We have discussed the risks of (chiropractic) spinal manipulation more often than I care to remember. The reason for this is simple: it is an important subject; making sure that as many consumers know about it will save lives, I am sure. Therefore, any new paper on the subject is likely to be reported on this blog.

Objective of this review was to identify characteristics of 1) patients, 2) practitioners, 3) treatment process and 4) adverse events (AE) occurring after cervical spinal manipulation (CSM) or cervical mobilization. Systematic searches were performed in 6 electronic databases. Of the initial 1043 studies, 144 studies were included.

They reported 227 cases. 117 cases described male patients with a mean age of 45 (SD 12) and a mean age of 39 (SD 11) for females. Most patients were treated by chiropractors (66%) followed by non-clinicians (5%), osteopaths (5%), physiotherapists (3%) and other medical professions. Manipulation was reported in 95% of the cases (mobilisations only in 1.7%), and neck pain was the most frequent indication.

Cervical arterial dissection (CAD) was reported in 57% of the cases and 46% had immediate onset symptoms; in 2% onset of symptoms took for more than two weeks. Other complications were disc rupture, spinal cord swelling and thrombus. The most frequently reported symptoms included disturbance of voluntary control of movement, pain, paresis and visual disturbances.

In most of the reports, patient characteristics were described poorly. No clear patient profile, related to the risk of AE after CSM, could be extracted. However, women seem more at risk for CAD.

The authors concluded that there seems to be under-reporting of cases. Further research should focus on a more uniform and complete registration of AE using standardized terminology.

I do not want to repeat what I have stated in previous posts on this subject. So,let me just ask this simple question: IF THERE WERE A DRUG MARKTED FOR NECK PAIN BUT NOT SUPPORTED BY GOOD EVIDENCE FOR EFFICACY, DO YOU THINK IT WOULD BE ON THE MARKET AFTER 227 CASES OF SEVERE ADVERSE EFFECTS HAD BEEN DESCRIBED?

I think the answer is NO!

If we then consider the huge degree of under-reporting in this area which might bring the true figure up by one or even two dimensions, we must ask: WHY IS CERVICAL MANIPULATION STILL USED?

85 Responses to Upper neck manipulations (by chiropractors) regularly cause serious harm. Why are they still used?

  • Thank you for this interesting article. Do you have the figures of how many of the 57% if cases of CAD were caused by mobilission as opposed to manipulation? Do you feel mobilisation is safer optio to use in the place of manipulation if do you feel both should be stopped. I would be interested in your opinion. Many thanks.

    • the vast majority must be after manipulations. mobilisations are usually less forceful and less risky. nobody is calling to stop mobilisations, as far as I know.

      • The vast majority of CAD’s “must be” after manipulations? Please specify where in the report I might find this statement, Edzard. Thank you.

    • This review as referenced did not claim that any of the CAD cases were CAUSED by either manipulation or mobilization. The review only claimed an association, not causation.

  • My comment might be somewhat off topic.

    During some research I did for my series of articles on the similarities between Al Capone and the CAM Empire, I came across this statement made in the NSW parliament – It made me think a lot. It was made by the director of Complementary Medicine Australia; “Medicines are founded on the principal of ‘first do no harm’ and the plain fact is that no one has died from using complementary medicines” – yep!

    We can now obviously have a long discussion about direct and indirect harm, the former being discussed in your blog post but the latter also being applicable – a lack of benefit arguably causes the most harm. Anyway, this director is standing in parliament and he is lying through his teeth, and he is not the only one doing this in order to protect the CAM empire. They just continue to defend it.

    My point is this. I honestly believe that you will find chiropractors (or any other CAM therapist), who has studied somewhere (and incurred debt), who has set up a practice somewhere, who has built up professional relationships with numerous patients, and also who knows pretty well that their treatments are ineffective but also sometimes dangerous. But, no amount of science or number of adverse reactions, even to the people that they treat themselves, will convince them that what they are doing is unethical and wrong.

    The only way, I see it, to effect chance on a large scale (including all the other CAM therapies) will be to develop an Exit Strategy, because very few people will give up their monthly income and security, have their characters assassinated by the remaining fraternity, struggle to find a job with a useless degree and experience etc etc. voluntarily. Think of it this way. As a bright eyed inexperienced student, you’ve been hoodwinked (not everyone of course) to go and study a pseudoscientific degree at some university and once you are in the system, there is just no way out. The only solution for them is to continue.

    So, as long as there is no workable exit strategy I fear we are just pissing against the wind. I am not saying that writing about the pseudoscientific issues regarding the CAM empire is a waste of time, it serves a very valuable purpose especially by informing the public. I just don’t think it will have much of an overall impact due to the sheer number of people, with their high profile connections, focus on marketing etc in the CAM empire. An exit strategy for those who wants out, might be a solution to the overall problem and it might even have an impact in a reasonable amount of time.

    • A hugely valuable point that’s similar to Dennett’s (US philosopher) and La Scola’s Clergy Project which protects the anonymity of religious employees / entrepreneurs who’ve realised the ludicrous nature of their industry and it’s reliance on charlatanry to survive.
      I’d not considered the similarity to CAM before. Thank you.

      When I first heard of the Clergy Project, funded by Richard Dawkins Foundation for Reason and Science, I was disgruntled that those who lie to kids should receive support. Time allowed me to digest the pragmatic realism and kindness of such an Project. I trust readers here will similarly overcome any initial reservations about your suggestion, Frank.

      • I am a person for solutions! But before I, or anyone else, can recommend a solution to a problem, the problem itself needs to be defined – and this is usually where we struggle . Usually we do not know what the exact problem is, even though our solutions are just flying all over the place. So the question is, what exactly is the problem?

      • You cannot compare CAM with religion, although the lack or decline in religion has aided in the rapid growth of CAM, especially in the Western world, that is about the only link that you can make between the two. The former lends itself to be tested by the standard scientific method whilst the latter cannot be tested. We are off topic.

        • @Frank van der Kooy

          I disagree that you can’t compare CAM with religion. Most examples of CAM are based on fantastic, unscientific claims that depend entirely on faith for their validation, and therefore cannot be reasonably tested. Indeed, proponents of CAM consistently demand that its opponents disprove their claims, which is beyond the scope of the tool of science.

          When you say “The former lends itself to be tested by the standard scientific method” you are really talking about specific claims of CAM. Compare and contrast equally specific claims of religions, e.g. miracles (which have continued to be claimed to the present day), divine intervention in response to prayer (which has been scientifically tested several times in a medical context) or via faith healing (ditto but with far less rigour!). I could go on, but I think you’ll get my drift.

          • There is no comparison of CAM to religion, Frank. You are really stretching the facts to allege otherwise. Suggesting that faith is indigenous only to a religion is simply wrong. An example would be the faith that the Wright brothers had in the possibility of building a craft capable of taking a human airborne; they had been subtly and overtly mocked for their beliefs…until they succeeded. They didn’t worship anything specific regarding their “faith” in their ideas. Alt Med proponents and consumers self-conclude differently than you regarding the benefit they receive from the substances they take. They have no less faith in those substances than CAMEDICS have in antibiotics. That is, they intellectually think they work just as well. Whether they do or not is not my point here. CAM is not religion.

          • “I disagree that you can’t compare CAM with religion. Most examples of CAM are based on fantastic, unscientific claims that depend entirely on faith for their validation, and therefore cannot be reasonably tested. ”

            How is manipulation to improve mechanical function of the spine untestable or unscientific?

            How is needling which is known to activate endogenous pain relieving mechanisms untestable or unscientific?

          • The word ‘faith’ has two meanings, L-B. You’re deliberately choosing the wrong one.

            1. complete trust or confidence in someone or something.
            2. strong belief in the doctrines of a religion, based on spiritual conviction rather than proof.

            I was talking about no. 2, as you must have known. Orville and Wilbur had no. 1.


            Manipulation and needling are not, in principle, either untestable nor unscientific. When manipulation is claimed to go beyond improving mechanical function and to relieve imaginary ‘subluxations’ and improve ‘innate healing’ mechanisms, it steps into the boundaries of quasi-religious teaching: definition no. 2.

