The “mind-body vicious cycle” model of RSI & back pain

post by Steven Byrnes (steve2152) · 2022-06-09T12:30:33.810Z · LW · GW · 32 comments

Contents

      This post will say a bit about the “mind-body vicious cycle” model, why I think it’s a frequent culprit, and how that impacts treatment.
  1. Reasons to question the orthodox model
    1.1 Anecdotes of practically-overnight-permanent-miracle-cures
    1.2 Studies showing that “orthodox”-incompatible treatments work quite well for most people
    1.3 Lots of “orthodox” theories seem wrong
  2. The “mind-body vicious cycle” model
    2.1 What’s the “mind-body vicious cycle” model?
    2.2 How does the “mind-body vicious cycle” model differ from John Sarno’s “sneaky subconscious” model?
  3. Positive evidence for the “mind-body vicious cycle” model
    3.1 Apparent involvement of medial prefrontal cortex in chronic (but not acute) pain
    3.2 Apparent involvement of vasoconstriction
    3.3 “Vicious cycle” seems like a pretty good fit to the dynamics
  4. If “mind-body vicious cycle” is the right model [for a particular person], then what?
None
32 comments

(Written in a hurry, but hopefully better than nothing.)

Here are three alternative models of what might be happening in people diagnosed with chronic back pain, and repetitive strain injury (RSI), and carpal tunnel syndrome, and maybe other things too:

My guess is that the “mind-body vicious cycle” model (on the right) is the correct story for most people with chronic hand / wrist or back pain (and maybe certain other conditions). Certainly not all people. It’s a big world; different people have different problems. For example, I bet this guy is feeling back pain right now for reasons best explained by the “orthodox” model:

(Granted, this guy wouldn’t technically fall under the definition of chronic back pain. But you get what I’m saying.)

This post will say a bit about the “mind-body vicious cycle” model, why I think it’s a frequent culprit, and how that impacts treatment.

Warning 1: I have no medical expertise, I’m just a rando on the internet writing a blog post. Please don’t trust me when it comes to important medical decisions. :-P

Warning 2: I have a horse in this race, as you’ll see in a second.

1. Reasons to question the orthodox model

1.1 Anecdotes of practically-overnight-permanent-miracle-cures

I’ll start with my own story. Hi! For about a year from 2006-7, I had bad and progressively worse RSI, eventually hampering my ability to use a keyboard, then also mouse, then also pen, and after a while I even got various other weird painful conditions that don’t even make sense. It was a miserable experience and I hate talking or thinking about it, but luckily I wrote up these notes shortly afterwards, so check that out if you want more details, and now let us never speak of it again.

Anyway, after trying everything else, I read the book Healing Back Pain by John Sarno (weirdly—recall that my pain was not in my back!), and within a few days I was totally better in every way forever. (More on that book later.)

(I’m writing this on a cramped laptop keyboard, with terrible posture in every way, just like I’ve been doing pretty much all day every day for years. And I feel perfectly lovely, thank you very much.)

I had read Healing Back Pain on the suggestion of my good friend Andy. He had had a very similar miracle-cure experience. I’ve heard from four people (two friends, two friends-of-friends) that they read my webpage and also had very similar miracle-cure experiences. (Quoth one: “it’s been nothing short of pure magic”.) (Update—make that eight people—see here [LW(p) · GW(p)], here [LW(p) · GW(p)], here [LW(p) · GW(p)], here [LW(p) · GW(p)] in the comments section of this very post!) The amazon reviews have page after page of miracle-cure stories like this, and you can find many more at “Rachel’s RSI homage to Dr. John Sarno”, or ThankYouDrSarno.org (exactly what it sounds like), or just by google searching. Celebrities who gushingly praise John Sarno include Howard Stern (who dedicated his first book to his wife, his parents, and John Sarno), Larry David (“the closest I ever had to a religious experience”), and John Stossel (the 20/20 anchor; here’s his effusive segment on Sarno). And you’ll presumably find even more miracle-cure stories if you expand your search beyond John Sarno, to like-minded people like Howard Schubiner, Alan Gordon, Nicole Sachs, etc.

