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0:14
[MUSIC] Welcome to the Osher Mini Medical School on low back pain. My name is Alexandra Chang and I'm an anesthesiologist and chronic pain physician at the San Francisco Veterans Medical Center. It's my pleasure to co-direct this course over the next six weeks with Paul Su, who is an anesthesiologist and chronic pain physician at UC San Francisco. Thank you, Dr. Chang. We're super excited that you're able to join us for the next six weeks as we do a deep dive onto lower back pain.
0:49
Lower back pain is something that Dr. Chang and I see in our patients on an everyday basis. It's going to be an excellent opportunity and a great pleasure of ours to spend some time with experts to talk to everyone about how we tackle and manage lower back pain. Dr. Su will be giving the first lecture in our course tonight about the basics of low back pain, including anatomy, physiology, and the initial evaluation. But first, a little bit more information about Dr. Su.
1:24
He completed medical school at Columbia University in New York. He then came to UC San Francisco where he completed anesthesiology residency, a research fellowship, and pain medicine fellowship. He has double-boarded and currently divides his time among many roles. Clinically, he cares for patients in multiple settings, including in the operating room, in the hospital, and in the pain clinic at UC San Francisco. He also conducts and presents research. He has published multiple book chapters and
1:59
articles and recently was awarded a prestigious research grant to study the role of a particular transcription factor in regulating acute and persistent post-surgical pain. He's also very involved in medical education, including teaching and mentoring medical students , residents and fellows. He has also given his time and efforts to multiple projects across UCSF campus and in the community, including a prior lecture he gave for Osher Mini Medical School a couple of years ago.
2:34
It is my pleasure to now hand it over to Dr. Su. Thank you, Dr. Chang. That was a really nice introduction. Before we get started with today's talk, I'm going to just share with everyone the outline that we're going to talk about. Before we have the opportunity to do a deeper dive on lower back pain, I do want to spend some time discussing with everyone just pain in general and how pain physicians tackle and think about pain. Then we'll talk about the statistics of lower back pain,
3:10
why it's so common and prevalent. We'll focus a lot on the anatomy of the lower back. Then with the latter part of the hour, we'll talk about two case scenarios which hopefully will set up the framework to introduce some of the topics to come in the subsequent weeks. Let's start with what is pain. Let's all take a moment here and try to define pain.
3:42
You might struggle to put the words to help define or explain what pain is to someone. Well, it might actually be easier to describe pain. I'm sure you've heard terms such as sharp, dull, achy, throbbing like I got hit by a bus, numbing zapping, tingling radiating and pins and needles. Now, these are all good descriptors for pain and they are so very different from each other. I want everyone to take a mental picture or categorization of these adjectives and
4:27
we'll revisit them throughout the lecture, but it will help us think about and categorize pain in different ways. Now, what do all these descriptors have in common?
4:42
Well, they're all unpleasant experiences, both sensory as well as carrying an emotional experience. They're associated with or resembling actual or potential tissue damage, especially that one about getting hit by a bus. Hopefully that person never actually got hit by a bus, but they're describing their pain experience in such a way of potential tissue damage. This is actually the official definition of pain by the International Association for the Study of Pain.
5:16
Now a couple of additional notes worthwhile to mention is that pain is a very subjective experience and it's one's experience. We have to respect that. Someone's experience of pain may be drastically different from another person's experience. Pain is a learned experience, which means it occurs over time. What we do know about pain is that it's not always protective. Pain sometimes can be pathologic or end up interfering with our ability to live everyday activities. The last thing is that pain
5:59
cannot simply be a direct activation of neurons. It's beyond that and it really is a composite experience. That's something that's really important to note as we go on.