            When both manipulation and needling have been repeatedly tested scientifically as therapies for specific disease conditions and have been demonstrated to offer nothing beyond placebo effects, continuing to believe they have clinical merit again steps into the second definition of ‘faith’.

          • @Frank Odds

            “Manipulation and needling are not, in principle, either untestable nor unscientific. When manipulation is claimed to go beyond improving mechanical function and to relieve imaginary ‘subluxations’ and improve ‘innate healing’ mechanisms, it steps into the boundaries of quasi-religious teaching: definition no. 2.”

            I agree with this point of yours. The rest of your comments….not so much.

    • You make a good point. I am sure that many CAM practitioners believe that they are doing good. For those whose livelihood depends on their practice, the realisation that they have fooled themselves and their clients, must be unpleasant as well as difficult. An organisation to help those who find themselves in such a position would be beneficial.

      • Indeed, it boils down to money.
        There are about 30 000 people employed by this industry (CAM) in Australia, just imagine the number of people in China employed by this industry – must be more than a million. The thing is, if you can’t solve this issue we can go and debate risks and benefits regarding all sorts of (ridiculous) CAM’s out there, but we wont solve the problem – how can the people involved in all this, escape it? By debating the whole issue we might save a couple of individuals, but it is not going to solve the problem.

        • Time was (before mid 18th century) when all ‘health care practitioners’ were trying to build practices with faith in one modality or another (not a ‘religion’ – in most cases. A few did ascribe results to deities) – and to some extent, all were quacks.

          That is precisely why systems for professional regulation were developed.
          Fact is, for some reason, some folks could not or would not, comply.
          And so have developed ‘alternative’ modalities and systems.

          And now, having failed to engage properly with a conventional regulated profession they impertinently seek to have their systems ‘integrated’ with the conventional.
          And thereby undermine modern medicine.

  • @ Edzard

    More evidence that chiros overuse manipulation instead of using the possibly safer and just as effective mobilisations.

    The abstract of the review doesn’t seem to refer to upper neck manipulations but rather to cervical spine manipulations. Is there more detail in the article to whether it is just upper neck manipulations that cause severe adverse events? Are lower neck manipulations just as dangerous?

    Also was there a further breakdown of professions, as 20% of patients seem to have no specified practitioner?

    • “Is there more detail in the article to whether it is just upper neck manipulations that cause severe adverse events?” mostly neck manipulations
      “Are lower neck manipulations just as dangerous?” probably not

      • @ Edzard

        Was it just chiropractors who were doing upper neck manipulations?

        • mostly [66 %] I think

          • @ Edzard

            Is there any evidence that lower neck manipulations are “probably not” as dangerous as upper neck manipulations?

            Also, are there any direct quotes from the article that refer to upper neck manipulation because it does seem from the abstract that they were looking at cervical spine manipulations? If there are actual quotes about upper neck manipulation, can you present them in the context they were written in the article.

  • Completely agree.
    But why not to extend this argument to all manipulations?
    Physios, osteopaths, and osteopractors (!), mostly use the same techniques.
    This body of evidence that goes against chiropractic manipulations should be generalised to other professions too.
    Manipulations are ineffective, besides being dangerous, no matter who use them!

    • “Physios, osteopaths, and osteopractors (!), mostly use the same techniques.”
      not quite true, I think
      chiros are mostly concerned because they employ manipulations with close to 100% of their patients.
      and they were responsible in 66% of all AEs.

      • I meant: when they manipulate, they use the same technique. The risk is in the technique, not in the profession.
        I agree that chiropractic is fundamentally based on manipulation, and are therefore mostly concerned.

        • Is it? Maybe this the techical difference between mobilization and manipulation, but don’t chiros use high-speed manipulations than, say, osteopaths?

          • Physios and osteopaths have several techniques they can use. But when they use manipulations (that is, by definition, high velocity low amplitude manipulations – HVLA) they perform them in the same way! It is important to realise that more and more physios, see “osteopractors TM”, consider HVLA their main treatment option. This is very sad and worrying for our profession.

      • What percentage of CAD’s were chiros responsible for, Edzard?

  • An objective and valid reason why upper cervical manipulation will be used as an on going intervention is it’s proven effectiveness in the clinical management of fibromyalgia..

    • This is very false Dr Epstein.
      Evidence on the effectiveness of manipulation in MSK conditions are controverse. When studies are well designed, and include a proper placebo comparison, clinical effectiveness drops to zero.
      This is particularly the case in fibromyalgia, where passive treatments are of no help. Everyone who states the opposite is unaware of the large amount of literature on the topic, showing a very complex clinical picture requiring inter-disciplinar care to target psychological, sleep, dietary, and physical aspects. All passive treatments proposed can sometimes work as adjunct, but they rarely are better than just placebo.
      You might need to look at F. Wolfe body of work on fibromyalgia.

      • Dear Andrea,
        Regarding your comment that MSK is controversial. I wish to bring to your attention that on 14 February 2017, the Annals of Internal Medicine published new guidelines established by The American College of Physicians on the management of acute, subacute and chronic low back pain. They now recommend that spinal manipulation should be considered before pharmaceutical intervention.
        I agree with you that spinal manipulative therapy should not be a stand-alone therapy for the management of fibromyalgia. However, I disagree that its use does not have evidence and science-based clinical merit. The multimodal approach that I use can be reviewed at

        • “They now recommend that spinal manipulation should be considered before pharmaceutical intervention.” Sure, but the devil is in the details. Here’s the full recommendation: “Given that most patients with acute or subacute low back pain improve over time regardless of treatment, clinicians and patients should select nonpharmacologic treatment with superficial heat (moderate-quality evidence), massage, acupuncture, or spinal manipulation (low-quality evidence). If pharmacologic treatment is desired, clinicians and patients should select nonsteroidal anti-inflammatory drugs or skeletal muscle relaxants (moderate-quality evidence). (Grade: strong recommendation).” [My emphases]

          So lower back pain (not a candidate for upper neck manipulations under any circumstances, which this thread is about) is a self-resolving condition; a good reason for avoiding pharmacological treatments in the first place. And the evidence for spinal manipulation is, as ever, of low quality, which is why chiropractic comes in for so much contempt on this blog. You have therefore not made any case for manipulation of the cervical spine by diverting readers to reccommendations for lower back pain. And your linked website contains all the usual garbage about chiropractic treatment for “disease and organ dysfunction”, including gastroesophageal reflux disease, highlighted on the home page, for which the evidence is zero.

  • I’m curious to discover how the 144(out of 1043) studies, and 227 cases of AE’s were selected, and how many of the dissections were alleged to have been associated with manipulations by chiropractic doctors. I’m also curious as to why Edzard failed to criticize the synopsis of this review as fastidiously as he does those which evince SMT to be quite safe. I note that Edzard didn’t criticize what he calls “weasel words” in this review as he does in pro-chiro studies. The words “appear” and “seem” are imbued in this review yet Edzard failed to mention them as equivocations.

    57% of the selected cases demonstrated cervical artery dissections? This number doesn’t pass the real-world plausibility threshold. I discussed this report at a district meeting last night with fellow DC’s, DO’s, and an MD. Literally tens of millions of cervical manipulations have been provided by this group and by me: ZERO CAD’s have occurred during their many years in practice. Further, no one in the room was aware of any friends/colleagues who had had a patient unfortunately experience a dissection. I will offer some thoughts on this matter:

    1. This review is about cervical manipulative therapy (CMT) not chiropractic treatment. Although it mentions that spinal manipulations were most commonly performed by chiropractors, it failed to specify that they are also done by members of the allopathic, osteopathic and physical therapy/physiotherapy professions.”

    2. There is no suggestion that CMT is inappropriate. (On current research evidence it is a first line option for many patients on the grounds of safety, effectiveness and patient preference/satisfaction – for example those with common forms of neck pain and headache(see A Best Evidence Synthesis on Neck Pain by Haldeman and Cassidy).

