A procedure commonly performed by chiropractors could be causing dozens of Canadians to have strokes every year, neurologists warn.

Chiropractic manipulation is safely done millions of times a year in Canada to treat back and neck pain and other ailments.

But more than 60 neurologists have signed a letter warning the treatment can lead to strokes. They say if the neck is rotated improperly, a blood vessel can tear, causing a clot to form.




Neurologists suspect the sudden jerking could be a leading cause of stroke in people under age 45 but many cases of stroke are slipping through unnoticed.

The neurologists issued their warning to doctors, patients and coroners performing autopsies. They want people to know the symptoms of strokes caused by neck manipulations.

In 1999, an unpublished study by the Canadian Stroke Consortium concluded 21 out of 50 cases of stroke were due to neck manipulation. Their results were based on figures from the Heart and Stroke Foundation.

Dr. Stanley Gorcynski
Dr. Stanley Gorcynski

"Someone essentially has to step up and say, 'Look these risks that we see are very real,'" said the study's researcher, neurologist Dr. Brad Stewart. "They are not as infrequent as the chiropractic community would make them out to be."

Some chiropractors say the risk of stroke from neck manipulation is as low as the risk from playing golf or cradling a phone. About 10 per cent of Canadians visit chiropractors.

"One to two incidents per million neck adjustments, so it's a very rare occurrence," said Dr. Stanley Gorchynski of the Canadian Chiropractic Association.

Gorchynski thinks the stroke consortium's research methodology is unclear and said their results have never been peer-reviewed.

The results will be presented at the American Stroke Association's conference on Friday.