6:12
Now that we have a common understanding of pain, let's get started with talking about how that experience of pain is formed. Back in 1644, a really smart guy, Descartes, actually published and proposed a theory about how pain is experienced and transduced in the nobody. In his hypothesis, which is very well true today, starts with a noxious stimulus. Something that actually induces pain, in this case, a fire. That painful stimulus is picked up by a nerve, and then travels up the spinal cord,
6:53
and then is then processed by the brain. Well, that seems pretty straightforward and pretty accurate. But our knowledge of the pain system has really expanded since then. Just as an example, looking at the different sensory nerves, we now know that there are specialized nerve endings for lots of different sensations in terms of how we interact with the world and pain fibers is only one subset. The pain fibers are called the nociceptive sensory system. This is a really complicated-looking slide.
7:33
But the takeaway here, if you look on the top layer, the very top of the diagram here is supposed to represent the skin. You can see lots of different nerve fibers going to the nerve of the skin and they all represent different ways to experience different modalities. A good analogy or good example would be if you go to the dentist and the dentist administers local anesthetic before they're doing whatever procedure they are doing, let's say a root canal.
8:05
After they administered the local anesthetic, it's not like all of a sudden you can't feel the presence or existence of your mouth. You still know whether your mouth is open or closed, so you still have the ability to detect the position of your body in space. When the dentist starts to work, you can still feel the dentist touching your jaw. Your ability to detect pressure or touch is still maintained. However, you don't feel pain and you also don't feel temperature.
8:40
This is just an illustration of how specialized the nervous system and the sensory nervous system can be and how there's dedicated fibers for pain.
8:52
Moving beyond the 16th century into the 21st century, our understanding of the pain circuitry has evolved to include not just the nerves that carry the sensation up to the brain, but we now have a better understanding of how the pain is processed in the brain, for example, we know that attention and expectation can play a big role in our experience of pain. Think about people who get injured during war or during a sports game. They may not actually experience
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the pain at that time because there's just so much adrenaline or their attention is focused on something else. There are also descending pathways that help us regulate pain. This actually leads us to one really key concept here, which is the different mechanisms by which we now try to explain people sensation of pain. Nociceptive pain is the type of pain that you would expect when the nervous system is doing its job. This is exactly like the picture depicts.
10:11
This is a type of pain that you experienced when you hurt yourself or do things that injure the tissue. That sharp, dull pain, that stabbing pain when you get that paper cut, for example, so that's the nociceptive system working and detecting what it's supposed to detect. Now that tingling, zapping pins and needles, and that numbing sensation, which is also still very painful, that we call neuropathic pain. That's pain that arises when there is disease or injury,
10:49
to the nociceptive sensory system. Examples of this would be people with diabetes, diabetic neuropathy, for example, people who get shingles or postherpetic neuralgia, and also people who have pinched nerves, let's say for sciatica, that sensation of pain is what we call neuropathic pain. Even more recently, I think in 2020, the International Association for the Study of Pain recognized this new pain that has existed all along, it's called nosy plastic pain. That is pain that is experienced even
11:35
without any tissue injury or injury to that nervous system. If you think about patients with fibromyalgia, patients with headaches, those are good examples of nosy plastic pain. What I presented before, are just biologic aspects of pain, of how we explain how pain is processed. But the pain is much more complicated than that, it's truly an experience. Our most current understanding of pain rests on this biopsychosocial model of pain. That is, we recognize the biologic factors that go
12:19
into generating and processing pain, but we also recognize the importance and the role of psychologic factors, for example, stress, being able to have good coping mechanisms, or poor coping mechanisms can really affect one's experience of pain. Childhood traumas. For example, physical abuse, domestic violence, sexual abuse, PTSD, all of those can negatively impact people's experiences of pain. Then there's also social factors. As we mentioned before,
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pain is a learned experience and a lot of what we learn is societal and cultural. All three components make up one's experience of pain. As you can see, we've moved quite ways from the original 1644 depiction of pain and hopefully I've also depicted and illustrated that pain is a lot more complex than just thinking about the tissue and the biology that's involved and truly is an experience that needs to be recognized. Now that we have a basic understanding of pain and how we think about pain,
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we can then pivot and focus on lower back pain in particular. Let's start with some statistics.
