Thursday, May 28, 2015

Muscle guarding, and so on..

From a Facebook thread started by Taylor Sun, in Skeptical Massage Therapists group:

>> "I would love to foster a discussion around the idea of "muscle splinting" or "guarding" as a protective mechanism that the organism is engaged in due to perceived threat or repeated exposure.... Can we think of muscle splinting as one of these plastic-stimulus-responses that as manual/massage therapists we can interact with in a site-specific manner order to give the organism a new engram or encoding to work with?"

(What follows is my reply:)
"I think this is a great question. I have many thoughts on it.

"In no particular order:
1. I think "muscle" is an innocent victim, too often blamed for shenanigans the NS gets up to. As long as it's not frankly diseased, muscle is just being obedient to whatever it's told to do by NS motor output.
2. It makes sense to me that the spinal cord (along with its assorted intrinsic, or more rostral but bidirectional, nuclei) is a "first responder" to nociceptive input. It dangles out there into the "body" with all its array of PNS coming out of it and into it; it's the oldest part of the CNS so it has seniority. The rest of the CNS came along a lot later, with one of *its* big jobs being to inhibit spinal cord reflexive activity.
3. Nociception is a stimulus to the spinal cord which may or may not be processed at more rostral levels of CNS, but for sure, the spinal cord (plus the nuclei it came with) will notice it.
4. The spinal cord operates reflexively. Smooth muscle is contracted by the ANS (cell bodies in lateral horn) and striate muscle is contracted by lower motor neurons (cell bodies in anterior horn). In comes nociceptive input. There are lots of interneurons, glia, all sorts of things in the spinal cord extending many segments. All of them affect each other. They get excited over nociceptive input if not discouraged from doing so by descending inhibition.
5. A nociceptive input doesn't even have to reach the brain before it will be dealt with reflexively by the spinal cord. (E.g., touch a hot stove by accident and the hand jerks away before any sensation arrives to conscious awareness.)
6. Nociception is occurring constantly. But phasically, not tonically. The spinal cord actively deals with it all the time.
7. Our more rostral centres adapt easily to stressful inputs of any kind, as long as they are spaced, and not too intense. This is the way graded exposure works, when it works. The brain gets used to fleeting discomforts, weird positions, gait disturbances, whatever. These are defenses (mounted by the spinal cord, reflexively), not defects of structure (most of the time anyway). (Asymmetric resting positions, combined with external mental focus, are the two biggest contributing behavioural factors to nociceptive input that goes under the radar, IMO)
8. Anyway, spinal cord takes care of business, unless and until some of its striate motor or smooth motor or both at the same time output, pulls some other portion of the 72km/45 miles of peripheral neural array, or any of its connected vasculature, into "mechanical deformation". Then, oops! we have something that could act just like a tunnel syndrome.
9. The literature on tunnel syndromes all says the same thing: the sensory system will be affected first, and pain felt in a region that's neuroanatomically plausible (same as the new description for neuropathic pain) will be the predominant complaint.
10. So, an evolutionarily conserved strategy, reflexive tightening/contraction, deployed by the oldest bossiest part of the CNS, the spinal cord, which doesn't have much more hard drive than when fish invented it in the Devonian period 500 million years ago, which seemed reasonable at the time (if we were still fish maybe), has led to a situation where *more* nociception, stemming from somewhere else, occurs. (Bear in mind that the oldest parts of the NS have been dealing with it this way since the beginning of the NS, and nature never gets rid of anything that works.)
11. But eventually something's gotta give, and descending inhibition doesn't work automatically anymore. Nociception has become so tonic and from so many more afferent nerves, that glia have glee-a-fully arrived to augment the process, and the entire input becomes a positive physiological feedback loop. Central sensitization has tipped the NS into "every movement hurts".
12. If the NS is normal, and if associated vasculature is normal, the possibility exists that the NS can be hacked successfully so it can reboot. But the reboot has to happen from rostral areas, backward. Thank goodness for yes-ciceptive exteroception and fast dorsal columns, that can bypass all the flood waters and cars in the ditch within the dorsal horn, and get some new fresh regional info up to the brain so it can have something novel and pleasant to work with and make new body schema/representations from.
13. Non-specific FX and descending inhibition must be juiced up as much as possible. If the attached human brain knows what's going on, because the person in it has been successfully recruited to the effort and is willing to do their part, hacking such a NS can proceed in a clinically successful manner, i.e., improved ROM and decreased pain on movement. Then movement homework can take care of the physiological details over the next few days until peace prevails in the entire NS.
14. What I find quite fascinating is how little the CNS gives a fig about the "person" who has to ride around inside it, feeling/dealing with all the pain nonsense it can generate. Not entirely sure about this, but it seems to me that the bigger/more connected the brain, the more suffering its conscious awareness may have to endure when pain arises.
15. It pays, big time, to explore all the movement corners of one's own body, well in advance of any pain problem, so one can stave off most of it through simple movement hygiene. Especially, avoiding consistent asymmetric sleeping on one side only or other default resting positions, stances, leg-crossing, bag-carrying, etc., is a good investment of whatever "will power" one may possess, to avoid a world of dumb hurt.

16. Barring some frank disease, or being hit by a truck, simple movement awareness could keep most people, mostly out of pain-treatment offices like mine, most of the time. If everyone practiced Feldenkrais for example, most of us would be out of business."



.....

None of this answered the question, of course... But the question stimulated a bunch of thoughts that had been roiling around in my brain for a long time, and acted like a spigot for me to splash them out onto an existing thread. So, thank you Taylor.