Needless to say, practically-overnight-permanent-miracle-cures are incompatible with the orthodox model. If I have a broken leg, no way am I going to just read a book and then bam, two days later I’m back at the gym jumping rope.

I guess an orthodox-model-advocate could say it’s the placebo effect, where people learn to ignore their pain. But, umm, this is a case where there’s literally no difference between “placebo effect” and “cure”. Call it what you will!

Alternatively, the orthodox model advocate could say that the orthodox model is right for some people but not for others, and that those anecdotes above are coming from the “others”. As mentioned at the top, I have little doubt that this is true to some extent.

Given that, the decision-relevant question for a reader would be: is the orthodox model right for me in particular? Well, check out Sarno’s book (or other resources at the bottom) for more specific diagnostic criteria, assuming you believe these people.

But another helpful datapoint is the base rate. Is the orthodox model right for almost everyone with chronic back or wrist pain, apart from a few weird exceptions like yours truly? Or is it right for most people? Or few people? Or vanishingly few people? This is a question which is obviously hard to answer with anecdotes alone. So let’s switch to other lines of evidence. I think these will be suggestive of the orthodox model being in fact at most a minority of cases.

1.2 Studies showing that “orthodox”-incompatible treatments work quite well for most people

I heard of these two studies from a recent Washington Post article. Note that this article was written (as usual!) by a guy with a horse in this race—his “lifetime of back, neck, stomach, elbow and sciatic pain, along with periodic headaches” were successfully treated by John Sarno.

First study:

“Effect of Pain Reprocessing Therapy vs Placebo and Usual Care for Patients With Chronic Back Pain: A Randomized Clinical Trial” is a newly-published study by a group of famous (and super-biased) people in the Sarno-sphere. Terminology: “Pain Reprocessing Therapy” is I guess some kind of therapy based on John Sarno’s “sneaky subconscious” model (see top diagram, and more on it below). I guess the therapist encourages the patient to believe that their pain is not serious tissue damage, but rather an expression of their anxieties or something.

Results: “Of 151 total participants, 33 of 50 participants (66%) randomized to [the Pain Reprocessing Therapy group] were pain-free or nearly pain-free at posttreatment (reporting a pain intensity score of 0 or 1 of 10), compared with 10 of 51 participants (20%) randomized to placebo and 5 of 50 participants (10%) randomized to usual care.”

Second study:

“Psychophysiologic symptom relief therapy for chronic back pain: a pilot randomized controlled trial” is another newly-published study by mostly authors at Beth Israel Hospital in Boston. In this case, the authors don’t have a glaring conflict of interest, which is nice. Yet the results are about the same:

Results: “At 26 weeks, 63.6% of the [psychophysiologic symptom relief therapy] arm reported being pain free (0/10 pain) compared with 25.0% and 16.7% in [mindfulness-based stress reduction] and usual care arms, respectively.” (Sample sizes of the three groups were 11,12,12, respectively.)

Again, pretty impressive!

As far as I can tell, these are not two cherry-picked examples contradicting a vast ocean of contrary literature. But please let me know if there’s other relevant evidence (for or against) that I should link here.

1.3 Lots of “orthodox” theories seem wrong

A general pattern seems to be:

• Objective measurements of the presumed root cause of the pain (according to the orthodox theory) reveals that it is actually only weakly (if at all) correlated with the pain; and/or
• Interventions that remove the presumed root cause of the pain (according to the orthodox theory) are weakly (if at all) more effective than an appropriately-matched placebo (e.g. sham surgery), which is to say, not very effective.

As far as I can tell, this pattern more-or-less applies to the theory that degenerated (or herniated) discs cause back pain, the theory that pressure on the median nerve causes wrist pain (“carpal tunnel syndrome”), the theory that finger pain comes from damage associated with repeated strain (hence the name “repetitive strain injury”), and so on. For example, lots of people in the general population (half?) have degenerated discs and no symptoms at all. Others have back pain, get a scan, find a degenerated disc, schedule surgery, read Healing Back Pain, cancel the surgery, and next month they’re running around as good as new, with that degenerated disc still as degenerated as ever.

Serious physiological damage should be easy to directly measure, I would think. And researchers have been trying to measure it so hard, for so long, that I think the absence of (better) evidence seems to me pretty damning evidence of absence.

