Thursday, January 31, 2008
Matthias, your post reminded me of (one of my many) recurring thoughts:
1. We are called Physical Therapists
2. Many within the profession want us to be strictly PHYSICAL therapists
3. I say we need to remain physical THERAPISTS.
Ideally we can fluctuate between our two poles smoothly and as needed, but I never want the therapeutic capacity our name implies to become defined strictly just by what we do with only our hands, i.e., physically. I'm sure robots will come along that will be precise about delivering physical forces to joints, etc. - they'll likely produce more quantifiable data than we ever have!
Instead, I want us to keep the human aspect, remain a profession that can continue to learn and evolve and adapt as science does - the more we understand the brain, the easier it should be for this profession we are part of to move into fully developing our empathic and genuinely therapeutic side. If one can learn to funnel "feeling" (i.e. therapeutic regard) through one's interview style, therapeutic presence, and hands, while retaining ethical conduct, remaining therapeutically boundaried and scientific accountable, now, THIS is therapy.
If we recognize that all pathways must be accessed/treated simultaneously, the profession will be in good shape in the future.
I think this passage from the article is the most important:
From the perspective of the brain, there are two distinct types of pain. The first type of pain is sensory. When we stub our toe, pain receptors in the foot instantly react to the injury, and send an angry message to the somatosensory cortex, the part of the brain that deals with the body. This is the type of acute pain that doctors are trained to treat. The hurt has a clear bodily cause: if you inject an anesthetic (like novocaine) into the stubbed toe, the pain will quickly disappear.
The second pain pathway is a much more recent scientific discovery. It runs parallel to the sensory pathway, but isn't necessarily rooted in signals from the body. The breakthrough came when neurologists discovered a group of people who, after a brain injury, were no longer bothered by pain. They still felt the pain, and could accurately describe its location and intensity, but didn't seem to mind it at all. The agony wasn't agonizing.
This strange condition - it's known as pain asymbolia - results from damage to a specific subset of brain areas, like the amygdala, insula and anterior cingulate cortex, that are involved in the processing of emotions. As a result, these people are missing the negative feelings that normally accompany our painful sensations. Their muted response to bodily injury demonstrates that it is our feelings about pain - and not the pain sensation itself - that make the experience of pain so awful. Take away the emotion and a stubbed toe isn't so bad.
Chronic pain is the opposite of pain asymbolia. It's what happens when our brain can't stop generating the negative emotions associated with painful sensations. These emotions can persist even in the absence of a painful stimulus, so that we feel an injury that isn't there. It's like having a permanently stubbed toe.
Doctors have traditionally focused on the bodily aspects of chronic pain. They assume that a healed body is a painless body. If a patient has chronic back pain, for example, then he is typically prescribed painkillers and surgery, so that the pain signals coming from his spinal nerves are stopped. But the dual pathways of pain mean that this approach only treats half of the pain equation. Unless you find a way to treat the emotional pathway, then the chronic pain will continue.
It might not be the perfect description of chronic pain - but it is very helpful to explain the connection between emotional states and pain - and why there is no "imaginary" pain.
All pain is real since it is always constructed in the brain.
Using fMRI to provide visual feedback is overkill. It's nice to see that feedback therapy works regardless of which type of feedback you give to the brain - put in the case of chronic (low back pain) it's much easier to do with tactile stimulation.
What I don't like about this type of therapy is it's reliance on high-tech.
After all: what good is this type of therapy if only a very small percentage of people can benefit from it?
If you want high-tech - think of our brains. Organic computers that are able to change, to evolve, to learn. We have to realize that our brains are the most high-tech "gadgets" out there so to speak - and use them accordingly.
I completely agree with Ian that we should start focusing inwards more. It's cheaper, more efficient in the long run (because if you work on yourself you learn for life) and puts responsibility and control back into the hands of the patient.
Wednesday, January 30, 2008
The article uses the word "mind"(Christof Koch would probably not approve); however, the gist of it is that if a person with chronic low back pain can access a way to visualize the regions of the brain involved in and perpetuating/fueling the "central sensitization" of the body zone involved, i.e., viewing their own brain on an fMRI screen, they can learn to reduce the back pain in a top-down manner. Excerpt from the last page of the article:
"Christopher deCharms, PhD, a lead author on Dr. Mackey’s paper, is trying to take this therapeutic approach mainstream. He has started a company called Omneuron, which makes the experimental treatment available to a wider audience. A standard session goes like this: A patient lies in a brain scanner while experiencing pain, and he watches as his brain flares up in agony. He sees the smear of neural activity that makes him suffer. Then, with the help of a trained therapist, the patient learns how to consciously turn off the specific brain areas that correlate with the chronic pain. After a few sessions, the awful symptoms begin to fade away. The pain is no longer permanent. It’s a real-world example of mind over matter."
Another general-reader article, called Seeing Your Pain, by Emily Singer, discusses Omneuron's work in a bit more detail.
I found these two articles linked into a thread called "The Psychology of Back Pain", at SomaSimple.com.
Both these articles but especially the second (all the way through) emphasize doing something with basic visualization;
1. Turn attention inward (in this case, with the help of a huge expensive MRI visual feedback machine, which provides an outside, visible "fixation" point; associative "learning" takes place)
2. Create a visible "thought object" (as per Antonio Damasio) to hold in one's attention, in this case a visual image that represents one's "pain" (in this case, it's a red spot on a screen flickering in a part of the brain that brain research has identified as being associated with persistent pain, therefore as close to "real", as closely associated as it's possible to get, probably - boosting the all important "trust" factor)
3. Find ways to "deconstruct" the now-'visible' "thought object", the visualization of the pain, the "source" of it.
I guess this works (finally) for those who can't just go ahead and do a facsimile of this on their own. In fact, I wonder if one could find correlations between low back pain and lack of imagination? Image-ination? Ability to form visual images?
