… wanted in 14 counties of this state, the condemned is found guilty of the crimes of murder, armed robbery of citizens, state banks and post offices, the theft of sacred objects, arson in a state prison, perjury, bigamy, deserting his wife and children, inciting prostitution, kidnapping, extortion, receiving stolen goods, selling stolen goods, passing counterfeit money, and, contrary to the laws of this state, the condemned is guilty of using marked cards and loaded dice. Therefore, according to the powers vested in us, we sentence the accused here before us Tuco Benedicto Pacifico Juan Maria Ramirez, known as the rat, and any other aliases he might have, to hang by the neck until dead. May God have mercy on his soul. Proceed. Call in the chiropractor.

The Good, the Bad and the Ugly Kind of.

I presume those who go into health care do so in part for semi-altruistic reasons. Whether practicing in reality-based or fiction-based medical systems, most practitioners want to do right by people. No one, or almost no one (there are always the psycho outliers) wants to harm their patients.

It is hard for practitioners to admit that they harmed people in the attempt to make them better. I do not find it surprising that doctors in general do not like to recognize that their interventions harmed the patient, although sometimes harm is the price of doing business. I found in my years of working in infection control and quality that surgeons were often a bit more reticent at admitting they harmed a patient. In medicine, the damage we do is often more indirect: the late complication of medications as an example. Much of what surgeons do is hands-on and the injury more direct.

I wonder, in a digression, how many of those in the SCAM community continue to practice despite a crisis of faith in their intervention. I can’t find any data as it relates to chiropractors, although in all the SCAM professions there must be those who are in too deep and can’t leave after realizing their SCAM is a farce. I can find that 16% of pastors have doubts about the existence of god. Maybe the same percent in SCAMs?

It is messy, of course. There are Chiropractic bodies that subscribe to the idea that

“.. teaching of vertebral subluxation complex as a vitalistic construct that claims that it is the cause of disease is unsupported by evidence. Its inclusion in a modern chiropractic curriculum in anything other than an historical context is therefore inappropriate and unnecessary.”

But if no subluxation, what it is the point of the whole SCAM, much less manipulating the spine? Why be a chiropractor?

Chiropractors, being very hands on, seem particularly recalcitrant to the idea that they can harm others, especially causing strokes. In my prior tour of duty here at SBM, I discussed the topic in 2008 (Chiropractic and Stroke: Evaluation of One Paper) and 2015 (Chiropractic and Stroke: The question is not answered).

My conclusion was, yep, chiropractic neck manipulation rarely causes stroke by way of a vertebral artery dissection (VAD) and that the pathology and mechanism resembled that of a hanging, a description that was not well received by chiropractors. Go figure.

Some chiropractors have a bit of self-awareness.  40% of those not practicing chiropractic agree that 

Being injured by a chiropractor or causing injury by chiropractic treatment can be a factor in leaving active practice.

Along with a variety of other reasons to abandon the field. Chiropratic seems like a profession (there is no good antonym for profession, which is a shame. I suppose you could call many SCAM providers a professional and their job a profession, but the terms seem wrong) with many issues, but some, at least, recognize that harm is a potential byproduct of their interventions.

I wondered, in the last 8 years, was there anything new on the topic. What piqued my interest was a New York Times article, Is It Safe to Get Your Neck Manipulated by a Chiropractor? The subhead concludes, “Most joint manipulations aren’t dangerous, but one rare complication can result in serious injury.”

The NYT, unfortunately, never uses references, but notes

For example, a small study found that 15 percent of arterial dissections occurred after a sporting activity, and 11 percent followed a chiropractic manipulation. Several studies have shown the risk of arterial dissection and stroke to be three to 12 times higher in people who’ve recently had a neck manipulation, according to a review by the American Heart Association’s Stroke Council.


It is unclear how common the complication is following chiropractic care — one estimate says that an arterial dissection occurs in one out of 1,000 neck manipulations, another says one in 5.8 million (three of the four authors on that study worked for chiropractic associations).

A review I found pegged it at

It is estimated that 1 in 20,000 cervical spine manipulations cause a stroke.

It is kind of scary how relatively minor trauma such as coughing, sneezing, or vomiting can precede a vertebral artery tear. I remember a case from early in my practice that occurred as a result of hyperextension during yoga.

Of course, professional chiropractors (there are amateurs) will have none of it:

…a visit to a chiropractor is more often the result of an arterial dissection, not the cause of it.
“These patients have an artery that’s been injured in some way,” causing neck pain and headaches, Dr. Lauretti said. “Some of them go to their primary care doctor, some of them go to their chiropractor. If the patient has a stroke following a visit to the chiropractor, the chiropractor gets blamed.”

Same as it ever was.

The NYT articles on SCAM are often interesting with the classic journalist propensity to give both sides of a discussion. As the fundamental construct of chiropractic, subluxation and their correction, is a complete fantasy unhinged from reality, I always find this entertaining. SCAMs are usually afforded a legitimacy other delusions, like stolen presidential elections or faked moon landings, are not.

