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ALTERATIONS IN TEMPORAL SUMMATION OF PAIN AND CONDITIONED PAIN MODULATION ACROSS AN EPISODE OF EXPERIMENTAL EXERCISE-INDUCED LOW BACK PAIN

Low back pain (LBP) is the leading cause of disability worldwide26, yet up to 90% of patients are diagnosed with non-specific LBP, meaning the pathoanatomical source is unclear10. Further, recurrence following an acute episode may be up to 80%25, with little understanding as to why some patients develop ongoing symptoms9. There has recently been increasing focus on alterations in pro-nociceptive and anti-nociceptive mechanisms, purported to explain or contribute to pain exacerbation and persistence across a range of acute to chronic pain conditions34,45,72.

ALTERATIONS IN TEMPORAL SUMMATION OF PAIN AND CONDITIONED PAIN MODULATION ACROSS AN EPISODE OF EXPERIMENTAL EXERCISE-INDUCED LOW BACK PAIN

Orginally Published At: Pain Journal

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CONTRIBUTIONS OF NOCIRESPONSIVE AREA 3A TO NORMAL AND ABNORMAL SOMATOSENSORY PERCEPTION

Somatosensory cortex in the postcentral gyrus of humans and other primates comprises four cytoarchitectonically, connectionally, and physiologically distinct cortical areas – Brodmann areas 3a, 3b, 1, and 2 (Figure 1AB). Each of these areas forms a long strip running along the central sulcus from the midline to the lateral fissure. The most anterior of these areas, area 3a, lies in the fundus of the central sulcus, flanked anteriorly by motor cortical area 4 and posteriorly by somatosensory area 3b.

CONTRIBUTIONS OF NOCIRESPONSIVE AREA 3A TO NORMAL AND ABNORMAL SOMATOSENSORY PERCEPTION

Orginally Published At: Pain Journal

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A novel finger illusion reveals reduced weighting of bimanual hand cortical representations in people with complex regional pain syndrome

Complex regional pain syndrome (CRPS) is characterised by excessive pain, usually in a peripheral limb such as the hand, and affects sensation, movement and function.32 Quantified deficits include higher thresholds for two-point discrimination in the index finger,45 impaired hand size estimation,35,44 finger misidentification,14,33 tactile processing disturbances;28 errors in bilateral limb positioning,30 fine motor26 and motor imagery performance.34,49,50 These deficits implicate distortions in body representation53 and are corroborated by evidence of cortical re-organisation in CRPS,9,10 although much remains unclear.

A novel finger illusion reveals reduced weighting of bimanual hand cortical representations in people with complex regional pain syndrome

Orginally Published At: Pain Journal

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Misdiagnosed for 35 years

Today’s post is about a truly perfect example of my favourite theme lately: surprising causes of pain, chronic pain mysteries that finally get solved. This one’s a doozy.

“When Chronic Pain Is Not “Chronic Pain“: Lessons From 3 Decades of Pain
Taylor et al. Journal of Orthopaedic & Sports Physical Therapy. Volume 47, Number 8, 515–517. Aug 2017.

That paper is all about a patient who had “sciatica” for thirty-five years and was misdiagnosed many times until finally getting not only a definitive diagnosis but a cure. He had a narrowed artery (arterial stenosis causing “claudication,” the pain of impaired circulation). That’s it! Not even a difficult a diagnosis in the end, really. There were some pretty glaring clues there that got ignored by a lot of people who should have known better.

But not only was he misdiagnosed many times over more than three decades, he was misdiagnosed fashionably: that is, each misdiagnosis neatly fit a paradigm in physical therapy, better than it fit his symptoms. This carried on right up to and including the present day fascination with psychosocial factors and sensitization (which served him no better than any of the other paradigms had).

Interestingly, the patient’s belief that something ‘was actually wrong’ had remained with him throughout the journey. This, of course, had been explained away to him (more recently) by current research and evidence-based thinking on central sensitization and pain.

Just fascinating. The authors thoughtfully explore the implications of this rather shameful episode (definitely aimed at pros, some jargon, but readable enough for anyone — and behind a paywall, unfortunately). The bottom line? Good diagnostic skills are never out of fashion. Or shouldn’t be, anyway!

Update: There are criticisms of this paper from a couple of my favourite experts and writers, pointing out in a letter to the journal that one of the “fashionable” paradigms impugned here, the biopsyschosocial model, “includes the considerations [the “bio” part] that eventually cured the patient’s pain.” I like the criticism and I like the authors’ response — I see only healthy debate here.

