Systematic Reviews Reveal Benefits of Acupuncture for Prevention of Migraines and Tension-type Headaches
Systematic Reviews Reveal Benefits of Acupuncture for Prevention of Migraines and Tension-type Headaches
Abstract & Commentary
By Dónal P. O'Mathúna, PhD. Dr. O'Mathúna is Senior Lecturer in Ethics, Decision- Making & Evidence, School of Nursing, Dublin City University, Ireland; he reports no financial relationship to this field of study.
Synopsis: Two systematic reviews concluded that acupuncture is somewhat beneficial in the prophylactic treatment of both migraine and tension-type headaches. The results of additional, recently published randomized trials provided more evidence of benefit compared to studies available for a 2001 version of these reviews.
Source: Linde K, et al. Acupuncture for migraine prophylaxis. Cochrane Database Syst Rev 2009;(1):CD001218.
This systematic review investigated whether acupuncture is more effective in reducing the frequency and intensity of migraine headaches in migraine patients than three other comparison groups: a) no treatment or routine care; b) placebo or "sham" acupuncture; or c) other treatments. Only randomized trials were included that had a post-randomization observation period of 8 weeks or longer. Trials with clinical outcomes such as headache frequency, pain intensity, analgesic use, etc., were included, but not those reporting only physiological or laboratory parameters. The main outcome measure was the proportion of responders during the 3-4 month period after randomization as measured by patient diaries. This outcome was selected because it was available for most studies. The meta-analysis used a random effects model due to the large clinical heterogeneity.
A total of 22 trials met the inclusion criteria, involving 4,419 participants. Twelve of these were not available at the time of the 2001 systematic review,1 of which this review was an update. Some trials compared acupuncture to more than one other intervention. Six trials compared acupuncture to no treatment or routine care in which acute treatment was given during a migraine attack. Much clinical heterogeneity existed in these trials, leading the reviewers to place little weight on pooled effect size measures. However, "the findings clearly show that response, headache frequency, headache days, and headache scores 3-4 months after randomization are more favorable in patients receiving acupuncture." Only one trial involved long-term follow-up (9 months after treatment stopped) and those who received acupuncture did significantly better than those on routine care.
Fourteen trials had a placebo or "sham" acupuncture group. The techniques varied widely, but included using needles without penetrating the skin or inserting needles at irrelevant needle points. The outcomes did not show statistical differences between the two groups.
Four trials compared acupuncture to pharmaceutical treatment, one to a relaxation program and one to combined relaxation and massage therapy. For the trials comparing acupuncture with pharmaceuticals, acupuncture was significantly more effective on almost all outcome measures. In all four trials, patients reported fewer adverse effects following acupuncture compared to the pharmaceuticals. The two trials involving relaxation groups were small and of low quality providing little useful data, although in both cases the results favored the relaxation group.
Overall, the authors concluded that acupuncture is more beneficial than routine care or treatment of acute migraines only, and that it is at least as beneficial as pharmacological treatments. However, an apparently contradictory finding is that true acupuncture is as effective as "sham" acupuncture for migraine.
Source: Linde K, et al. Acupuncture for tension-type headache. Cochrane Database Syst Rev 2009;(1):CD007587.
This systematic review used the same methodology as the above except that it searched for trials involving patients with episodic or chronic tension- type headaches. Randomized trials were examined where acupuncture was compared against the same three types of controls: a) no prophylactic treatment or routine care; b) placebo or "sham" acupuncture; or c) other interventions.
Eleven trials involving a total of 2,317 participants met the inclusion criteria, of which six were published since the earlier version of the review.1 Two large trials in which acupuncture was added to routine care and acute treatment found statistically significant and clinically relevant benefits in the acupuncture groups. The benefits were found up to 3 months, but were not investigated beyond this. Six trials compared acupuncture treatment with a "sham" acupuncture intervention. A meta-analysis found small but statistically significant benefits of acupuncture over "sham" on a number of outcomes. Four trials compared acupuncture with physiotherapy, massage, or relaxation. Three had significant methodological limitations and their results were difficult to interpret. The results with acupuncture tended to be less beneficial than with the other interventions.
Overall, the authors concluded that acupuncture could be a valuable non-pharmacological intervention for patients with frequent episodic or chronic tension-type headache.