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Everyone here probably knows somebody who's experienced lower back pain at some point in their lives, whether it'd be themselves or a family member or a friend. That's because chronic pain or lower back pain is one of the most common pain complaints. Way more than knee pain from arthritis, neck pain, headaches, as well as you can see in this diagram. In fact, lower back pain is the leading cause of disability in Americans under 45. The prevalence of lower back pain just
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continues to rise with age. The older you get, the more likely that you're going to experience lower back pain. It's estimated that 31 million Americans will experience lower back pain at any given time. That's about the population, just a little shy of the population of California out of the entire United States, so that's a huge number. Not surprisingly, back pain also makes up the largest health care costs in terms of pain treatment. With all these statistics combined,
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there's no doubt that lower back pain is something that is important for patients, but also has a major public health implication and focus.
15:21
You might be wondering why lower back pain affects so many people. Those adjectives that I showed earlier on with a dog, achy, tingling, zapping sensation, those are all descriptors that patients of mine have used to describe their lower back pain. The lower back pain is actually a really broad category. It's almost like a catch-all category for pain that's in the lower back. Now that we know so much more about the mechanisms of possible pain generators, we can start to appreciate that there
16:05
are lots of different ways that pain can occur. To really appreciate that, we need to take some time now to look at the anatomy of the lower back.
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The anatomy of the lower back, I like to think about, here I have the example of a Build-A-Bear workshop. But another good analogy to look at the anatomy of the lower back is to think about renovating a house or building a house. Hopefully that'll be a little more concrete example. You need structure when you're building a house or in this case a back, it's supporting a lot of our body weight. You need something that will provide that structure. In the human body, that's bones.
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In this case, it's the vertebrae. Now, if you just had one vertebrae, that would get the job done in terms of support. But in order to move, to bend, twist, lean back, you need to have multiple vertebrae so that you can include some mobility in joints. That's why we actually typically have five lumbar vertebrae. Sometimes you can have six, but mostly most people have five. The vertebrae connect to each other via joints and discs, as you can see in this figure in the lower right-hand corner,
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the inclusion of these joints and discs allow for that mobility.
17:44
Now that we have the structural supports there, we've got to keep it in place, and that's where the glue and the tape comes in. In the human body, those are ligaments, as you can see here within and supporting, keeping the vertebras together are a network of ligaments which allow the vertebrae to connect to each other but still maintain that mobility in the structure. Next we run the electricals, and in this case, it's the nervous system. They are foramens or holes as well as
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canals that are formed so that the spinal cord can connect to the brain, which is like the motherboard or the electrical panel, and to the rest of the body.
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And lastly, to make the whole system work, we need motors, so these are the muscles. So the muscles will then contract and relax to instill those motions that we expect from the back. Voila altogether, you have the anatomy of the back. So to summarize, there's the vertebraes which are connected to each other via disks and joints, and they're glued together with the ligaments. The spinal cord runs and connects to the brain, which then exits through the foramens, which connects to the muscles,
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and controls the muscles to allow for movement. Then overlying all that are the skin and connective tissues to keep everything separated from the outside world.
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Now that you understand the anatomy of the lower back, we can jump into some case scenarios. Let's start with Case one. This is patient Kelly. As we're getting into spring cleaning, a lot of you might be doing this activity. So Kelly is a 50-year-old individual, otherwise healthy. While lifting boxes in the garage, Kelly experiences a sudden pop followed by severe sharp pain in the right lower back. Kelly shows up to the urgent care clinic to be evaluated. I'm sure a lot of people will have
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lived this experience before. We call this acute lower back pain. Now acute lower back pain simply refers to any pain that is less than three months in duration. In fact, the chronicity of pain is another measurement by which we characterize pain.
