The Neuroscience of Pain | Hacker News Reader

The Neuroscience of Pain

newyorker.com

111 pointsdevy18 comments

Not sure what this article is trying to say, other than a 7 Tesla MRI is godawful powerful.

Yes, we all experience pain differently. I've had more than a standard share myself (ripped arm from shoulder, in the region of ~20 dislocations followed before it got fixed). And I've never heard of chronic pain (hypersinsitivity to pain). And yes, pleasure is pain's opposite, but an even more evil beast. Because true, unadulterated pleasure is an ephemeral beast - it doesn't come often, and it never stays. Pain can stay. For a long, long time.

And that brings me to what the article doesn't discuss - how we (and how different people) deal with pain. I can take a lot - apparently more than most, because of that shoulder. Had to go under full anaesthetic every time to get it set. And until then I had to just... take the pain.

And after a few dislocations taking the pain got to be surprisingly easy. I somehow disassociated myself from it. I could feel the pain, but somehow it registered a bit like a pilot light, and a lot less that what I feel when I stub my toe or bash my shin. It was as if I was telling myself that hey there's the pain, it hurts, but it's not that agony that it is. Or was. I don't know how to describe it.

So I read that article, and I said all of this stuff, and I'm still not sure what the point of it all was, other than inform me that someone's hoping to provide a definitive measure of the severity of pain using MRI.

It is a New Yorker article - it isn't trying to make a singular point and convince you of it... it is storytelling about some interesting work being done.

As far as you not having heard of hypersensitivity, that isn't a shock. I first heard of it as a diagnosis from the Mayo clinic, after my local docs weren't able to find anything wrong with me. And they said that many doctors aren't yet familiar with it yet. It is a fairly new area of research.

But again, that circles back to the article -- it talked of how their findings support the effectiveness of cognitive behavioral therapy for chronic pain. (Also what the Mayo clinic recommended, BTW.) I found much of the article resonated well with my experiences of chronic pain, and I am hopeful that someday research such as this will be able to find reasonable treatments that dial the sensitivity back down to normal for people with abnormal pain responses.

Another term you can research if you really want to dig into this is "central sensitization".

You managed to teach yourself to dissociate nociception from suffering.

When one experiences pain, many parts of their brains light up, including the somato-sensory cortex, part of the insula (which is pain-specific) and emotion/identity-related areas in the cingular cortex. You managed to prevent the painful signals from activating the emotion/identity parts of your brain.

That is usually done through meditation/hypnosis, and it is an important part of pain management, but I don't know if it is commonly recommended in clinical settings.

I think what the author is trying to across is that despite the technological and scientific advances we still struggle with our understanding of how pain works. I mean a 7T MRI is ridiculously powerful and at the end of the article one of the scientists from the lab tells the author "That map is actually really difficult to make sense of".

They do discuss a little bit about the brain coping with pain in religious versus atheist participants about halfway down the article where in the religious population they found that a neural area was engaged that is associated with ability to override physical response.

I think this article is important right now because pain and pain management has been one of the driving forces behind the opioid epidemic that has been sweeping across the continent. Understanding pain is an important part of managing it.

> One of her most striking experiments tested the common observation that religious faith helps people cope with pain.

I know there is always the problem that popular reports have to so simplify research results that they veer into misrepresentation. But as described, the stated conclusion is impossible to support. Devout Catholics and atheists, collectively, had similar responses to pain stimuli. But if you shows both a picture of the Virgin Mary before the pain, Catholics reported one point lower pain scores.

How could the conclude that? What if instead they segregated the groups into (US) football fans and non-fans, and showed both pictures of, say, Mike Ditka, a famous tough, non-whiny guy? If the football fans reported lower pain scores, would that mean sports helped them cope? Or are they simply primed to act more manly?

Or rap fans/non-fans were primed with pictures of 50-cent? Or history buffs pictures of Earnest Shackleton?

> In 2000, Congress declared the next ten years the “Decade of Pain Control and Research,” after the Supreme Court, rejecting the idea of physician-assisted suicide as a constitutional right, recommended improvements in palliative care. Pain was declared “the fifth vital sign” (alongside blood pressure, pulse rate, respiratory rate, and temperature), and the numerical scoring of pain became a standard feature of U.S. medical records, billing codes, and best-practice guides.

This is one of the reasons that I find the push to solely blame physicians and pharma for the opioid epidemic misleading. In the early 2000's treatment of pain was being pushed, and it was deemed the "fifth vital sign", even though it is subjective unlike the other four vital signs. Physicians were being evaluated on how their patients said they treated pain. Given this environment, it is no surprise that pharma developed powerful drugs to target pain, and physicians prescribed these drugs in large amounts. We are today dealing with the fallout of this push.

