The latest study to investigate whether a unique association between chiropractic manipulation and risk of cervical artery dissection / stroke exists has yielded similar encouraging findings, with the authors noting "no excess risk of carotid artery stroke after chiropractic care" and no significant risk difference between patients receiving care from a DC or a primary care medical provider.
Moreover, as has been suggested previously, the authors state that the incidence of stroke in these instances is "likely due to patients with early dissection-related symptoms seeking care prior to developing their strokes."
The study by J. David Cassidy, DC, PhD, DrMedSc, Scott Haldeman, DC, MD, PhD, and colleagues1 identified all carotid artery stroke cases admitted to hospitals in Ontario, Canada over a nine-year period, with exposure to chiropractic vs. PCP services determined by review of billing records. Overall, 15,523 cases were compared to 62,092 control periods using exposure windows of 1, 3, 7, and 14 days prior to stroke onset.
Readers will recall that Drs. Cassidy and Haldeman both served on the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and its Associated Disorders, whose research included the finding, as Dr. Haldeman stated in a 2008 DC article,2 that "the risk of vertebrobasilar (VBA) stroke associated with a visit for a chiropractor's office appears to be no different from the risk of stroke following a visit to an MD's office. It is likely that patients in the early stages of VBA stroke are presenting to both chiropractors and family doctors because of neck pain and headache due to pre-existing vertebral artery dissection, which is a risk factor for VBA stroke."
References
- Cassidy JD, Boyle E, Côté P, et al. Risk of carotid stroke after chiropractic care: a population-based case-crossover study. J Stroke Cerebrovasc Dis, 2016 Nov 21 (epub ahead of print).
- "Task Force Results Explained to Media, Health Care Professionals." Dynamic Chiropractic, May 20, 2008.