Monday, May 04, 2015

Overkill

This is the title of a very good piece in the NewYorker by Atul Gwande.

Overkill.

It's a perfect complement to the last blogpost, Like a Bridge Over Diagnosis.

Here are a few choice excerpts:


"Bruce’s father had a stroke during the cardiac surgery. “For me, I’m kicking myself,” Bruce now says. “Because I remember who he was before he went into the operating room, and I’m thinking, Why did I green-light an eighty-something-year-old, very diseased man to have a major operation like this? I’m looking in his eyes and they’re like stones. There’s no life in his eyes. There’s no recognition. He’s like the living dead.” .. A week later, Bruce’s father recovered his ability to talk, although much of what he said didn’t make sense. But he had at least survived. “We’re going to put this one in the win column,” Bruce recalls the surgeon saying...“I said, ‘Are you fucking kidding me?’ ”His dad had to move into a nursing home. “He was only half there mentally,” Bruce said. Nine months later, his father died. That is what low-value health care can be like."


"Overtesting has also created a new, unanticipated problem: overdiagnosis. This isn’t misdiagnosis—the erroneous diagnosis of a disease. This is the correct diagnosis of a disease that is never going to bother you in your lifetime. We’ve long assumed that if we screen a healthy population for diseases like cancer or coronary-artery disease, and catch those diseases early, we’ll be able to treat them before they get dangerously advanced, and save lives in large numbers. But it hasn’t turned out that way. For instance, cancer screening with mammography, ultrasound, and blood testing has dramatically increased the detection of breast, thyroid, and prostate cancer during the past quarter century. We’re treating hundreds of thousands more people each year for these diseases than we ever have. Yet only a tiny reduction in death, if any, has resulted."


Atul Gwande; Overkill: An avalanche of unnecessary medical care is harming patients physically and financially. What can we do about it? The New Yorker, May 11 2015






Thursday, April 30, 2015

"Like a bridge over diagnosis"

Or, if you prefer,  Like a Bridge Overdiagnosis. 
Anyway, this link crossed my path, about how verbs of clinical observation are turned into "nouns" of diagnosis, and how this can be a real disservice. 
Why?
Because as soon as an event or a verb or a set of symptoms floating by in awareness are turned into a "noun" that has a "name" it is then regarded by our human brains as a "thing". 
This is called "reification" - treating an abstraction as if it were a real thing. 

Then the instinct to go after that thing, hunt it down and nail it, switches on.  Especially perhaps in the medical world, because of the momentum for preserving "life" by fighting anything that has been labelled a "disease". 

For your listening and viewing pleasure:



A few days ago I blogged about some papers indicating that yes-ciception (or, as I like to call it, social grooming) can trigger growth of new neurons in the spinal cord that inhibit nociception.

I think this is a wonderful start to a vindication of keeping manual therapy (or as I like to call it, human primate social grooming) in our scope. 


I included a video of Martin Hey speaking at a conference about the state of the profession

PT is kind of a mess these days, everywhere, not just in the UK.
Every so often though, I see something that cheers me up again. 


I had not seen Nancy Zimny's paper before, but I like the gist of it.
Nancy J. Zimny; Diagnostic Classification and Orthopaedic Physical Therapy Practice: What We Can Learn from Medicine. J Orthop Sports Phys Ther • Volume 34 • Number 3 • March 2004 (FULL TEXT)

This paper comes even closer to taking Occam's Razor to all the clutter of orthopaedic overdiagnosis.
RenĂ© Pelletier, Johanne Higgins, and Daniel Bourbonnais; Is neuroplasticity in the central nervous system the missing link to our understanding of chronic musculoskeletal disorders? BMC Musculoskelet Disord. 2015; 16: 25.  (FULL TEXT)

Finally, because it is so engaging and brilliant, 
Arnold C; Ants Swarm Like Brains Think. Nautilus April 23 2015

(It's basically a reprint of her article from about a year ago, by the same title: Ants Swarm like Brains Think, April 24 2014 with the idea of positive feedback loops extracted/emphasized, and blogged about here: The ants go marching one by one.)

It seems to me that positive feedback loops operate at societal levels too, maybe even easier than they do at ant levels or neuronal levels. 
Maybe that's why medicine and especially orthopaedic medicine and certainly the app to orthopaedic medicine, known as PT, has succumbed to overdiagnosis. 

Isn't it all long overdue for some social inhibition?





Sunday, April 26, 2015

Yes-ciception inhibits nociception in the spinal cord


At last. 

Finally a paper has come along that provides a bit of solid evidence for gate control theory of pain. It only took 50 years (..for petesake!), so I guess we shouldn't get all downcast over how hard it is to get physiotherapy to change course. (I just hope this doesn't turn into some huge TENS revival..)

But I digress..  
I'm thrilled. My confirmation bias bells are all going pingpingping
Why? because this supports manual intervention/human primate social grooming. 

