Acupuncture May Have Late Effects in Migraine Prophylaxis

Pauline Anderson

January 13, 2012

January 13, 2012 — New research has found no significant difference between 3 styles of traditional Chinese acupuncture and sham treatment in the number of days patients had a migraine during the study period, the primary endpoint.

However, significant differences on this measure did become apparent several weeks after the end of treatment. The researchers, led by Ying Li, MD, PhD, and Hui Zheng, MD, PhD, from the Chengdu University of Traditional Chinese Medicine, Sichuan, China, also found small differences in the frequency of migraine, the intensity of migraine, and the intensity of pain, all of which were secondary outcomes of the trial.

"I think this study showed that there is a difference between real and sham acupuncture, but the difference is clinically minor," corresponding authors Fan-rong Liang, MD, professor and vice president of the Chengdu University of Chinese Medicine, told Medscape Medical News.

The study was published online January 9, 2012, in the Canadian Medical Association Journal.

Yang Meridians

In Chinese medicine, migraines are said to affect the yang meridians. The Shaoyang meridians are thought to be superior for treating migraines, as they go through the lateral side of the body, Dr. Liang said.

"In the view of traditional Chinese medicine, migraine is classified as a disease of the Shaoyang meridian, so specific points of the Shaoyang meridian are the best choice for migraine management," said Dr. Liang. "Nonspecific points of the Shaoyang meridian are the secondary choice, whereas the points of other meridian should be the last choice."

To test this hypothesis, researchers set up 3 acupuncture groups (Shaoyang-specific, Shaoyang-nonspecific, and Yangming-specific [another approach based on Chinese theory]) and a control group (sham treatment at nonacupuncture points).

The analysis included 476 patients in China with a mean age 36.9 years and onset of migraine before age 50 years, who had experienced acute migraine attacks for more than a year and had experienced 2 or more attacks per month during the previous 3 months. They had not taken prophylactic migraine medication during the previous month. The patients were randomly assigned to 1 of the 4 groups.

During a 4-week period, patients received 20 electrostimulation treatments. Acupuncture was applied unilaterally, alternating between the left and right sides. The goal was to elicit a de qi sensation, or sensations typically generated by inserting a needle into an acupuncture point and then manipulating it, in the 3 acupuncture groups, but not in the sham group.

During weeks 5 to 8, the study's primary endpoint, there were no significant differences in the number of days with a migraine between any of the acupuncture groups compared with the sham group, or between any of the 3 acupuncture groups.

However, there was a significant difference during weeks 13 to 16 in all treatment groups compared with the control group.

Table. Change in Days With Migraine (Weeks 13 - 16) With Acupuncture vs Sham Acupuncture

Acupuncture Type Change (Days) P
Shaoyang-specific −1.06 .003
Shaoyang-nonspecific −1.22 < .001
Yangming-specific 0.91 .011

Researchers were somewhat surprised that the differences between real and sham acupuncture were not more significant, said Dr. Liang. This might be a result of the protocol used, or the placebo effect may be larger than previously thought, he said.

The findings raise question of whether the effects would have increased even more with a longer follow-up period. This, said Dr. Liang, "needs to be studied."

Shaoyang-specific acupuncture proved to have an edge over control treatment on a number of measurements. "It was superior to sham in reducing the number of days with migraine during 13 to 16 weeks, and the frequency of migraine attacks and [visual analogue scale] score during 5 to 8 weeks and during 13 to 16 weeks," said Dr. Liang. "It was also better than Shaoyang-nonspecific acupuncture and Yangming-specific acupuncture in reducing pain intensity of migraine attack."

The finding that secondary outcomes, including pain intensity, are more improved with Shaoyang-specific acupuncture "confirmed that acupuncture points are effective for migraine management," said Dr. Liang.

Overall, the study demonstrates that acupuncture treatments have a significant effect on migraine, said Dr. Liang. "At baseline, patients had an average of 6.3 headache days a month, and at 13 to 16 weeks after study inclusion, the average of headache days was 2.2 days, so acupuncture removes 65% of headache days."

Although the electrostimulation occurring with acupuncture contributes to part of the effect, it does not explain it all. This issue is complex, said Dr. Liang. "The effect may be composed of several factors, including acupuncture effect, placebo effect, good doctor–patient relationship, and patients' expectation of the treatment."

Results of the study may be difficult to generalize to Western populations. For one thing, said Dr. Liang, North Americans may not be keen on receiving 20 acupuncture treatments within a 4-week period.

The study had a relatively short follow-up period. Other limitations were that physicians were not blinded to treatment assignments, patients in the Shaoyang-specific acupuncture group reported the highest number of days with a migraine at baseline (and the greatest effect after treatment), and the number of acupuncture points used was small.

Body of Evidence

In an accompanying editorial, Albrecht Molsberger, MD, from Ruhr University Bochum in Germany, and from the Center for Sensory Disorders at the University of North Carolina, Chapel Hill, points out that unlike other alternative therapies for migraine, acupuncture now has a body of evidence from trials of sound methodology. Evidence from more than 20 trials involving 4419 patients with migraines was summarized in a 2009 Cochrane review, concluding that there is benefit from acupuncture for migraine prophylaxis, he points out.

However, many of these trials have also failed to find a difference between "true" and "sham" acupuncture, he writes. The finding has fuelled debate on the role of placebo effects in these findings, but it also solves the problem to some degree of which school or acupuncture or particular set of pressure points provides benefit, Dr. Molsberger writes.

"On the basis of the existing evidence, acupuncture should be an option for the first-line treatment of migraine to supplement other nonpharmacologic treatment options," he concludes.

"It is at least as effective as prophylactic drug therapy, has longer lasting effects, is safe, seems to be cost-effective, and reduces drug intake with possibly severe unwanted effects," he adds. "All of this can be achieved even if point selection is not as dogmatic and precise as proposed by the Chinese system."

Asked to comment on the findings, Mary A. Whelan, MD, a retired neurologist from New York City, and a member of the American Academy of Neurology, said the study was "somewhat imperfect," as it was not double-blind.

"That's a potential bias, but it probably would bias things in the direction of favoring the acupuncture treatment, and in fact, there were no significant differences found between the control group and the treated group, so that argues that acupuncture is not an effective treatment for preventing migraine," she told Medscape Medical News.

Dr. Whelan noted that the purpose of the study was to determine whether acupuncture reduces the number of attacks, not whether it relieves migraine.

The study was supported by the National Basic Research Program of China. The authors have disclosed no relevant financial relationships.

CMAJ. Published online January 9, 2012. Abstract, Editorial


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