    3. It is acknowledged that there is no clear evidence that cervical artery injury and stroke are caused by CMT, as opposed to being associated in time with it. Causation with CMT was not proven. On this the AHA has in the past explained:

    a. Study of the forces reaching the cervical arteries during manipulation/CMT shows that these are insufficient to strain the arteries and are less than “during passive range of motion.”. In other words less than during normal medical examination procedures.

    b. The only study comparing the frequency of stroke after visiting either a chiropractor or a primary care medical doctor, reports no difference. In the AHA’s words: “Because patients with VAD (vertebral artery dissection) commonly present with neck pain, it is possible that they seek therapy for this symptom from providers, including CMT practitioners, and that the VAD occurs spontaneously, implying that the association between CMT and VAD/vertebrobasilar artery stroke is not causal.”

    4. It is acknowledged that the association between stroke and CMT is rare. It is fair to say that the AHA statement does not make this sufficiently clear. On this:

    a. The AHA authors, in the conclusion say that “the incidence of CD (cervical artery dissection) in CMT patients is probably low.”

    b. In fact it is generally described by researchers as extremely low or rare with an incidence of about 1 in one million treatments. This can be better understood by most people if described as one incident in a group of 25 CMT practitioners all of whom have been in practice for 40 years. This jibes with my personal experience as well as that of the doctors with whom I met last evening.

    c. This form of ischaemic stroke is found following many apparently mild activities, such as turning to back the car, overhead painting, sports activities, yoga, prayer, etc. Again, it is very rare. No-one knows whether it is more common after CMT or any of the activities mentioned.

    d. CMT/neck manipulation is far safer than other common medical treatments for neck pain. By comparison, nonsteroidal anti-inflammatory drugs (NSAIDS) cause 153 stroke deaths per one million people and spinal surgery of the neck causes 500 stroke deaths per one million people. Tu Quo Que, I admit(I couldn’t resist!).

    5. The AHA’s past conclusion was that health care professionals performing CMT should be aware of the possible association between CMT and CD, in rare patients with both severe neck pain or headache and with other factors associated with stroke that can be discovered from the patient history and exam. There should be informed consent where appropriate. I believe such is agreeable to the vast majority of clinicians who expertly provide CMT in their practices.

  • Professor Ernst,
    You ask, why is cervical manipulation still used?
    One answer is because it is beneficial in the treatment of patients with Fibromyalgia Syndrome. “The addition of upper cervical manipulative therapy in the treatment of patients with fibromyalgia: A RCT.”
    Please read this March 2015 paper published by Moustafa and Diab in Rheumatology International.
    A randomised control trial with one year follow-up.

    • Please read this March 2015 paper published by Moustafa and Diab in Rheumatology International.

      I did, and I shouldn’t have because I really shold have been attending to something else. But, it was a good excercise.

      I have to say I am rather worried, very worried actually. The study is ambitious and intricate, too intricate in my opinion. The paper is quite legible, despite some irritating errors like lack of a whole row of data in the baseline participant demographics table.
      The pair of authors, Moustaffa and Diab, seem to be ardent researchers and have previously found delayed positive effects of adjustments/manipulation on posture. They are undoubtedly happy to find something to interpret as support for their previous work.
      Here they studied two groups of 60 persons, had a low dropout so the power is acceptable for the expected effect size.
      They gave all participants a collection of different standard fibromyalgia treatments including excercise, cognitive therapy and education.
      The hypothesis they are testing is problematic. They declare in the paper: “the main hypothesis of the present study was that the addition of upper cervical manipulative therapy to a multimodal program would result in short- and long-term improvements in 3D spinal posture parameters and FMS management outcomes.” Instead of comparing manipulation to no manipulation, the study interventions consisted of one group receiving non-thrust mobilisations and the other HVLA thrusts to the upper cervical spine. No control group with only “standard” FMS therapy was constructed. The outcome conclusion seems to have been based on an “a-posteriori” hypothesis. (I have not had a look at the regsitration of this trial to check what they stated there as their trial hypothesis)

      They compared the groups pre- post- intervention and at one year with on one hand, a collection of well known standardised tests including Fbromyalgia impact questionnaire, Algometric score, Pain catastrophizing scale, Sleep quality index, and Beck’s depression and anxiety scales.
      On the other hand, they used something called “Rasterstereographic posture analysis”, which seems to be a German 3D-imaging instrument producing strange (to me?) squiggly diagrams called “formetric scans” that can be interpreted to determine a large colection of parameters, i.e. “lumbar angles”, “thoracic angles”, “trunk inclination”, “trunk imbalance” and “lateral deviation”, “vertebral surface rotation” and “pelvis torsion”.
      I admit that I have no prior knowledge of this methodology and its validity but my concern is how well validated and standardised these complex measurements really are? I am rather technically minded and to me this smells like a de novo (based on a single inventors ideas) invention not based on independently validated methodologies and not widely and independently tested and standardised? I also have the feeling it may be prone to observer/interpreter bias?
      I may be wrong in these speculations but I fear not. If someone wants to correct me with credible information I will gladly change my mind about this, but please keep it clear and concise.

      If someone is by now starting to think in terms of “p-hacking” and “effect sizes” then you’re absolutely right, that is exactly what concerns me.
      Here’s a passage that describes well the author’s interpretation of their findings:

      This randomized controlled trial compared the outcomes of
      FIQ, PCS, algometric score, PSQI, BAI, BDI, and 3D postural
      measures between a group that received an upper cervical
      manipulation and a multicomponent intervention program
      and a group that received only the multicomponent
      intervention program. The comparison of the 3D postural
      parameters between the experimental and control groups
      revealed significant differences at the two follow-up points.
      In contrast, after 12 weeks of treatment, the FMS management
      outcomes indicated that both of the intervention
      programs were equally successful in improving the
      patients’ FIQ, PCS, algometric score, PSQI, BAI, and BDI parameters. Thus, although the experimental group
      exhibited improved 3D posture, this did not translate into
      improvements in the FMS management outcomes compared
      to the control subjects at 12 weeks.
      However, at the one-year follow-up after the end of
      the treatment, there were statistically significant changes
      that indicated that the FMS management outcomes of the
      experimental group exhibited continued improvement and that the control subjects’ scores regressed back toward the
      baseline values (i.e., the scores worsened). Therefore, the
      one-year follow-up analysis provided objective evidence
      supports our study’s main hypothesis.
      In our opinion, the one-year improvements in the FMS
      management outcome measures observed in the experimental
      group are the most significant findings of our investigation.
      The normalization of the afferent input of the upper
      cervical spine seems to offer an explanation for these oneyear
      improved outcomes in the experimental group.

      Thus, they found differences in all the 3-D scanning parameters. I get the impression that in addition to my concerns about the validity and standardisation of these measurements, and the possibility(?) of interpretation bias, this is a case of advanced p-hacking.
      They found no difference between pre- and post- treatment fibromyalgia related parameters but found a marked difference at one year, especially in the Fibromyalgia Impact Questionnaire with an impressive effect size. That, as the authors admit, is not explicable in any biological / physiological way. They go on in speculative lengths but without any conclusion, about proprioceptors and posture but these differences may to my eyes be due to many factors, even chance. It would be interesting to have a look at the raw data?
      What I find strange is that the Algometric score, a number derived from assessment of point tenderness in fibromyalgia patients, goes significantly up as time passes, while other related parameters, namely the fibromyalgia impact score and the pain catastrophizing scale go down at length. This is puzzling as I cannot find any indication that this score should have an inverse significance and if I am not mistaken it ought to covariate positively with the FIQ and the PCS at least.

      Further and most serious, there is no blinding… none at all! Even if some of the measurements are very prone to subjective interpretation and bias.
      The authors even openly admit that “The use of a blinded, independent outcome assessor is highly recommended for future research.” I am almost certain, by the wording in the discussion part, that the authors were lucky to get this paper published after being told off and to add an upright declaration that this study’s primary limitation is the lack of blinding.
      This blatant error in study design should have been enough to throw the whole thing in the dustbin of any respected journal. Especially seeing as the authors have an interest in supporting their previous findings and thereby subliminal bias is to be expected. It is probably the overall quality of the work that got them accepted with an admission of this error.

      Finally, why on earth did they not include an arm that received only sham or at least no cervical manipulation in addition to the standard FMS therapy?? The outcome of this study could just as well be interpreted thus:
      Non-thrust mobilisation prevented long term spontaneous improvement of FMS!!
      Had they included a non-manipulation arm, God only knows how results cold have been interpreted, perhaps this:
      HVLA manipulation… is equal to placebo and non-thrust mobilisation prevents long term spontaneous improvement of FMS

      This study is non-conclusive until someone independently supports its findings in a better study.