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So we've talked about all the different component that goes into building the anatomy of the lower back. Unfortunately, every single one of those components has the capacity to generate pain, and to get injured, and that's why for lower back pain, you can hear lots of different characterizations depending on which structures are injured. For example, most commonly there may be strains of the lower back muscles, and pulling of the ligaments. Sometimes the disks can
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protrude out and cause disc herniation that themselves might be really painful or the extrusion or herniations might actually pinch on the nerve roots that are coming out, and cause neuropathic pain. The good news is for acute lower back pain, most of that pain will self resolve within a couple of weeks. When you present to an urgent care or your primary care doctor, his or her role is to look out for any red flags or any other signs or clues to suggest that,
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hey, maybe this lower back pain isn't just what we're seeing from the anatomy of the lower back. For example, are there underlying infections? What was the mechanism? Was there a car crash, are there fractures? Anything that's a little more out of the ordinary. Now I won't go too much further into red flags because that's a topic that we're going to focus on next week. Which is red flags of when lower back pain isn't just lower back pain, and we need to do a little more investigative work.
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But again, acute lower back pain will resolve without any further management. So that's good news for us. What can we do for acute lower back pain? Well, like I've mentioned, it will go away. A lot of times it's just tincture of time. Now sometimes the pain is just so insufferable and we still need to get on with our daily activity. So what else can we do to help kind of temporaries that? Well, the recommendation is that you want to start incorporating activity as soon
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as it feels comfortable for you. As you start feeling better and better, you want to start moving more and more. You don't want to push yourself and injure yourself even more, but you do want to start rehabilitating as much as early as possible.
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If you were to need some additional help, the first step is to think about non-pharmacologic, so not medication base. So things like heat, things like stretching, those can all be really helpful for managing your pain without having to reach for that pill bottle. Now, let's say you try all those different maneuvers and it's still too much pain for you to endure, then you can think about some low-risk medications. Now it's really important for you to consult with
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your primary care physician to make sure that medications such as Tylenol, nonsteroidal anti-inflammatory medications, or even muscle relaxants are safe for your specific individual medical condition. But those are the typical medications that we usually recommend to help with acute lower back pain. Now some myths. The classic teaching is that after injuring your lower back, you should exercise bed rest. Well, that turns out to be false, in fact, lying in bed actually makes your pain
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worse and actually prolongs your pain. That's why we recommend including functional rehabilitation as much or as early as tolerable.
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Because lower back pain gets better by itself without much further intervention, it doesn't really matter which intervention you try first and it's really up to you what's available for you, what within your budget,
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what's compatible with your lifestyle? Now, there are a couple of things that have been shown to really not be as helpful for managing acute lower back pain. Turns out ice is not as helpful, traction devices are not helpful, getting new mattresses is not necessarily helpful, doing yoga is not necessarily helpful. That being said, none of these things are harmful, so if they happen to work for you, that's totally okay as well. Because again, the main thing is that
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acute lower back pain will resolve 90% of the time without anything at all.
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Let's look at another case, this time patient Alex. Alex is also 50-year-old who comes into the pain management clinic complaining of lower back pain that has started since 2019. The pain was insidious in onset, so it crept on and actually worsen during the COVID-19 pandemic. The fact that this pain has lasted more than three months, we classify this as chronic lower back pain. In fact, a lot of the pain that we think about when we say lower back pain really implies chronic lower back pain
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because that's what sticks around. What are some of the causes of chronic lower back pain? Well, all the causes for acute lower back pain can lead to chronic back pain by definition. But some of the other causes are a little more long-term in nature, for example, with time, naturally the vertebraes or the discs between the vertebraes will become dehydrated and degrade. That unfortunately it just happens with time, which we can't really do anything about.
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Additionally, the joints of the back which allow the backward extension can also become arthritic and degenerative over time. Very similar to how people develop arthritis in their knees and in their fingers.
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Some of the other things that can happen over time is that the nerves can get compressed whenever the spaces for these nerves to travel gets impinged because of the degrading disk for example or because of the degrading joint and all of that can feed into a biologic reason for people to experience pain. But that doesn't cause pain for everyone. That's because chronic lower back pain or chronic pain has a psychological and social component, which we talked about before.
