Dr. Allan Horowitz, published newspaper article, The Liberal, Copyright December 5, 1990

Today’s column discusses the findings of a study done in Seattle and San Antonio, the results of this study appearing in the New England Journal of Medicine, June 7, 1990. The study was designed to test the effectiveness of something known as transcutaneous electrical nerve stimulation (T.E.N.S.).

As the name implies, TENS is an electrical nerve “block” where electrical stimulations are used to crowd the messages reaching the brain. This “confuses” and “blocks” many of the pain messages reaching the brain.

Another theory states that TENS causes the release of “endorphins” which is the body’s own morphine-like pain medicine.

Whichever theory one accepts, we do know that the problem is still present, but the patient doesn’t feel as much pain.

TENS is used to control chronic pain such as that which is felt in headaches, back pain, arthritis, and so on.

This is the second study which was reported in the September 1990 issue of the Harvard Medical School Health Letter. The first study, which I reported on last week, gave the findings of a British study done to test the effectiveness of chiropractic care on patients with chronic back pain. (This study found that chiropractic care was more effective than the more traditional approach in treatment of back pain.)

Because TENS is another commonly used mode of treatment for those suffering from lower back pain, the Harvard Medical School Letter published both studies’ results side by side.

PHONEY TENS

            The investigators took 145 patients who had lower back pain for more than three months. Twenty-five per cent of these subjects received TENS only. Another 25 per cent received the same treatment, but it was not real TENS, just a sham or phoney treatment. Another 25 per cent were treated with real TENS and exercises and another 25 per cent were given phoney TENS and exercise. Patients did not know if their TENS unit was real or fake.

Patients were given the electrical stimulation (real or false) for 45 minutes, three times a day. They received 80-100 impulses a second, but at a very low voltage, and they therefore barely felt the current at all.

During the first month, everyone in all four groups improved. After three months, most patients’ pain increased again.

There was no difference in the groups receiving the real and false TENS treatment.

The researchers tested the subjects’ desire to continue receiving the TENS, their pain levels, and their functional disability, and there were no differences in those receiving the two types of TENS.

EXERCISE

Exercise did make a difference however, and after one month, people who were exercising reported less frequent pain and less intense pain. They were also more active than those receiving just the real or sham TENS.

After two months, these people in the exercise group stopped exercising, and their problems returned.

This study does not mean that those who have benefitted from TENS treatment are “nuts”, and their relief is all in their minds. This is just one study which shows that TENS is not effective.

Many other studies show that it is very effective, and many patients will tell the same story.

The verdict is still out on TENS, and although this study would imply that those with chronic lower back pain should not bother with TENS, it does remain an option, and many would support its use.

DIFFERENT TYPES

            There are also different types of TENS now being used, and this study tested only one type. It may be that as more information of this type becomes available to us we can sort through the good from the bad and find out what it is about TENS that does work, and what doesn’t.

Maybe then we can begin to use TENS in its proper form, for the proper condition, in the proper patient.