Results of 30 Years of Data on Electrical Nerve Stimulation for Chronic Pain

Electrical nerve stimulation (ENS) is a treatment for chronic pain. The electrical energy is sent in various wave forms to the nerves. It is delivered through electrodes placed over the skin. It works by overriding or blocking signals from the nerves to the spinal cord and brain.

Whether or not ENS works for pain relief has been the subject of many studies. The results have not been consistent. The authors of this study thought the varied results may have been caused by studies that were too small. So they reviewed and combined all the studies from 1976 to 2006 that met their selection criteria. This method of studying the success of a particular treatment option is called a meta-analysis

The studies had to be published in English about patients who had chronic (more than three months) musculoskeletal pain. The main measure of outcome was pain at rest. Pain was measured before and after treatment.

Different types of ENS were used but all were either transcutaneous (through the skin) or percutaneous (under the skin). All studies included both pain patients and placebo (control) groups. Animal studies were not allowed in the data analysis.

The results showed that ENS provided three times the pain relief received by a placebo. Percutaneous ENS worked better than transcutaneous ENS. The authors concluded from these combined study results that ENS is an effective way to treat chronic musculoskeletal pain.