The Hashish view on jaw pain

The Hashish view on jaw pain
Our group, like many, have pondered the meaning and place of placebo. Here are a couple of ‘golden oldie’ pieces of research that are worth a rethink.

In 1988, a remarkable experiment with results that clinicians who use electrotherapy should ponder (as well as those who don’t) was carried out by the Hashish group (true!).

The researchers set different levels of ultrasound intensity to see what was best for pain and jaw stiffness after extraction of wisdom teeth. The patient and therapist were blinded to the level of ultrasound intensity. There were benefits for all intensities and remarkably (then!) the best was when the machine was turned off. If the patients used the ultrasound on themselves there was no effect. It had to be a clinician doing it. Note also that the beneficial results were not only pain reduction but in jaw stiffness and swelling. Thoughts can change stiffness?

I have often been in trouble for using the above word; an electrotherapy distributor once boycotted a national physiotherapy conference when they heard I was to be a keynote speaker. But clearly, in these cases it was not what came out of the ultrasound transducer head that had an effect, but belief, enhanced by therapeutic interaction. The message is if the patient believes it will work, then use it if it is safe, but use the opportunity to introduce more evidence based tools.

Sham heart surgery
Fifty years ago, the now ethically impossible Cobb and Dimond studies (1959, NEJM 20:1115) revealed that sham internal mammary artery ligation, a common operation then for angina worked as well as actual ligation of the artery. This operation was done to supposedly shift blood from the pectoral muscles to the heart. The improvements were in walking distance, consumption of drugs and even ECGs with some improvements maintained at 6 months. A thought can have significant physiological effects at 6 months?

These two stories were often told by Pat Wall of gate control fame, who wrote very eloquently about placebo. Wall died 8 years ago – remarkable in itself as it still seems as though he is with us. Pat made a comment on placebo, something like this:

“if it shows that a particular treatment which works is actually a placebo, do not despair, but seek what it was in the placebo that made the person better”

(I can’t find the actual quote, but I am sure that was pretty close).

These days as we take Wall’s work further with pain definitions along the lines proposed by Moseley (2003, Manual Therapy 8:130-140) of pain as a brain event constructed more by perceived threat than actual tissue damage, placebo makes a little more sense. And if we add this to notions of pain as an output of the brain not dissimilar to motor, inflammatory, sympathetic and other outputs, the reduction in jaw stiffness and changes in ECG have a paradigm to fit into. Don’t hang up your ultrasound just yet!

At the NOI2010 conference in Nottingham as we merge neurodynamics with the neuromatrix, there will be plenty of brain stories. And you can be sure that the wonderful placebo will raise its head many times.

Your turn
Send in your best story of a placebo response  (inadvertent or not) in the clinic for a chance to take home a copy of ‘Explain Pain.’

Last month’s notes on neurodynamic research
Thankyou for all the research suggestions. They have been noted and we do have quite an army of undergraduate students looking for research projects. There were suggestions for asessing the role of neurodynmaics in multiple sclerosis (never previouly attempted), the role of neurodynamics in exertional compartment syndrome in the leg (a big problem in the defence forces), the possibility of identifying early laterality problems in wrist fractures, a call for shared data amongst small pain clinics, the need for measuring how other health professions view neurodynamics and a call to measure and therefore create awareness of the importance of therapists beliefs and values in therapeutic outcomes.

It is extremely hard to select one – they’re all valuable and need doing. We simply picked the winner out of a hat and the winner is Jon from Australia with his curious thoughts on the role of neurodynamics in patients with exertional compartment syndrome in the leg. Congratulations, you will be sent a copy of The Sensitive Nervous System.


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