Breakthrough Research: CSF Flow Impacts Peripheral Nerves! | Podcast Ep. 457

Hello and welcome to the Evidence Based Chiropractor. I am your host, Dr. Jeff Lengmaid. On today's episode we are talking research. A brand new study that is all around cerebrospinal fluid and how it smashes the long held belief of the hard difference between the central nervous system and the peripheral nervous system. This, this showcases how that CSF fluid extends to the peripheral nerves and really unifies our entire nervous system. We're gonna dive into this and much more on today's episode. Before we get started, I'll say a few words about Jane. Jane is proud to bring today's episode to you. They're also my favorite emr. Jane has designed a user friendly online booking system to give your patients the freedom to book their appointments at their own convenience. Even if it's after hours or on weekends. Patients can manage their appointments, fill out intake forms, enable remind all saving you time and as a listener to this podcast, we're actually going to hook you up. Get a one month grace period using the code EBC1MO. Click the link down below to connect with their team and see how Jane can help you run your practice more efficiently. But as I said at the top and I'm going to drop a link down to this paper as well down in the show notes. Paper we're going to highlight today is titled Cerebrospinal fluid flow extends to peripheral nerves, Further unifying the nervous system. And I'm going to put myself out there and say this study is going to be one of those that we look back on many years down the road that sort of fundamentally moved our understanding forward. Why? Because we've traditionally felt as though there's relative hard lines between the CNS central nervous system and PNS peripheral nervous system. However, this study showcases some really, really important things for all healthcare providers. I'm gonna say specifically chiropractors. We'll get into that towards the end. But it all starts with our fundamental understanding. What is csf? Well, CSF is produced in the ventricles of the brain. And what does it do? Well, it kind of bathes those tissues of the central nervous system via a low pressure flow. The CSF is continuously produced. If you would have asked me before, and I'll ask you right now, how much is produced per day? I had no idea. The answer is about a half liter per day in humans of CSF is produced, it's continuously produced and it provides a few different things. Physical cushioning and this we see with stenosis. I could picture this in my mind looking at MRIs right now. So it provides the physical cushioning around the spinal cord, it provides nutrients and, and it also removes waste. Important component that I had forgot about. So what does the CSF really do? Well, it's critical for maintaining homeostasis within the nervous system. Homeostasis, that age old word within chiropractic and within life and health quite often probably gets overlooked a lot in today's world. So it is critical for that maintenance. And outside of the ventricular system, the CSF is contained, as we all know as chiropractors, in that subarachnoid space of the brain and spinal cord. And it creates a space between the two meningeal layers, the pia and the arachnoid mater. The outermost layer, the dura, contains the venous sinuses and lymphatics, functioning as basically like immune surveillance, as they say in the study. And interestingly, peripheral nerves, interestingly I'm a little bit of almost a pun there, but interestingly, peripheral nerves have a similar connective tissue compartment build, so to speak, that's contiguous with the CNS meninges at what they refer to as the peripheral root attachment zones, the RAZ root attachment zones. This is going to come up really, really important later on. So the epineurium, which is really similar to the dura bundles, these nerves, fascicles, each of which are enclosed by a perineurium very similar to the arachnoid mater. This enclosed region contains the endoneurium, loose connective tissue space, and it's basically filled with a fluid similar in composition to cerebrospinal fluid. The endoneurium contains bundled axons in a fluid filled space and ultimately creates a really, really nice environment for nerve function. Now the origin of the endoneurial fluid is debated. Separate topic for a separate day. But that is really, it's a heavy lift at the beginning of this episode with a lot of technical terms. But the bottom line is that is to showcase to you the basic anatomy. We know that the CSF flows in, through and around the central nervous system. We know it delivers nutrients, it provides cushion, it also can eliminate waste. So then we move on to the peripheral nervous system and, and basically a lot of the same infrastructure applies in the peripheral nervous system and the point at which they meet, I'm simplifying it a little bit here, but the point at which they meet could be deemed the peripheral root attachment zones. Root attachment zones. So in this study, what were they looking at? Well, they were looking to watch the CSF Flow from the sites of production in the central nervous system all the way to peripheral nerves. This was done in mice. So that's what they were doing and why they were doing