Sunday, July 07, 2013

Melzack & Katz, Pain. Part 13b: Managing neuroplasticity

The paper, Pain

Most recent blogposts:

Part 13: Pain and Neuroplasticity

I really couldn't leave this topic without mentioning just a few of the wonderful lines of work that support the idea that by changing the brain's input, its output, including but not limited to ideation,  and including pain, can be changed. 

Mirror therapy
This was invented by VS Ramachandran, around 1997. 

Humans are primates, and in primates, the visual processing centers of the brain are incredibly well-developed and dominating. Nothing seems to get past the brain unless it has convinced the visual centers first.

Here is Ramachandran in a 25-minute TED talk from 2007, 3 clues to understanding your brain, discussing the brain in general, and mirror therapy in particular for phantom limb symptoms and pain, minute 9: 38. He discusses "learned paralysis" in the phantom limb of his first patient, an idea on how it was generated (arm was in a sling, paralyzed, for a long time, pre-op; Hebbian "neurons that fire together wire together" learning occurred - the brain wanted to move the arm but the visual cortex saw no movement, over and over, pre-op). He used a mirror box to convince the patient's brain, via visual illusion, that the "arm" could move, and helped it re-neuroplasticize itself out of the associated learned paralysis. 

"I study the human brain, the function and structure of the human brain: I just want you to think for a minute about what this entails - here is this mass of jelly, a three-pound mass of jelly you can hold in the palm of your hand and it can contemplate the vastness of interstellar space, it can contemplate the meaning of infinity, and it can contemplate itself contemplating on the meaning of infinity. And there is this peculiar recursive quality that we call self-awareness which I think is the holy grail of neuroscience, of neurology, and hopefully some day we'll understand how that happens." - VS Ramachandran, from the video
Mirror therapy has spread all over; by now, almost 20 years later, you're scarcely a good therapist
SOURCEMatthias Weinberger PT
demonstrates mirror therapy
for upper limb pain
unless you use mirrors in your office, because what works for phantom limb pain also works for other kinds of pain, felt ( the brain..) in actual limbs. Here is a link to another video, about 3.5 minutes, by a German colleague, with ideas for treating pain in various parts of limbs using a mirror. It's the only one I've found that shows treatment for shoulder pain (about minute 1:20), using a full length tilting mirror. 

In this video (about 7 minutes), David Butler explains in detail how to use mirrors and mirror box therapy for various kinds of persisting pain.  


Here we see a simple set-up for treating phantom limb in legs. 
The beauty of this form of pain relief is that it is cheap, non-invasive, can be carried out by people independently any time they want. It can be utilized in any country, by anyone who can get hold of a mirror

Results from studies show promise. See 
Ezendam DBongers RMJannink MJ; Systematic review of the effectiveness of mirror therapy in upper extremity functionDisabil Rehabil. 2009;31(26):2135-49.
 Here are a few more papers on the topic: 
Sae Young Kim, MD and Yun Young Kim, MD; Mirror Therapy for Phantom Limb Pain. Korean J Pain. 2012 October; 25(4): 272–274. (Full text) 
Peter Praamstra, Laura Torney, R. Chris Miall; Misconceptions about Mirror-Induced Motor Cortex Activation. Cereb Cortex. 2011 August; 21(8): 1935-1940 (full text) (The authors acknowledge mirror therapy "works" - just not the way one hypothesis suggested.) 
Lorimer Moseley; The Mirror Cure for Phantom Pain. Scientific American April 16 2008


Graded Motor Imagery
Graded motor imagery shows a lot of promise. It gets into not only the visual cortex but also other cognitive evaluative parts of the brain, and works over time to help the brain recognize it's own body parts as being the right size and right way around. Here is a link to a review I did of a book that has been published outlining the whole approach, spearheaded by David Butler supported by research done by the Lorimer Moseley group's research. Here is a link to over 1000 papers written on the topic so far this year

Cognitive Behavioural Therapy
What is it? Here is a wikipedia description. Here's my take as someone not certified in CBT: it's a way a patient can change unhelpful cognitions they may hold, yet never chose, and beliefs that don't support their progress. 

We all grow up in and and are subject to cultural influences, some of which aren't good at all. To move forward, we must find our center, our core, the thing inside each of us that is a representation of "self", of inviolable self, moving through life unperturbed by much or most of it. This is "internal locus of control."
Locus of control does NOT mean that pain is a patient's "fault." Locus of control is self-management. 

When assumed by the patient, and used properly, maturely, locus of control is their way through and out. In pain management it is a way people can identify and think their way around unhelpful cognitions: For example, instead of thinking, "Oh, there is my pain again - I'm always going to have pain, I'll never be able to do xyz", the thought itself is challenged by another; e.g., "Hmm... I can feel pain right now... I know that it varies - it comes and goes, and I've come to know it well enough that I know can plan my life around its presence and absence. I also know that it increases if I feel stressed or under more pressure... it could be stress around preparing for my son's wedding this weekend... I know hurt doesn't equal harm, and that motion is lotion, so I'm not going to let pain stop me attending and enjoying my son's wedding. Hey, it already feels better, just by having figured that out." 

A description of Cognitive Behavioural Therapy can be found in this document on page 20
Here is a great blogpost by Bronnie Thompson, OT, on the topic of self-management, in her excellent HealthSkills blog. 


I think we can accept the idea that a body-self neuromatrix has a past, a journey it has traveled. I think we can accept therefore that it has a future. I think we can accept that the present moment is an opportunity for change. Any present moment. We can't change the past, but we can shape neurotags by understanding that each present moment, as it passes by, will contain cognitions that can either contribute to a given neurotag's strength, or help undermine it. The present moment, every one that passes, is the only moment we ever really have. "You can't stand in the same river twice" Heraclitus is said to have said. If anyone understood how life is a verb, not a noun, it was he. 

As near as I can see, from my limited viewpoint, the trick is to be able to get descending modulation going again. No one has examined the effects of therapeutic psychosocial intervention to the extent that Fabrizio Benedetti at the University of Turin has. A member of the European Pain School, he has published extensively and wrote the book, The Patient's Brain: The neuroscience behind the doctor-patient relationship. Here is a BrainSciencePodcast interview with Ginger Campbell from 2011, in which he outlines his work. 

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 

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