1. Here is Mo Costandi's piece on the topic (the word "pain" should be replaced by the word "nociception", as usual..) :



2. Here is a link to the actual paper. 


Foster, E., et al. (2015). Targeted Ablation, Silencing, and Activation Establish Glycinergic Dorsal Horn Neurons as Key Components of a Spinal Gate for Pain and Itch. Neuron, 85: 1289-1304 [PDF].
Here is the abstract: 
SUMMARY The gate control theory of pain proposes that inhibitory neurons of the spinal dorsal horn exert critical control over the relay of nociceptive signals to higher brain areas. Here we investigated how the glycinergic subpopulation of these neurons contributes to modality-specific pain and itch processing. We generated a GlyT2::Cre transgenic mouse line suitable for virus-mediated retrograde tracing studies and for spatially precise ablation, silencing, and activation of glycinergic neurons. We found that these neurons receive sensory input mainly from myelinated primary sensory neurons and that their local toxin-mediated ablation or silencing induces localized mechanical, heat, and cold hyperalgesia; spontaneous flinching behavior; and excessive licking and biting directed toward the corresponding skin territory. Conversely, local pharmacogenetic activation of the same neurons alleviated neuropathic hyperalgesia and chloroquine- and histamine-induced itch. These results establish glycinergic neurons of the spinal dorsal horn as key elements of an inhibitory pain and itch control circuit.
My bold.


3. Here is a link to the original gate control theory of pain paper. 
Melzack, P. & Wall, P. D. (1965). Pain Mechanisms: A New Theory.Science150: 971-979 [PDF].

.....................
MORE:  Here is a link to a great great set of very short and wonderful videos of David Krakauer discussing intelligence, genius, whether or not stupidity is the opposite of intelligence (spoiler alert - it's not..) and all sorts of things. It's great. I can't recommend it highly enough. 


"...what genius does is it just changes the rules of the game. It doesn’t just make it better, or easier, or more efficient. And one of the very interesting characteristics of genius, as opposed to intelligence, is it looks a little crazy. Because an intelligent solution is almost always—and I gave some examples of stupidity—clear to most people that that is a better way of doing things. Yes, that is a better way of doing things. But when you change the rules, you make a lot of people uncomfortable, and it looks a little crazy. So in some sense, my diagnostic, my litmus test for genius as opposed to extreme intelligence is it made everything simpler, but the people, when they first saw it thought it was lunatic; because formally, it’s changing the basis set. It’s just changing the nature of the representation of the problem so completely that you get the kind of vertigo of unfamiliarity. So that for me would be genius."

My bold. There is no way to classify Melzack and Wall's work other than they are genius and so was/is their work. They pushed back the boundaries of pain research. They changed the rules. There was pushback - bitter pushback. Even nowadays Melzack remarks on what a surprise that pushback was, in some ways, and shakes his head. 
I bet he feels vindicated, a bit at least, by this new paper.
............

MORE:  I just today spotted a video of Martin Hey, head of the WCPT pain network, presenting an overview of pain physiotherapy in the UK. It's about 40 minutes long, was filmed in Seville in October last year and a Pain and Physiotherapy conference, and uploaded to Youtube in December 2014. 
It's very good. 
Hey describes most aspects of the mess PT is in, without actually calling it such..




Martin Hey of WCPT's Pain Network
...........
EDIT:


YET MORE (courtesy of Fred Wellens):   

Shechter RBaruch KSchwartz MRolls A.;  Touch gives new life: mechanosensation modulates spinal cord adult neurogenesisMol Psychiatry. 2011 Mar;16(3):342-52

ABSTRACT:

"The ability to respond to a wide range of novel touch sensations and to habituate upon repeated exposures is fundamental for effective sensation. In this study we identified adult spinal cord neurogenesis as a potential novel player in the mechanism of tactile sensation. We demonstrate that a single exposure to a novel mechanosensory stimulus induced immediate proliferation of progenitor cells in the spinal dorsal horn, whereas repeated exposures to the same stimulus induced neuronal differentiation and survival. Most of the newly formed neurons differentiated toward a GABAergic fate. This touch-induced neurogenesis reflected the novelty of the stimuli, its diversity, as well as stimulus duration. Introducing adult neurogenesis as a potential mechanism of response to a novel stimulus and for habituation to repeated sensory exposures opens up potential new directions in treating hypersensitivity, pain and other mechanosensory disorders."


.

Thursday, April 23, 2015

Dear Motor Vehicle Insurer, I want a divorce

Yeah... I know, I should never have led you on.. I should never have hooked up with you in the first place. I had divorced all the other ones I was ever hooked up to, a decade ago, and was living happily ever after.
Then, you came calling, and at first I said no, but then I thought, what the heck, making myself available to see clients of yours who are traumatized after being in an MVA and needing help getting over the emotional and physical shock of it all and pain problems resulting.. heck, I've been there and I know how it feels..
And you were all accommodating of me at first - I was clear about my boundaries and described how I work - one patient at a time, an hour of treatment, no programs, no testing apart from range of movement recording, no questionnaires.. just interacting verbally and non-verbally with another human nervous system, giving it a chance in a quiet space to develop a different way of handling physiological regulation and reducing its own pain output, after having shared some information about the nervous system and what it needs and wants and likes.
You said yes. You even said I could bill and be paid for an hour at the going rate.

Time passed, and we grew used to each other. I didn't see clients of yours very often, but the ones I did got better in a timely way and you seemed happy with my work and paid me well for it.
Things seemed to be working out.

Until now.

One of your agents contacted me. Let's call her Stacy. That is not her real name, but I wanted to use a name that would evoke all the qualities of an alpha female who works out hard at the gym and is upwardly mobile and authoritative, who has that chirpy, energetic, extraverted no-nonsense sort of voice. So I'll call her Stacy.