(To be sure, everything I mention here has a competing orthodox-model explanation. Maybe surgery often doesn’t work because most surgeons are lousy, or confused about what they’re supposed to be doing, or more generally working off the wrong orthodox-model explanation. Maybe the serious physiological damage in question is in fact extremely hard to measure for whatever reason. Etc. I haven’t dug deeply enough to take a firm stand here.)

2. The “mind-body vicious cycle” model

2.1 What’s the “mind-body vicious cycle” model?

I mostly made up the “mind-body vicious cycle” model, although I imagine that I’m reinventing a wheel. (If so, please share links!) (Sort-of-example [LW(p) · GW(p)].)

As in the diagram at the top, my favored story would be:

• (1) you think that part of your body is injured, and/or you feel stressed out about the pain, therefore
• (2) your brain sends (involuntary, viscero-)motor commands that constrict blood flow to that part of your body,^[1] therefore
• (3) using that part of your body is painful, therefore
• (1) you think that part of your body is injured, and/or you feel stressed out about the pain.

Let’s walk through each step:

The (1) → (2) step might be the well-known (IIUC) tendency for stress to cause vasoconstriction.^[2] Alternatively, maybe this step exists as part of an evolved response to mitigate blood loss. We do, after all, know that there’s global blood pressure reduction in response to seeing or imagining bleeding and other injuries (cf. “vasovagal syncope”), presumably to reduce blood loss. Local reduction in blood flow to an injured area seems if anything even more of a good idea, from the perspective of evolutionary design, I figure.

(Of course, you’re not actually bleeding!! But who says that involuntary physiological reactions need to be objectively appropriate to the situation?? By the same token, an elevated heart rate and sweaty palms and dilated pupils aren’t exactly helpful ways to get a high score on your history exam. But your body does it anyway. Or a more direct example is: people get lightheaded when they see someone else bleeding. The point is: these things can misfire.)

The (2) → (3) step seems intuitive enough—for example, blood flow provides oxygen and energy and raw materials to muscles and nerves, and removes waste products. Insufficient oxygen causes muscle soreness, spasms, weird nerve firing, and (presumably) various other effects—or at least, so says John Sarno (see Healing Back Pain chapter 3).

The (3) → (1) step seems like a perfectly sensible psychological response, especially for people who strongly believe in the “orthodox” model.

So, that’s my “mind-body vicious cycle” model.

2.2 How does the “mind-body vicious cycle” model differ from John Sarno’s “sneaky subconscious” model?

John Sarno’s model,^[3] as described in Healing Back Pain, is the center column in the image at the top of this post. It shares steps (2) and (3) from the bulleted list above—in particular, the theory that reduced blood flow and oxygen deprivation are the proximal cause of pain—but the ultimate cause is said to be a psychological defense mechanism where your subconscious is trying to cause pain as a sneaky scheme to distract you from stressors like childhood trauma or whatever.

I mostly don’t like John Sarno’s model because I just don’t believe that humans have a “sneaky subconscious” that would do that kind of thing.

The “sneaky subconscious” model also doesn’t jive with my personal experience, although I guess that’s not going to convince anyone else.

3. Positive evidence for the “mind-body vicious cycle” model

3.1 Apparent involvement of medial prefrontal cortex in chronic (but not acute) pain

(This one is really evidence for either “mind-body vicious cycle” or “sneaky subconscious”.)

There’s an article Shape shifting pain: chronification of back pain shifts brain representation from nociceptive to emotional circuits (Hashmi et al., 2013). Here’s the juicy bit:

The mean activation map in early [acute or sub-acute back pain] showed activity extending from the anterior to mid insula bilaterally with contiguous activations in the thalamus, striatum, and lateral aspects of the orbitofrontal and inferior cortex, as well as the dorsal parts of the anterior cingulate cortex. In contrast, [chronic back pain] patients’ mean brain activity was localized bilaterally in the perigenual anterior cingulate cortex (Brodmann area 32) extending into the medial prefrontal cortex (Brodmann area 10) and parts of the amygdala.

