Vascular Complications and Chiropractic Cervical Manipulation

What does the literature have to say?

The recent description of a near fatal stroke following chiropractic cervical manipulation has reopened a very old debate. Is chiropractic cervical manipulation (adjustment) associated with stroke? Can it cause vascular injury?

The medical literature identifies cervical artery dissection (CAD)—primarily involving the vertebral arteries or internal carotid arteries—as the most serious vascular injury associated with chiropractic cervical spinal manipulation therapy (cSMT).

Key Findings in the Medical Literature

1. Association with Cervical Artery Dissection (CAD)

Case reports and case series have long linked cSMT with vertebral artery dissection (VAD) and subsequent posterior circulation stroke, particularly in young and otherwise healthy individuals.

I reviewed the world literature in 1978 and found some 700 case reports of stroke following cervical manipulation. Many more cases have been reported since.

Dissection can occur spontaneously or be triggered by minor trauma, including neck manipulation, sneezing, or turning the head.

There are epidemiological studies describing an association, for example:

Rothwell et al., 2001 (Neurology)

A population-based case-control study in Ontario found an increased risk of stroke associated with chiropractic visits in patients under 45 years. However, they acknowledged that patients with evolving symptoms may have sought chiropractic care for neck pain or headache before the stroke.

Cassidy et al., 2008 (Spine)

This large population-based study found that the association between stroke and visits to chiropractors was similar to that for visits to primary care physicians, suggesting that patients were already in the early stages of artery dissection and sought care for symptoms like neck pain or headache before stroke onset.

There are also systematic reviews describing the association.

Church et al., 2016 (CMAJ Open)

A systematic review noted that although there is a plausible association between cSMT and CAD, causation could not be established due to limitations in study design, biases, and confounding factors.

Biller et al., 2014 (AHA/ASA Scientific Statement, Stroke)

This American Heart Association statement concluded that cSMT may be associated with cervical artery dissection, but emphasized that a direct causal relationship was difficult to confirm.

Although the evidence is insufficient to prove a direct causal relationship, there is clearly an association. Many dissections may be spontaneous, and patients may seek chiropractic care after early symptoms (headache, neck pain).

However, in many of the case reports, no preceding symptoms were described.

Manipulation may cause mechanical stress on the vertebral or carotid arteries, potentially leading to intimal tear and intramural hematoma.

The absolute risk appears to be low—estimated at 1 in 100,000 manipulations.

Dissections following manipulation tend to occur more often in younger patients (under 45).

Neck pain, headache, dizziness, visual disturbance, and neurological deficits after manipulation should prompt urgent evaluation.

Chiropractic cervical manipulation has clearly been associated with cervical artery dissection and stroke in some case reports and observational studies, but large-scale epidemiological studies suggest that the absolute risk is low.

Most medical bodies recommend caution, especially in younger patients presenting with recent-onset neck pain or headache.

Vascular Injury and Chiropractic Cervical Manipulation: Summary of Medical Literature

Cervical Artery Dissection (CAD) — particularly vertebral artery dissection (VAD) or internal carotid artery dissection (ICAD) — is the primary vascular complication associated with chiropractic cervical spinal manipulation therapy (cSMT).

It may lead to ischemic stroke, especially in the posterior circulation

Risk Summary

Estimated absolute risk: Between 1 in 100,000 manipulations.

More often reported in younger patients (<45 years).

Often but not always preceded by headache or neck pain, which may reflect early dissection rather than manipulation-induced injury.

Clinical Pearls

Temporal association ≠ causation: Dissections often develop before the patient seeks care.

High-risk symptoms after cSMT:

Sudden neck pain or headache

Dizziness, diplopia, dysarthria

Facial numbness, limb weakness, ataxia

Urgent neuroimaging (MRI/MRA or CTA) is warranted if CAD is suspected.

Current evidence does not establish a direct causal link between chiropractic cervical manipulation and stroke, but a low risk of vascular injury is associated. The decision to perform cSMT should weigh this rare risk, particularly in young patients with acute or atypical neck pain. All patients should be informed of this association before cervical manipulation is performed as part of informed consent.

Prepared for Educational Use – June 2025

Compiled from peer-reviewed literature and official statements (AHA/ASA, CMAJ, Neurology, Spine)