The word "stroke" conjures images of a bolt out of the blue. No one ever imagines that they will have a stroke, much less that it might happen as a result of a chiropractic treatment for neck pain -- but it does. Just ask Sandra Nette, a woman from Edmonton, Canada who was seeing her chiropractor for "preventive" treatment. According to a recent news story, she suffered a severe brainstem stroke as a result of a neck adjustment by her chiropractor.
Throughout my lengthy career, I have seen several patients just like Sandra. What brought her case to worldwide attention was the fact that after the stroke, the chiropractor forged her signature on a consent form.
Arteries That Nourish the Brain
There are four major blood vessels that carry blood, oxygen, and nutrients to the brain. They branch off the aorta, the large blood vessel that carries blood from the heart to all parts of the body. Two of these blood vessels, the vertebral arteries, travel inside the bones in the neck and supply blood to the most vital area of the brain, the brainstem. It is this part of the brain that controls heartbeat, respiration, swallowing, eye movements and important centers that coordinate movements. Since the vertebral arteries travel inside the bones of the neck, neck injuries can pinch or damage them. It is common for people to experience dizziness when they look upward tipping by their neck backwards. For example, an elderly woman may feel lightheaded as she reclines in the sink at the beauty parlor. As the hairdresser applies that mysterious blue tint, the blood vessels in the woman's neck may become pinched, and the she may feel dizzy -- or, on rare occasions, pass out.
Chiropractors, osteopaths, and physical therapists commonly use spinal manipulation. There are two primary types of spinal manipulation: the "low-velocity" adjustment, or the "high-velocity" thrust, which rapidly adjusts joints. Chiropractors believe that these adjustments reposition the joints, nerves and spinal cord, relieving pain and improving spinal health. Unfortunately, spinal manipulation of the neck remains controversial with physicians, and chiropractors are unable to agree upon its effectiveness. To date, carefully performed studies have shown some benefit in the treatment of low-back pain, but do not show any convincing evidence that it treats neck pain.
When does a chiropractic treatment go wrong -- which part of the treatment causes the stroke? The evidence suggests that in rare cases, the rapid movement of the neck can tear the vertebral artery and cause what is called a dissection. The lining of the artery tears away from its wall, causing a blood clot to form. Blood can then no longer reach the all-important brainstem, causing a severe stroke and leaving the majority of patients with permanent disabilities.
Are You at Risk?
A study by Ernst and another by Haldeman and his colleagues looked at a large series of brainstem strokes, including those caused by spinal manipulation or trauma. Some type of "adverse effect" was not uncommon after manipulation of the neck. Headaches, dizziness and neck pain were the most common side effects. For the most part these side effects were benign and self-limiting, although a small number of people did experience a severe stroke and death.
Although one can argue that strokes caused by spinal manipulation are very rare, I suggest looking at the risk/benefit ratio. You may be going in to see the chiropractor for a nagging headache or annoying neck pain, but you are being exposed to a treatment that has potentially severe side effects. The data suggests that strokes and serious side effects are more likely to occur in young, healthy adults, making it difficult to predict precisely which of these individuals will have a serious side effect. Sandra Nette claimed she was going to the chiropractor for "preventive" use of manipulation, but ended up with a serious lifelong disability.
What Should You Do?
- "Wait," you may say. "Dr. Senelick is a medical doctor (M.D.), and he is obviously biased against chiropractors." Not so. But it is true that the lack of cooperation between medical doctors and chiropractors has not helped the deficiency of high-quality scientific studies on cervical (neck) manipulation. While this cooperation may never happen, there are some common-sense approaches that we can all agree upon.
The Last Word
An editorial accompanying an article on chiropractic manipulation and stroke summarizes the issue. "In the meantime, chiropractic cervical manipulation cannot be considered risk-free, particularly in view of the fact that ... vertebral artery dissection can present with neck pain as the only symptoms, thus leading the patient to consult a chiropractor." Simply put, manipulation of the neck is like a semicolon: When in doubt, leave it out.
For more by Richard C. Senelick, M.D., click here.
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