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Let's look at some of these factors. A little more about Alex. Alex has a history of anxiety and depression.
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Whenever Alex thinks about the pain, Alex tries to avoid activities that cause pain and always he's worried about things that could precipitate it. When you ask Alex about how they think about the pain, they say that the pain will never get better, there's nothing I can do to make it better, woe is me. Alex spends most of the time in bed or lying on the couch.
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All of these factors actually are risk factors for developing chronic pain and they have nothing to do with what's going on in the lower back. Again, this highlights the complexity of chronic lower back pain, that is the physcho-social factors play a huge role in developing lower back pain. Coming back to some of these risk factors. Unfortunately having some pre-existing psychologic conditions, psychiatric conditions, for example anxiety and depression,
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predisposes people to developing chronic pain. Fear avoidance behaviors. Being fearful and avoiding certain actions all the time for separating on the pain can train the brain to actually fire in a painful way. Pain catastrophizing, so this over-exaggerated response to the experience of pain can also promote experience of chronic pain. If there's a high degree of functional impairment so that's why function is so important in treating patients with chronic pain. Hopefully at this point,
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I've been able to convince you that chronic pain may not be as simple as what's going on with the anatomy of the lower back, it definitely has a huge role to play but for chronic pain, the picture is much more complex. Now, I don't want to paint a picture of just doom and gloom as well because the reality is, we've come a long way in terms of offering patients ways to manage their pain. Because chronic pain is so complex with social psychological, biologic factors, we need to also take
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a very multi-dimensional approach to treating and managing lower back pain. That's going to be the focus of our future seminars with specialists from each specific area. I'm just going to briefly touch on the different topics that we'll be going over in the future weeks. Next week we will have Dr. Carolyn Cloping talking to us about the red flags that I mentioned, things that your primary care doctor is looking for when you present with lower back pain.
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Dr. Paul Chen, who is another pain physician, will be talking about different medications and different interventions, including injections and even more advanced pain therapies that have been developed in helping people manage lower back pain. We will also focus on the role of surgery. There's definitely pluses and minuses of surgery and in order to fully understand that, we have Dr. Alan Ding who's a neurosurgeon at the Veterans Hospital to come and discuss with us.
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Then as I've mentioned before, functional rehabilitation is extremely important, if not the most important role in helping people with chronic lower back pain. We have two pain specialists, physical therapist, that will come and discuss with us the role of functional rehabilitation. These are just teasers of the lectures in the weeks to come.
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But before we wrap up for today to start our discussion, I do want to touch on a topic that I'm sure that everyone has questions about, which is, if I have lower back pain, should I get imaging, so to image or not to image? That is the question. Well, it turns out for acute lower back pain because I've stressed that it gets better by itself, there's usually not any imaging modality that's indicated. This is the exception is if there are red flags symptoms. Again, that's the main exception
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when the picture is not just lower back pain, that there's something else that might be going on that might indicate additional imaging. But for your run-of-the-mill lower back pain, there's nothing to do except to slowly incorporate your physical activities once you feel up for it. For chronic lower back pain, there's no definitive guidelines for the role of imaging. Now, there are three different types of modalities for imaging and whether they are suitable for you needs to be determined by
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your physician depending on your specific case, unfortunately, there's not a blanket clause. The three different types of modality is X-ray. The X-rays bounce off hard structures like bone so it's really good for evaluating bony structures. Things like instabilities, things like fractures, degeneration, and scoliosis can be done with a simple X-ray. MRIs can evaluate the soft tissues like the nerves, the disks, the ligaments, the spinal cord, as well as the bones.
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They can give you a little more information. However, this is traded off by the fact that MRIs can be very costly. In fact, studies with MRIs did not show any sort of functional improvement for patients who had MRIs, only that people with MRIs ended up having surgery more frequently. Interestingly though, patients that got MRIs were generally more satisfied. Now, I'm not sure if that's because they felt like that was something that was able to be done and thus was done,
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and they are just happier about that but that MRIs themselves didn't really lead to any improvement in outcomes. Now, if there's any contraindications to MRIs, CT scans can also demonstrate and highlight soft tissues as well as bony structures. Obviously, the major thing to know about CT scans is that they are exposing individuals to a lot more radiation than a simple X-ray or no X-ray at all.