      • @Geir

        This was a nicely written and well thought out review of the Rheumatology Intl. study. Thank you for your time in typing it.

        Would you kindly comment specifically on the methodology of the upper neck SMT study you originally brought to our attention?

      • Dear Ernst and Geir,
        By writing your opinion, you have improved my ability to critique a research paper. Thank you!

        If we return to the original purpose of this whole conversation. What is conclusive in Moustafa and Diab’s quality paper is that the 60 patients who had upper cervical spinal manipulation three times a week for 12 weeks did not experience any reported damage to their carotid or vascular arteries. If anything, only benefit albeit inconclusive until a blinded study can be performed. In addition, would you consider the non thrust manipulation a placebo intervention to be compared with the SMT group?

        • @Michael Epstein

          I was recently obliged in this same thread to comment on another chiropractor’s evident lack of familiarity with basic anatomy and epidemiology. I see that my fears of chiropractors being poorly familiar with basic vascular anatomy may be reasonably founded? The main arteries in the neck are not the “carotid [and] vascular arteries”. They are the Carotid and ‘Vertebral’ arteries. The denial must be deeply rooted if you aren’t even familiar with the name of the artery being suspected to be most at risk in one of your most common “adjustments”

          I am also obliged to comment on your (seemingly?) poor understanding of basic concepts of risk, ratios and large number arithmetics.
          If you have an estimated risk of an adverse event happening at a ratio of one in several hundred thousand or even millions of instances of the intervention under study, then you would have to repeat an experiment involving only 2160 (60x12x3) interventions several tens of thousand times to have a reasonable likelihood of one AE occurring during your series of experiments. It was not only good luck that saved Moustafa and Diab from having one of their participants entering nursing home with a feeding tube for life. The risk of such an event is low. But there is always the odd person who wins at the lottery and if this had happened to one of the 60 participants in Moustafa & Diab’s little study, I am quite sure we would not have been discussing this paper here.

          Risk always needs to be related to benefit. When no definite benefit is demonstrable as in the case of upper neck HVLA-manipulation (and M&D’s paper in question does not change that fact) then the risk ratio would be the risk of AE divided by nothing. It does not matter what number you estimate the risk to be, If you divide this number by a figure that is zero or close to zero, your risk benefit ratio will for all practical purposes approach infinity, which is of course unacceptable. That means the risk is so high in relation to the benefit that the intervention is unacceptably risk prone.
          When on top of all this, the consequences of ONE adverse event happening are likely to be severe brain damage with catastrophic disability or death, THEN WHY IN [replace with your favourite long and strong profanity] DO CHIROPRACTORS VEHEMENTLY KEEP THEIR HEADS IN THE SAND AND REFUSE TO TAKE THE CONSEQUENCES!!!??
          If this was a situation involving a drug or a medical procedure, all hell would have broken loose long ago and the drug or procedure stopped immediately.
          If chiropractors had any guts (or functioning intellect?) they should recommend against any kind of cervical HVLA “adjustments” and warn against such practices by laymen. At the very least, they would start a large scale, independently monitored investigation of their own and recommend informed consent for any neck wringing, pre-adjustment screening for signs of arterial compromise (and of course referral to proper medical care if present). If no signs of suspected compromise and patient willing to consent and they find it indicated, then due dilligence with extremes of motion in all HVLA thrusts or even mobilisation procedures.


          …would you consider the non thrust manipulation a placebo intervention to be compared with the SMT group?

          Note my concluding remarks about how this study might just as well have been interpreted.

          • I am very mindful and educated of human anatomy. It was a typographical error caused by my spell checker. I should had waited till the morning and replied on my PC and not on my mobile phone just before going to sleep.

            Now back to the paper. The facts is this. It was a prospective piece of quality research of which only benefitiall outcomes were reported. Nothing devastating!

            Empirically I have been in practice for 33 years and have had not one catastrophic event with any of my patients. According to the Australian Health Practitioner Regulation Agency cervical manipulation carries a real but rare risk.
            Trust I am clear.

          • @Michael Epstein

            It was a typographical error caused by my spell checker.

            Ah, the “spell-checker gambit” 😀
            Seeing how spell checking algorithms work, I have a very hard time buying this. I even tried misspelling the word “Vertebral” using a spell-checker. The conclusion of this impromptu experiment is that either my spell checker is much smarter than yours or you are mistaken.
            I note that you seem to have disabled your spell checker now 😉

            Anyway… let’s get serious.
            You claim:

            Empirically I have been in practice for 33 years and have had not one catastrophic event with any of my patients.

            Are you sure?
            Do you keep records of which “adjustments” you perform at each performance and of the immediate reaction and symptomatology of each person after your manipulation? Do you follow up on your customers after a set time? Our staff calls each patient the day after and after one week to see how they are doing after their surgery. Are you doing something similar? We also report to a national registry that does an annual audit including search in hospital records and death registries.
            Do you follow up on the status of customers who do not return?

            Symptoms and consequences of CAD are not always immediate following the predisposing event. Customers may have left your premises sometime during these 33 years with little or no symptoms only to throw the brain-killing blood clot minutes to hours later, or even died in their sleep that same night. The family or coroner may not be aware of the preceding cervical “adjustment” or know to connect the two.
            How can you be sure none of your customers suffered a Vertebral artery intimal tear at one of your cervical adjustments, that led to a blood clot that dislodged some hour(s) later and is now lying in a Clinitron bed somewhere, screaming inside his apparently vegetative locked-in state?
            I certainly hope not… but hope is not good enough when lives are at stake. The chiropractic congregation needs to get its act together!
            As was reasonably concluded in the paper professor Ernst refers to in this post:

            …there seems to be under-reporting of cases.

            There certainly is a very good reason to believe there is not only under-reporting of chiropractic associated stroke, there may very likely be SEVERE UNDER-REPORTING!

            Disclosure: This comment was spell checked. Any unintentional exchange of terms or honorifics have been ruled out.

          • Review question noted in Cochrane database for systematic reviews

            “What are the effects of weight loss (bariatric) surgery for overweight or obese adults?


            Obesity is associated with many health problems and a higher risk of death. Bariatric surgery for obesity is usually only considered when other treatments have failed. We aimed to compare surgical interventions with non-surgical interventions for obesity (such as drugs, diet and exercise) and to compare different surgical procedures. Bariatric surgery can be considered for people with a body mass index (BMI = kg/m²) greater than 40, or for those with a BMI less than 40 and obesity-related diseases such as diabetes.

            Study characteristics

            We included 22 studies comparing surgery with non-surgical interventions, or comparing different types of surgery. Altogether 1496 participants were allocated to surgery and 302 participants to non-surgical interventions. Most studies followed participants for 12 to 36 months, the longest follow-up was 10 years. The majority of participants were women and, on average, in their early 30s to early 50s.

            Key results

            Seven studies compared surgery with non-surgical interventions. Due to differences in the way that the studies were designed we decided not to generate an average of their results. The direction of the effect indicated that people who had surgery achieved greater weight loss one to two years afterwards compared with people who did not have surgery. Improvements in quality of life and diabetes were also found. No deaths occurred, reoperations in the surgical intervention groups ranged between 2% and 13%, as reported in five studies.

            Three studies found that gastric bypass (GB) achieved greater weight loss up to five years after surgery compared with adjustable gastric band (AGB): the BMI at the end of the studies was on average five units less. The GB procedure resulted in greater duration of hospitalisation and a greater number of late major complications. AGB required high rates of reoperation for removal of the gastric band.

            Seven studies compared GB with sleeve gastrectomy (SG). Overall there were no important differences for weight loss, quality of life, comorbidities and complications, although gastro-oesophageal reflux disease improved in more patients following GB in one study. One death occurred in the GB group. Serious adverse events occurred in 5% of the GB group and 1% of SG group, as reported in one study. Two studies reported 7% to 24% of people with GB and 3% to 34% of those with SG requiring reoperations.

