TENS is NOT recommended for treatment of low back pain

Why are we not at all surprised?

If you've been using TENS for ages, noting how poorly it works for anything other than transient pain gating for neurologic pain, here's another shot againt that practice that you may want to review.

From Medscape Medical News
AAN Guideline Recommends Against TENS for Chronic Low-Back Pain
Susan Jeffrey


December 31, 2009 — A new evidence-based review from the American Academy of Neurology concludes that transcutaneous electric nerve stimulation (TENS) is not recommended for use in treating chronic low-back pain but adds that TENS should be considered to treat diabetic neuropathy.

The report, from the academy's Therapeutics and Technology Assessment Subcommittee, was published online December 30 in Neurology. Authors on the new document are Richard M. Dubinsky, MD, MPH, from Kansas University Medical Center in Kansas City, and Janis Miyasaki, MD, MEd, from Toronto Western Hospital, Ontario, Canada.

"In the highest-quality studies of chronic low back pain, there was no benefit of TENS compared to sham or placebo TENS, leaving us to conclude that it is of no benefit, and make a recommendation that it should not be used for chronic low back pain," Dr. Dubinsky told Medscape Neurology.

In diabetic polyneuropathy, some studies showed slight benefit, he added. "We concluded it should be considered in the treatment of diabetic polyneuropathy."

Systematic Review

TENS has been used to treat neurologic and other disorders for decades, the authors write. The biologic basis of its analgesic effect is not known, but it is used is based on the gate theory of pain, they note. In this assessment, the authors carried out a systematic literature search of Medline and Cochrane Library up to April 2009, looking for controlled clinical trials in which TENS was used to treat pain associated with neurological conditions.

Acute low back pain not normally seen in neurologic conditions was not considered in this review. All but 1 of the studies excluded patients with known causes of low-back pain, such as pinched nerves, severe scoliosis, severe spondylolisthesis, or obesity.

"We only found 2 conditions that had adequate rigor in the research, and that was chronic back pain and diabetic polyneuropathy," Dr. Dubinsky said.

The studies included showed conflicting results in chronic low back pain. Two class 2 studies showed benefit, but 2 class 1 studies and another class 2 study showed no benefit. "Because the Class I studies are stronger evidence, TENS is established as ineffective for the treatment of chronic low back pain," they write.

Two class 2 studies suggested that TENS is probably effective in treating painful diabetic neuropathy. The only specific neurologic cause of chronic low-back pain in which TENS was studied was multiple sclerosis, for which TENS was not shown to be of benefit.

The document makes 2 main recommendations:

TENS is not recommended for the treatment of chronic low-back pain because of a lack of proven efficacy (level A, 2 class 1 studies).
TENS should be considered for the treatment of painful diabetic neuropathy (level B, 2 class 2 studies).
The document also gives some guidance on the need for further research into TENS, Dr. Dubinsky noted. Among their recommendations were determining what the best paradigm is, in terms of current, pulse-width, and frequency, and then using it in patients who are naive to TENS so that they will be truly blinded to treatment allocation, and studying TENS in patients with well-defined neurological conditions.

Absence of Evidence

In an editorial accompanying the new document, Andreas Binder, MD, and Ralf Baron, MD, from the Division of Neurological Pain Research and Therapy in the Department of Neurology at Christian-Albrechts-Universität Kiel, Germany, write that the conclusions of Dr. Dubinsky and Dr. Miyasaki "may heat up the discussion on the usability of TENS and may be viewed as supporting the critics who questioned the value of TENS in pain therapy.

"However," they add, "absence of evidence is not evidence of absence. The clinical impact of meta-analyses is always limited by the quantity and quality of conducted trials."

TENS has had a long-standing role in pain management, is easy to handle, has a favorable benefit-to-risk ratio, and can be discontinued easily if it is not efficacious — all "desirable properties when treating pain," they write. The new document calls for further trials and even provides "clearcut recommendations for their conduction," they note.

"This updated evidence-based review is valuable in providing the limits of our evidence base," Dr. Binder and Dr. Baron conclude. "Nevertheless, it is not unreasonable to take a practical position that, in spite of the relatively weak scientific and clinical evidence, TENS still represents a valuable therapeutic alternative in neurologic pain disorders.

"Taking the favorable benefit-risk ratio when compared with other pain relieving methods into account, TENS remains a valuable part in the armamentarium of pain therapy."

Dr. Dubinsky serves on a scientific advisory board and speakers' bureau for Allergan Inc, receives honoraria from BrioMed, and receives research support from Allergan Inc, Merz Pharmaceuticals GmbH, and the National Institutes of Health, the NIAM/National Institute of Neurological Disorders and Stroke, and the National Center for Complementary and Alternative Medicine, and his spouse owns stock in Abbott. Disclosures for coauthors appear in the paper. Dr. Binder has received travel expenses for lectures and educational activities not funded by industry and has received honoraria for speaking engagements and educational activities from Grünenthal, Allergan Inc, and Pfizer Inc. Dr. Baron serves on scientific advisory boards, as a consultant, and on speakers' bureau for Pfizer Inc, Genzyme Corporation, Grünenthal, Mundipharma International, Allergan Inc, Sanofi Pasteur, Medtronic Inc, Eisai Inc, UCB, Eli Lilly and Company, and Astellas Pharma Inc; has received travel expenses for lectures or educational activities not funded by industry; serves as an associate editor of Pain and on the editorial advisory boards of Nature Reviews Neurology and the European Journal of Pain; and has received research support from Pfizer Inc, Genzyme Corporation, Grünenthal, the German Ministry of Research, and DFG, Deutsche Forschungsgemeinschaft.

Neurology. Published online December 30, 2009.

Authors and Disclosures
Journalist
Susan Jeffrey
Susan Jeffrey is the news editor for Medscape Neurology & Neurosurgery. Susan has been writing principally for physician audiences for nearly 20 years. Most recently, she was news editor for thekidney.org and also wrote for theheart.org; both of these Web sites have been acquired by WebMD. Prior to that, she spent 10 years covering neurology topics for a Canadian newspaper for physicians. She can be contacted at SJeffrey@webmd.net.

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