From the Advertiser, October 27 2015
Adelaide researchers find a way to switch off pain
The clue to stopping pain at its source emerged in an unusual way – from a Pakistani boy who was busking by walking on hot coals. Five years ago curious scientists wondered how he would stand the pain.
Investigations found he had a rare genetic mutation, lacking a gene which notifies the brain of pain.
A team at Flinders Medical Centre, led by Associate Professor Nick Spencer, is using the information to develop a pain switch, potentially eliminating the need for highly-addictive painkillers such as morphine.
The work is now being done on animals, but Prof Spencer said genetic therapies using harmless viruses are now being used in more than 80 studies around the world as similar delivery systems for cancer and other conditions.
“We know in humans that if you have an extremely rare mutation and lack this gene you don’t feel pain at all.
“The virus takes a molecule to shut down the gene, it shuts down the channels for pain.”
Prof Spencer said it would provide long lasting suppression at the site of the pain.
The FMC team has been working on the therapy for three years trying to find the exact location of all of the body’s nerve endings that detect pain from different internal organs and how these pain receptors are activated.
In his laboratory experiments so far on animal models, Prof Spencer has reduced pain by about 75 per cent from a specific organ, the gastrointestinal tract, without affecting other organs.
Last year Prof Spencer was awarded more than $900,000 in funding by the National Health and Medical Research Council to conduct research. (Emphasis added)
It just won’t go away. “Pain switch”, “pain channels”. The reporter get a pass, but a researcher with a million bucks in his pocket…..
Two questions.
1. If you have the extremely rare mutation, do you not feel pain because your body can’t send ‘pain messages’ or is it because you’ve never experienced nociception and therefore have not learnt what pain is/how to make it? If this is the case would shutting down this gene in someone who has learnt how to make pain (probably too well if we’re talking chronic pain) really be the answer?
2. If research is based on erroneous notions of “pain channels”, ‘finding nerve endings that detect pain’ and ‘flicking the pain switch’, how likely is it to succeed?
-Tim Cocks
PS – Isn’t fire walking just a trick anyway? People without any genetic mutations do it all the time – without feeling any pain.
Hi Tim,
If peripheral afferent firing can be totally switched off, what a solid test for the Neuromatrix model. It could be a very positive thing, whether the research succeeds or fails.
EG.
Hi EG
I see where you are coming from here, but I’m not sure that, even if we were 100% certain that nociception was “switched off”, we would learn anything new.
Pain continues in deafferented limbs (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3359448/), and in fresh air in cases of amputation – granted that there is evidence of neuropathic mechanisms continuing to send afferent signals from severed peripheral nerves/dorsal horn/DRG in these cases (http://noijam.com/2014/06/24/bold-phantom-claims/).
But what if pain did stop? What conclusions can we make? Nociception is just one of many ‘inputs’ on the left hand side of the neuromatrix model – ceasing it may or may not alter the emergent outputs, and how could we ever know that it was *just* the cessation of nociception that led to the cessation of pain? This assumption leads back to a Descartian approach to pain.
Perhaps the most useful outcome, from an understanding pain perspective – not for the patient, would be for pain to persist even after nociception has been switched off, hence providing more evidence for the emergent nature of pain. Having written all of this, I’m thinking that perhaps this was your original point – if so, consider me caught up :)!!
Cheers
Tim
Yes… the last paragraph! Say they figure out how to switch off the gene and make the afferent signals go completely silent (as measured by a nerve conduction test)….is the pain still there? Knowing this will really open things up in terms of the existing model. As you say, it would seem unlikely to block pain completely because of all the other known inputs.
Electrical stimulation doesn’t look like it can make the afferent firing switch off completely, but it can certainly reduce firing temporarily. TENS style devices (surface or implanted) do seem to have some effect on chronic pain, so…. makes me wonder.
Regards, EG
Been doing a bit of reading on TENS and inhibition of the spinothalamic tract. I’m outside my comfort zone. How about some comments from those who know this material? Come on, share your knowledge!
Here’s a few things I came across which can be used immediately in the rooms:
TENS affects the spinothalamic tract afferents via the peripheral nerves. http://www.ncbi.nlm.nih.gov/pubmed/6089073
The effect lasts up to 30 minutes post stimulation. So new exercises and movements should probably be attempted in this 30 minute window, since they will probably be much more comfortable. This will reduce anxiety.
Then this one: http://www.ncbi.nlm.nih.gov/pubmed/6472874 “The most effective way to produce analgesia by peripheral nerve stimulation would be by high frequency stimulation of a nerve innervating the area from which pain originates with an intensity at least strong enough to activate A delta fibers”. So turn the TENS/IF up as high as possible within comfort limits, switch the frequency to high, and in the case of referred pain, put the electrodes on the arm/leg, not centrally.
The other thing I found was this study about vagal nerve stimulation: http://www.ncbi.nlm.nih.gov/pubmed/2038494 Clinically, this can be applied by simply asking the client to take a deep breath and perform a Valsalva manoeuver. This will “cause[s] a general inhibitory effect at all levels of the spinal cord on neurons which transmit nociceptive information”. Simple and easy to apply in the rooms.
EG.
The ‘Pain Switch’ is such an interesting concept. I’d be more inclined to see it as a function of subliminal consciousness, rather than a physiological event, although its effects may very well be physiological….if the switch exists at all ! Consciousness can be either ‘consciously decided’ or ‘subliminal’ depending on whatever created any particular thought/process. It might seem that subliminal consciousness might have direct inter-relationships with the non-conscious, and that is where we already know that pain events can be switched off…or maybe simply cannot register in any way which can feed back to a conscious awareness. ‘Consciously decided’ consciousness, on the other hand, seemingly does not have this inter-relationship with the non-conscious, and so has no influence over any pain switch which might exist.
Perhaps, if it were possible to influence subliminal consciousness by means of repetitive conscious instructions, and then, by default, subliminal decisions are made which reflect that conscious manipulation, then a certain access to the non-conscious pain switch might be possible. Some kind of self-convincing mantra which creates a direct link to the non-conscious ! If I were to attempt to analyse how Yoga Gurus and Whirling Dervishes can seemingly achieve this ‘Pain Switched Off’ state, these are the aspects I would want to explore.
On the other hand, I’m not so sure that it is a ‘pain switch’ in the non-conscious which allows for pain to not register……perhaps it is simply a non-requirement for pain to register because it would be meaningless in terms of requiring a response when consciousness has been temporarily for re-charging…..possibly !
Edit last sentence…….’ when consciousness has been temporarily shut down for re-charging….possibly !’