Analysis: Did spine manipulation cause the death of Katie May?

A recent case report on Katie May, who died in 2016 after receiving chiropractic cervical spine manipulation (CSM) from a DC, has concluded it did not cause her death.

The case report’s author, Steven Brown, DC, DIPL MED AC, came to the conclusion that CSM did not cause the vertebral artery dissection (VAD) or the stroke that took May’s life. The study, “Causal analysis of vertebral artery dissection and fatal stroke following chiropractic cervical spine manipulation,” appeared in December 2024 in the journal Forensic Science International: Reports.¹

Spotlight on Katie May

May’s February 2016 death from a stroke that followed CSM was the highest-profile case of its kind in the history of the chiropractic profession.^2,3 May, a professional model and social media celebrity with a large following on Snapchat, X (Twitter) and other platforms, received persistent media coverage that soon spread her story around the world.

May’s wrongful death case against the DC who performed the CSM was settled for $250,000 in January 2021.⁴

Information for the case report came from publicly available documents in the November 24, 2020, Appendix of Declarations and Evidence in Support of Plaintiff’s Opposition to Defendant’s Motion for Summary Adjudication.⁵ These documents include the declaration of the plaintiff’s chiropractic expert, a transcript of the defendant’s deposition, chiropractic records, hospital records and a certified copy of May’s autopsy report. Background information was taken from publicly available investigative journalism and media coverage of this case.^4,6

Expert: cervical spine manipulation did not cause VAD

The case report concludes that CSM did not cause the VAD, and that the dissection had been present before the CSM. May entered the chiropractic office with a history of trauma, neck pain, headache and nausea consistent with existing VAD.
Some medical doctors still insist that CSM causes VAD in such cases.⁷ However, the findings of the case report are supported by studies from neurological and chiropractic researchers who conclude that in cases of VAD and stroke diagnosed following CSM, it is likely the VAD was present before the CSM.

In a 2016 systematic literature and meta-analysis, Church, et al., concluded, “There is no convincing evidence to support a causal link between chiropractic manipulation and CAD [cervical artery dissection].”⁸ This study was published in the Cureus Journal of Medical Science by six neurosurgeons from the Department of Neurosurgery at Penn State Hershey Medical Center.

In a 2014 review study, Biller, et al., states that the biomechanical evidence is insufficient to establish the claim that CSM causes CAD, and recommends that practitioners strongly consider the possibility of CAD as a presenting symptom.⁹ This study appeared in the journal Stroke on behalf of the American Heart Association Stroke Council, endorsed by the American Association of Neurological Surgeons and Congress of Neurological Surgeons.

In the well-known 2008 Cassidy, et al., epidemiological study, the authors conclude that the increased risk of vertebrobasilar artery stroke associated with chiropractic and primary care provider visits is likely due to patients with headache and neck pain from VAD seeking care before their stroke. This clinical scenario, experts concluded, is precisely what happened in the May case. Similar epidemiological studies in 2015 by Kosloff, et al., and Whedon, et al., had similar conclusions to those of Cassidy, et al.^10-11

Review of May’s records found the stroke did not occur until approximately 7.5 hours after CSM, and no plausible mechanisms of causation exist for a stroke occurring 7.5 hours after CSM.¹² While the chiropractic physician failed to recognize characteristic symptoms of VAD and refer the patient to medical emergency services, CSM did not cause the dissection or the stroke, the reviewer concluded.

How to exclude VAD before a CSM

The case report concludes that adherence to the standard of care for the chiropractic profession with attention to differential diagnosis could prevent stroke in such cases. If the chiropractic physician in this case had taken a thorough history and performed a physical examination to rule out VAD before doing the CSM, the outcome of this case might have been avoided.

A clinical examination strategy to exclude VAD before performing CSM has been published by Chaibi, a chiropractic physician with a PhD in headaches, and co-author Russell,¹³ a medical neurologist. The authors propose a risk-benefit assessment strategy tool to exclude VAD before performing CSM. Had this clinical strategy been followed in the May case, her stroke could have been prevented.

A similar clinical examination strategy, the International Framework for Examination of the Cervical Region for potential of vascular pathologies of the neck prior to Orthopaedic Manual Therapy (OMT) Intervention, has been published by the International Federation of Orthopaedic Manipulative Physical Therapists (IFOMPT).¹⁴ Chiropractic researcher Sidney Rubinstein co-authored the IFOMPT document.

Final thoughts: The need for medicolegal experts

The chiropractic profession endured significant negative publicity from the Katie May case as the medical examiner opined that CSM caused the VAD, which embolized to cause the fatal stroke.