Stacy wanted to know what was going on with Lucy. OK, here's the backstory on Lucy (also not her real name, but I wanted to pick a name that evoked the sort of quiet honest thoughtful earnest individual Lucy is). She's a grade 1 teacher.
She was walking (in a crosswalk for petesake) in December (cold, snowy, but in daylight) meeting friends for lunch. In the crosswalk she was struck by a truck. Yup, a pedestrian minding her own business, hit by a truck. Fortunately the truck stopped in time. Lucy remembers being struck on her right side, holding out her right arm to try to stop the truck, and yelling at the driver. There was physical contact of Lucy by the truck.
The driver got out and apologized.
Lucy proceeded to have lunch with her friends, a few of whom were nurses. They were concerned for her. She filed a claim. The claim covered her. The adjustor assigned to Lucy was nice. Let's call her Julie. (That's not her real name, but I want to call her something that evoked boundaried and professional but still friendly concern and caring.)
Julie told Lucy that the Insurance Company would keep her file open for 6 months, which sounds reasonable...

Lucy came to see me shortly after her injury with arm and neck pain. She had low back pain too which she had had for a long time and got massage for.
I treated her and we made a followup appointment. She was leaving the province to visit family for holidays, and wouldn't be back until the new year. I saw her again in the new year. She was 80% better, she said. I worked with her again, and said, come back if there is anything more I can help you with.

Time passed, she did not make any more appointments.
About a week ago, Stacy called me about Lucy. Stacy wanted to close the file, which had been given over to her when Julie took another spot in the company. Where Julie had been people-smart, Stacy was all corporate, this-is-the-way-we-do-things smart. She wanted that file closed and she wanted a discharge note, now.
I replied, well, I want to call Lucy first and just make sure everything is OK with her.
I called Lucy and Lucy said, I feel better, but yes, I would like to make an appointment (about the low back stuff, as it turned out..).

I told Stacy that Lucy had made another appointment and that I would hold off on the discharge note until after I'd seen her. Stacy said, OK, we'll pay you for that visit but then I'm closing her file for non-compliance. I asked what non-compliance are you referring to? Stacy said, people go into programs. Lucy hasn't been in any program so she's non-compliant with treatment. I said, I don't put people in "programs" - you should be glad I save you all that money by not treating people unnecessarily. Stacy said, no, people have to be in programs or we don't cover them. I said, what about what Julie said about leaving the file open for 6 months? Stacy said, no, we don't do that. People go into programs and when they are finished the program we close their file. We never keep files open just in case. We don't work that way. We're an insurance company. Julie was new and made a mistake.

Oh. I see. I said.

Then why (I asked) did you say you would pay me for that final visit Lucy made and that you wanted a discharge note, but then you closed her file anyway, and when I submitted request for payment I couldn't access the e-pay system? I do have a billing number..
Stacy said, you do? What is it? I gave it to her. She said oh, it's under your name and not your clinic's name? I said yes, it was a small practice, not a corporation, and I and Sensible Solutions Physiotherapy were the same. She found that very odd. I could hear her brain filing this new information under That-is-not-how-we-do-things-here.
I was getting increasingly angry; Stacy could hear it in my voice, so she accused me of being rude. I wasn't rude, I was angry. Those are two completely different things, but she had decided I was rude, and tried to change the conversation to it being about that, instead of about the client and the situation.
So I told her I wanted my name removed as a "partner" of the company. She said I'd have to contact Kathy (not her real name) to do that. I said fine. And hung up.

Then I called Lucy, and asked her if she wanted copies of anything in case she wished to pursue the company further, but she declined.. she was willing to let go of the whole ordeal with the change of adjustors and all the drama. Plus, she felt fine now, including her low back which had plagued her for a long time, since way before the MVA.

I said, it looks like I won't be paid for that last visit, but it's OK, because I'm just glad to not be their "partner" and having them shove me around and shove you around and not let me have my preferred style of interaction with their clients which is more 'catch and release' - instead they seem to think I need to have you come in three times a week for useless treatment and waste all kinds of money on that and have you be treated unnecessarily and me be bored trying to treat you even when you don't need it as if the "program" were the most important thing in the world instead of your sense of wellbeing back out in the world not needing to be a "patient" of mine... I'll take the bite for the treatment you had that they won't pay for because it wasn't your fault.

Then Lucy said, no, I'll pay you for that last visit.. I can send the receipt into my work insurance - they cover PT. If my workplace didn't have good insurance I might be more willing to fight the Motor Vehicle Insurance company, but really, I just want it to be over.

Fair enough Lucy, fair enough. And thank you for being you. And Stacy, go perch on a pivot. And MV Insurance company, I divorce you as of today. Our little adventure together is over.


UPDATE: April 27
I just got off the phone with an official smoother-outer person from the insurance company who called, left a message, asked me to contact her, please (!), and begged me to return, expressed how much the company doesn't want to lose any PT partners out in the hinterland, wanted to hear the whole story. Sort of the relationship counsellor from the company side. Nice woman..
We talked. She listened more than talked. She asked me to return if I could possibly see my way clear to do so.
I agreed to be reinstated. As long as I don't have to deal with the Stacy's of the world. (Actually, I should have given her the name Rocksy.) I was told that Stacy would be chatted to/with as well.
So, the marriage is back on, insurance company.  It's all good, for now at least.

Thursday, April 09, 2015

Five papers that seem to all go together

Lately I've seen or have been sent one paper after another that chase each other around in my head, so I'm going to put them all in here, for later digestion. 

1. A very interesting paper that supports the idea that the brain does its own thing, mostly, and uses up a large amount of energy to do so. There is a section in there pointing out how very little sensory information actually reaches the brain. I saw a video a long time ago that spelled this out for vision, but alas I couldn't find it again. Something like only 2% of raw sensory input ever makes it in there to be processed. Shocking, I know. Such an illusion we enjoy, that we are perfectly aware of everything around us all the time. Our brain makes us believe that even while it burns up large amounts of fuel doing its own thing. 