I think “emotional circuits” in the title is a confused way to talk about medial prefrontal cortex (mPFC) and anterior cingulate cortex. Instead I offer the following model (based on How Do You Feel by Bud Craig):

I’m never quite sure how much to trust fMRI studies, but this result seems remarkably well-aligned with what I would have expected:

• The acute back pain group is following the “orthodox model”—the main event in their brain is a pain signal going up from their damaged body to their insula;
• The chronic back pain group is following the “mind-body vicious cycle model”—the main event in their brain is their medial prefrontal cortex sending (involuntary, viscero-)motor commands for vasoconstriction (and maybe other things too) down to their back.

(It would have been a better match to my expectations if both insula and mPFC were active in the chronic group. Not sure what’s up with that. Maybe the insula was active in both groups, but less active in the chronic group? Not sure—the paper is confusing.)

3.2 Apparent involvement of vasoconstriction

(This one is likewise evidence for either “mind-body vicious cycle” or “sneaky subconscious”.)

There’s a paper “A vascular basis for repetitive strain injury” by Pritchard et al. 1999 which claims that “in diffuse forearm pain the radial artery is relatively constricted compared to the controls and fails to vasodilate with exercise”, based on ultrasound imaging. If I understand correctly, that paper’s authors suggest an “orthodox” model where the proximal cause is structural (obstruction of the arteries prevents them from expanding), whereas I want to explain the same observation via a “mind-body vicious cycle” model where the proximal cause is in the nature of the visceromotor commands being sent from the brain to the (involuntary) vasoconstriction muscles.

(That’s just one paper, but different researchers found compatible results by a different method here. I haven’t done a deeper dive than that.)

Another possibly-relevant datapoint on this topic that I’ve seen is—and I hardly need to mention that this is not a particularly reliable source—an anecdote from this weird book with a creepy alien on its cover that my wife and I read at a hospital birthing class before our first kid:

When the mother approaches labor with unresolved fear and stress, her body is already on the defensive…. This causes the arteries going to the uterus to tense and constrict, restricting the flow of blood and oxygen. Labor and birthing nurses and midwives have told me of seeing uteruses of frightened birthing women that are white from lack of blood, just as a person who is experiencing extreme fright often has the blood drain from his face.

With limited oxygen and blood, vital to the functioning of the muscles in the uterus, the lower circular fibers at the neck of the uterus tighten and constrict, instead of relaxing and opening as they should… When these two sets of muscles work against each other, it causes considerable pain for the laboring mother… —p53 here

Again, this is not a great source, but I find it intriguing, especially if the (sketchy, undocumented) claim that terrified women have white, starved-of-blood uteruses is both true and has the implied cause-effect relationship.

What about back pain? Healing Back Pain has some references:

There is also laboratory evidence for this concept. In 1973 two German research workers, H. G. Fassbender and K. Wegner, reported finding microscopic changes in the nuclei of biopsied muscles from back pain patients suggesting oxygen deprivation in “Morphologie und Pathogenese des Weichteilrheumatismus,” Z. Rheumaforsch (Vol. 32, p. 355).

For additional evidence on the critical role of oxygen in [chronic back pain] we are indebted to a group of research workers who have demonstrated in their laboratories in recent years that muscle oxygenation is low in patients suffering from a disorder known as primary fibromyalgia. Typical of these reports is one published in the Scandinavian Journal of Rheumatology in 1986 (Vol. 15, p. 165) by N. Lund, A. Bengtsson and P. Thorborg titled “Muscle Tissue Oxygen Pressure in Primary Fibromyalgia.” Using an elegant new laboratory tool, they were able to measure muscle oxygen content with great accuracy and found that it was low in the painful muscles of patients with fibromyalgia.

(I think the two papers he cited, like everything else in this section, should be treated as merely suggestive, as opposed to strong evidence. I haven’t tried to dive into the literature myself.)

3.3 “Vicious cycle” seems like a pretty good fit to the dynamics

Leaving aside the exact nature of the vicious cycle, the general idea that there’s a vicious cycle seems to me like the right dynamic. A vicious cycle provides a natural explanation for why the pain tends to have better and worse phases over days and weeks and months—whereas your mood can change in minutes, and your thoughts in seconds.

