This cool study in the JNNP[1] reminds us that pain is determined by the brain’s answer to the question ‘how dangerous is this?’ Pain relief is determined by the brain’s answer to the question ‘How dangerous is this NOW?’ These researchers randomly allocated back surgery patients to either be shown the parts of their disc that had been removed or to not be shown them. The surgeon was blinded, the assessors were blinded. The results clearly show that if you are shown the bits they have taken out you have less pain, disability and weakness than if you were not shown the bits. OK OK, they had 25% drop out which raises the possibility that the effect would not hold up in the full sample. But let’s say it does – why might it work? This is what the authors said:
How does giving patients their excised disc material in a pot improve outcome after LMD? There are several possibilities: firstly, the pot may provide a powerful visual confirmation to the patient that the operation was technically successful.
Secondly, we found that patients often keep the pot for several months, which may augment the disc fragments’ beneficial effect. One patient reported that referring to the excised disc prevented recurrence of symptoms.
Thirdly, since many patients show the pot to friends and family, we speculate that the positive comments made by these people amplify the benefit produced by merely seeing the disc material.
It is all, as far as i can see, providing the patient’s brain with important evidence with which to answer the question ‘how dangerous is this, now that the dangerous bits are here in a glass pot, not inside my back putting me at risk of spinal cord injury’. It seems pretty powerful. Of course it is.
If you are really interested in this sort of thing, check out Dan Moerman’s book: Meaning, Medicine and the Placebo Effect
if you are either clever or poor or both, you could get out of buying the book and read this paper instead:
Daniel E. Moerman and Wayne B. Jonas, (2002) Deconstructing the Placebo Effect and Finding the Meaning Response. Annals of internal medicine 136, 6, 471-6
Reference
[1] Tait MJ, J Levy, M Nowell, C Pocock, V Petrik, B A Bell, M C Papadopoulos (2009) Improved outcome after lumbar microdiscectomy in patients shown their excised disc fragments: a prospective, double blind, randomised, controlled trial. Journal of Neurology, Neurosurgery, and Psychiatry 80, 1044-6
{ 1 comment… read it below or add one }
Yes , read all of Dan Moerman’s work –it’s great and the example of blue pills that work for different reasons between the sexes in Italy for an example is fascinating……I like the meaning response instead of the usual remarks made in the context of placebo……This may relate to your post re the NICE guidelines too…….Meaning is enhanced by prestige ,cost and the social construction of the clinic, so if a pain clinic is staffed by people of a certain calibre who inject things into people proves to be no different to a shaman putting hot bandages what are we to do??! I personally think there is no difference between the two types of practitioner in relation to back pain management just different cultural interpretations of what needs to be done (usually too much for the wrong reasons).
The arthroscocpic knee ‘lavage study was an interesting example of meaning too ……(has not altered how many are performed) same as evidence of ineffectiveness of many pain intervention treatments . I think the exploration of meaning ,vested interests, politics and belief all merge and ‘prove’ that medicine is seldom a ‘neutral’ scientific discipline. Per Fuegeli a great medical writer suggested that medicine is biology times culture times politics squared …….often the biology alone is not enough to explain much of what goes on in the clinic (a lot of it would make good drama)
ian
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admin Reply:
September 18th, 2009 at 6:01 pm
Thanks for commenting Ian – I agree that Dan Moerman’s stuff is pretty cool and has important implications for how we think of pain and the effects of treatments.
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