American Heart Association experts are warning that the neck manipulations often used by chiropractors and physicians may be associated with stroke.
The association can't be proven but a small tear in a neck artery, called a cervical dissection, is among the most common causes of strokes in young and middle-aged adults. A dissection can lead to a blood clot that travels to the brain and triggers a stroke.
In a statement published in the heart association's journal Stroke, Dr. Jose Biller of Loyola University Medical Center said that while the association isn't proven, it is grounds for concern.
"Most dissections involve some trauma, stretch or mechanical stress," Biller said. "Sudden movements that can hyperextend or rotate the neck -- such as whiplash, certain sports movements, or even violent coughing or vomiting -- can result in a cervical dissection, even if they are deemed inconsequential by the patient."
Although techniques for cervical manipulative therapy vary, some maneuvers used by health practitioners also extend and rotate the neck, and sometimes involve a forceful thrust.
"Although a cause-and-effect relationship between these therapies and cervical dissection has not been established and the risk is probably low, a dissection can result in serious neurological injury," Biller said. "Patients should be informed of this association before undergoing neck manipulation."
Biller is chair of the Department of Neurology of Loyola University Chicago Stritch School of Medicine. He is an internationally known expert on strokes, especially strokes in children and young adults.
The association between cervical artery dissection and cervical manipulative therapies was identified in case control studies, which aren't designed to prove cause and effect. Thus, it's not clear whether other factors could account for the apparent association between manipulative therapy of the neck and a greater incidence of cervical dissection/stroke. The relationship is difficult to evaluate because patients who are beginning to have a cervical artery dissection may seek treatment to relieve neck pain.
What to do
You should seek emergency medical evaluation if you develop neurological symptoms after neck manipulation or trauma, such as:
- Pain in the back of your neck or in your head
- Double vision
- Unsteadiness when walking
- Slurred speech
- Nausea and vomiting
- Jerky eye movements or other eye movement disorders
- Limb weakness on one or both sides
- Disorientation, memory loss or altered level of consciousness
"Tell the physician if you have recently had a neck trauma or neck manipulation," Biller said. "Some symptoms, such as dizziness or vertigo, are very common and can be due to minor conditions rather than stroke. But giving the information about recent neck manipulation can raise a red flag that you may have a cervical dissection rather than a less serious problem, particularly in the presence of neck pain."
Neck manipulation is widely used to treat a variety of musculoskeletal complaints, with nearly 85 percent involving adjustment or manipulation of the spine. With cervical manipulative therapy, a force is applied to the spine.