it. Now we know as chiropractors, specifically related to what I like to call compressive pathology, the csf, and more importantly, the buffer it provides between the spinal cord and the bone, disc and ligament, so to speak, of the segment of the vertebral segment, really critically important. And when we see that smashed up, that provides what? Well, compression, right? Anytime you see no space left or compression or decreased space of, let's say less than 10 millimeters in the central canal, you're gonna say, hey, that's spinal stenosis. If it's a little off center from that, you're gonna call that lateral recess stenosis. If it's all the way in the foramina, we're gonna call that foraminal stenosis, as we all know. So understanding that the space the CSF creates for us, compressive pathology wise, critically important from a nerve function perspective, the waste elimination and the nutrient delivery are absolutely critical. And these live in small, small spaces. Again, we are talking millimeters to tenths of millimeters that become super meaningful. We are talking tight spaces that are built really well when things are working appropriately and can cause a lot of issues really fast when there starts to be changes. And that is why it is so critically important for us as these healthcare providers, movement based healthcare providers in our patients lives, they don't need to understand every intricacy that we do. That's what our job is, that's what we're paid for. But our job also is to translate that information into meaningful action for the patient. So it can't just be technical jargon. I just went through a lot of technical jargon. But it can't just be that for your patients. It has to be, how do you put that into actionable information so that they can understand one, if they're in to see you, what's going on? Two, is there opportunity to improve or not? That's a real question. And three, how do you get there? What's the best plan of action? So those are really the important components. And again, when we're talking about millimeters, tens of millimeters, and this stuff matters real quick, you can go from totally normal to a lot of dysfunction really, really quickly. And we know that over the past 10, 20 years, interest in the CSF flow has really skyrocketed and there's a lot of unknown, previously, I should say unknown roles for The CSF in our overall health and homeostasis of the central nervous system tissues. So the nervous. Our nervous system, of course, lacks traditional lymphatics. Right. So that's important to keep in mind. And there's a restriction of free movement of molecules throughout the CSF whenever there's compression. Now, there's also that physical cushioning component Delivering nutrients and removing waste, all really important. But there's little known historically about how these mechanisms work or if they even exist in the peripheral nerve system. So the understanding to date has been that CSF flow is restricted to within the central nervous system. And this was established with a variety of studies that used dye and tracers many moons ago that were unable to detect CSF flow into the peripheral nervous system. But as this study points out, hey, those studies were done a while ago. They might have just not had the detection necessary. Their tools might not have been sensitive enough to pick up what was really going on. It's an important thing to keep in mind with all research as well. The research is only as good as our analysis and our analysis and our understanding and our tool set constantly, from a research perspective, constantly improves. So going back and redoing studies that seem like they're open and closed books sometimes can be a really good idea because it highlights, as we advance our understanding and we advance the sensitivity of the tools that can be provide meaning, meaningful differences. So the nervous system has, again, as we talked about originally, it's been really segmented into these two big parts, right? Central nervous system, peripheral nervous system. But this study really demonstrates that there's an interconnectedness of the nervous system through CSF flow from the central nervous system to the peripheral nerves, and suggests that there's an important role in that balance between both systems, which are really one. So their results did reveal that they used gold infusion technique basically to map this stuff out. That gold infused entered the CSF through the peripheral nervous system at those razs, at those attachment zones, rather than at the subarachnoid angle. In contrast with previous studies that thought, well, maybe it's. Maybe something's happening at the subarachnoid angle. No, these attachment zones seem to be a really, really key component, which would make them named appropriately. Attachment zones would highlight the fact that that's where stuff's going on. Right? So we also know that axons emerging from the central nervous system to the peripheral nervous system are contiguous. They keep going across the transition from central nervous system to peripheral nervous system within those attachment zones as well. So these axons don't stop at the end of the central nervous system and become something else. And they are it. And they move through and around those