The May case occurred in February 2016. Ronald Richards, attorney for the plaintiff, reported that no chiropractic expert witness would review the case for the plaintiff for 3.5 years, until late 2019.

The chiropractic expert who ultimately reviewed the case for the plaintiff concluded that the chiropractic physician did not cause the VAD or the stroke. Had a chiropractic expert witness reviewed the case promptly in 2016, the profession may have been spared some undeserved negative publicity. This case highlights the need for more chiropractic medicolegal experts to review plaintiff cases.¹⁵

STEVEN BROWN, DC, DIPL MED AC, is an expert witness for the plaintiff or defense, emphasizing cases of cervical spine manipulation, vertebral and carotid artery dissection and stroke. For more information, visit thechiropracticexperts.com.

References

1. Brown SP. Causal analysis of vertebral artery dissection and fatal stroke following chiropractic cervical spine manipulation. Forensic Science International: Reports. 2025;11:100400. https://www.sciencedirect.com/science/article/pii/S2665910724000495.

2. TMZ. Model Katie May “Queen of Snapchat” dies at 34. TMZ. Published online February 4, 2016. https://www.tmz.com/2016/02/04/model-katie-may-dies-stroke/. Accessed March 22, 2024.

3. TMZ. Model Katie May Stroke Triggered by Brutal Photo Shoot Fall. TMZ. Published online February 5, 2016. https://www.tmz.com/2016/02/05/model-katie-may-stroke-fall-photo-shoot/.

4. City News Service. Suit by minor daughter of late ‘Snapchat Queen’ ends with $250,000 settlement. WEHO Online. Published online January 21, 2022. https://wehoonline.com/2022/01/21/suit-by-minor-daughter-of-late-snapchat-queen-ends-with-250000-settlement/.

5. Richards R, Stelmach M. Appendix of Declarations and Evidence in Support of Plaintiff’s Opposition to Defendant’s Motion for Summary Adjudication. Published online November 24, 2020.

6. Hamill S. Medical examiner says neck manipulation killed Internet phenom. Pittsburgh Post-Gazette. Published online October 22, 2016. https://www.post-gazette.com/local/region/2016/10/23/Neck-manipulation-killed-Internet-phenom/stories/201606140162.

7. Brown S. The Irrelevance of Being Ernst. Dynamic Chiropractic. Published online October 2024. https://dynamicchiropractic.com/article/102466-the-irrelevance-of-being-ernst.

8. Church EW, et al. Systematic Review and Meta-analysis of Chiropractic Care and Cervical Artery Dissection: No Evidence for Causation. Cureus. 2016;8(2):e498. https://www.cureus.com/articles/4155-systematic-review-and-meta-analysis-of-chiropractic-care-and-cervical-artery-dissection-no-evidence-for-causation#!/.

9. Biller J, et al. Cervical arterial dissections and association with cervical manipulative therapy: a statement for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2014;45(10):3155-3174. PubMed. https://pubmed.ncbi.nlm.nih.gov/25104849/.

10. Kosloff TM, et al. Chiropractic care and the risk of vertebrobasilar stroke: results of a case-control study in U.S. commercial and Medicare Advantage populations. Chiropr Man Therap. 2015;23:19. PubMed. https://pubmed.ncbi.nlm.nih.gov/26085925/.

11. Whedon JM, et al. Risk of stroke after chiropractic spinal manipulation in Medicare B beneficiaries aged 66 to 99 years with neck pain. J Manipulative Physiol Ther. 2015;38(2):93-101. PubMed. https://pubmed.ncbi.nlm.nih.gov/25596875/.

12. Brown SP. Plausible Mechanisms of Causation of Immediate Stroke by Cervical Spine Manipulation: A Narrative Review. Cureus. 2024;16(3):e56565. https://www.cureus.com/articles/239108-plausible-mechanisms-of-causation-of-immediate-stroke-by-cervical-spine-manipulation-a-narrative-review#!/.

13. Chaibi A, Russell MB. A risk-benefit assessment strategy to exclude cervical artery dissection in spinal manual-therapy: a comprehensive review. Ann Med. 2019;51(2):118-127. PubMed. https://pubmed.ncbi.nlm.nih.gov/30889367/.

14. Rushton A, et al. International Framework for Examination of the Cervical Region for potential of vascular pathologies of the neck prior to Orthopaedic Manual Therapy (OMT) Intervention: International IFOMPT Cervical Framework ©(2020). Published online 2020.

15. Brown S. So, you want to be a chiropractic malpractice expert witness? Chiropractic Economics. 2025;71. https://www.chiroeco.com/so-you-want-to-be-a-chiropractic-malpractice-expert-witness/.