We already know that the brain can't tell the difference between something "real" and something "illusory". It will respond to a sufficiently convincing image and downregulate pain successfully, as Ramachandran's mirror work for phantom limb pain has shown.
MRIs are still pretty expensive to use as feedback devices. As Ian S. pointed out in the thread,
"sitting still and learning to meditate costs $0... I think the interventions are interesting but fit in with the culture of high tech solutions to what are low tech approaches (paying attention / learning to take responsibility / reducing threat )."
Tuesday, January 15, 2008
I don't think you have to worry Matthias, about falling off your functionalist track when studying brain parts. ;)
Brain parts can't do much in isolation - they need to grow up with and be constantly stimulated by other brain parts in order to do anything, plus they seem to need to have that nice steady stream of 10,000 new neurons a day folded into the mix to keep the entirety working well. It seems to me that brain as a whole is much less about "parts" and much more about "function" than the rest of the body:
1. Some "parts" can take over for other "parts" in a pinch.. I met a young woman a few years ago who had had a hemispherectomy for extreme epilepsy as a young child. The remaining half had taken over function quite readily.
2. Constraint induced movement therapy (CIMT) can retrain remaining parts of the brain to take over from parts that have been wiped out by stroke. (For more on this you can listen to Ginger Campbell's podcast interview with Edward Taub, the originator of this form of therapy, in her brain science podcast #28.)
It seems to me that neuroplasticity is such a feature that it likely may have been and in many cases likely still is a confusing factor for researchers who really, really want to find direct relationships between brain parts and functions.
I know where you're coming from - I'm a PT too. We started out being taught structure - "This is the knee joint. It bends thusly. It is covered in cartilage to make movement smoother." Etc etc...
What helped get me out of this structuralist mind set training was embryology. The physicality of the body we deal with as PTs is a blend of mesodermal and ectodermal derivatives (well, endodermal too, but we don't deal directly with or concern ourselves with endoderm much.)
We get taught all about the mesodermal derivatives (overwhelmingly!) in school: mesoderm derivatives account for 98% of the whole body. Their structure IS their function.. unfortunately the educators don't realize what they are doing to our poor brains! :D
Direct ectodermal derivatives, by contrast, account for only 2% of the body's mass - and that includes outermost layer of skin, brain, spinal cord, and all the 45 miles of nerves that lace throughout all that mesoderm. We have a brain 5 times BIGGER than needed to operate a mammal our size - and still, direct ectodermal derivatives account for only 2% of mass! That's tiny!
However (and this is a very clear distinction), direct ectodermal derivatives use 16%-20% of all the oxygen taken in. (Streidter, Principles of Brain Evolution) That's huge! The nervous system and the rest of the body are clearly out of proportion here. Big, big difference physiologically.
This is still astonishing to me, every time I think of it. What a busy system. What a huge oxygen sink our brains are, so big and so busy. So "functional". Function is its business - brain "structure" is less relevant by comparison. In fact, sometimes when I remember that fact that humans have a brain 5 times bigger than necessary for operating a mammal our size, I wonder if its high-maintenance oxygen-neediness contributes to most of our problems..
Anyway, back to the point - I don't think brain parts can be classified into "this part does this, and that part does that" as easily as the rest of the body can. And everyone, at all times, will do well to remember that correlation does not = causation. One notes when reading papers that the authors are usually very careful to skirt around declarative statements such as, "the x part is responsible for y." Instead they say something like, "Y was found to be associated with abc waves in the z frequency when neurons in the x part were stimulated" or "when the animal exhibited x behavior." That way, they can describe a relationship between parts and function, but don't run the risk of sounding prematurely categorical or final.
"If you think about patients with chronic pain it all starts making sense:
pain leads to stress - stress leads to gray matter loss in the brain (not just in the hippocampus) - thereby limiting the amount of neurons you have to be able to learn something new. It really is a vicious circle. Scary stuff."
But, maybe stress can also lead to pain... or maybe neuron loss in the brain can lead to less adaptation to stress which might lead to pain... I don't think anyone has it figured out for sure yet. It's really all one great big circle of function/adaptation. As Quinter et al. have said, pain seems to be an aporia. (Not that we can't do something to help!)
One thing we can take comfort in (as PTs) is that movement appears to be associated with better brain function as well as all sorts of other health benefits. Motion is lotion for the brain/nervous system, not just the joints. :)
Monday, January 14, 2008
Diane - I have to admit that I haven't done much research on specific brain structures yet. I guess I'm so far out on the purely functionalist track that anything having to do with structure scares me to death. ;-)
However - when it comes to the brain things might be different after all.
I found another interesting article about the effects of severe stress on hippocampal volume.
If you think about patients with chronic pain it all starts making sense:
pain leads to stress - stress leads to gray matter loss in the brain (not just in the hippocampus) - thereby limiting the amount of neurons you have to be able to learn something new. It really is a vicious circle. Scary stuff.
I wonder if an increase in hippocampal volume is universal, i.e. can these new neurons then be used for other tasks as well or are they built for one task only?
Sunday, January 6, 2008
Here is another about motivation in physical learning called Romancing the Body.
He has many other 2007 articles archived here, and other years here, for those interested.