            Two studies found that biliopancreatic diversion with duodenal switch resulted in greater weight loss than GB after two or four years in people with a relatively high BMI. BMI at the end of the studies was on average seven units lower. One death occurred in the biliopancreatic diversion group. Reoperations were higher in the biliopancreatic diversion group (16% to 28%) than the GB group (4% to 8%).

            One study comparing duodenojejunal bypass with SG versus GB found weight loss outcomes and rates of remission of diabetes and hypertension were similar at 12 months follow-up. No deaths occurred in either group, reoperation rates were not reported.

            One study found that BMI was reduced by 10 units more following SG at three years follow-up compared with AGB. Reoperations occurred in 20% of the AGB group and in 10% of the SG group.

            One study found no relevant difference in weight-loss outcomes following gastric imbrication compared with SG. No deaths occurred; 17% of participants in the gastric imbrication group required reoperation.

            Quality of the evidence

            From the information that was available to us about the studies, we were unable to assess how well designed they were. Adverse events and reoperation rates were not consistently reported in the publications of the studies. Most studies followed participants for only one or two years, therefore the long-term effects of surgery remain unclear.

            Few studies assessed the effects of bariatric surgery in treating comorbidities in participants with a lower BMI. There is therefore a lack of evidence for the use of bariatric surgery in treating comorbidities in people who are overweight or who do not meet standard criteria for bariatric surgery.

            Currentness of data

            This evidence is up to date as of November 2013.”

            I wonder why such surgeries continued to be performed after this review was published? By Edzard’s
            “standards” for EBM relative to paramedical disciplines, such procedures should be thrown into the dumper until there is no longer a “lack of evidence” for its use.

  • @Logos-Bios
    The recent article you cited in point 3b :
    Risk of Carotid Stroke after Chiropractic Care: A Population-Based Case-Crossover Study
    Interesting that chiropractors utilize CMT while PCP doctors do not yet their conclusion “We found no excess risk of carotid artery stroke after chiropractic care. Associations between chiropractic and PCP visits and stroke were similar and likely due to patients with early dissection-related symptoms seeking care prior to developing their strokes.”
    Causation has not been proven. Association is the issue but this article looks at it!

    • @CC


    • Once again I have to remind the disciples of DD Palmer that the Carotid artery is not the one at most risk from their neck-wringing performances. It is the VERTEBRAL ARTERY. If you look it up in anatomy textbooks (You do have one from chiro-school, don’t you?) you will see how it travels in a zig-zag manner through holes in the bones you are trying to move about when you manhandle the neck. This can lead to tearing inside of this artery that may sometimes lead to blood clots that may sometimes dislodge and travel to the brainstem. A minute clot may just cause transient dizziness and nausea, but it may also be enough to kill if it hits the respiratory centre. It may also cut the connections to consciousness and cause the dreaded “locked in syndrome”.

      This latest study by chiropractor Cassidy and co. EXCLUDED ALL STROKES FROM THE VERTEBRAL ARTERY!!!! and looked only at carotid artery strokes. From the full text of the article (my added emphasis):

      Our study aims to investigate associations between chiropractic exposures and carotid artery-related stroke and compare them to PCP exposures in the same analyses.


      We also excluded cases who had concurrent stroke discharge diagnoses (i.e., ICD-9-CM 430, 431, 432.1, 432.9, 433.0, 433.2, and 435.0) because we could not be sure if the main stroke was related to carotid artery injury

      433.2 is “Occlusion and stenosis of precerebral arteries: vertebral artery” and 435.0 is “Transient cerebral ischemia: basilar artery syndrome”, which may also stem from dislodged blood clots from the vertebral artery.
      Doctors (real) who care for stroke victims are very careful to diagnose which artery is the damaged one and record this. This has consequences for the treatment and securing the outcome. For this they have good diagnostic methods so misclassification is unlikely.
      If chiropractor Cassidy was looking for a possible association of chiropractic neck wringing with subsequent strokes, he was certainly looking in the wrong place!

      Further, chiropractor Cassidy (conveniently?) seems to have forgotten to look in the mortuary and study the post-mortem diagnoses. A good number of victims of VAD who never made it alive to a hospital may be found there and may even have been correctly classified as to cause of death if the coroner discovered the sometimes tiny infarction in the brainstem and bothers cutting open the vertebral artery at all.
      Let’s suppose that a victim of a VAD stroke caused the motor-cycle driver on his way from the chiro-office to swerve off the road and hit a tree, one cannot blame the coroner if he didn’t find the true cause of the accident in the skin-bag of bones that used to be the person’s head.
      Do you think chiropractor Cassidy and friends will devise a study to look for such patterns?? I doubt it.

      As we have seen, there is a plausible likelihood and even evidence that chiropractic associated strokes are under-diagnosed and under-reported.
      This irrelevant paper by chiropractor Cassidy and friends does not change that fact.

      • It’s worth noting that David Cassidy, when testifying before the Connecticut State Board of Chiropractic Examiners, said that he believed that he once caused a stroke by giving a patient an ‘adjustment’, but then changed his mind following his 2008 study even although that study concluded “we have not ruled out neck manipulation as a potential cause of VBA strokes”.

        Watch the brief clip here:

        How’s that for logic?

        • Dr. Cassidy’s answer was honest and forthright. His opinion of the past event had changed based on new research results. His answer was not illogical in the least. Why do you think otherwise?

          • Cassidy et al’s assertion “we have not ruled out neck manipulation as a potential cause of VBA strokes” speaks for itself.

            Further, in order to testify before the Connecticut State Board of Chiropractic Examiners, Cassidy was required “to appear as a representative of the International Chiropractors Association (ICA), the organization of the super-straight-Daniel-David-Palmer-Innate-Intelligence chiropractors…”

            So there’s another credibility problem right there.

            A little more:

            So what did the chiropractors say, under oath, about the need for informed consent regarding neck manipulation and stroke? To quote one chiropractic witness (which is pretty much to quote them all, as their testimony on this point varied little): “There is no scientific evidence of a cause and effect relationship between a chiropractic neck treatment and a subsequent stroke.” That’s right — “no scientific evidence.”
            …decades of case reports of stroke following neck manipulation introduced into evidence were dismissed by one chiropractor, who testified that these constituted mere anecdotal evidence. This from the profession for which anecdotal evidence, dressed up as “clinical experience,” repeatedly trumps scientific plausibility.”


          • @Blue

            Why do you think Dr. Cassidy’s answer was illogical? An alleged (by you) conflict of interest on the part of the researcher does not make your case that his answer was illogical. What do the statements of “other chiropractors” have to do with whether Dr. Cassidy’s answer was illogical?

      • @Geir

        “Let’s suppose that a victim of a VAD stroke caused the motor-cycle driver on his way from the chiro-office to swerve off the road and hit a tree, one cannot blame the coroner if he didn’t find the true cause of the accident in the skin-bag of bones that used to be the person’s head.
        Do you think chiropractor Cassidy and friends will devise a study to look for such patterns?? I doubt it,” stated Geir.

        I wonder if the NIH or the deep pockets of altruistic doctors within “modern medicine” might fund such a search to potentially benefit future “victims” of evil DC’s? Don’t hold your breath.

      • @Geir

        You have failed to remember proper etiquette when referring to accomplished, professional people. Note: you should write Dr. David Cassidy, not “Chiropractor” Cassidy. Would you be honored to be referred to as Lap-Bander Geir?

        Dr. Cassidy’s credentials are robust: below are excerpts from his bio:
        Dr. Cassidy is a Senior Scientist in the Division of Health Care & Outcomes Research at the Krembil Research Institute, Professor in the Division of Epidemiology at the Dalla Lana School of Public Health and Professor in Clinical Epidemiology in the Department of Health Policy, Management and Evaluation in the Faculty of Medicine at the University of Toronto. He also holds the Research Directorship in Artists’ Health at the University Health Network.

        Originally trained as a chiropractor, Dr. Cassidy practiced in both Ontario and Saskatchewan, where he was a member of the Medical-Dental Staff at the Royal University Hospital and a consultant chiropractor to the Division of Orthopedic Surgery. He also holds a Bachelor’s degree in Anatomy, a Master of Science in Surgery and a Doctorate in Anatomical Pathology from the University of Saskatchewan. His second doctoral degree (Dr.Med.Sc.) was earned in Epidemiology and Injury Prevention at the Karolinska Institute in Stockholm, Sweden.