Raichle ME; The restless brain: how intrinsic activity organizes brain function. Philosophical Transactions B 
30 March 2015 (FULL TEXT)


ABSTRACT: Traditionally studies of brain function have focused on task-evoked responses. By their very nature such experiments tacitly encourage a reflexive view of brain function. While such an approach has been remarkably productive at all levels of neuroscience, it ignores the alternative possibility that brain functions are mainly intrinsic and ongoing, involving information processing for interpreting, responding to and predicting environmental demands. I suggest that the latter view best captures the essence of brain function, a position that accords well with the allocation of the brain's energy resources, its limited access to sensory information and a dynamic, intrinsic functional organization. The nature of this intrinsic activity, which exhibits a surprising level of organization with dimensions of both space and time, is revealed in the ongoing activity of the brain and its metabolism. As we look to the future, understanding the nature of this intrinsic activity will require integrating knowledge from cognitive and systems neuroscience with cellular and molecular neuroscience where ion channels, receptors, components of signal transduction and metabolic pathways are all in a constant state of flux. The reward for doing so will be a much better understanding of human behaviour in health and disease.


2.  Abstract only, I'm afraid.. but great paper. It explains, among much else, why octopuses and other very brainy non-vertebrates never made it to the moon while we did. 


"There are two major groups on Earth that have highly developed sensory systems and large brains: the chordates and the cephalopods. Part of the Mollusc phylum, the cephalopods (the nautilus, squid, octopus, and cuttlefish) have never evolved myelin. In addition, they use hemocyanin, which has one-quarter of the oxygen-carrying capacity of hemoglobin. These two factors, the lack of myelinated axons and hemoglobin, hindered the evolution of the cephalopod nervous system, while the descendants of the jawed fish landed on the Moon."

OrĂ³ JJ. Evolution of the brain: from behavior to consciousness in 3.4 billion years. Neurosurgery. 2004 Jun;54(6):1287-96 (ABSTRACT ONLY)


ABSTRACT: Once life began as single-cell organisms, evolution favored those able to seek nutrients and avoid risks. Receptors sensed the environment, memory traces were laid, and adaptive responses were made. Environmental stress, at times as dramatic as the collision of an asteroid, resulted in extinctions that favored small predators with dorsal nerve cords and cranially positioned brains. Myelination, and later thermoregulation, led to increasingly efficient neural processing. As somatosensory, visual, and auditory input increased, a neocortex developed containing both sensory and motor neural maps. Hominids, with their free hands, pushed cortical development further and began to make simple stone tools. Tools and increasing cognition allowed procurement of a richer diet that led to a smaller gut, thus freeing more energy for brain expansion. Multimodal association areas, initially developed for processing incoming sensory information, blossomed and began to provide the organism with an awareness of self and environment. Advancements in memory storage and retrieval gave the organism a sense of continuity through time. This developing consciousness eventually left visible traces, which today are dramatically evident on cave walls in France and Spain. We will take this journey from the single cell to human consciousness.

3.  All about the formation of the nervous system. I LOVE this paper. Why? because it tracks how everything started and how it's all still in there.  Plus I love the "skin/brain thesis" for all my usual biased reasons. Plus it is congruent with all the work Seth Grant has done on protenomics, the proteins that are found at brain synapses, the complexity of them in humans but especially the point he makes about how the ones that work are highly conserved, even from membrane pores of single-cell organisms (like yeast for petesake.. ! Yes, some of our brain synaptic proteins are same as those yeast invented!)

Fred Keijzer; Moving and sensing without input and output: early nervous systems and the origins of the animal sensorimotor organization. Biology & Philosophy 10.1007/s10539-015-9483-1 - FULL TEXT



ABSTRACT: It remains a standing problem how and why the first nervous systems evolved. Molecular and genomic information is now rapidly accumulating but the macroscopic organization and functioning of early nervous systems remains unclear. To explore potential evolutionary options, a coordination centered view is discussed that diverges from a standard input–output view on early nervous systems. The scenario involved, the skin brain thesis (SBT), stresses the need to coordinate muscle-based motility at a very early stage. This paper addresses how this scenario with its focus on coordination also deals with sensory aspects. It will be argued that the neural structure required to coordinate extensive sheets of contractile tissue for motility provides the starting point for a new multicellular organized form of sensing. Moving a body by muscle contraction provides the basis for a multicellular organization that is sensitive to external surface structure at the scale of the animal body. Instead of thinking about early nervous systems as being connected to the environment merely through input and output, the implication developed here is that early nervous systems provide the foundation for a highly specific animal sensorimotor organization in which neural activity directly reflects bodily and environmental spatiotemporal structure. While the SBT diverges from the input–output view, it is closely linked to and supported by ongoing work on embodied approaches to intelligence to which it adds a new interpretation of animal embodiment and sensorimotor organization.


4. Massive amount of information about the skin and all the neurology therein. I have not yet even begun to absorb everything this paper offers. It's likely of interest to dermatologists, mainly, but hey, there is plenty in there to learn about the neurology in/of skin.


