Nerve Stimulation Device Doesn't Ease Most Back Pain

ByABC News
December 30, 2009, 4:23 PM

Dec. 31 -- WEDNESDAY, Dec. 30 (HealthDay News) -- If you're thinking of using the portable device called transcutaneous electric nerve stimulation (TENS) to ease your chronic low back pain, the American Academy of Neurology has some advice for you: Don't bother.

There are no controlled studies showing that TENS is effective against back pain of unknown origin persisting for three months or longer, said Dr. Richard M. Dubinsky, a professor of neurology at Kansas University Medical Center and chair of practice improvement for the academy. He is the lead author of a review article on the technology in the Dec. 30 online issue of Neurology.

"We did a systematic research review, also looking at a database for clinical trials," Dubinsky said. "We found very few of sufficient quality to analyze. We were looking for studies which were controlled by use of a placebo, and also had a sufficient number of subjects."

All but one of the studies excluded people whose back pain had known causes, such as a pinched nerve, severe scoliosis (curvature of the spine), displacement of a backbone or vertebra, or obesity. Those studies showed no benefit of TENS for chronic pain. The one study that looked at low back pain associated with known conditions found no benefit, the study authors noted.

An exception was diabetic nerve pain, also known as diabetic neuropathy, which can cause symmetrical numbness, decreased sensation and a feeling of burning, usually involving the legs but sometimes affecting the hands, Dubinsky said. There is good evidence that TENS is effective in this condition, which develops in about 60 percent of people with diabetes, he said.

TENS uses a portable, pocket-sized device to apply a mild electric current to the nerves through electrodes placed against the skin. It has been used for pain relief in a number of disorders for years, even though there is no established theory about how it may provide relief for pain. One theory is based on the belief that nerves can carry only one signal at a time, and that the stimulation provided by the device prevents the pain message from getting through to the brain.