture, the PENS medical technique uses very fine needles to stimulate a nerve or group of nerves via a small electrical current. During the procedure, the electrically conductive needles (electrodes) are pressed into the skin very near or immediately on top of the location of the chronic pain. Anywhere from 5 to 15 needles are used to puncture the top layer of the skin usually to a depth that varies from about 2 to 4 centimeters (3/4 to 1-1/2 inches). However, some newer PENS machines utilize a pad with hundreds of very short needles to break the skin's surface instead of a few longer needles. In either case, even though many needles are used to puncture the skin, this treatment is still considered to be minimally invasive.
PENS therapy can be used to treat a range of pain causing ailments. It is most often used for chronic joint or muscle pain, but it can also be used for pain associated with recent surgical procedures and sometimes neuropathy and osteoarthritis. The best areas to treat include the lower back, neck, shoulder, legs, knees, hips, hands, ankles and feet.
According to one study, PENS provided "highly effective short-term pain relief for patients with diabetic peripheral neuropathy" [Hazma, 2000]. While this therapy can be a good treatment for peripheral nerve pain, it may have reduced benefits for pain centers located in deep tissues, as accurate needle placement may be difficult.
PENS vs TENS
PENS Therapy: Percutaneous Electrical Nerve Stimulation - Uses needles to pass a current through the soft tissues underneath the skin to reduce pain.
TENS Therapy: Transcutaneous Electrical Nerve Stimulation - Uses adhesive pads to pass a current through the skin's surface to reduce pain.
Once the electrically conductive needles have been placed under the skin, a small current is applied to the them via a battery pack. The treatment typically lasts anywhere from 20 to 30 minutes per session. Usually the treatments are given 2 to 3 times per week over a period of a month or two. Some patients experience immediate pain relief however others may not see results until after they have undergone several treatments.
Adequate penetration of the needles is needed to help ensure good electrical conductivity across and through the origin of the pain. This is because the subcutaneous body tissues are significantly more conductive than the skin's surface. For this reason, PENS therapy has obvious advantages over other electrical therapies such as TENS (Transcutaneous Electrical Nerve Stimulation) treatment, which relies on passing current across the skin's surface. A 2004 study at the Okayama University Medical School in Japan showed that PENS therapy was more effective for treating long term chronic back pain then TENS therapy was [Yokoyama, 2004].
PENS Therapy Treatment Results and Expectations
With PENS therapy pain relief can sometimes be permanent however in most cases relief will last from several weeks to a few months or until that specific location is aggravated or injured again. The typical patient may experience positive results that last at least 3 months. The amount of pain relief can range from minor to significant as well. In one study conducted by the McDermott Center for Pain Management, 42% of patients reported that PENS therapy significantly reduced their sciatica pain. This is nearly double the number of patients who reported feeling relief with TENS therapy (23%) and more than 5 times those who underwent a placebo treatment (8%) [El-sayed, 1999]. In another study, 91% of patients chose the PENS treatment method as their preferred pain management solution and 80% indicated that they would be willing to pay more out of pocket to receive this treatment in the future [Ghoname, 1999].
What are the Risks and Side Effects of PENS?
During treatment most patients find this method of electro stimulation comfortable and endurable only reporting having a tingling sensation under the skin in the area where the needles were inserted. However, some people who have undergone PENS treatment have experienced certain side effects. For example, bleeding or bruising could occur at the site of the needle punctures during and after the treatment. If the area being treated is near the spinal cord some patients could experience headaches or bladder problems [Poinier, 2015]. There is also a small risk of scar tissue forming around areas that have been treated multiple times. In some rare cases patients reported that the pain they were trying to treat actually worsened with PENS.
In any case, patients are able to drive themselves home after the procedure and are advised to eat, drink and otherwise live as they normally would. Patients should also take care to keep the puncture site clean, dry and covered with a bandage for at least 24hrs or until it fully heals.
Also, PENS therapy may not be for everyone and certain individuals should avoid this treatment. Specially, people who rely on a pacemaker should not undergo a PENS treatment for obvious reasons nor should individual who have heart disease or have been diagnosed with epilepsy. Women who are pregnant should also avoid PENS therapy. Finally, this technology has not been tested with children and is therefore not recommend for them.