Dirk Roosterman , Tobias Goerge , Stefan W. Schneider , Nigel W. Bunnett , Martin Steinhoff;  Neuronal Control of Skin Function: The Skin as a Neuroimmunoendocrine Organ. Physiological Reviews October 1, 2006 Vol. 86 no. 4, 1309-1379 FULL TEXT



ABSTRACT: This review focuses on the role of the peripheral nervous system in cutaneous biology and disease. During the last few years, a modern concept of an interactive network between cutaneous nerves, the neuroendocrine axis, and the immune system has been established. We learned that neurocutaneous interactions influence a variety of physiological and pathophysiological functions, including cell growth, immunity, inflammation, pruritus, and wound healing. This interaction is mediated by primary afferent as well as autonomic nerves, which release neuromediators and activate specific receptors on many target cells in the skin. A dense network of sensory nerves releases neuropeptides, thereby modulating inflammation, cell growth, and the immune responses in the skin. Neurotrophic factors, in addition to regulating nerve growth, participate in many properties of skin function. The skin expresses a variety of neurohormone receptors coupled to heterotrimeric G proteins that are tightly involved in skin homeostasis and inflammation. This neurohormone-receptor interaction is modulated by endopeptidases, which are able to terminate neuropeptide-induced inflammatory or immune responses. Neuronal proteinase-activated receptors or transient receptor potential ion channels are recently described receptors that may have been important in regulating neurogenic inflammation, pain, and pruritus. Together, a close multidirectional interaction between neuromediators, high-affinity receptors, and regulatory proteases is critically involved to maintain tissue integrity and regulate inflammatory responses in the skin. A deeper understanding of cutaneous neuroimmunoendocrinology may help to develop new strategies for the treatment of several skin diseases.



5. Lastly but far from leastly, a recent paper that makes sense of physical contact, providing the PT world with a good reason to retain manual therapy in our profession. Just in case there was ever any danger of it being discarded. Which I hear rumours about from time to time. Also with a path into new avenues of research into what we can do with people, and how we might get the attention of their marvelous, massive, evolved, nervous systems whose parts have been jealously conserved since they evolved and are still all in there, mostly getting along but sometimes not, sometimes one bit creating problems for some other bit, and how we try to help all those bits all get along together better again. Izabela Panek , Tuan Bui, Asher T.B. Wright, and Robert M. Brownstone;  Cutaneous afferent regulation of motor function. Acta Neurobiol Exp 2014, 74: 158–171 FULL TEXT


ABSTRACT: Motor systems must be responsive to the environment in which the organism moves. Accordingly, there are many sensory systems that affect intrinsic motor programs. In this mini review, we will discuss the effects that inputs from cutaneous low-threshold mechanoreceptors have on motor function, focusing on locomotion and hand grasp. A mathematical analysis of grip strength is provided to quantify the regulation of the forces required in maintaining the grip of a moving object. These two behaviours were selected because the neural control of locomotion has been primarily studied for hind-limbs in cats and rodents, whereas hand grasp has been primarily studied in fore-limbs in human and non-human primates. When taken together, insight can be gleaned on the cutaneous regulation of movement as well as the role these afferents may play in mediating functional recovery following injury. We conclude that low-threshold mechanoreceptors are critical for normal motor function and for inducing plasticity in motor microcircuits following injury





Tuesday, March 24, 2015

How I cut myself some slack and fixed my TMJ syndrome

When I say I cut myself some slack, I don't mean I pushed aside all care and responsibility and went on a holiday or anything like that. I mean, I cut myself some physical slack.

Let me digress for a moment. 

Life catches up to you in odd little ways. I'm in my mid-sixties now, and my relationship to physical exercise has always been on-again off again. The longest relationship with physical exercise I ever had was in my early twenties, when I practiced yoga every single day for two years solid. I never have regretted putting the time and effort in, and I never have regretted abandoning it and getting interested in other things. Both. At the same exact time. (Yes, I'm a walking contradiction.)

Anyway, I've become a lot more sedentary in the last 5 years or so. Moving back to a place where there is a lot more snow, and where sidewalks are never fully cleared, cured me of a tendency toward compulsive walking. That, plus being online a lot of the time.

Anyway, a month or two ago I was surprised when I felt/heard my TMJ pop, loudly, in my ear, on the left. There was a bit of pain, nothing much, lots of grinding and crunching.
I did all sorts of DNM and movement and even some taping, but no matter, it still popped, snapped, cracked and crunched like some new kind of kid-friendly cereal ad.

One night recently in a fit of insomnia I got up at 3:30 am and stood in bare feet in the kitchen and did some yoga. Just one thing. Complete forward and complete backward bending, three times each way.

I'm happy to report not only was the jaw thing mostly gone by the next day, but a bunch of other naggy wee bits and pieces also disappeared - little things I didn't even realize I had until I did the yoga move. How do I know they went away too? Because this morning I repeated the process, and did not feel them anymore. So, yay about that I guess.

What is the trick? I think taking my 72 kilometers of folded and branched and three dimensional neural tree for a good ride, first one way, then the other, likely got rid of a bunch of accumulated neural tension and mechanical deformation, gave it a chance to mop itself up really well.

You don't have to do much physical exercise to deal with physical discomforts and keep them at bay, but you do have to do a bare minimum. What is the bare minimum? That's for each human to decide for him/herself.

