All health treatments have the potential for adverse effects and, on rare occasions, neck adjustment has been associated with stroke and stroke-like symptoms. A Canadian study, published in 2001, concluded that stroke symptoms associated with neck adjustments are so rare that it is difficult to quantify. Similarly, a medical review published in 2002 looked at 73 studies of chiropractic care and found no serious complications reported in any of them. By way of comparison, neck adjustment is significantly safer than other common treatments for headache, neck and back pain.