root attachment zones or through those peripheral attachment zones. So the presence of this CSF flow along the CNS into the peripheral nerve has really big impacts for peripheral nerve health and neuropathologies. And this is where I'm gonna. They don't dive into chiropractic at all in this study, but I'm gonna dive into it. So in the study, they highlight the fact that in the central nervous system, CSF is known to provide cells with metabolites. It is important in maintenance, eliminating waste from all these neurons. And a unified flow system, as they describe it, which is a great term for this, a unified flow system really encompasses all aspects of the nervous system, allowing the CSF to function consistently, to consistently deliver nutrients, remove waste, and provide cushioning for all. All neural tissues. Big change there. So while the CSF is in a low pressure situation, that means here's the clincher. Small alterations to CSF production or flow would have outsized effects on the health of peripheral nerves. So they highlight the fact that their results suggest that infusion into the CSF compartment may be a effective method for direct delivery of medications and therapeutic agents to peripheral nerves. I'm gonna go one step farther than that, or maybe I'm gonna take it a little bit of a different direction. And what I'm about to say is not proven in the research. It's literally just what I'm gathering from what they're highlighting here. They're literally saying that the CSF flows central nervous system all the way to peripheral nervous system. This happens, and the transmission happens at these attachment zones. We also know the csf, it is low pressure. So in other words, it's not like the pressure associated with our blood pressure, let's say where that's at. More of a high pressure situation. CSF flows and pumps sort of naturally based upon our movement. Because of that low pressure, small alterations, AKA compression, can cause big challenges, not only in the central nervous system, but in the peripheral nervous system. Now, we have seen this in terms of the nerve root being compressed in the spine and causing a radiculopathy. But that's almost, say, a terminal point. All your space is gone. Right? I mean, the CSF is being crunched at that point. The nerve is being crunched. This is massive and hugely mechanical. Small spaces, but it can be. That is a terminal pinch, in other words. But small alterations. Here's where I'm going with this you might not have radicular symptomatology. However, the compression and suboptimal spacing in the central nervous system, they're saying right here, can absolutely cause peripheral nerve dysfunction. That is powerful. Why? I don't look at that for the fact of, well, can we get a medication and a drug in there? Which is immediately what this research looks at. I couldn't think the more opposite way. I say, what are those things we can do proactively to help guide our patients so that we reduce the likelihood that there is a compression, even if minor, secondarily, for those that have compressive pathology, that already have pain and dysfunction, really thinking about the fact and taking it to heart that just because somebody feels a little bit better and the pain goes away doesn't mean that they are optimally functioning again. And this drives the nail into that by saying a small compression, it might not be even having true symptomatology of pain in the peripheral can affect the peripheral nerve. How? Because when there's a minor change at the central nervous system, that peripheral nerve is going to have waste management issues potentially, it is going to have nutrient transfer issues potentially, and it is ultimately going to have spacing issues potentially, depending upon what's going on at that remote site. So these are really, really important things that I learned from this study. I hope you're geeking out on it like I am because this for the first time pins together the fact that the nervous system is one unit, that our central, that our cerebrospinal fluid flows in and among our entire nervous system and that small changes can have big impacts. And that is a powerful message for us to understand, for us to keep an eye out on. And again, this is where I said at the beginning, this study does not give us all the answers, but man, does it really plant the flag in terms of what future research can show. So I love this study. I hope you did as well. I'm going to drop a link down to it in the show notes so you can check it out. And if you are into objective assessments, if you're listening to this podcast, you probably are. I highly recommend you go over to neccare.com and check out their assessment tool. They are the best in the business. That's just what it is. Reliable assessments and exercises for neuromuscular control, proprioception, range of motion and sensory motor integration. The design is awesome. The units look great, they're easy to use, the reporting is fantastic. What more can you ask for? Netcare.com if you reach out to that team, let them know that I sent you. They will give you a great deal as a listener to this podcast. Other than that, I hope you have a fantastic week in practice and I will talk to you soon.

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