Chiropractic Neck Treatments Increase Risk of Stroke
What Rothwell and colleagues actually found, says Powers, "is over a period of six years -- in all of Ontario -- six patients under age 45 who had chiropractic manipulation within one week of stroke. So this is very, very rare; it causes very few strokes. If you get your neck manipulated, your chances are very, very low of getting it ... but still, about five times higher than if you didn't."
Powers says that for years he has advised against chiropractic manipulation.
"When people ask me, I specifically say that it's OK to get your lower back manipulated, but don't let them mess with your neck," she tells WebMD.
"The type of data Rothwell used is not the most reliable, says Larry Goldstein, MD, director of the Stroke Center at Duke University in Durham, N.C.
"It can only show that visits to the chiropractor and this type of stroke are associated, not that the one causes the other," he tells WebMD. "We've all seen patients who have had neck manipulations and minor neck trauma or no neck trauma that have developed ... stroke. They're reporting that there seems to be a relationship between recent manipulation and stroke. Even with that though, the overall risk appears to be somewhat low -- 1.3 cases per 100,000 under age 45 receiving chiropractic manipulation -- that's pretty low."
So what's a tolerable risk?
"It has to be balanced by benefit," says Goldstein. "If there's no benefit, then any risk is not worthwhile. On the other hand, if there is benefit, then we tolerate various levels of risk. Medical therapies are not risk-free. What this does is raise the issue that there is this potential risk, and like anything else we do in medicine, patients need to know about that risk."
Leaders in the chiropractic community take issue with the findings -- and the implications.
"[Rothwell's study] is a deliberate and unethical scare tactic that does not stand up to critical analysis," says Terry A. Rondberg, DC, president of the World Chiropractic Alliance.
"This is pure conjecture," Rondberg tells WebMD. "I see this, frankly, as an attempt to discredit chiropractic and discourage people from seeking the care of doctors of [chiropractic].
"Chiropractors are trained to deliver a chiropractic adjustment," he continues. "Manipulation is not something we do. Manipulation is the forceful passive movement of a joint beyond its active limit of motion. ... It's not synonymous with chiropractic adjustment. And these cases of spinal manipulation are often performed by nonchiropractic practitioners like osteopaths and physiatrists."
As pointed out in Rothwell's study, says Rondberg, the rate of stroke is estimated at 1.3 incidents per one million adjustments given. "Other studies, including one covering a 28-year period reviewing 110 million chiropractic visits, showed conclusively that the risk of stroke from chiropractic adjustments is so small that it's statistically insignificant," he says.