I’ve previously written about the problems with chiropractors and osteopaths claiming to be able to treat all types of headaches. The Advertising Standards Authority (ASA) permits chiropractors and osteopaths to advertise their treatments for only two specific types of headache:
- Headache arising from the neck (cervicogenic)
- Migraine prevention
In this post I’m going to look more closely at chiropractic and osteopathy treatment for the prevention and treatment of migraines. How strong is the evidence behind these treatments?
Evidence for chiropractic and osteopathy for migraine prevention
I don’t know the source of the ASA guideline permitting chiropractors and osteopaths to advertise their treatments for migraine prevention. However, it’s probable that at least part of the source is the Effectiveness of manual therapies: the UK evidence report (Bronfort report). Within this publication it states: “The impetus for this report stems from the media debate in the United Kingdom (UK) surrounding the scope of chiropractic care and claims regarding its effectiveness particularly for non-musculoskeletal conditions.” That’s not a very good reason for carrying out research. Regardless, let’s look at what it says about migraine prevention.
The Bronfort report states that there is “Moderate quality evidence that spinal manipulation has an effectiveness similar to a first-line prophylactic prescription medication (amitriptyline) for the prophylactic treatment of migraine”. This is based on 2 systematic reviews of manual therapy for migraine headache. The Bronfort report chooses to discard the results of 1 of the systematic reviews because it “evaluated study quality using a scale that is no longer recommended by the Cochrane Collaboration and did not apply evidence rules for their conclusions”. They chose instead to follow only the conclusions from the other systematic review. Who was the lead author for that systematic review? Gert Bronfort, the same person who is lead author for the Bronfort report. There is clearly a potential conflict of interest here so let’s have a look at the actual papers that formed the basis of both systematic reviews (there are only 3 of them and the same papers are in both reviews):
- Why does migraine improve during a clinical trial? Further results from a trial of cervical manipulation for migraine – This paper is focused on the reasons why migraines may improve during a trial. It is not intended to measure effectiveness of manual therapy
- A randomized controlled trial of chiropractic spinal manipulative therapy for migraine – This trial reported an improvement in migraine frequency, duration, disability, and medication use (but not pain intensity) compared with a sham treatment (detuned interferential therapy).
- The efficacy of spinal manipulation, amitriptyline and the combination of both therapies for the prophylaxis of migraine headache – This trial reported a similar effectiveness of spinal manipulation to an accepted medical treatment (amitriptyline).
The first thing that surprises me here is that both systematic reviews found only 3 trials related to manual therapy and migraines. This suggests that it’s an area that is under-researched and makes drawing strong conclusions difficult. Furthermore, the conclusion drawn by the Bronfort report that “Moderate quality evidence that spinal manipulation has an effectiveness similar to a first-line prophylactic prescription medication (amitriptyline) for the prophylactic treatment of migraine” is rather strange. It is based on just a single trial. Drawing conclusions from a single trial is always problematic and we would usually like to see similar results independently replicated in another trial before making any significant recommendations. In fact, given the apparent success of SMT found in this trial, which was conducted over 20 years ago, it’s surprising that there isn’t further published research looking at the same thing in the 12 year period to 2010 (when the Bronfort report was published).
For a more definitive and recent view it makes sense to look at the NICE guidelines. There are two key publications from NICE on this topic: NICE guidelines on Headaches in over 12s: diagnosis and management and the Clinical Knowledge Summary for Migraine. Neither of those publications makes any recommendation in favour of the use of the main treatments provided by chiropractors or osteopaths (manual therapy). If you look into the evidence behind the guidelines in more detail it’s easy to see why. This is what the NICE GDG (Guideline Development Group) had to say: “For migraine, there was one study showing some benefit. The GDG were concerned that the evidence reviewed was of low to very low quality with a lot of uncertainty in the effect estimates, and that rare adverse events may be severe when they do occur. It was agreed that better evidence was required to make a recommendation.”
The NICE guidelines recommend the use of medication-based treatments for the prevention and treatment of migraines. This should be in addition to use of a headache diary as well as providing appropriate information and support. All of these treatments and approaches are available from a GP.
Overall, the lack of research in this area makes it difficult to draw any significant conclusions about the effectiveness of osteopathy or chiropractic for migraines. There is certainly not enough evidence in order to make a recommendation in favour of using these treatments. It makes sense to use the NICE guidelines as the most reliable source of evidence and they recommend treatments that are available from a GP rather than those from a chiropractor or osteopath. I would summarise the current position as follows:
Based on the currently available evidence there doesn’t seem to be any good reason to recommend osteopathy or chiropractic for the treatment or prevention of migraines.
It would, however, make sense to conduct further research to see whether osteopathy or chiropractic could be of benefit. (The NICE guidelines make a similar recommendation for further research.)
In view of the lack of evidence, it’s surprising that the ASA guidelines allow chiropractors and osteopaths to advertise their treatments for migraines. The ASA guidelines would probably benefit from a review and update based on the evidence that’s available, in particular the NICE guidelines. In the meantime, if you have migraines it is best that you receive evidence-based treatments and these are all available from your GP.