Blog | Monday, October 31, 2011

Supporting the unsupportable

This is entirely my fault. I have been staying away of late from more confrontational posts about alternative medicine, mostly out of fatigue. I also would prefer to blog about medicine, family, and various train-of-thought nonsense. But I went and got myself quoted and a number of folks seem displeased. Supporters of chiropractic neck manipulation, a practice I recommend against, are quoting a number of studies and making a number of comparisons that aren't really supportable, so I have to respond.

First, my bias: for a medical practice to be routinely recommended, it should work, and how much it works should be worth whatever risk attends it. In order to prove its worth, there should be studies that, in aggregate, support the practice. For those studies to be taken seriously, the must be well done and the practice must have a plausible mechanism of action.

Let's look at neck pain. This is a common condition, affecting most of the population at some point, but rarely associated with significant disability; those are what the statistics say, but when your neck hurts, you want it to feel better and you might seek professional advice. And, like low back pain, neck pain does tend to recur. It also tends to remit spontaneously, especially in younger people, the same people unlikely to have significant spine pathology. In assessing neck pain outside the setting of trauma, X-rays, a common practice among both chiropractors and doctors, do not appear to help guide diagnosis in a significant way.

In a typical primary care practice, neck pain without alarm signs (such as weakness, fevers, weight loss) tends to be treated quite conservatively, with stretches, Tylenol or non-steroidal anti-inflammatory drugs (NSAID) for pain relief, and tincture of time. When this fails to give relief, patients are often referred for imaging and physical therapy. It's certainly plausible that manipulation of the neck, whether done by a chiropractor, masseuse, physical therapist, or beneficent spouse may help. The question becomes does it help, and if so how much and with what risk.

NSAIDs, despite their easy over-the-counter availability, are potent drugs and come with significant risks, risks which increase with length of use and with other risk factors. NSAIDs probably increase the risk of cardiovascular events in certain subsets of patients, and are one of the two primary causes of stomach ulcers. But short term treatment with NSAIDs, as would be typical for someone with benign neck pain or low back pain, is relatively safe. There is very little risk to an otherwise healthy young person who uses NSAIDs at a normal dose for a week or two. They probably do not lead to quicker resolution of an episode of neck pain, but they may give comfort while the episode resolves.

From what I gather having read the above-referenced blog post, the main arguments seem to be that chiropractic neck manipulation never leads to vertebral artery dissection, and that other treatments are much more dangerous.

As to the first claim, my colleague Mark Crislip has given a nice explanation of the data, the gist of which is that we shouldn't be seeing vertebral artery dissections in young people, and the fact that many of these rare events are coincident with chiropractic neck manipulation should give us pause.

The writer's strong emphasis on the risk of NSAIDs is based on a misunderstanding of the use of NSAIDs to treat benign neck pain. What patients choose to do on their own is less relevant, but as physicians, we rarely give long courses of high-dose NSAIDs to these patients. They tend to get better on their own, and short courses of NSAIDs in young, healthy patients come with little risk.

Most benign neck pain is self-limited. According to the study cited by the chiropractors: "Quality of life years (QALYs) associated with standard NSAIDs, Cox-2 NSAIDs, exercise, manipulation, and mobilization were compared in a decision analytic model. None of the active treatments was found to be clearly superior to any other in the short or long term when estimates of the course of neck pain, adverse event risks, treatment effectiveness and risk, and patient-preferences for health outcomes were considered."

Given that most treatments for neck pain probably provide a bit of relief while the condition resolves on its own, what most physicians and chiropractors should do is simply get out of the way. Patients should be assessed for non-benign causes of their pain, NSAIDs can be prescribed safely for short term use, and patients will get better. There is no evidence that chiropractic provides additional benefit, especially in the long term.

But when it comes to risk, there is a small but definite association between chiropractic neck manipulation and the rare form of stroke known as vertebral artery dissection. This correlation is most clearly seen in young patients, those who would not normally suffer from strokes. Given the lack of superiority of chiropractic, and the small but real association with VAD, I stand by my advice that one should not allow a chiropractor near the neck.

Peter A. Lipson, ACP Member, is a practicing internist and teaching physician in Southeast Michigan. After graduating from Rush Medical College in Chicago, he completed his internal medicine residency at Northwestern Memorial Hospital. This post first appeared at his blog, White Coat Underground. The blog, which has been around in various forms since 2007, offers "musings on the intersection of science, medicine, and culture." His writing focuses on the difference between science-based medicine and "everything else," but also speaks to the day-to-day practice of medicine, fatherhood, and whatever else migrates from his head to his keyboard.