A couple of readers have asked me to comment on a study that appears in this month’s Journal of the American Veterinary Medical Association, Comparison of decompressive surgery, electroacupuncture, and decompressive surgery followed by electroacupuncture for the treatment of dogs with intervertebral disk disease with long-standing neurologic deficits.
The study was performed in Brazil at the School of Veterinary Medicine and Animal Science in Sao Paulo, where a similar study published last year and another in 2007 were also performed. The authors created 3 study groups, all of which consisted of dogs that had severe neurological disease of >48 hours duration attributed to intervertebral disk disease (IVDD). Group 1 (DSX) was a group of dogs (N=10) selected retrospectively from patients that had undergone surgery for IVDD at the authors’ hospital between 2003 and 2006. Group 2 (dogs treated with electroacupuncture-EAP, N=19) and Group 3 (dogs treated with both surgery and electroacupuncture-DSX+EAP, N=11) consisted of dogs seen at the hospital between 2006 and 2008, and patients were assigned to these groups based on their owners’ choice.
All dogs were treated with oral steroids. Dogs in Group 1 were treated surgically with a couple of different techniques and presumably with whatever unspecified medical treatment and post-surgical care the individual surgeon elected. Dogs in Group 2 were treated surgically (and again presumably with additional unspecified followup care) and were also treated with electroacupuncture. This treatment consisted of the insertion of metal electrodes into the body at points determined by “traditional Chinese theory.” Electrical current was passed through these electrodes for 20 minutes weekly for from 1-6 months. Scores were assigned to quantify the level of neurologic dysfunction initially and at 6 months after the beginning of treatment. Improvement was judged based on decrease in neurologic score and regaining the ability to walk unassisted.
The results can be summarized as follows:
The text indicates that the proportion of dogs in the DSX group that improved was statistically significantly lower than in the other two groups, and the proportion of DSX dogs that remained unchanged was significantly greater than in the other groups. From this, the authors concluded that “EAP was more effective than DSX for recovery of ambulation and improvement in neurologic deficits in dogs with long-standing severe deficits attributable to thoracolumbad IVDD.”
So is this conclusion justified? I believe not. To begin with, of course, we must decide what if anything this paper has to do with “acupuncture.” Electroacupuncture has been referred to as a bait-and-switch, because it is arguably not acupuncture at all. Obviously, the ancient Chinese lacked electricity, so the theories and guidelines developed for acupuncture in humans are not really relevant to the effects of electricity on the body (there were no specific guidelines for animals, and despite claims to the contrary it does not appear the Chinese routinely practiced acupuncture on animals before the mid 20th century). There is, however, a scientific medical therapy involving electrical stimulation to treat pain, transcutaneous electrical nerve stimulation (TENS). The only difference between TENS and electroacupuncture appears to be the selection of electrode location. TENS places electrodes in locations associated with known nerves, and in electroacupuncture the electrodes are placed at acupuncture points with no consistent relationship to any identifiable anatomic structures. However, by chance or perhaps some trial and error experience, some acupuncture points do happen to coincide with the locations of nerves, so it is possible that electroacupuncture might effectively be the same thing as TENS in some cases. So one might justifiably question whether any benefit seen in this study represents a validation of the theory and practice of acupuncture or an example of TENS with irrational selection of electrode locations.
However, there are other reasons to view the authors’ conclusions skeptically. A major methodological flaw of the paper is the process of selecting and assigning subjects. It is highly likely that there are biases inherent in allowing owners to choose what treatment group their pets should be in and in selecting one group retrospectively from one period of time and another prospectively during a different time period. This process does not allow the owners or researchers to be blinded in any way to the treatment, and it makes it likely that the patients and the treatment they receive in the various groups will differ with respect to many variables other than the one of interest in the study. The lack of blinding is of particular concern since the research center has consistently produced papers showing positive results for electroacupuncture and thus the researchers likely have a strong a priori bias in favor of the approach.
Very little information is presented to allow us to evaluate whether the patients differed in meaningful ways in terms of the medical therapy, surgical care, and post-surgical care they received. We do know that the EAP and DSX+EAP subjects received weekly treatments at the hospital for from 1-6 months after the onset of the study, and it is likely that they received much more intensive followup and post-surgical care (for the DSX+EAP group) as well as better owner compliance due to seeing the doctor so often after the study commenced. It is also quite possible that the differences in outcome were due to any number of differences in the populations of the various groups or the biases of the authors since these were not controlled for effectively.
There are other methodological problems, particularly the small number of subjects, but overall the two factors already discussed are enough to make me question the strong conclusions the authors draw from their results. It is certainly possible that electrical stimulation of some parts of the body could have a beneficial effect on outcome for dogs with neurological deficits attributable to IVDD. Better studies involving random prospective allocation of subjects, more consistency in the treatment of the subjects, blinding of the researchers and owners, and perhaps more precise assessment criteria would be valuable. I would be particularly interested, if there turns out to be some value to so-called electroacupuncture for this condition, in seeing a comparison of this procedure with electrode locations selected according to anatomic structures such as nerves compared with locations selected according to traditional Chinese medicine principles (insofar as such principles can be called “traditional” with respect to treating animals with electricity). It would take a robust and repeatable superiority of treatment at traditional acupuncture points compared with locations selected according to the principles of TENS to convince me that this procedure has anything to do with acupuncture.