[Go to this post on PainScience.com]

Misdiagnosed for 35 years


Orginally Published At: Pain Science

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Design and reporting characteristics of clinical trials of select chronic and recurrent pediatric pain conditions: An ACTTION systematic review

Chronic and recurrent pain are common in the pediatric population, with median prevalences ranging from 11-38% reported in the literature depending on the type of pain and criteria used to define chronic and recurrent pain.25 However, a paucity of clinical trials is available that provide adequate evidence to inform pediatric pain management and evidence-based treatment guidelines.13 Many of the current pediatric pain treatment recommendations, therefore, rely on efficacy data extrapolated from studies that included only adults.

Design and reporting characteristics of clinical trials of select chronic and recurrent pediatric pain conditions: An ACTTION systematic review

Orginally Published At: Pain Journal

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Higher Dispositional Optimism Predicts Lower Pain Reduction During Conditioned Pain Modulation

Optimism, or a generalized expectancy for positive outcomes, is associated with lower pain sensitivity, higher placebo analgesia, and better adjustment to chronic pain [8,9,26]. The initial conceptualization of optimism was developed from a broader model of behavioral self- regulation [10,32,33]. Based on this model, optimists are people who expect positive outcomes, making them more likely to engage in health promoting behaviors [33]. While optimism is viewed as a stable individual personality difference, it is also associated with coping strategies and positive affect, which lead to better health outcomes [10,26,31].

Higher Dispositional Optimism Predicts Lower Pain Reduction During Conditioned Pain Modulation

Orginally Published At: Pain Journal

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Neuropsychological humility

Memories influence not just how we interpret what we see, but literally what we actually see. Dr. Steven Novella, summarizing some recent science on this topic:

Memory is explicitly involved in this construction process [generating what we perceive]. It’s a fundamental aspect of neuropsychological humility: just understanding how your brain works is critical to being skeptical. After listening to this show you should no longer say things like ‘I know what I saw’ or ‘I clearly remember.’

Dr. Novella coined the term “neuropsychological humility” back in 2013:

Neuropsychological humility [is] the understanding that our perceptions and memories are deeply flawed and biased. There appears to be almost no limit to the extent to which people can deceive themselves into believing bizarre things.

Neuropsychological humility is relevant to my work here on PainScience.com in many ways. It’s why the words “in my experience” are the “three most dangerous words in medicine” (Crislip), why there’s such chronic tension between clinical experience and evidence-based medicine, why anecdotes can’t be trusted, why patients think they were helped even by “treatments” that are actually harmful, why massage therapists think they can feel things that aren’t there, why we perceive the things that we want to believe, why “obvious” explanations for pain are usually wrong, even why pain is such a weird and unreliable sensation.

[Go to this post on PainScience.com]

Neuropsychological humility


Orginally Published At: Pain Science

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Pain with surprising causes, or literally no specific cause at all

Drawing of a knob representing the intensity of back pain, dialed up to 11.

[Image caption: There many paths to pain that never make the headlines.]

The question that haunts everyone with unexplained chronic pain: “What if there’s a cause that’s been missed? What if it’s treatable?”

It can happen, and most people are aware of at least a couple ways it can happen. But not many people suspect how many surprising ways to hurt there are.

I’ve recently “completed” a major reboot and expansion of my article, Surprising Causes of Pain: Trying to understand pain when there is no obvious explanation. There’s more to do (always), and suggestions and requests for additions are very welcome (even more than usual), but it’s definitely now a much more comprehensive survey of all non-obvious causes of pain. I hope this will become one of the most useful articles on PainScience.com.

The article has always been inspired by the many fascinating stories I’ve heard over the years about people who eventually discovered a specific cause of their pain, like a sneaky drug side effect or a slowly worsening disease, problems with clearly biological origins. However, pain that truly has no particular source is yet another fascinating kind of problem, and likely all-too-real. Here’s an excerpt from the article about that bizarre idea:

Like other complicated things in life, pain may not have any specific cause at all. Although we often speak of pain being multifactorial, we still tend to assume that just one of those factors is the specific cause of pain, and the others — sleep loss, stress, etc — are only piling on, making a bad situation worse. That picture may be wrong: some chronic pain is probably an emergent property of a big mess of synergistic stresses, with literally no specific cause. It may crop up only with an unholy combination of many factors.

