The relationship between chiropractic and acupuncture has also grown stronger over the past few years. Surveys from the National Board of Chiropractic Examiners show that nearly one in seven chiropractors uses acupuncture to treat patients; another two-thirds employ acupressure or "meridian therapy."1 In fact, results from a recent ChiroPoll (www.ChiroWeb.com/chiropoll/99archive/11_15_99.html) show that nearly 64% of chiropractors refer their patients to acupuncturists for treatment.
Numerous theories abound as to how acupuncture works. Some researchers believe that inserting acupuncture needles along certain points ("meridians") on the body stimulates the production of natural protein substances (endorphins) which have a painkilling effect. Another theory proposes that stimulation of the acupuncture points prevents pain impulses from reaching the brain.
Whatever the mechanism may be, there have been few definitive studies relating to the efficacy of acupuncture for pain relief. A new study presented at last month's meeting of the Radiological Society of North America, however, may have finally provided the proof that acupuncture advocates have been looking for. The study, conducted at the University of Medicine and Dentistry of New Jersey, has shown objective evidence that acupuncture works as a form of pain relief and that certain types of acupuncture work better than others.
The study involved a group of 12 patients who were monitored using functional magnetic resonance imaging (fMRI), a technology that reveals what parts of the brain are receiving increased blood flow. Increased blood flow to different areas of the brain is a reaction to pain stimulus.
The pain stimulus the 12 patients were subjected to came in the form of a tiny filament used to prick the inside or outside of their upper lip. Initial tests showed via fMRI that all 12 people reacted strongly to the pain stimulus, as there was an increased flow of blood to the parietal and stem areas of their brains.
Concurrently with being pricked with the filament, seven subjects received traditional acupuncture at the Hegu point, an acupoint located between the thumb and forefinger. The remaining five subjects received electroacupuncture at the Hegu point, with a low-level electrical current delivered through the needle.
During 30 minutes of treatment, the patients rated their pain level on a scale of one to 10 every five minutes, with the fMRI continually monitoring the patients' brains. In four of the seven subjects who received traditional acupuncture (57%), the fMRI showed considerably decreased levels of brain activity associated with the pain.
"We found activity subsided in 60 to 70 percent of the entire brain," said Wen-Ching Liu, an assistant professor of radiology at UMDNJ and a co-author of the study. "Interestingly, in each subject, we detected pain-induced activity in different areas of the brain."
The response was even greater among those who received electroacupuncture. Pain-related brain activity decreased in all five patients who received electrical stimulation, and those subjects showed a greater tolerance to pain than those who received traditional acupuncture treatment.
"We could see the brain activity associated with the pain subsiding even as the patients reported they were experiencing relief," added Dr. Huey-Jen Lee, the study's lead author. Lee noted that since the MRI definitively shows brain activity, it was highly likely that the increased tolerance to pain was real and not a placebo effect.
"The brain actually shows differences," Lee said, "and that is convincing."
The New Jersey study is just the latest in a growing wave of published reports showing that acupuncture is safe and that it does relieve certain types of pain. Recent studies in the journals Pain2 and Cephalalgia3 have demonstrated the therapeutic effects of acupuncture in treating shoulder tendinitis and recurrent migraine headache, respectively.
While the results of this study appear favorable for those who have been looking for clinical proof that acupuncture works, Dr. Lee warns others against jumping to the wrong conclusions. "It's still premature," she said of the study results. "We'd like to get more data."
Dr. Lee expects to conduct more studies in the near future, including a project to see whether acupuncture can help relieve chronic pain in cancer patients. While the researchers don't expect the treatment to be a panacea, they are optimistic that acupuncture could eventually be used to reduce the dosage needed for certain pain medications or as an alternative to non-steroidal anti-inflammatory drugs (NSAIDs), some of which carry less-than-desirable side-effects.
"So many people with pain, whether from cancer, headache or a chronic, unexplained condition, rely on medications such as morphine, which can become addicting," Dr. Lee concluded. "Acupuncture has no side effects, and other studies have shown the pain relief it provides can last for months."
References
1. Job Analysis of Chiropractic By State. Greeley, CO: National Board of Chiropractic Examiners, 1994.
2. Kleinhenz J, et al. Randomised clinical trial comparing the effects of acupuncture and a newly designed placebo needle in rotator cuff tendinitis. Pain 1999;83:235-241.
3. Melchart D, et al. Acupuncture for recurrent headaches; a systematic review of randomized controlled trials. Cephalalgia 1999;19(9):779-786.
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