Here is how I do forward and backward bend.
1. Bare feet, firm floor (no carpet). Organize body weight as exactly as possible over the fronts and heels of two feet. Sounds easy, but it can be a real trick. So, even weight as if on four table legs. Keep the imaginary table (i.e., yourself) level. The entire time. Harder than it sounds.
2. Breathe. Slowly. Completely in and completely out. From the pubic bone. Maintain throughout. Again, harder than it sounds.
3. Find the anti-gravity suit and deploy it. This means, grow up toward the ceiling. As soon as you even think that, you will feel your abs kick in, your spine lengthen, your breast bone start to lift, and your neck lengthen. Enjoy the feeling and keep that feeling going for a few breaths. It's a verb, not a noun. When you can't grow up any taller, stay tall as you managed to become, breathe in and out a few times up there, then slowly let yourself shorten again.
4. Now it's time to start the forward bend. Let your head be like a tulip head. Let the neck bones move one by one. Let gravity have your head, but hugely control the descent. Let your arms and shoulder girdle be limp as over-cooked spaghetti. Their angles will change as you descend. Feel how delicious it feels to feel your shoulder blades slide all by themselves over your ribcage. Knees straight, and soft, at the same time. Go as slow as you possibly can while noticing as much as you possibly can about how it all FEELS. If you can, once you've set the agenda, and the very slow speed, let the critter brain do all the rest. Let the critter brain manage the relationship to gravity and angles and descent, and all you have to do is focus on the breathing and making sure the pressure is even through all four contact places of your feet. If you're doing this slow enough for it to do any good, it should take a good three or more minutes to get all the way over. No, I'm not kidding you.
5. Let gravity have all of you it wants. Hang there. Breathe in, and then out. Pause after an exhale. Wait until you crave oxygen before inhaling. You are regaining locus of control over autonomic bits of your nervous system. You are taking charge. You are giving it all the oxygen it could ever want, but you are setting the pace and making it ask first. You are reminding it that you live in that brain too. You are playing frisbee with your inner dog beast. You are giving it your full attention. 

6. When you have dangled for awhile, focused, breathing, feet square, and have stopped noticing any lengthening of your upper body, it's time to come back home. Begin your ascent. Go up just as slowly as you went down. This is a huge project, so notice as much about how it FEELS as you possibly can. Keep the feet square, even weight, maintain the frisbee game of breathing with your inner dog beast/critter brain (inhale -> send the frisbee out, exhale -> the dog brings it back, make the dog wait until you're ready to throw again..). Feel all the fibres figuring out how to lift up half your body weight. Feel the wonderful orchestration as they all cooperate to do this amazing feat. Go very very slowly. It will feel good, not uncomfortable. All sorts of images will pass through the mind as you rise up. A recurring one that goes through mine: a fisherman, carefully hauling up a huge net full of fish, using the side of the boat as a fulcrum, careful to winch slowly so he doesn't catch the net and rip it on anything. Another - a huge crane lifting up over tall rooftops, slowly. All sorts of gears making the mechanics of it be all spread out, long ropes/big pulleys inside making the work be pretty much effortless for any one structure. 
7. Once you're back up on top of yourself, another slow grow up toward the ceiling. You might feel taller this time. Then shorten back into gravity. Time to descend backward.
8. Neck softens, but this time let the tulip head travel back. Let the tulip stem fold back as much like a real tulip stem as you can manage. It's ok to pause at intervals to let more slack cut itself. You are not going to fall over backwards. Your critter brain will do everything it can to not ever let that happen. You are giving it a problem to solve, and its favourite thing in the world to do is combat gravity. It's a human anti-gravity suit, after all. (When I did this, for the first time in decades, probably, in the middle of the night, the first thing I felt was how tight the front of my neck felt, like it was covered all over on the inside with coach tape or something. Then I could feel how tight my abs were, right at the ribcage. I noted everything, but didn't worry about it in the slightest, because I knew my critter brain would be capable of dealing with it, if not right then, later on. It's not about anatomy, it's about physiology.) Go as far as you can. Stay there. Breathe fully in and fully out as ever. Your abs might stutter and shudder a bit. Don't worry about it. Retain control of the direction, the speed, the breathing, the weightbearing. Let the inner dog beast worry about sorting out all the rest, over the next 24 hours.
9. This one is more tiring than forward bending. You likely won't last as long because it feels like way more work. Stay there as long as you can anyway. Then start back up again.

10. Repeat the whole beeswax, times 3. If you're doing it right, i.e., going slow enough, the entire sequence will take about 15-20 minutes. On the second round you'll find yourself able to go further. The third round won't add much more information, but it seems like a third round helps lock in whatever you learned from the first and second round. So, three times is the magic number. Any more than three times is a waste of time in my opinion.

Once you've practiced a few days you'll become way more adept and bendy, and it won't take as long anymore.

What I noticed repeating the entire process a few days later was that the coach tape was gone from inside the front of the neck and the abs lengthened out the way they should, and the shuddering was gone. I succeeded in cutting myself some physical slack. The critter brain had reestablished its own motor control. Good, because motor control is its job, not mine.


Friday, March 06, 2015

Pain and stress in a systems perspective

Today Ian Stevens sent me a link to an old paper (old by publishing metrics) from 2008, Pain and stress in a system's perspective. It's open access and a joy to read, the way it describes the connectivity of systems within a multi-cellular organism such as ourselves.

I bring it forth, not just because it's a great paper, but also because I want to draw attention (yes, again...) to the point that astroglia are not immune cells. 


