Does Chiropractic Manipulation Cause Strokes?
Recent publicity regarding deaths of young adults after chiropractic manipulation have increased public attention about the safety of chiropractic manipulation of the cervical spine. The apparent association between cervical manipulation and arterial dissection has been reported several times in the literature, with increasing frequency in the last 20 years, coinciding with the rising popularity of chiropractic treatment.
In 1999, an unpublished study by the Canadian Stroke Consortium concluded that 21 out of 50 cases of stroke were due to neck manipulation. Their results were based on figures from the Heart and Stroke Foundation.
There are also reports of spontaneous cervical arterial dissection resulting in strokes. Approximately 16 to 19 percent of strokes in young patients are attributed to spontaneous cervical arterial dissection, often accompanied by neck or head pain. While most spontaneous cases do not have a clear cause, certain uncommon conditions, as well as trauma, can be a pre-disposing factor.
Neurologists suspect the sudden jerking may be a leading cause of stroke in people under age 45, but many causes of stroke are not determined. Some chiropractors, however, assert that the risk of stroke from neck manipulation is as low as the risk from playing golf or cradling a phone.
A groundbreaking study on vertebral artery dissection (VAD) and stroke following chiropractic office visits is pending publication in Spine and the European Spine Journal. The study, conducted as part of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders, looked at the association between chiropractic office visits and the incidence of vertebral artery strokes. The recently published “Current Concepts: Spinal Manipulation and Cervical Arterial Incidents 2005” (NCMIC) [ 8 ] concludes in it’s Executive Summary: “Unfortunately, opinion rather than fact has tended to dominate discussions regarding CVAs and chiropractic, even though there has been no definitive evidence that chiropractic adjustments (actually) cause strokes.” There is note, however, of an associative relationship between the two because people may go to chiropractors for relief of stroke-related symptoms”.
In 2006, the Journal of Neurology published a German Vertebral Artery Dissection Study Group report about 36 patients who had experienced vertebral artery dissection associated with neck manipulation. Twenty-six patients developed their symptoms within 48 hours after a manipulation, including five patients who got symptoms at the time of manipulation and four who developed them within the next hour. In 27 patients, special imaging procedures confirmed that blood supply had decreased in the areas supplied by the vertebral arteries as suggested by the neurological examinations. In all but one of the 36 patients, the symptoms had not previously occurred and were clearly distinguishable from the complaints that led them to seek manipulative care. Indirectly, the study supports the assertion that neck manipulation can cause strokes—which many chiropractors deny.
Many people are tremendous proponents of the benefits of chiropractic treatment and we are not suggesting that such benefits be discounted. However, individuals who undergo chiropractic treatment should be aware of the possible risks associated with cervical manipulation and may want to address those potential risks with their health care provider, particularly if cervical manipulation is part of the treatment plan. Whether the stroke of an individual patient has been caused or contributed to by cervical manipulation is probably a matter for forensic experts to address on a case by case basis.