Those who recognize that chiropractic is a fiction are noted to be, “critics (who) claim the field lacks scientific validity.” Well, duh. And claim?  I also claim there is no scientific validity to the tooth fairy or Zeus. Just what is the bar one must reach for  lacking scientific validity?

All of medicine is a risk-benefit. The risk associated with an intervention (fixing said subluxation) that has zero, nil, nada, zip, zilch, probability of doing anything beneficial should have zero complications. Relief of self-limited pain should have zero catastrophic complications. Small benefits should have small risks.

The article, as is often the case with discussions of chiropractic, is not specific about the benefits of have one’s neck manipulated to fix an imaginary subluxation or for pain vs. the multimodal interventions for neck pain one might receive in addition to manipulation: heat, massage, traction, ultrasound, etc.

Since I last wrote on the topic, not much new has been published on the topic. Some case reports and series, like

Of the 141 patients with cervical artery dissection, 12 had documented chiropractic neck manipulation prior to the onset of the symptoms that led to medical presentation.

And another series where

34 out of our 310 patients suffered a chiropractor-associated injury. These patients tended to be younger (p = 0.01), female (p = 0.003), and have fewer comorbidities (p = 0.005) compared to patients with other-cause VADs.

Those are numbers that should give one pause.

There was the chiropractor (one of several case reports) who proudly reported that he recognized a vertebral artery stroke before he could do manipulation. Ohhhhh. Minimal competency in neurology. Impressive.  And see? The stroke comes before the chiropractor, and we feel the need to publish the fact we can recognize very basic neurologic conditions. Kind of sad.

The problem, of course, with rare events is determining causality. Although 12/141 and 34/310 ain’t that rare. But the literature is murky at best depending on what approach is taken to determine the incidence of post chiropractic stroke. It is unlikely that chiropractors are going to apply the precautionary principle any time soon.

When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically. In this context the proponent of an activity, rather than the public, should bear the burden of proof.

Definitive proof will always be lacking, so how’s about, for hoots and giggles, applying Hills Criteria to the topic? Hills Criteria have been applied to the subluxations and

There is a significant lack of evidence in the literature to fulfill Hill’s criteria of causation as regards chiropractic subluxation. No supportive evidence is found for the chiropractic subluxation being associated with any disease process or of creating suboptimal health conditions requiring intervention. Regardless of popular appeal, this leaves the subluxation construct in the realm of unsupported speculation. This lack of supportive evidence suggests the subluxation construct has no valid clinical applicability.

But no one has applied Hills to chiropractic and stroke. Let us run through Hills list and see what we get.

Strength : How strong is the association between the cause and the effect?
That’s a tough one, but I would rate it as reasonably strong when all the relatively minor causes of vertebral artery dissection are considered. 8/10.

Consistency: Consistent findings observed by different persons in different places with different samples strengthens the likelihood of an effect.
I give this a 9/10. All the negative studies are by chiropractors, so it is a go to Midas get a muffler situation.

Specificity: Causation is likely if there is a very specific population at a specific site and disease with no other likely explanation. The more specific an association between a factor and an effect is, the bigger the probability of a causal relationship.
10/10 here.

Temporality: The effect has to occur after the cause.

Biological gradient (dose–response relationship): Greater exposure should generally lead to greater incidence of the effect.
That’s also a tough one since VAD is so rare. 6/10.

Plausibility: A plausible mechanism between cause and effect is helpful.

Coherence: Coherence between epidemiological and laboratory findings increases the likelihood of an effect. However, Hill noted that “lack of such laboratory evidence cannot nullify the epidemiological effect on associations.”
NA. I know of no lab data that would apply.

Experiment: “Occasionally it is possible to appeal to experimental evidence.”
NA. I know of no lab data that would apply.

Analogy: The use of analogies or similarities between the observed association and any other associations.
Like a hanging? 10/10.

Of course, Hill’s Criteria are not the 9 commandments for determining causation, but a nice conceptual framework to apply when considering causation when definitive data is wanted.

Might one conclude from Hills criteria that chiropractic manipulation can lead to vertebral artery dissection and stroke? You bet. Do professional chiropractors care? Not so much. There is no good, only the bad and the ugly.


  • Mark Crislip, MD has been a practicing Infectious Disease specialist in Portland, Oregon, from 1990 to 2023. He has been voted a US News and World Report best US doctor, best ID doctor in Portland Magazine multiple times, has multiple teaching awards and, most importantly,  the ‘Attending Most Likely To Tell It Like It Is’ by the medical residents at his hospital. His multi-media empire can be found at edgydoc.com.

Posted by Mark Crislip

Mark Crislip, MD has been a practicing Infectious Disease specialist in Portland, Oregon, from 1990 to 2023. He has been voted a US News and World Report best US doctor, best ID doctor in Portland Magazine multiple times, has multiple teaching awards and, most importantly,  the ‘Attending Most Likely To Tell It Like It Is’ by the medical residents at his hospital. His multi-media empire can be found at edgydoc.com.