We now know one more treatment for chronic low back pain which does not work-at least in some situations.
The American Academy of Neurology's Therapeutics and Technology Subcommittee recently issued new guidelines, and among the pronouncements was the declaration that transcutaneous electric nerve stimulation (TENS) is not advised as a treatment for chronic low back pain that has lasted for three or more months.
On the other hand, it appears that a TENS unit continues to have a role in the treatment of painful diabetic neuropathy, regardless of the duration of the suffering.
TENS units have been used for chronic pain of various etiologies for over 40 years, the unit delivering a mild electrical current through electrodes placed in the area of the pain complaint. How it works, when it does work, is certainly not clear. The published literature is certainly not of the strongest scientific rigor.
Nevertheless, the American Academy of Neurology team scoured the scientific literature in order to come to some sort of conclusion regarding the utility of the TENS unit for chronic low back pain. This is what they found:
Two studies showed a modest benefit from the use of a TENS unit.
Two more rigorous studies concluded that TENS unit treatment lasting four or six weeks was not effective for chronic low back pain; one other study had similar disappointing conclusions regarding the TENS treatment.
And so the reviewers of the literature on the TENS unit concluded that the stronger evidence shows that TENS treatment is not effective for chronic low back pain.
And while the literature did show benefit for certain types of painful diabetic neuropathy, the literature is such that TENS treatment has not been compared to other accepted (pharmacologic) treatments currently used for painful neuropathy. In other words, we still do not know just how good TENS treatment is in these situations. We also need to try to predict exactly what type of patient will preferentially respond to a TENS unit.
Despite these findings, it should still be emphasized, particularly for those aficionados of the TENS unit, that it is too early to conclude that the TENS unit has little value in pain therapy. More research must be done.
As the saying goes, Absence of evidence is not evidence of absence.
