By Martha Kerr
SAN ANTONIO (Reuters Health) – Study results presented here Friday night are prompting some Canadian neurologists to campaign against neck manipulation by chiropractors.
At the American Stroke Association's 27th International Stroke Conference, Dr. John W. Norris, at the University of Toronto, and colleagues presented data collected from the Canadian Stroke Consortium in an ongoing prospective study. They have identified 158 cases of stroke linked to cervical arterial dissection.
Dissection was linked to trauma in 98 patients (63%). In 38 cases of trauma (39%), the injurious event appeared to be chiropractic neck manipulation. Other traumatic events included turning the head while reversing the car, golfing, and painting the ceiling.
There is increasing evidence that cervical artery dissection is the most common cause of ischemic stroke in persons younger than 45 years of age, the Canadian team notes. The cause can be spontaneous, but trauma as a cause is often overlooked, the investigators noted in their presentation.
"The cervical arteries are vulnerable to dissection, particularly the vertebral artery, due to its tortuous route [along the cervical spine]," Dr. Norris' group commented.
Of the 38 chiropractic patients experiencing stroke, vertebral artery dissection occurred in 30 and carotid artery dissection occurred in eight. Sixteen percent of patients were found to have congenital malformations in their cervical arteries, including Marfan's Syndrome and fibromuscular dysplasia.
Strokes occurred in 81% of patients with vertebral artery dissection and in 67% of patients with carotid artery dissection. Subarachnoid bleeding occurred in two cases.
The majority of stroke patients (46%) were left with a slight neurological deficit, Dr. Norris and colleagues reported. Twelve percent were left with a severe deficit, while 37% were left with no deficit. Two deaths occurred in the patients who experienced artery damage after neck manipulation.
Data collected by the Canadian Stroke Consortium indicate that 24% of cases of cervical artery dissection were linked to chiropractic manipulation in stroke patients under 45 years of age.
"There is serious underreporting" of strokes associated with neck manipulation, Dr. Norris and colleagues conclude. They speculate that this may have something to do with fear of litigation.
The Canadian team and other neurologists are planning to start a movement to ban the practice of neck manipulation