This is a “systems” perspective on pain, and it overlaps substantially with sensitization — it’s basically saying that sensitization may be triggered by a bunch of different stresses — but it’s a different enough perspective to be worth considering separately. The idea of pain that truly has no specific cause is something more patients probably need to consider.

Pain without no one cause is a good news scenario in the sense that it might be treated by relieving enough of the contributing factors… but bad news in the sense that it may be like fighting a hydra.

This is line of thinking was directly inspired by a pair of articles by Todd Hargrove:

Do you have a story about pain that was eventually clearly explained? Or never was? Again, I’m more than usually interested in suggestions from both patients and professionals on this topic. I’d love to create the most complete possible list of “surprising ways to hurt,” and I know there’s more than I’ve included so far. Send me an email, or reply to the Tweet or Facebook post.

[Go to the link featured in this post]

[Go to this post on PainScience.com]

Pain with surprising causes, or literally no specific cause at all


Orginally Published At: Pain Science

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Science cranks

“Therapy babble” is an irritating combination of jargon, bafflegab, pseudoscience, and abused science that sounds impressive but means little, and it’s particularly common in alternative health care. Science cranks are a significant sub-species of therapy babbler. They have a lot of admirably sincere enthusiasm about science, which sets them apart from most other therapy babblers, who are merely paying lip service to science. The crank is truly keen on science, but just isn’t any good at it — downright terrible, actually.

Just like conspiracy theorists seem a bit brain-glitchy, like they might have a mild form of mental illness (because they probably do), so too science cranks exhibit some suspiciously consistent types of reasoning problems, which might be more about malfunctions than mere mistakes. They suffer from crippling confusion about the relevance and weight of ideas. To them, whatever they aim their attention at is significant, nothing that seems similar is a coincidence, and the scientific method is basically just identifying superficial connections and blowing them way out of proportion. Speculation is always good enough.

After languishing in my drafts file for about eight years, I finally added this train of thought about science crankery to PainScience.com, a small new section of:

Exhibit A: “I’M PURE SCIENCE”

Over the years, I have received many pain-cure pitches from delusional cranks who believe that they have a lock on a cure for “all” or “most” chronic pain. Some of them, rather than being pissed at me for my anti-quackery activism, are so delusional that think I’ll be impressed by their theory. They might hope that they can woo me (pun intended), and many are obviously hoping to recruit me to become an evangelist for their nonsense. Some are more condescending, and probably don’t think I’m likely to see the light, but it can’t hurt to try, right? They all remind me of kooky inventors who are convinced that they have a perpetual motion machine.

The following is surely the apotheosis of this phenomenon. This is a transcribed voice mail, presented it to you here for your amusement and amazement, in the form of a free verse poem. The emphasis is mostly mine for dramatic effect, but not entirely — he was definitely hitting some of these words as hard as the capitals imply. Behold the dazzling ego!

found you on the net by accident
I would love to have a discussion with you about TRUE pain healing science
which is non-medical
which apparently you have no been made aware of
I am an expert in it, I’ve written a book on it, I’ve done the work
I’ve healed migraines, dozens, actually hundreds of them
in less than 20 minutes!
very, very, very easy to do WHEN you understand the TRUE science
not the medical science, which is nonsense
but true quantum science, quantum physics, biophysics, epigenetics!
that kind of thing, you know
I’d love to have a talk with you to help you understand how REAL science is helping people to heal pain
not just cope with it
and I am the expert on it
and I do this work around the world
I’m not a flake, I’m not some kind of weirdo
I’M PURE SCIENCE
and I’d love to share this with you
and maybe I’ll enlighten you a bit on how things really work on this planet
when you look at the ADVANCED science

What a truly classic example of a “science crank”! This was added to:

[Go to this post on PainScience.com]

Science cranks


Orginally Published At: Pain Science

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“Why would he mislead people like that?”

I once explained to a reader that a claim made by a popular massage therapist author was completely bogus, and she earnestly asked, “Why would he mislead people like that?” She was actually puzzled! Apparently it had never occurred to her that any health care professional might be a crank, or self-serving, or even just too optimistic. It’s hard for me to relate to such innocence. The world is overflowing with misinformation, particularly about health. Indeed, most of it is problematic in some way, even though much of it is produced with good intentions.

That little anecdote is now the new intro to an old article:

[Go to the link featured in this post]

[Go to this post on PainScience.com]

“Why would he mislead people like that?”


Orginally Published At: Pain Science