Stroke

The Mechanics of Neck Manipulation With Special Consideration of the Vertebral Artery

By Frank M. Painter|November 22, 2012|Chiropractic Care, Stroke|

The Mechanics of Neck Manipulation With Special Consideration of the Vertebral Artery

SOURCE: J Can Chiropr Assoc. 2002 (Sep); 46 (3): 134–136

Dr. W Herzog, BSc, PhD and Dr. B Symons, DC

University of Calgary,
2500 University Drive N.W., Calgary,
Alberta, Canada T2N 1N4.
walter@kin.ucalgary.ca

In recent weeks, we have learnt that chiropractors may have to carefully review the application of high-speed, low-amplitude spinal manipulative treatments to the neck. The concern is the possible risk associated with neck manipulation. Specifically, vertebral artery dissection, or ther mechanical injury, are an acknowledged, albeit a very low, risk.

The vast amount of research on vertebrobasilar injury in the past has been focused on blood flow through the vertebral artery during diagnostic, and before and after manipulative treatment. There was (is) concern that vertebral artery occlusion may occur during neck manipulation, and that a lack of blood supply to the brain may lead to a series of complications. This line of argument has always struck us as weak, because a high-speed, low-amplitude thrust to the cervical spine lasts typically less than 150 ms, and the brain has sufficient oxygen to survive such a small amount of (possible) loss of blood flow from one of its many supply arteries.

Another way of attempting to gain insight into the possible risk of neck manipulation and vertebrobasilar accidents is a statistical (epidemiological) approach. The basic question that people would like to answer is: are people who receive neck manipulative treatments at a greater risk of vertebrobasilar accidents than people who do not receive such treatments? On the surface, this approach seems feasible, and so it would be, if the occurrence of such accidents was high (let’s say one time in a hundred or a thousand). However, it appears that we deal with incidence rates (if there is an actual incidence) of one in several millions (i.e. very low). Therefore, any statistical pproach has a miniscule power, and a couple of “fluke accidents” (i.e., accidents that occur, let’s say in a chiropractic clinic, but in reality have nothing to do with the chiropractic treatment) may produce a “statistical error” that may persist for years in a community as small as Canada. Also, using an epidemiological approach, the question of “cause and effect” cannot be resolved.

When starting to tackle the problem of the mechanics of neck manipulative treatments three years ago with my student B. Symons (DC), we were surprised that, to the best of our knowledge, there were no data on what actually happens mechanically to the vertebral artery during cervical spinal manipulation. I was further surprised, when asked to review a case on a vertebrobasilar accident, that one of the arguments went as follows: Pathology revealed no dissection of the vertebral artery, therefore, the vertebrobasilar accident cannot be associated with chiropractic treatment.

Discussing this particular statement within the chiropractic community, it became apparent that mechanical injury to the vertebral artery was an accepted, but very, very very rare occurrence; but nevertheless, accepted. And all this without a shred of scientific evidence about the mechanics of the vertebral artery during cervical manipulation.

So, when does the vertebral artery, or for that matter, any tissue, become injured?

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Strokes May Seem Rare, But Can Occur 230% More Often Using The Pill

By Frank M. Painter|June 14, 2012|Announcement, Oral Contraceptives, Public Health, Stroke|

Strokes May Seem Rare, But Can Occur 230% More Often Using The Pill

The Chiro.Org Blog

SOURCE: MedPage Today ~ June 13, 2012

By Todd Neale, Senior Staff Writer

A large Danish registry study found that the risks of thrombotic stroke or myocardial infarction (MI) roughly doubled in women taking oral contraceptives with low-to-moderate doses of ethinyl estradiol.

Note that the overall number of thrombotic strokes or MIs was small.

The relative risks of thrombotic stroke and myocardial infarction (MI) are higher among users of hormonal contraception, although absolute risks remain low, a Danish study showed.

Use of oral contraceptives combining low-to-moderate doses of ethinyl estradiol and various progestins was associated with up to 2.3 times the risks of thrombotic stroke or MI compared with non-use, according to Øjvind Lidegaard, DrMedSci, of Copenhagen University Hospital, and colleagues.

The type of progestin in the pill had little effect on the risks, the researchers reported in the June 14 issue of the New England Journal of Medicine.

To put the risk in perspective, they estimated that among 10,000 women taking a pill combining desogestrel with ethinyl estradiol at a dose of 20 μg for 1 year, two will have arterial thrombosis and seven will have venous thrombosis.

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Who’s Asleep Over at MedScape?

By Frank M. Painter|April 27, 2011|News, Stroke|

Who’s Asleep Over at MedScape?

