Chiropractic SMT & Stroke Revisited...Again

Last month, like many other months, the medical community was mal-educated by a published case study regarding the threat of CAD following SMT.

Cureus:

…cases of spontaneous dissection of the vertebral artery do have a history of trivial or minor injury involving some degree of cervical distortion such as chiropractic neck manipulation, as the extreme hyperextension and/or rotation of the neck may create areas of stretch and lead to intimal or adventitial tears in the vertebral artery causing dissection. It is a relatively rare, potentially disabling and sometimes an under-diagnosed cause of stroke. It accounts for 2% of all ischemic strokes …This report demonstrates the potential hazards associated with neck trauma, including chiropractic manipulation, as it is under reported…” (Almuaigel et al.)

Chiropractors armed with quality data can refute these inaccurate associations. Check out this blog, video, and new infographics for our compelling reply to this author’s opinion, including the current facts about the safety of SMT. Plus, three practical tools that you can employ today to change attitudes tomorrow.

A Continuum of Problems:

1. Almuaigel’s ambiguous wording in the abstract (“It accounts for 2%...”) could be interpreted to suggest neck manipulation is responsible for 2% of all ischemic strokes. The paper’s body somewhat clarifies that SMT is only one potential cause of the 2% of strokes from spontaneous dissections.

“Extreme hyperextension and/or rotation of the neck may create areas of stretch and lead to intimal or adventitial tears in the vertebral artery, thereby causing dissection. Hence, chiropractic is a potential risk factor for vertebral dissection.” (1) 

2. Almuaigel (1) establishes his connection between neck manipulation and stroke based on his accompanying case report and a hypothesis (2) from a 2015 study of 24 CAD cases. The referenced assumption, by Thomas et al., quantifies an association between SMT and stroke because 4 of the 24 documented dissection cases had seen a chiropractor sometime in the preceding month:

“Four participants with CAD had undergone recent chiropractic treatment of their neck in the month prior to their dissection; in 2 cases, this reportedly involved rotary high-velocity thrust manipulation to the cervical spine, and in another case deep massage to the suboccipital region.” (2)

A sign of fine literature- sentences with more flaws than punctuation marks:

• Is “2” a relevant number to establish causation?

• Rubbing the skin over the suboccipital can tear arteries?

• But most notably- association does not mean causation!

Yes, impending stroke patients with associated neck pain and headaches tend to visit all types of providers before full expression of their CAD. But quality literature concludes that the subsequent dissection rate is nearly identical in patients who underwent neck manipulation and those visiting a medical physician. (3-6) The rate of detection for pre-stroke presentations is also similar. (4)

The authors of these low-level case reports and case reviews could have better served the scientific and medical community had they referenced more authoritative sources:

An Annals of Medicine comprehensive literature review:

“Manual therapy does not result in an increased risk of Cervical Arterial Dissection.” (3)

A Cassidy study comprising 100 million-patient-years of data:

“No evidence of excess risk of stroke associated chiropractic care compared to primary care.“ (4)

 The findings from a review of 39 million patients:

“No significant association between stroke and chiropractic visits. Manipulation is an unlikely cause of stroke.” (5)

Or even this conclusion (from the same Cureus Journal) of all published literature:

“No excess risk of stroke for chiropractic manipulation compared to primary (MD) care”(6)

Almuaigel and his fellow neurologists fall victim to the errant reporting style highlighted by Annals of Medicine:

“The assumption that the cervical manual-therapy intervention triggers CAD in rare cases has been dominated by single-case reports and retrospective case series or surveys from neurologists who naturally lack substantial methodological quality to establish definitive causality. These neurological case reports have probably contributed to an over-reporting of serious and catastrophic adverse events.” (3)

Unfortunately, this type of assumptive reporting shows up in the general medical literature many times each year. Well-intentioned physicians read this literature and develop a natural bias away from treatments that are perceived as threatening. Patients are subsequently discouraged from undergoing care (chiropractic SMT) that is significantly safer than medical alternatives. (7)

Overcoming ingrained perceptions can only happen via relaying facts and repeated positive clinical outcomes. Check out the following video with three tools for overcoming medical bias toward cervical manipulation.

As responsible chiropractors, we must not allow the Annals paper and similar data to lull us into a false sense of security. We should not dismiss the risk of stroke or any other reasonable threat. We must continue to carefully assess each patient’s history, adequately screen for vascular pathology before treatment, recognize & refer patients who require medical consultation, and choose alternatives to cervical manipulation for higher-risk patients.

Check out our prior blog detailing the Annals of Medicine study, including concerning presentations and worrisome symptoms that could suggest an impending stroke.

New research continues to shape how we manage patients, and as a ChiroUp subscriber, you can practice with ultimate confidence, knowing that your care is backed by the most up-to-date, evidence-based research. Thanks for joining us on our mission to make chiropractic care the undeniable best and safest choice for patients and payors alike.

• References

  1. Almuaigel MF, Althwanay A, Alamri A. Spontaneous Bilateral Dissection of the Vertebral Artery: A Case Report. Cureus. 2020 Jul;12(7). Link

  2. Thomas LC, Rivett DA, Attia JR, Levi C. Risk factors and clinical presentation of cervical arterial dissection: preliminary results of a prospective case-control study. journal of orthopaedic & sports physical therapy. 2015 Jul;45(7):503-11. Link

  3. Chaibi A, Russell MB. A risk–benefit assessment strategy to exclude cervical artery dissection in spinal manual-therapy: a comprehensive review. Annals of medicine. 2019 Feb 17;51(2):118-27. Link