The paper has this to say about glial cells:
"Microglia, oligodendrocytes and astrocytes reside within the CNS and contribute to inflammation and peripheral injury-induced pain, including the spread of pain. Microglia are immune cells closely related to macrophages that express the same surface markers. Injury and other events that threaten homeostasis activate microglia. These immune cells contribute to hyperalgesia and alloydynia by releasing pro-inflammatory cytokines and chemokines, and they are probably involved in several neuropathic pain conditions. 
"The astrocyte, a non-migratory subtype of glial cell, diversely supports CNS function. Through its direct contact with blood capillary networks, it provides vasomodulation of localized blood flow, metabolic support (e.g., glucose delivery), and control of the blood brain barrier function on micro and macro levels. Subpopulations of astrocytes surround neurons and their synaptic connections, thereby influencing pre-synaptic neurotransmitter release through modulation of synaptic cleft calcium concentration and membrane polarization. In controlling local environments, they functionally organize regional synaptic connections. In addition, they provide the important function of neurotransmitter uptake, thus protecting against glutamate neurotoxicity, which is implicated in several central pathological states."
As you can see, the paper explicitly points out that microglia are immune cells, which is correct, but unfortunately it isn't QUITE as explicit about pointing out that astroglia are non-neuronal neural cells. It doesn't however, SAY that astroglia are immune cells. Which gives me a feeling of relief.
I regret to say that at the moment there is a line of confusion moving along that has astrocytes conflated with immune cells.
Yes, they have certain immune capabilities, but it seems to me, that along with other kinds of macroglia (microglia excluded) their MAIN job is to keep neurons protected from direct contact with blood, even as they extract glucose and oxygen to supply to neurons, which (greedy little hogs that they are) require a vastly disproportionate amount of same in order to function, collectively, as the nervous system. Two percent of the body, using up 20% of its fuel.

At the San Diego Pain Summit, I heard Lorimer Moseley refer to glia as immune cells.
(Erk.) 
I'm still a fan girl, but I wish he and the others would stop conflating all glia as being immune cells. 

There is a vast difference based on embryologic origin that is easily discernible, and learnable from the most easily accessible source by googling.
"Most glia are derived from ectodermal tissue of the developing embryo, in particular the neural tube and crest. The exception is microglia, which are derived from hemopoietic stem cells. In the adult, microglia are largely a self-renewing population and are distinct from macrophages and monocytes, which infiltrate the injured and diseased CNS.
"In the central nervous system, glia develop from the ventricular zone of the neural tube. These glia include the oligodendrocytes, ependymal cells, and astrocytes. In the peripheral nervous system, glia derive from the neural crest. These PNS glia include Schwann cells in nerves and satellite glial cells in ganglia." Wikipedia 
From: thebrain.mcgill.ca
Understanding embryonic origins of cells helps place them in a developmental tree of most primitive to most recent. I'm pretty sure that a clear understanding of primitive <-> recent helps one understand better how things work together as nested systems in a multicell organism like us, with so many different cell types, all requiring differing levels of fuel, the most outrageous example of which is the nervous system's greedy-pants need for such an overwhelmingly large proportion of whatever O2 and glucose happens to be available 24/7.



1. Chapman CR, Tuckett RP, Song CW;  Pain and stress in a system's perspective: reciprocal neural, endocrine and immune interactions. J. Pain 2008 Feb; 9(2): 122-145 (Open access)


March 15/2015 UPDATE:

After writing this blogpost, a long twitter conversation ensued. I did not buckle. I stand by my opinion: to call astrocytes "immune cells" is categorically incorrect. 

Among all sorts of other deflective offerings, it was declared that using Wikipedia as a reference is wrong because it has errors.
In response to that, I now have a perhaps better reference, that may elicit more respect, full text:

Kessaris N, Pringle N, Richardson WD;  Specification of CNS glia from neural stem cells in the embryonic neuroepithelium.  Philos Trans R Soc Lond B Biol Sci. 2008 Jan 12;363(1489):71-85.
"The nervous system is composed of neurons and glial cells. Glial cells in the central nervous system (CNS) include both the ‘macroglia’, which are derived from the neural tube, and the ‘microglia’, which are derived from haemopoietic precursors. Microglia are the resident macrophages of the CNS and play a key role in immune surveillance and defence." 

Macrophages are immune cells, very primitive, that can move autonomously, are attracted to chemogradients, and will eat up dead things, or any else that moves that they can sense and move toward and ingest. Scavengers. Sea-gulls of the body. Or fly larvae. Yes, the ecosystem of the physical body needs those.

Other glia, macroglia, including astrocytes, are brain cells. OK? Do we really have to argue anymore about this? Astrocytes = brain cells. I.e., NOT immune cells.

Haemopoietic stem cells come from bone marrow and before that, from embryonic support tissue. I.e., not ectoderm/ brain cells.  Immune cells = blood cells. I.e., Microglia = NOT brain cells. Is everyone clear on this? 
Screenshot March 15/2015

One of the biggest jobs glia in both brain and body have is to keep blood AWAY from neurons, by wrapping them, protecting the sensitive little things AWAY fom all the caustic chemical barrage blood has to offer. It's called maintaining the blood/brain or blood/nerve barrier. Not that it doesn't fail sometimes. Not that it's perfect. But it evolved, it's there, and works fairly well most of the time, in most people.
By the same token would it not make sense that astro and other macroglia keep microglia, etc., from sensing/being attracted toward neurons? How could a system evolve that had microglia being attracted to and chomping down on neurons? Wouldn't a creature like that would be selected against, not develop much in the way of brain?
Not that we aren't all gonna die some day anyway, through systems failure. Not that a lot of us won't go down with one kind of dementia or another, or have pain of one sort or another, maybe a kind created by systems failure of a glial sort, even.
No argument from me about that.

But I will go to my grave (earlier than I should have to maybe, because of all the twitter protestation) stating that this sentence is incorrect.