The Chiro.Org Blog

In general, I find the reporting at MedScape to be top notch, but I have significant problems with their 4-20-11 essay titled: “The Potential Complications of Chiropractic Therapy”.

Answer this question:

If I sneeze, and there is a car accident across the street,
have we discovered the *cause* of car accidents?

The scientific method would propose that we sneeze a hundred times, and count the car accidents.

That’s how you begin to determine if there is an actual relationship between one event (like drinking milk) and it’s potential consequences (like developing cancer).

The Bone and Joint Decade Task Force was appointed by the World Health Organization (WHO) to look at the causes of, and treatments for neck pain, and after years of review, they published their results in the prestigious Spine Journal. One of the most relevant articles (to this conversation) was titled:

“Risk of Vertebrobasilar Stroke and Chiropractic Care: Results of a Population-based Case-control and Case-crossover Study”
Spine 2008 (Feb 15); 33 (4 Suppl): S176–183

CONCLUSION: VBA stroke is a very rare event in the population. The increased risks of VBA stroke associated with chiropractic and PCP visits is likely due to patients with headache and neck pain from VBA dissection seeking care before their stroke. We found no evidence of excess risk of VBA stroke associated chiropractic care compared to primary care.

There was an association between chiropractic services and subsequent vertebrobasilar artery stroke in persons under 45 years of age, but a similar association was also observed among patients receiving general practitioner services. This is likely explained by patients with vertebrobasilar artery dissection-related neck pain or headache seeking care before having their stroke.

This Blog (and our website in general) has published regularly on this topic:

WARNING: Conducting an Orchestra Can Cause Vertebral Artery Dissection and Stroke
https://atlas.chiro.org/?p=5005 (more…)

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WARNING: Conducting an Orchestra Can Cause Vertebral Artery Dissection and Stroke

By Frank M. Painter|March 29, 2011|Research, Safety, Stroke|

WARNING: Conducting an Orchestra Can Cause Vertebral Artery Dissection and Stroke

The Chiro.Org Blog

SOURCE: J Stroke and Cerebrovascular Diseases 2011 (Mar 24)

During the past decade, the issues of cerebrovascular accidents [CVAs] and spinal manipulation have become linked in a debate of ever-increasing intensity. A copious number of studies have investigated spinal manipulation as a putative causative factor of CVAs; however, a common theme among these is the failure to adequately explore the possibility that the majority of CVAs may be spontaneous, cumulative, or caused by factors other than spinal manipulation itself. The problem is only exacerbated by the sometimes hysterical reactions apparent in the mass media over the past three years in reaction to these flawed investigations. [1]

Previous studies have shown that vertebral artery dissections (VADs) have been “caused” by things as innocuous as:

Salon shampoos
Archery
Coughing
Dental procedure
Watching aircraft
Telephone call
Yawning
Bleeding nose
Overhead work (more…)

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Do You Still Beat Your Wife?

By Frank M. Painter|September 20, 2010|Editorial, Stroke|

Do You Still Beat Your Wife?

The Chiro.Org Blog

SOURCE: A Chiro.Org Editorial

There are certain accusations that are impossible to respond to, without sounding like a guilty party, trying to weasel out of a tight spot.

The accusation that chiropractic somehow “causes stroke” is one such unsupported and yet impossible-to-defend claim.

The simple truth is that there is absolutely no scientific evidence to demonstrate that chiropractic adjusting in the cervical region has ever “caused” a stroke.

Here’s a simple example of how flawed that logic is:

If I sneeze, and there is a traffic accident across the street, it may be convenient to claim that my sneeze “caused” that accident (especially if someone stood to benefit financially from that claim), but where is the evidence? (more…)

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Chiropractic and Stroke Incidence

By Frank M. Painter|January 30, 2010|Chiropractic Care, Education, Stroke|

Chiropractic and Stroke Incidence

The Chiro.Org Blog

SOURCE: Chiro.Org’s Stroke and Chiropractic Page

Recent reports of individuals suffering strokes proximal to receiving chiropractic care are sensationalized by the media all out of proportion to their actual frequency. Although medicine admits that tens of thousands die needlessly from medical accidents, even from things as innocuous as venipuncture, that doesn’t excuse chiropractors from their duty to protect our patients.

The Stroke and Chiropractic Page was crafted to keep our profession abreast of information that may help predict (and perhaps prevent) strokes.

This Introduction reviews those physical findings that may indicate whether a new or existing patient is in the prodromal state of stroke onset, so that we can refer them for co-management. I hope you will read this information closely.

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