Chiropractors and the reflex arc

Many of you may have seen the episode of Catalyst that aired on 11 July, 2013, which discussed the chiropractic profession.  It can also be seen here.

I’ve been pleasantly surprised by the positive reaction of many members of the public and indeed chiropractors to the show.  It confirms what I pointed out in my previous post – that the chiropractic profession here in Australia is currently divided between those who cling to the concept of the subluxation as a cause of extra-spinal disease like colic, asthma, diabetes and even cancer (the “straights”) and those who are struggling to establish an evidence based chiropractic scope of practice.  To the latter, as I’ve said before, I say go forth and publish!

I’m fairly critical of research papers I study, and that includes my own.  For example, one of my own studies that was published recently lacks randomisation, is a single surgeon series, and has quite a wide range of followup periods.  That indicates that one must be careful about what conclusions we draw from it.  That’s me criticising my own work, as a short example.

Pardon me?

In response to the programme, several papers have been presented to me as evidence that chiropractic can cure deafness, ala William Harvey Lillard.  One study is a hypothetical discussion of a complex neurological pathway involving the spine and the middle ear causing Ménière’s disease.  See the word hypothetical there?  It’s not evidence.

Another is this paper from 1995, on the association of late whiplash injury syndrome (LWIS) and tinnitus.  It was in the second ever issue of a biannual journal, and the author was the journal’s founding editor.  Hmmmm.  It may be the case that people with LWIS get tinnitus, but LWIS is clearly not a simple diagnosis.  In fact, when you remove the medicolegal implications of having a chronic injury, it’s found that “Expectation of disability, a family history, and attribution of pre-existing symptoms to the trauma may be more important determinants for the evolution of the late whiplash syndrome.”  Neither is the cause of the tinnitus clear – it’s could very well be the temporomandibular joint!

Scoot forward to 2008 and you find that,

With respect to hearing and balance problems due to whiplash, the exact nature of the lesion is not known but the following have been put forward as possible explanations: Transient ischaemia or haemorrhage in the labyrinth as a result of transient compression of the vertebral artery, direct labyrinthine concussion, brain stem concussion, the noise of the collision causing acoustic trauma or psychological triggering of a pre-existing hearing disorder. With so many suggestions it is a cynical truism to say we do not know the exact cause and site of the lesion.

We do not know.  We just don’t know.

Another paper that was sent to me was on a case series of people with hearing improvement after chiropractic treatment.  Without a control group, it does little to provide evidence of efficacy.  As the authors themselves said,

Further research in this area is required, in the form of a well designed randomised controlled trial.

So that was in 2006.  It’s been seven years, and still no followup study.  Why not?  If I wanted to do a research project, this would be my first one – interesting topic, straight forward design, short time period.  Why hasn’t it been done?  Why?

Yet another paper, in German, discusses a condition “vertebragenic hearing disorder”.  The author himself admits that the condition’s very existence is disputed.  The hearing testing is poor and so is the description of the intervention.  No control group, once again, means that it is not to be regarded with any sense of gravity.

Protecting their turf

As predicted, several chiropractors wrote to me attempting to denigrate my profession.  Claims of high morbidity and mortality rates of conventional medicine abound, yet what these people fail to appreciate is the logical fallacy they had fallen into: tu quoque.  Criticising my profession doesn’t validate yours.

The other irony is that, at least in my practice, I rarely treat patients with back pain alone, or, for that matter, asthma, autism, deafness or colic.  I treat patients who have pathological conditions that are demonstrable on imaging studies, and therefore, I have no vested interest in the chiropractic subluxation.  I have no turf to protect.


The chiropractic profession in Australia, as far as I know, does not have a systematic way of collecting adverse events.  Conventional medicine doctors are subject to regular peer review of our practice, as part of our registration.  I attend monthly review meetings of both hospitals I practice at.  The RACS runs the Australian and New Zealand Audit of Surgical Mortality.  We’re open, transparent, and provide reliable data.

If you don’t look for something, you can’t claim it’s not there.  Before we looked for exoplanets (planets outside our solar system), there was discussion based upon poor quality data about how many are out there.  Since we’ve been looking, we’ve found over 900.  How many adverse events are there from chiropractic therapy?  Let’s start looking.  Maybe there’s none, maybe there’s lots, but until you look systematically, I can’t see how you can make any claims.  But that’s just me.

As I’ve said before, unless you base your practice upon good evidence, then you’re not necessarily practicing evidence based medicine.