Tuesday, July 09, 2013

Melzack & Katz, Pain. Part 14c: PW Nathan was an interesting pain researcher

The paper, Pain

Most recent blogposts:

Part 14: Side trip out to the periphery! Part 14b: Prevention of pain neurotags is WAY easier than cure


Here we are, still in fog, still slowly and carefully moving.
"It does not matter how slowly you go as long as you do not stop"

We left off yesterday at the second paragraph of "Denervation Hypersensitivity and Neuronal Hyperactivity", in Melzack & Katz. The references are about brain surgery. Our trip through this paper moved through brain surgery further back in our voyage through this paper, in Part 9c, Neuromatrix MORE than just projection areas in thalamus and cortex. 

I think, since we are still too deeply bound by fog to be able to travel very fast, that to amuse ourselves we examine only the reference by Nathan PW, Pain and Nociception in the clinical context.

It is quite old-timey (1985), quite interesting, non-surgical. It looks like Melzack and Wall read and commented on Nathan's work in their book, Challenge of Pain - five of his papers are cited (although not this particular one). 
Peter W Nathan

Anyway, Peter Nathan is not with us anymore. He died in 2002 at the age of 88. Here is a list of all the papers I could find by him, in Pubmed. There are 103, and 42 appear to be free access. (The one cited in the Melzack and Katz paper isn't, though.., unfortunately.)

From a lengthy and touching obituary at IASP, comes fascinating little tidbits:
"A pivotal event in his life occurred in Munich. The woman in the family where he lodged was working as a social worker in a child guidance clinic, and Peter witnessed the therapeutic benefits of psychological approaches to childhood disorders such as bed-wetting. This prompted Peter to take up medicine..."
He became a psychiatrist, then ended up taking war related posts where he was confronted by head injury.. long story short, ended up in research. He did a bunch of work on cordotomy, spinal cord contributions to all sorts of body functions, worked out all kinds of pathways, was friends with Patrick Wall (except he didn't think TENS was so hot, disagreed on its use. Go Peter!).

"The role of the sympathetic nervous system in pain had intrigued Peter ever since the war, when he encountered numerous patients with painful peripheral nerve injuries. Countering Leriche’s vasoconstriction theory, and Lewis’ vascular stasis hypothesis, Peter speculated in a prescient paper on causalgia, published in 1947, that some form of artificial synapse between the sympathetic and afferent nervous systems might be involved."
He liked cats and chocolate. He didn't like fascism. He helped start IASP. He maintained a small clinical practice to "keep his feet on the ground." His lifelong quest was to understand how the sympathetic nervous system was tied into pain:
“.. he joked he wanted to be informed in heaven after he had died when it was known how the sympathetic system was involved with pain. His last paper, The crossing of the spinothalamic tract [full text pdf], appeared in Brain in 2001 when Peter was aged 87. How few of us would be able to publish a major paper at that age, and would also declare that their life’s work was now complete and that they would write no more."
All in all, sounds like he was a real nice guy. 


His paper, Pain and Nociception in the clinical context, cited by Melzack and Katz, has to do with..
"(i) the changes brought about in the central nervous system by a noxious input; (ii) certain states of consciousness in which human beings do not feel pain."
He thought there might be memory traces left in the central nervous system after injuries healed. In one of his patients, a lower limb amputee, he had been injecting saline into stump neuromas (some things never change, like saline injections for pain!).. to achieve paraesthesia. Anyway, he managed to ding something nociceptive with the needle, and hurt the stump instead. 

That night the patient woke up in pain - the pain wasn't the stump pain elicited the day before by the needle - it was pain from 5 years earlier when he still had a leg, when it had been skated over and lacerated by a bunch of guys playing hockey. 
"What he felt during the night were the identical sensations in his leg that he had had five years before. It was not that he remembered having such sensations; the sensations were present once again." 
(Talk about iatrogenesis...)
Another patient came in for cordotomy for cervical cancer pain. If her skin was provoked by pinprick above the lesion, more rostrally, she could feel all the pain she had experienced from a comminuted fracture of her right patella 6 years earlier. 
Nathan says, 
"Where are these memory traces laid down in the nervous system? I don't think we know. In neurology, we tend to hope that things are more peripheral and more distal than at higher levels of the central nervous system, because we know more about the physiology of such levels and find it easier to think about them."
If you think about it, that's been the story in medicine and in all manual therapies all through the 20th century. Really, it's high time we all moved beyond the periphery.

Same guy Larbig studied, slightly different snapshot.

Check out the ice pick through his throat. 

In the second part of the paper Nathan discusses Greek firewalkers and fakirs (not fakers, fakirs..) guys who teach themselves to raise and lower their own blood pressure by entering a trance state, then shoving steel knitting needles through their arms, etc.
One guy who was studied ( by somebody in Germany, in German, named Larbig) took 2 or 3 hours to get "there" .. it took a lot of "acoustic and visual stimulation".. once "there," though, he was able to not blink for 5 minutes straight, and subsequently could shove daggers through the skin over his chest, his tongue, no bleeding. (He had kind of a low pain threshold when not in trance, though, wincing during blood pressure cuff inflation, venepuncture, etc.)