        • I think I told you somewhere we only do proper bariatric procedures Lap-band is not a good procedure and we never use it.
          Is Cassidy not a chiropractor?

          • I don’t think you previously mentioned that you don’t perform the lap-band procedures. Perhaps your discernment is at least above average when you confine your opinions to subjects(bariatric surgery) about which you know something; not so much relative to other disciplines.

            To drive my previous point a bit more deeply into your memory, the proper way to address Cassidy is as “DOCTOR.” I hope you now understand.

          • I am fully aware of David Cassidy’s merits.
            I have referred to him as a “chiropractor” to avoid the confusion the honorific prefixes “Dr.” or Doctor” will cause here and to remind of his primary position in the matter.
            Cassidy is NOT a medical doctor and it is very important that he is not confused with such, even if he is probably one of the more educated and merited chiropractors in this world.
            Chiropractors, namely the american kind like to flaunt the honorific “Dr.” as short for “Doctor of chiropractic” which may be technically correct given the amount of academic points amassed (not the content of it 😉 ). However, I consider their ostentatious use of this title an abject practice, primarily intended to embellish themselves and deceive their customers regarding their competence. Note that I avoid referring to chiropractor’s customers as patients as I have come to the conclusion that chiropractors are not qualified to attend to people with medical problems. It is important to be clear that the practice of ‘chiropractic’ denotes nothing more nor less than a toolset of deceptive tricks and fake theories devised by a 19th century snake-oil salesman without any medical knowledge or skills. There are of course some practitioners who have added services of genuine medical origin but the aforementioned toolset is the signature service of chiropractors worldwide and is still as fake and fatuous as it was the day the janitor was supposed to have regained hearing from a thump on his back.

            David Cassidy is certainly in possession of more functioning intelligence than the majority of chiropractors as he has proven by earning several bona fide academic degrees.This I fully respect and admire. He has a Masters degree and if I am not mistaken, double PhD degrees, in anatomy and epidemiology if memory serves me. He is therefore more than academically competent to carry out research in the field.
            Many would claim that by the PhD degrees he has fortified his right to the honorific title of Doctor /Dr. As I said before, its use would only cause confusion in the context of this discussion. Wherever necessary, I would instead add the abbreviation “PhD” after David Cassidy’s name, which is more customary, at least on my side of the big pond.

            David Cassidy is in the context of this discussion first and foremost a chiropractor. The distinction is important in regard to possible conflicting interests that may affect his research on chiropractic manipulation as a possible causative factor for stroke.

            It is with some hesitation but after much thought that I have decided to also add the following information regarding David Cassidy. It is of course public knowledge and I doubt he would try to withhold it but it is not the kind of information expected to be revealed in a declaration of conflicting interests even if it may likely have been to that effect.
            In a hearing before the Connecticut State Board of Chiropractic Examiners Cassidy admitted upon a direct question, that a patient of his suffered stroke after spinal manipulation. He was asked whether he considered the manipulation to have caused the stroke. His reply was to the effect that he did think so at first but after researching the matter he no longer did.
            This fact does cast a different light on the whole matter and should be kept in mind when considering his choice of study subjects, designs and conclusions and when evaluating his results against other researcher’s findings. I certainly find it easier to understand some rather peculiar aspects of his study designs and deductive reasoning.
            I would not blame any therapist or clinician who has faced such a terrible adverse outcome in someone who placed their trust in his hands, if they looked for and tried to find support for the notion that they or their vocation were not to blame.
            David Cassidy has certainly pursued the question with ardour and an admirable academic arsenal, but has the incident, which must have been tormenting, affected his work and his deductive reasoning? I am inclined to suspect it did.

            As for L-B’s latest imbecile innuendoes and incessant inaccuracies, in spite of being repeatedly corrected – I do not consider them worth my time and effort.

          • @Geir

            As always, I’m amused by Geir’s inevitable walk-backs when confronted with the fallaciousness or disrespectfullness of his often sub-cogent comments. At least here he has admitted(er, sort of) his faux pas.

            Geir claimed that he withheld using the correct and respectful term “Doctor” when he referred to Dr. Cassidy so as to avoid confusion. While I agree that many posters who support Geir on this site share his propensity to become confused easily, I don’t think that he needed to”dumb down” his comments to facilitate understanding; rather, it’s obvious that he is attempting to clean up his gaffe. BTW, Geir, it’s not you who gets to decide how countries license and title professionals within various disciplines: it’s the countries and their licensing boards who have this responsibility.

            I appreciated Psychologist-wannabe Geir’s assessment that Dr. Cassidy’s current, well supported position regarding stroke and CMT has been affected by a past negative event which supposedly compromised “his work and deductive reasoning.” Actually, I more than appreciated it….I’m still LMAO over the ridiculous speculation. Leave it to Geir: when he is unable to successfully argue against a brilliant researcher’s conclusions, he resorts to a bogus pseudo-psychological reason as to why the researcher’s particular conclusion had been reached. Priceless!

          • The L-B really dislikes me 😀
            Its rants make me proud
            but it would of course be more interesting and entertaining if it had something to clever to contribute, not only childish attempts at personal insults.

          • Why would Geir believe that I dislike him? He is a wonderfully pleasant, opinionated-albeit-seldom-perspicatious Icelander whose comments on subjects, which fail to reconcile to his biased, personal meta-narrative, are typically nonsensical. He makes me smile when he feigns knowledge regarding mainstream chiropractic.

      • Geir stated, “This latest study by chiropractor Cassidy and co. EXCLUDED ALL STROKES FROM THE VERTEBRAL ARTERY!!!”

        Not to worry, Geir, Dr. Cassidy’s 2008 study on VBS stroke vis a vis chiropractic care can easily be downloaded.

        I quote from that paper: “We included all incident vertebrobasilar occlusion and stenosis
        strokes (ICD-9433.0 and 433.2) resulting in an acute care hospital
        admission from April 1, 1993 to March 31, 2002. Codes
        were chosen in consultation with stroke experts and an epidemiologist
        who participated in a similar past study (SB).

        • Then it appears that new Cassidy study has not taken us forwards. We stand where we stood in 2008.

          Which means there is need to worry.

          I refer you to Xuemei Cai et al. 2014.

        • Cassidy 2008 and other similar attempts at estimating away the risk of CAD after SMT has been reevaluated in later work and the mistakes analysed. Here is an excerpt from
          “Case Misclassification in Studies of Spinal Manipulation and Arterial Dissection”
          Xuemei Cai, MD, Ali Razmara, MD, PhD, Jessica K. Paulus, ScD, Karen Switkowski, MS, MPH, Pari J. Fariborz, Sergey D. Goryachev, MS, Leonard D’Avolio, MS, PhD, Edward Feldmann, MD, David E. Thaler, MD, PhD

          The earlier studies omitted the dissection-specific codes
          (443.xx) in their case definition because they were not in
          use in Ontario at the time (personal communication, Navin
          Goocool, April 30, 2013). The population in our study did
          have these codes available, and therefore, to avoid an
          overestimation of case misclassification, we included the
          3 additional dissection codes in our initial EMR query
          (‘‘modified Rothwell/Cassidy strategy’’).

          Cassidy et al [2008] suggested that the association between cases and
          PCP/SMT exposure was because of patients with preexisting
          dissections seeking care for neck pain (reverse
          causation). However, if the ICD-9 code positive predictive
          value measured in the VA database is generalizable to the Ontario health system data, then the Cassidy study actually found an association between PCP visits and patients
          with conventional strokes due to atherosclerotic and cardioembolic
          mechanisms. This association is well known and
          has been described before. It is because of the frequent clinical
          visits needed to manage established vascular risk factors.10
          Our sensitivity analysis suggests that the ORs for
          the association between SMT and CAD would be very
          large with accurately identified cases. Lastly, the misclassi-
          fication may disproportionately affect ORs for those less
          than 45 years of age—a group of patients with a lower
          prevalence of atherosclerosis-related infarcts and a higher
          prevalence of strokes due to dissections.16 Given the small
          numbers of true cases, ORs within age strata could not be
          calculated, but our sensitivity analysis suggests the association
          between SMT and CAD in younger patients is markedly
          stronger after adjusting for case misclassification

          And what do they mean by “large” ?