Also, a vicious cycle suggests a susceptibility / trigger split that rings true to me:

• Susceptibility to the vicious cycle means that, if there’s pain, it’s liable to become self-sustaining. People might be more or less susceptible to the vicious cycle for various reasons, including general stress and anxiety etc., or simply from very strong belief in the orthodox model! (…with extra bonus points if they have friends who were forced to quit their jobs and upend their lives due to chronic pain!)
• Trigger would be something that starts the vicious cycle—I presume typically a conventional / “orthodox” cause of pain or discomfort (acute injury, muscle soreness, spasm, etc.) That original cause of pain would heal itself on the usual schedule, but in the meantime the vicious cycle has spun itself up and persists.

4. If “mind-body vicious cycle” is the right model [for a particular person], then what?

For me, it was just reading Healing Back Pain, and all the testimonials in Section 1.1, then deciding to live normally starting the next morning (keeping in mind that my muscles would be sore from exercise after a long period of disuse), and I felt better over the course of the next couple days.

Ironically, I didn’t even like Healing Back Pain that much—most of it struck me as a bunch of baloney, for the reason mentioned above (i.e., I don’t believe that humans have a “sneaky subconscious” of the type that Sarno was proposing). But that’s not too weird. After all, it’s very common in medicine for people to come up with an effective treatment despite a wrong theory (or no theory) about why that treatment works. Maybe the main thing I got out of the book was self-confidence that I didn’t have very-slow-healing semi-permanent tissue injuries, and that’s all I needed.

(It was only many years later that I invented (or maybe reinvented) the “mind-body vicious cycle” model.)

Oh, I also liked some of the practical advice in the book. For example, Sarno’s book suggested “talking to your brain”. I recall finding that tip very helpful. If memory serves, I had some very choice words for my brain, which need not be repeated in this family-friendly blog post.

In hindsight, the other thing I should have done before starting is to go through the “positive reframing” technique from Feeling Great (see my book review [LW · GW]). If there were a magic button that eliminated all the caution, stress, anxiety, tension, etc., that I felt before and during typing, would I have any motivation not to push that button? I have to admit that I did have such counter-motivations—in particular, (1) Even after all the reading and thinking, maybe I still had slight lingering concern that the “orthodox” model was correct after all, and the caution and tension were protecting me, and I was going to make things even worse, (2) I had certain unsympathetic friends who I knew would declare “It was all in your head after all, I told you so, nyah nyah nyah pfffft”, if I were to have the miracle-cure experience that I was hoping for, and that was an aversive thought.^[4] In my case, those counter-motivations were weak enough that they didn’t cause any problem—the treatment immediately worked for me anyway. But I imagine that counter-motivations are a bigger roadblock for some other people, just as counter-motivations are often a roadblock for people suffering depression, anxiety, phobias, OCD, and all sorts of other unpleasant conditions (again, see Feeling Great [LW · GW]). That may account for why Sarno-style treatments can (apparently) sometimes not work immediately, but work after some therapy and talking about childhood trauma or whatever.

Other possibly-relevant resources that I haven’t tried and can’t vouch for:

• Curable Health app
• Nicole Sachs has a $295 course Freedom From Chronic Pain, along with a podcast and other things.

And most importantly, reading the testimonials in Section 1.1.

(Previous discussion on LessWrong: Alex Turner’s anecdote [LW(p) · GW(p)], rmoehn’s anecdote & discussion [LW · GW], related question [LW · GW]. See also Scott Alexander’s “Book Review: Unlearn Your Pain”.)

(Thanks rmoehn for critical comments on a draft.)

1. ^{^}

   I’ll be arguing for a particular model involving blood flow and oxygen deprivation, but I can imagine various other possibilities in the same “genre”, and these might not even be mutually exclusive. For example, maybe stress causes inappropriate muscle tension which makes the muscles painful to use which causes stress.

2. ^{^}

   See Why Zebras Don’t Get Ulcers for more discussion of the stress-body connection.

3. ^{^}

   Warning: I’ve only read Healing Back Pain by John Sarno. I assume that his fellow-travelers like Howard Schubiner, Alan Gordon, Nicole Sachs, etc. all espouse the same theory, but I didn’t check; it’s possible that there are differences among them.

4. ^{^}

   As it turns out, I needn’t have worried, everyone was very kind and sympathetic. But I didn’t know that at the time.

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