We read with interest the case report by Jeong and Hwang.1) Case reports, while having value, are, as we are all aware, very low-level evidence. Causation can never be inferred from a case report. Given this well-known fact we were surprised that the authors predominately used case reports/case series as their supportive evidence in their discussion where they say that chiropractic manipulation “can injure the neck vessels.”1)

Given the rarity of vertebral artery dissection 1.52 per 100,000,2) the highest level of evidence one can reasonably use to determine causation is a case-control study. Jeong and Hwang do cite Rothwell et al.3) However, Cassidy et al.4) have revised Rothwell controlling for protopathic bias. They found that the likelihood of a vertebral artery dissection after seeing a chiropractor was statistically identical to the likelihood after seeing a medical physician. Given the fact that medical physicians do not generally perform spinal manipulation the causal arrow rather than pointing to spinal manipulation points to dissections causing neck pain and/or headaches thus seeking care and the progress of the dissection is unrelated to the care, i.e. protopathic bias.5)

Generally, the highest level of evidence in used today would be systematic reviews and the most recent by Church et al.6) concludes: “There is no convincing evidence to support a causal link, and unfounded belief in causation may have dire consequences.” Thus, Jeong and Hwang's conclusion “Injured patients who have undergone cervical chiropractic manipulation should be assessed for a vertebral artery injury, which may minimize the poor prognosis of cerebellar infarction” may be harmful in leading to advanced imaging when inappropriate.

Finally, given the fact that there is no yet registration in South Korea for chiropractors one cannot be certain that an individual self-designating as a chiropractor is actually trained to internationally recognized standards.7) We know that often spinal manipulation is labeled as being performed by chiropractors, when in fact the person performing the manipulation was anything but a qualified chiropractor.8) Thus, one does not know if the treatment rendered was actually one performed by chiropractors.

Not using the current best evidence nor confirming that the individual involved was a qualified chiropractor vastly diminishes the value of this case report. Unfortunately, these kinds of errors are common.9)