The makers of OxyContin have been losing lawsuits [0, 1] for aggressively and misleadingly marketing (saying that it wasn't addictive) the drug for pain management leading to the levels of opioid addiction that we see in cities around North America. I think pharma, particularly Purdue, deserves the lion's share of the blame in this.

[0]https://www.cbc.ca/news/health/oxycontin-class-action-1.4093... [1]http://fortune.com/2018/05/16/oxycontin-purdue-pharma-lawsui...

After I read this I went off to learn more about the dorsal posterior insula and pain. It's role in being a necessary but not sufficient or just something correlated is still being debated with many experiments for and against.

https://www.nature.com/articles/nn.3969 and https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4706052/

then http://journals.plos.org/plosbiology/article?id=10.1371/jour...

As far as I can tell on my very quick literature survey lately it's against, and because of invasive studies done with actual electrodes covering the relevant areas of the insula. And the activity there (which would be later picked up as blood flow inferred by MRI) doesn't seem to necessarily "track" pain like the foundation paper(s) on the theory suggested.

What are the evolutionary advantages of extreme or chronic pain? Some pain is a message and an incentive to do something about it, but extreme pain and chronic, high levels of pain paralyze people without any apparent benefits.

Perhaps I assume too much, that humans are such evolutionarily fined tuned machines that every 'bug' must be a feature.

Negative mutations such as chronic pain would normally get selected out of a species but because humans have become quite adept at survival we don't select out these traits as easily as a less intelligent species might.

Humans also have an exceedingly long lifespan. Is it even possible to perceive the effects of evolution on the human race?

Bacteria, on the other hand, have lifespans on the order of hours and reproduce at a much faster rate. They can also absorb DNA from the environment, transfer DNA to other bacteria and receive a literal DNA injection from a virus.

> What are the evolutionary advantages of extreme or chronic pain?

That is a funny question. It is like asking: what is the evolutionary advantage of a broken leg? Sometimes things go wrong and the result is pain. There is no purpose to it; it just happened. Not everything has an evolutionary purpose.

My wife has Ehlers Danlos Syndrome, resulting in malformed collagen throughout her body. As a result, her tendons are too stretchy and don't work well, and so her bones don't align as they should, leading to wear and tear on joints and now incessant pain.

Also, many kinds of failures show up after the typical reproductive window. There is little evolutionary pressure to prevent such failure mechanisms.

> That is a funny question. It is like asking: what is the evolutionary advantage of a broken leg?

i'm unconvinced... a broken leg isn't a normal biological function, while (afaik) pain is an entirely internal process that is a 'response' mechanism.

> Sometimes things go wrong and the result is pain. There is no purpose to it; it just happened. Not everything has an evolutionary purpose.

the ostensible purpose of 'some' pain is to cause you to stop or avoid doing something damaging, or being aware of a need to seek remedy. for those few people who don't feel any physical pain (congenital analgesia)... life is actually more dangerous.

when it comes to incapacitating levels of pain, things seem to get murky. there is some arguable benefit to adopting a protective posture (covering a wound, adopting a fetal position, etc) to mitigate further harm... but it seems these same behaviors can also increase risk of harm as well, especially when it comes to pain causing reduced situational awareness and other reasoning impairments.

> It is like asking: what is the evolutionary advantage of a broken leg? Sometimes things go wrong and the result is pain.

Pain and femurs are the result of over 3 billion years of evolution from prokaryotes (the simplest of single-celled organisms) to modern humans. It's a good question: What was the advantage that led to leg bones, and in particular to leg bones that break under that kind and direction of stress? Why not stronger or weaker? Why not more shear and less compression strength? What was the advantage of a nervous system, including one that produces pain, and one that produces that amount of pain or continuous pain?

> many kinds of failures show up after the typical reproductive window. There is little evolutionary pressure to prevent such failure mechanisms.

Pain occurs throughout life. Also, after reproduction successful organisms, at least of the human variety, raise and prepare their offspring for life, and even the offspring of their offspring.

Children born with pain insensitivity gives you some sense for it’s evolutionary selection.

These kids can lose fingers from chronic injury and no signal that something is wrong.

Right, but extreme pain is far more than is needed for the person to grasp that there is something wrong with their finger. In fact, it inhibits the person from doing anything about their finger.

>For this reason, the International Association for the Study of Pain (I.A.S.P.) has a code of ethics, and its members are pledged not to inflict or increase pain except in an experimental setting.

What would we do without ethical codes?

Just like any "obvious" rule, these rules are there because something stupid and terrible happened and people said "we need a rule against this."

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