          Among the subgroup of the population
          less than 45 years of age and applying the above assumptions,
          those with a chiropractor visit within 30 days of
          their stroke would have nearly 7 times the odds of CAD
          (OR 5 6.91, 95% CI 2.59-13.74).

          That means that the risk is most likely about seven fold and there is 95% chance that the true odds ratio is about between 2,6 to 13.7. That is nothing less than horrendous if correct.

          Now, why don’t you go play doctor or something? But don’t touch the necks, you might tear something.

          • Björn Geir wrote: “…the risk is most likely about seven fold and there is 95% chance that the true odds ratio is about between 2,6 to 13.7. That is nothing less than horrendous if correct.”

            Given their past history, I wonder if chiropractic trade bodies have been keen to send that information off to the NCMIC and as many neurologists as possible…


            “FOR IMMEDIATE RELEASE: July 09, 2008

            ACA Targets 16,000 Neurologists with Latest Research on Neck Pain

            The American Chiropractic Association (ACA) today announced it has mailed copies of a report issued by the Task Force on Neck Pain and its Associated Disorders to more than 16,600 neurologists across the country. The seven-year, international, multidisciplinary study was published in the journal Spine and is designed to help health professionals apply the best available evidence to prevent, diagnose and manage neck pain.
            In the cover letter accompanying the study, ACA President Glenn Manceaux, DC, noted that ACA encourages evidence-based clinical practice and interprofessional cooperation in patient care. “There is growth in the referral of patients between chiropractors and neurologists and therefore, it is important that all practioners be on the same page regarding the most current research in treating this pervasive condition,” Dr. Manceaux said.
            In distributing the study findings, ACA worked closely with NCMIC, the nation’s leading provider of chiropractic malpractice insurance for doctors of chiropractic.


            …the Task Force also initiated a new population-based, case-control and case-crossover study into the association between chiropractic care and vertebrobasilar artery (VBA) stroke. This Canadian study investigated associations between chiropractic visits and vertebrobasilar artery stroke and compared this with visits to primary care physicians and the occurrence of VBA stroke.
            The study — which analyzed a total of 818 cases of VBA stroke admitted to Ontario hospitals over a 9-year period (more than 100 million patient-years of observation) — concluded that VBA stroke is a very rare event and that the risk of VBA stroke associated with a visit to a chiropractor’s office appears to be no different from the risk of VBA stroke following a visit to a family physician’s office.”

            Ref: https://web [DOT] archive [DOT] org/web/20100621192227/

  • The basic science research suggests that ANLs such as checking one’s blind spot during driving or checking for active cervical rotation during an exam produces for strain to the cervical arteries than manipulation. So the applied forces for c-SMT is less than every day activities and examination methods.

    The epidemiological research states there is no difference in stroke rates between MDs and DCs for both the vertebral and carotid arteries.

    “We compared 15,523 cases to 62,092 control periods using exposure windows of 1, 3, 7, and 14 days prior to the stroke. Positive associations were found for both chiropractic and PCP visits and subsequent stroke in patients less than 45 years of age. These associations tended to increase when analyses were limited to visits for neck pain and headache-related diagnoses. There was no significant difference between chiropractic and PCP risk estimates. We found no association between chiropractic visits and stroke in those 45 years of age or older.

    We found no excess risk of carotid artery stroke after chiropractic care. Associations between chiropractic and PCP visits and stroke were similar and likely due to patients with early dissection-related symptoms seeking care prior to developing their strokes.”

    C-SMT has less adverse events than NSAIDs, injections, surgeries and opioids for neck pain. The majority of the American public in a random survey state that medications are more dangerous than spinal manipulation as well according to the Gallup survey.

    • @evidencebasedDC

      Don’t they teach the difference beetween the Carotid artery and the Vertebral artery in Chiro-college?

      …and for that matter, the difference between science and a Gallup Survey asking the public for their opinion??

    • Cassidy et al. 2008, first suggested that associations between AD, stroke and spinal manipulation may be due to pre-existing dissections of patients of both MDs and DCs, having found associations for both MDs and DCs.

      Xuemei Cai et al. 2014, found that Cassidy’s results were the result of case misclassification. When adjusted to identify true cases of AD, the association for MDs could be explained in terms of patients with atherosclerotic and cardioembolic strokes requiring frequent clinical visits. They found a much stronger association between spinal manipulation and AD in patients younger than 45 – as they had predicted.

      Unfortunately, this new study by Cassidy et al. is with Elsevier.

      Is there any mention of Xuemei et al.?

      • Does case misclassification threaten the validity of studies investigating the relationship between neck manipulation and vertebral artery dissection stroke? No

        Donald R. Murphy,corresponding author1 Michael J. Schneider,2 Stephen M. Perle,3 Christopher G. Bise,4 Michael Timko,5 and Mitchell Haas6
        Author information ► Article notes ► Copyright and License information ►

        The purported relationship between cervical manipulative therapy (CMT) and stroke related to vertebral artery dissection (VAD) has been debated for several decades. A large number of publications, from case reports to case–control studies, have investigated this relationship. A recent article suggested that case misclassification in the case–control studies on this topic resulted in biased odds ratios in those studies.


        Given its rarity, the best epidemiologic research design for investigating the relationship between CMT and VAD is the case–control study. The addition of a case-crossover aspect further strengthens the scientific rigor of such studies by reducing bias. The most recent studies investigating the relationship between CMT and VAD indicate that the relationship is not causal. In fact, a comparable relationship between vertebral artery-related stroke and visits to a primary care physician has been observed. The statistical association between visits to chiropractors and VAD can best be explained as resulting from a patient with early manifestation of VAD (neck pain with or without headache) seeking the services of a chiropractor for relief of this pain. Sometime after the visit the patient experiences VAD-related stroke that would have occurred regardless of the care received.

        This explanation has been challenged by a recent article putting forth the argument that case misclassification is likely to have biased the odds ratios of the case–control studies that have investigated the association between CMT and vertebral artery related stroke. The challenge particularly focused on one of the case–control studies, which had concluded that the association between CMT and vertebral artery related stroke was not causal.

        It was suggested by the authors of the recent article that misclassification led to an underestimation of risk. We argue that the information presented in that article does not support the authors’ claim for a variety of reasons, including the fact that the assumptions upon which their analysis is based lack substantiation and the fact that any possible misclassification would not have changed the conclusion of the study in question.


        Current evidence does not support the notion that misclassification threatens the validity of recent case–control studies investigating the relationship between CMT and VAD. Hence, the recent re-analysis cannot refute the conclusion from previous studies that CMT is not a cause of VAD.

        Keywords: Vertebral artery dissection, Cervical manipulation

        This response to the case-misclassification paper is available for free online. It does mention Xuemei Cai.

        • L-B fails to notice, or conveniently misses, that this is not really a response to “the case-classification paper” but a parallell debate article published in the same issue of a journal. L-B also conveniently omits providing the links to the article(s) but instead copy-pastes a chosen passage from the article supporting the “cause”.
          The proper way to refer to readily available material is to provide a link to the whole material and describe one’s interpretation. Voluminous copy-pastes should only be used when necessary and be enclosed in *blockquote* tags.

          I find the “Yes” article way more convincing and yet again repeat my concerns over why chiropractors continue keeping their heads in the sand regarding this grave matter.

          Judge for yourselves:

          “Does case misclassification threaten the validity of studies investigating the relationship between neck manipulation and vertebral artery dissection stroke? Yes”

          “Does case misclassification threaten the validity of studies investigating the relationship between neck manipulation and vertebral artery dissection stroke? No”

          The very least the chiropractic community could do would be to issue a grave warning against cervical manipulation of any kind without prior informed consent and prior screening for signs of possible vascular compromise.
          Something for example in line with what their brothers in arms, the osteopaths seem to be trying:
          “A ‘system based’ approach to risk assessment of the cervical spine prior to manual therapy”

        • The above citation was part of a debate, so it is only fair to publish the other side’s argument:

          Does case misclassification threaten the validity of studies investigating the relationship between neck manipulation and vertebral artery dissection stroke? Yes

          Jessica K. Paulus and David E. Thaler
          Chiropractic & Manual Therapies201624:42

          For patients and health care providers who are considering spinal manipulative therapy of the neck, it is crucial to establish if it is a trigger for cervical artery dissection and/or stroke, and if it is, the magnitude of the risk.