Commentary
Most people who get migraine headaches can manage them with acute treatment at the onset of the attack. However, some migraine patients get attacks so frequently or respond so inadequately to acute treatment that prophylactic treatment is desirable. Drugs such as propranolol, valproic acid, topiramate, and others are available and effective at reducing migraine frequency, but many patients discontinue them because of their side effects. Relaxation and biofeedback can help some people, but other non-pharmacological interventions would be welcome. In the same way, tension-type headaches can be treated acutely. However, for people experiencing these headaches chronically (defined as more than 15 days per month) prophylactic therapy would be desirable.
Acupuncture is a popular complementary therapy for the relief of migraine and other headaches. This review team published a systematic review of acupuncture for idiopathic headache in 19992 and updated it in 2001.1 That review concluded that while the evidence was supportive of acupuncture as an effective treatment for idiopathic headache, the quality and amount of evidence was not convincing. Within the Cochrane Collaboration, authors are expected to update their systematic reviews regularly to take account of new studies. For this update, the authors decided to split their original review in two because of the number of new studies that had become available.
Systematic reviews have been criticized for combining high- and low-quality studies. These two systematic reviews included only studies in which randomization was appropriately carried out. They also used the new risk of bias approach developed by the Cochrane Collaboration.3 Rather than giving a single quality score, this approach examines study quality on the basis of sequence generation, allocation concealment, blinding, incomplete outcome data, incomplete follow-up outcome data, and selective reporting. The methodological quality of the trials varied considerably, with newer trials tending to be of higher quality than older ones.
One of the main limitations with both reviews was the heterogeneity of the studies. Some studies included patients with various types of headaches. Therefore, for the migraine review, the included studies were only those involving migraine patients or where data for migraine patients could be separated from all other data. In the other review, only studies in which data were available for episodic or chronic tension-type headache were included. The adequacy of the acupuncture intervention in the trials was assessed by members of the review team who were experienced acupuncturists. Only needle acupuncture in which the needles were inserted at acupuncture points, pain points, or trigger points were included. Methods such as laser acupuncture were not included. However, acupuncture is practiced differently in different countries and trials came from several countries. Curiously, none of the studies included in either review were conducted in China. The most frequently represented country was Germany, where acupuncture is most often practiced by physicians trained according to traditional Chinese medicine. The next most commonly represented country was the United Kingdom, where acupuncturists are usually not physicians and are trained in a more Western approach. The impact of these differences is not known.
While some benefit can be seen in some of the comparisons made in the two reviews, the size of the effect is difficult to establish because of the study heterogeneity. Explanations for the apparently contradictory findings in the migraine review were proposed. First, acupuncture might have a particularly strong placebo effect so that even "sham" acupuncture elicits a relatively large clinical effect. Second, the "sham" acupuncture often used acupuncture points believed to be irrelevant for migraine. However, some of the proposed mechanisms of action for acupuncture do not involve these points and instead suggest that the needles act through a more non-specific mechanism. These theories would suggest that "sham" acupuncture would be as effective as "true" acupuncture. The third explanation is that since participants were blinded only in the "sham" acupuncture trials, bias was introduced into the other trials. In addition, acupuncturists often question the appropriateness of acupuncture in clinical trials because of highly restrictive protocols that do not support individualization of therapy. This is particularly the case in trials involving "sham" acupuncture.
While many issues regarding acupuncture trials for migraine or tension-type headaches remain unresolved and require further research, these systematic reviews show that the evidence of benefit from acupuncture has become stronger in recent years. For prophylactic treatment of migraines and chronic tension-type headaches, acupuncture can be considered a treatment option for patients interested in trying it. Migraine patients who have experienced adverse effects from pharmaceutical treatments might be particularly interested.
References
1. Melchart D, et al. Acupuncture for idiopathic headache. Cochrane Database Syst Rev 2001; (1):CD001218.
2. Melchart D, et al. Acupuncture for recurrent headaches: A systematic review of randomized controlled trials. Cephalalgia 1999;19:779-786.
3. Higgins JPT, Green S, eds. Cochrane Handbook for Systematic Reviews of Interventions, Version 5.0.0. Malden, MA: Wiley InterScience; 2008.
Two systematic reviews concluded that acupuncture is somewhat beneficial in the prophylactic treatment of both migraine and tension-type headaches.Subscribe Now for Access
You have reached your article limit for the month. We hope you found our articles both enjoyable and insightful. For information on new subscriptions, product trials, alternative billing arrangements or group and site discounts please call 800-688-2421. We look forward to having you as a long-term member of the Relias Media community.