Larbig noted that there was increase in theta brain activity during trance states.
Nathan remarks:
"Increased theta activity is usually associated with drowsiness. But it also occurs in some other states, such as selectively inactivating certain cortical areas and increasing the activity of others. This occurs when one's attention is concentrated on one field, such as intense mental work entailing the solution of mathematical problems within a limited time. Examples are given in Larbig's (1982) book. The most striking example is that reported by Adey et al (1967) of the eeg of the astronaut Frank Borman. For a few minutes before takeoff and just before landing there was a great increase in temporal, parietal and occipital theta. This was interpreted as an extreme focusing of attention in the situation."
Well, I don't know what to make of that. All I know is that Buzsaki has a whole book about theta waves and oscillations, etc. Nathan quotes Larbig:
"One can learn to narrow the field of attention, which leads to a trance-like change in consciousness; with this is associated an eeg change consisting of large amplitude theta waves, and with this state there is an inhibition of pain."
My bold. But learning how to do such a thing is far from easy, Larbig was quick to add: "Selective focusing of attention is an active intellectual achievement" and "..part of the skill includes learning not to fall asleep."

Nathan was interested in the sympathetic response. In trance states, increased blood pressure and a feeling of euphoria and excitement were associated. One had to be able to easily detach from ordinary worries and preoccupations. An ascetic lifestyle seems conducive because attachment to mundane things is automatically avoidable. 

(Yeah.. how convenient! Tuck yourself away in a monastery and rely on others to bring you food, so you can practice trancing your brain! The stuff humans don't get up to to impress themselves and each other..  anyway, back to Nathan.)

Nathan comments:
"These methods of not feeling pain are used for acute pain, the pain from being noxiously stimulated. I do not know how well they can be used for chronic pain; neither do I know if they could be used for central pain, pain arising in the central nervous system, such as thalamic pain. It is likely that this way of not feeling pain is using the descending inhibitory pathways, which we have learned about in species other than man, the raphe-spinal and/or the reticulo-spinal pathways and/or the pathways originating in the locus ceruleus going to the 5th nerve nuclei and the spinal cord. It may be that learning to induce this kind of trance state includes learning to activate this kind of inhibitory mechanism."
He brings up hypnosis, says there are interesting puzzles to be solved, and leaves us with a 'we still don't understand much about any of this' comment. 

From here, I propose we sail (carefully!) over to this little island, to get out of the boat for a bit, stretch our legs, and look at different batch of research to do with one of my favorite topics, neural crest. Get ready for an interesting landing, because I think in order to make sense out of this section of Melzack and Katz paper, and get out of this dense fog, and on our way, we need to understand a bit better what a "nervous system" actually is. We won't be stopping, we'll just be having a lunch break. 


The neuronal pathways, ganglia etc., the wiring, are one aspect, for sure, but there is a lot more to the nervous system than mere pathways and firing patterns. There is a whole bunch of very interesting cell signalling, not only or exactly or strictly neural, going on in there. We'll look at Scholz and Woolf's paper from 2007, The Neuropathic pain triad: neurons, immune cells and glia. And we'll check out the Nedergaard group's latest paper, Glia and pain: Is chronic pain a gliopathy? And we'll maybe draw a tidbit or two from Keijzer et al's paper, What nervous systems do: early evolution, input!output, and the skin brain thesis, and from Bhatt et al's paper, Signals and switches in Mammalian neural crest cell differentiation. 

The starting argument will be, neural crest derivatives and neural tube derivatives are both directly ectodermal. Not mesodermal. Therefore it's fair to include neural crest derived structures and cells in with ectoderm-as-nervous-system. 

Previous blogposts

Part 1 First two sentences Part 2 Pain is personal Also Pain is Personal addendum., Neurotags! Pain is Personal, Always.

Part 3a Pain is more than sensation: Backdrop Part 3b Pain is not receptor stimulation Part 3c: Pain depends on everything ever experienced by an individual

Part 4: Pain is a multidimensional experience across time

Part 5: Pain and purpose

Part 6a: Descartes and his era; Part 6b: History of pain - what’s in “Ref 4”?; Part 6c: History of pain, Ref 4, cont.. : There is no pain matrix, only a neuromatrix; Part 6d: History of Pain: Final takedown Part 6e: Pattern theories in the history of pain Part 6f: Evaluation of pain theories Part 6g: History of Pain, the cautionary tale. Part 6h: Gate Control Theory.

Part 7: Gate control theory has stood the test of time: Patrick David Wall;  Part 7bGate control: "The theory was a leap of faith but it was right!"
Part 8: Beyond the gate: Self as mayor Part 8b: 3-ring circus of self Part 8c: Getting objective about subjectivity
Part 9: Phantom pain - in the brain! Part 9b: Dawn of the Neuromatrix model Part 9cNeuromatrix: MORE than just spinal projection areas in thalamus and cortex Part 9d: More about phantom body pain in paraplegics
Part 10: "We don't need a body to feel a body." Part 10b: Conclusion1: The brain generates its own experience of being in a body Part 10c:Conclusion 2: Your brain, not your body, tells you what you're feeling Part 10dConclusion 3: The brain's sense of "Self" can INclude missing parts, or EXclude actual parts, of the biological body Part 10eThe neural network that both comprises and moves "Self" is (only)modified by sensory experience
Part 11We need a new conceptual brain model! Part 11b: Intro to a new conceptual nervous system Part 11c: Older brain models just don't cut it Part 11d: The NEW brain model!
Part 12: Action! 12b: Examining the motor system, first pass. 12cMotor output and nervous systems - where they EACH came from Part 12d... deeper and deeper into basal ganglia Part 12e: Still awfully deep in basal ganglia Part 12f: Surfacing out of basal ganglia Part 12gThe Action-Neuromatrix 
Part 13: Pain and Neuroplasticity Part 13b: Managing neuroplasticity

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