How Much Does PENS Therapy Cost?
In office PENS therapy can vary depending on location and region however most individuals report spending between $40 and $100 per treatment. Some health insurance plans will cover at least a portion of the cost of treatments however many plans don't cover PENS therapy at all. This is because some insurance companies may consider PENS as an experimental or investigational treatment due to the small body of knowledge surrounding this technology.
Depending on the location of your pain and it underlying cause, your doctor may advise you to do PENS therapy in the comfort of your own home. After the initial purchase of the PENS therapy unit, which ranges in price from $100 to $500 (and a commitment to purchase batteries), a significant cost savings can be realized with in-home treatment.
PENS therapy is a relatively new, low cost solution to chronic pain management. With PENS therapy, the risk of side effects are generally low and the potential benefits for pain relief often outweigh these risks. If you have tried other pain management techniques and failed to see results or if you are worried about the potential side effects of today's medications, then PENS therapy may be good alternative for you.
Demonstration of a PENS unit Being Used for Pain Management
References and Additional Resources
Blue Cross Blue Shield of Tenessee Medical Policy Manual, "Percutaneous Electrical Nerve Stimulation (PENS) and PercutaneousNeuromodulation Therapy (PNT)," March 2017. <http://www.bcbst.com/mpmanual/Percutaneous_Electrical_Nerve_Stimulation_PENS_.htm>
El-sayed, A. Ghoname, et al. "Percutaneous electrical nerve stimulation: an alternative to TENS in the management of sciatica." Pain 83.2 (1999): 193-199. Web 27 June 2017.
Ghoname EA, Craig WF, White PF, Ahmed HE, Hamza MA, Henderson BN, Gajraj NM, Huber PJ, Gatchel RJ. Percutaneous Electrical Nerve Stimulation for Low Back Pain: A Randomized Crossover Study. JAMA. 1999;281(9):818-823. doi:10.1001/jama.281.9.818 .Web 27 June 2017. <http://jamanetwork.com/journals/jama/fullarticle/188949>
Hamza, M.a., P.f. Whit, W.f. Craig, E.a. Ghoname, H.e. Ahmed, T.j. Proctor, C.e. Noe, A.s. Vakharia, and N. Gajraj. "Percutaneous Electrical Nerve Stimulation-A Novel Analgesic Therapy For Diabetic Neuropathic Pain." Journal of the Peripheral Nervous System 5.2 (2000): 118. Diabetes Journal. Web. 27 June 2017. <http://care.diabetesjournals.org/content/diacare/23/3/365.full.pdf>
MD Junction. "PENS (Percutaneous Electrical Nerve Stimulation)," Online Support Groups, 2017, <http://www.mdjunction.com/forums/reflex-sympathetic-dystrophy-discussions/medicine-treatments/10936647-pens-percutaneous-electrical-nerve-stiulation>
Poinier, Anne C, "Electrical Nerve Stimulation for Chronic Pain," WebMD, February, 2015 <http://www.webmd.com/back-pain/spinal-cord-stimulation-for-low-back-pain>
Wikipedia, "Electroacupuncture," March, 2017. <https://en.wikipedia.org/wiki/Electroacupuncture>
Wanich, T, Gelber, J, Rodeo, S, Windsor, R. Percutaneous Neuromodulation Pain Therapy Following Knee Replacement. The journal of Knee Surgery. 2011 Sep;24(3):197-202. PMID:21980881
Yokoyama, Masataka, Xiaohui Sun, Satoru Oku, Naoyuki Taga, Kenji Sato, Satoshi Mizobuchi, Toru Takahashi, and Kiyoshi Morita. "Comparison of Percutaneous Electrical Nerve Stimulation with Transcutaneous Electrical Nerve Stimulation for Long-Term Pain Relief in Patients with Chronic Low Back Pain." Anesthesia & Analgesia (2004): 1552-556. Web. 27 June 2017. <http://journals.lww.com/anesthesia-analgesia/Abstract/2004/06000/Comparison_of_Percutaneous_Electrical_Nerve.8.aspx>.