Dr. Bradley Andre 5/18/26 Dr. Bradley Andre 5/18/26

Chiropractic Care, Vertebral Artery Dissection, and Stroke: What Recent Peer-Reviewed Research Actually Shows

Few topics in healthcare generate as much controversy as the alleged relationship between chiropractic cervical manipulation, vertebral artery dissection (VAD), and stroke. For decades, headlines, malpractice cases, and anecdotal reports have fueled public concern. However, when the peer-reviewed literature is examined carefully, the distinction between correlation and causation becomes critically important.

Recent studies and systematic reviews continue to show that while an association between chiropractic visits and cervical artery dissection may exist in some datasets, establishing direct causation remains far more difficult.

Understanding Vertebral Artery Dissection

A vertebral artery dissection occurs when a tear forms in the inner lining of the vertebral artery, which supplies blood to the brain. This can allow blood to enter the arterial wall, potentially causing clot formation or reduced blood flow. In rare cases, this may lead to stroke.

Importantly, VAD is already known to occur spontaneously or after relatively minor mechanical events, including:

Sudden neck movements
Sports injuries
Motor vehicle accidents
Coughing or sneezing
Weightlifting
Connective tissue disorders
Migraine disorders

Recent research also highlights migraine and vascular abnormalities as independent risk factors for cervical artery dissection.

Correlation Does Not Automatically Mean Causation

One of the most cited modern analyses is the 2016 systematic review and meta-analysis by Penn State University. The researchers reviewed the available literature on chiropractic care and cervical artery dissection and concluded:

A small statistical association existed between chiropractic visits and cervical artery dissection.
The overall quality of evidence was rated “very low.”
Available studies suffered from major confounding factors and bias.
There was “no convincing evidence” supporting a direct causal relationship.

One major confounder repeatedly identified is that patients developing a vertebral artery dissection often experience neck pain and headache before the dissection is diagnosed. Those symptoms commonly drive patients to seek care from chiropractors, primary care physicians, or emergency departments.

In other words, the patient may already be dissecting before any treatment occurs.

The “Reverse Causation” Problem

Researchers frequently describe this issue as reverse causation.

A patient develops early symptoms from an evolving arterial dissection:

neck pain
stiffness
headache
dizziness

The patient then seeks treatment for those symptoms. Later, when the dissection progresses or is finally diagnosed, it may appear that the healthcare visit caused the event, when in reality the dissection was already underway.

This phenomenon has been repeatedly discussed in the literature and remains one of the strongest arguments against assuming direct causation from timing alone.

Recent Literature Continues to Debate Causation

A 2024 review titled Cervical Spine Manipulation and Causation of Cervical Artery Dissection evaluated multiple published case reports and concluded that temporal association alone is insufficient to establish causation.

Similarly, a 2024 forensic review of malpractice cases reported:

No convincing evidence that cervical manipulation directly causes cervical artery dissection
Greater evidence that missed diagnosis and delayed referral may contribute to poor outcomes
Many patients likely presented with pre-existing dissections before treatment

Another 2021 study examining 34 chiropractic-associated vertebral artery dissection cases among a cohort of 310 dissections suggested chiropractic manipulation may represent a potential risk factor, while also acknowledging the rarity of events and the complexity of proving direct causation.

The Difference Between Case Reports and High-Level Evidence

Much of the public concern surrounding chiropractic manipulation and stroke comes from individual case reports. These reports are important because they identify possible safety concerns, but they do not prove causation.

Case reports typically lack:

control groups
statistical power
ability to eliminate confounding variables
confirmation that the dissection did not pre-exist

Systematic reviews and meta-analyses sit much higher on the evidence hierarchy because they evaluate the totality of available research rather than isolated incidents.

The current body of high-level evidence generally supports the following conclusions:

Cervical artery dissection is extremely rare.
Some patients who experience dissection had recent chiropractic visits.
Similar associations are also seen with primary medical care visits because patients seek care for early symptoms.
Existing evidence has not definitively established chiropractic manipulation as a direct cause of cervical artery dissection.

Risk Recognition Remains Critically Important

Although the literature debates causation, nearly all researchers agree on one point:

Healthcare providers NEED to recognize warning signs of possible cervical artery dissection.

Red flag symptoms may include:

sudden severe neck pain
unusual headache
dizziness
double vision
slurred speech
facial numbness
limb weakness
difficulty walking
nausea or vomiting after neck pain onset

A 2023 systematic review specifically emphasized that many patients with undiagnosed VAD initially present with neck pain or headache to chiropractors. The authors stressed the importance of early recognition and emergency referral when dissection is suspected.

What Patients Should Understand

Patients deserve accurate, evidence-based information rather than fear-driven headlines or oversimplified claims.

Current peer-reviewed evidence suggests:

Serious vascular events following cervical manipulation are exceedingly rare.
An association between chiropractic visits and VAD exists in some observational studies.
Correlation alone does not prove causation.
Many cases likely involve patients already experiencing an evolving dissection before seeking care.
Providers should remain vigilant for vascular warning signs regardless of profession.

The scientific discussion is still evolving, but modern literature increasingly emphasizes careful interpretation of data, recognition of confounding variables, and avoidance of assuming causation from timing alone.