          We discuss the biological plausibility of how neck manipulation could cause cervical artery dissection. We also discuss how case misclassification threatens the validity of influential published studies that have investigated the relationship between neck manipulation and dissection. Our position is supported by the fact that the largest epidemiologic studies of neck manipulation safety with respect to neurological outcomes have relied on International Classification of Diseases-9 codes for case identification. However, the application of these codes in prior studies failed to identify dissections (rather than strokes in general) and so conclusions from those studies are invalid.

          There are several methodological challenges to understanding the association between neck manipulation and vertebral artery dissection. Addressing these issues is critical because even a modest association between neck manipulation and cervical artery dissection could translate into a significant number of avoidable dissections given the widespread use of neck manipulation by providers from various backgrounds. We believe that valid case classification, accurate measurement of manipulative procedures, and addressing reverse causation bias should be top priorities for future research.

          Full text here:


          “Chiropractic is the correct term for the collection of deceptions DD Palmer invented.”
          Björn Geir Leifsson, MD

        • There is a link to Murphy, on the page which I linked to Xuemei Cai et al. I had already looked at it. There is also a link to Cassidy et al.’s response to Cai et al. which unfortunately is behind a pay-wall. There is a further response to Cassidy from two of Cai et al’s authors, Paulus and Thaler, which I have also read.

          So I am wondering what, if anything, Cassidy et al. may have said in their new study, in relation to this debate. At the heart of it, is Cassidy et al.’s contention that the best interpretation of their results is reverse causation: Patient’s already have CAD when they go to chiropractors. Cai et al., on the other hand, do not believe that is a safe assumption. It’s possible, but it has not been proven. No more has it been proven that spinal manipulation can cause CAD.

        • Ah, when I posted my reply, those of Björn and Blue were not up.

  • Regarding actions which can result in serious harm, I submit the following for everone’s enjoyment:

    A woman stops by, unannounced, at her son’s house. She knocks on the door then immediately walks in.

    She is shocked to see her daughter-in-law lying on the couch, totally naked. Soft music is playing, candles are lit, and the aroma of perfume fills the room.

    “What are you doing?!” she asks.

    “I’m waiting for Jeff to come home from work,” the daughter-in- law explains.

    “But you’re naked!” the mother-in-law exclaims.

    “This is my love dress,” the daughter-in-law answers.

    “Love dress? But you’re naked!”

    “Jeff loves me and wants me to wear this dress. It excites him to no end. Every time he sees me in this dress, he instantly becomes romantic and can’t get enough of me!”

    The mother-in-law leaves, inspired by what she has learned.

    When the mother-in-law gets home, she undresses, showers, puts on her best perfume, dims the lights, puts on a romantic CD, and lays on the couch, expectantly awaiting her husband. Finally, her husband comes home. He walks in and sees her lying there provocatively.

    “What are you doing?” he asks.

    “This is my love dress,” she whispers sensually.

    “Needs ironing,” he says. “What’s for dinner?

    He never heard the gunshot.

  • Interesting blog and comments, as usual. As a result I now read the Cai & al study and both the Yes and No debate articles cited above. I have also read the (in)famous Cassidy study many times. Now it turns my stomach upside down to see that the neck manipulation lovers still today stick their heads in the sand and refuse to play safe, as all other health providers would have done in a similar situation.
    I find it very ironic that they stubbornly (and cynically) dismiss all possible fears of a causative association between neck manipulation and vertebrobasilar artery dissection with the mantra:
    “…a cause-effect relationship was assumed because several cases were reported in which an individual experienced VAD after receiving CMT. This is a common logical fallacy known in formal logic as post hoc ergo propter hoc (from the Latin meaning: “after this, therefore because of this”). Correlation, however, is not synonymous with causation.” (Murphy & al. in the No article, and similarly in many other pro-chiro articles.)

    —This at the same time as “post hoc ergo propter hoc” anecdotical stories are the ONLY basis they have for claiming that their manipulations have any beneficial effects at all.
    How can they sleep well?

    • I think that for those without a conflict of interest your response is a natural one.

    • Irony 1: Research evinces SMT to be safe. Millions of chiropractic cervical SMT’s are provided yearly with nary a claim of an alleged resultant CAD. Chiropractic malpractice rates are a FRACTION of those paid by allopaths an represent a market-based indicator of safety. Yet bloggers here wonder why DC’s(and PT’s, DO’s, and MD’s) who perform SMT can sleep well.

      Irony 2: The preponderance of research relative to SMT and CAD suggests that stroke is a very rare occurence. Yet bloggers here would have practitioners of SMT ignore the research and abandon the treatment despite the rarity of stroke because….well, the bloggers simply want it to be so.

      Irony 3: The Cassidy 2008 study was robust and was performed by an ardent, well qualified researcher. Yet his study was (in-)famous? I suppose it still is infamous to those whose meta-narratives were in a state of upheaval after having read it.

      • If CSM is safe, then it does not cause cervical dissection. Then the incidence of stroke is neither here nor there.

        It is not proven that CSM is safe. There is sufficient evidence that it may not be safe, to be of serious concern.

        Therefore, there has to be very good evidence that CSM can provide sufficient clinical benefits to warrant the risk of possible serious adverse effects, however rare.

        Where is that evidence?

  • Irony 1, 2 and 3 Chiropractor’s utter inability to assimilate information that contradicts their cultic conviction.
    Innumerable posts and comments in this blog are filled to the brim with referenced information that contradicts it, still L-B echo’s the same irrelevant claims, fallacies and false information over and again like there is no tomorrow.
    Note to self: try to be better at ignoring those who have nothing to contribute.

    • Nothing proffered in this thread contradicted any of my positions: opinions were offerred on both sides of the issue, nothing more. It’s not surprising that you would naturally accept opinions which are consistent with your anti-SMT views. Note to Geir: your redundant posts, inevitably chock-full of misinformation, eptiomize confirmation bias.

      I note that you still have failed to specifically criticize the research paper on upper cervical SMT you previsously mentioned. Could it be that you only offer critiques of papers which demonstrate that your concerns regarding the safety of chiropractic treatment are ill-founded. Say it ain’t so, Geir!

      I wonder why you have not directly addressed Dr. Flum’s conclusions(previously posted) regarding the blatant under-reporting of fatalities/morbidity relative to bariatric surgeries and that studies have cherry-picked results from only the “very best” surgeons for the apparent purpose of deceiving the public about their safety.

      Irony 4: Geir posts studies as authoritative if he likes the conclusions. He assiduously nitpicks perceived flaws in studies whose conclusions fail to reconcile with his biases. Geir is consistently ironical in most of his rants about chiropractic, in particular, and paramedical disciplines, in genreral.

  • @Edzard,

    sorry if somone had asked this. Manipulation was present in 95% and mobilisation only in 1.7%. What was done in the remaining 3.3% of cases?

  • I think you mean the 200 DEATHS PER DAY currently being caused by pain medicines MDs prescribe all day long? The risk of chiropractic care is not in the same universe as the risks from things like spinal surgery, and your “227” cases is surely from many million treatments over many years which you forgot to mention.

  • One thing your numbers clearly show is that adjustments given by chiropractors is far safer than mobilizations done by physical therapists or other non-chiropractor providers. We perform the vast majority of adjustments (about 90%) and yet cause less than half of the serious reactions to them (which is a ridiculously low number anyway). That means other providers are causing serious reactions 10 times more often per treatment. It’s simple math. See a chiropractor, we’re far safer doing adjustments, and a magnitude safer than pain pills or surgery of any kind.

  • Bjorn

    Bjorn said:
    “The question is not if they are safe, the question is if they are effective. Due to its extremely serious nature, any degree of risk is unacceptable as long as efficacy is in doubt.”

    Please apply that same standard to this surgery that is still being performed all over the world by the thousands:

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