Neurologists warn about link between chiropractic, stroke

More than 60 Canadian neurologists have issued a statement warning that chiropractic neck manipulation can cause stroke and death. The neurologists and the Canadian Stroke Consortium caution that chiropractic manipulation involving the neck can cause arterial dissection. They make 6 recommendations and call for a ban on manipulations involving infants and children. “If there are no clear benefits, any risk is unacceptable,” says Calgary neurologist Brad Stewart.

But Jim Duncan, executive director of the Canadian Chiropractic Association, says that neck manipulations help relieve chronic back pain and migraine, and chiropractors have “an enviable safety record” in providing such treatments. The stroke consortium says that 1 in 5000 to 10 000 strokes is caused by neck manipulation. In Canada, about 100 cases of arterial dissection are linked to neck manipulation each year. A recent CMAJ report (2002;166[1]:40-1) indicated that the incidence is likely vastly underreported, largely because the link is seldom made between the neck adjustments and stroke.

Dr. Murray Katz, a Montreal pediatrician and vocal opponent of chiropractic manipulation involving children, says warning signs of vascular accidents, such as neck pain, visual impairment, nausea, dizziness and numbness, often don't appear until a week or 2 after the chiropractic visit, and some victims don't understand the severity and don't seek medical treatment.

The neurologists, including the chiefs of neurology at Canada's teaching hospitals, are urging physicians to question patients with stroke symptoms — especially those under 45 years — about recent neck manipulation. They say Canadians need to know that the symptoms are not normal and “that under no circumstances should individuals allow their necks to be manipulated if any of these symptoms are present.”

The news release says neck manipulation is one of the leading causes of stroke in people under 45 years. A recent study by researchers from the Institute of Clinical Evaluative Sciences in Ontario found that patients younger than 45 who had experienced stroke related to posterior circulation are 5 times more likely than controls to have visited a chiropractor within a week of the event (Stroke 2001;32:1054-60). “No one knows who is most susceptible to strokes caused by manipulation,” says Katz. “So chiropractors shouldn't be doing them until more studies are done and risks can be assessed on a per patient basis.”

The neurologists also want chiropractors to post warning signs, but Duncan says patients already sign consent forms and are made aware of the risks of neck manipulation by chiropractors, including the “slight risk of stroke.” — Jennifer Jones, Ottawa