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To illustrate this example, I'm going to pose this question to the audience. On the left here, we have an MRI of an individual. You can see the really white thing in the MRI photograph is actually the cerebral spinal fluid. It's the fluid that surrounds the spinal cord, so within the white structure, that gray structure is the spinal cord and you can see the spinal cord floating really freely within the spinal canal. Compared to the MRI scan on the right,
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you can see that where that arrow is pointing, that disk has bulged out and started encroaching on the spinal canal and perhaps even pinching the spinal canal there. Now the question is, is the patient on the right having pain? That's the question that can't be answered with any sort of scan. What I tell patients with MRI scans is that, especially as we go into 2023, 2024 and our technology gets better and better, chances are, it's like getting the best iPhone that the camera is just so good
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that you're bound to find these, ''abnormalities on these scans'', but they don't necessarily correlate with pain. You can actually have quite severe spinal stenosis without any symptoms. I think the key here is that we need to recognize that you cannot image pain. Perhaps that's why people with MRIs ended up going with surgery because you see these abnormalities, but they don't necessarily correlate with pain. That's the ultimate dilemma with the imaging modalities.
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Before we start our question-and-answer period, I want to use this opportunity to just summarize some of the topics that we've touched on. We've talked about the anatomy and physiology of the nociceptive system. That is the nervous system that's responsible for detecting pain or detecting noxious stimulus. Now that, again, does not equal the experience of pain as we've illustrated. Pain is a complex experience that's influenced by not only the biology,
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but also includes the psychologic and social factors. When we talk about acute lower back pain, I can't stress enough that most of the lower back pain will improve with time without doing anything at all. Now, the transition and the development of chronic lower back pain can be much more complex than simply the biologic causes. In the coming sessions, we will be discussing how spine specialists tackle and manage lower back pain using a multi-disciplinary approach.
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Thank you so much for your attention. Thank you so much, Dr. Su for that lecture. I think now we have some time to answer some questions from our audience. I think we have one question here about exercising and the health of your low back. What types of exercises do we think are best for keeping your back in good shape? For example, yoga, swimming, hiking, or weightlifting. Is there any type of exercise that we should be doing on a regular basis? Yeah, that's a great question.
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I think what I tell people is that motion is lotion. Any exercise that strengthens the core is really good for your back. That anatomy slide that I had pulled out where the muscles actually, even though they control the movement for the lower back, they themselves can actually provide structural support and end up functionally like an external brace, but internally to help support the lower back. Exercises that focus on the core are extremely good for the lower back.
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Something that we don't really think about all the time is that the core is any muscle that attaches to the torso, especially in the lower back. The back muscles, the obliques, the abs actually also contribute to the core muscles as well as muscles of the hip as well. I see here the question is if there's any specific exercises that are good for that. The answer is any exercise that tones and tones those muscles. Swimming, I think is a great exercise as well, especially for patients that find it
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really painful to engage in exercises on land. Or are just starting out and want to find that happy middle ground because with swimming you get that buoyancy, you get that extra assist so that there's not as much pressure or stress on your lower back. This is a great question about the imaging. What we see on MRIs or CAT scans and the patient's symptoms. In your lecture, Dr. Su, you mentioned that sometimes the imaging doesn't really reflect how much pain somebody may be experiencing.
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Is the reverse also true that imaging can look fine where we may not see any pathology that a patient may still have chronic back pain? If that's the case, how much time do we spend figuring out what their function is like in terms of moving, sitting, slouching, working? Absolutely. I think the reverse is definitely true. Many a times, we're talking about the recommendation to get imaging.
42:19
A lot of my patients will come to me and they already have an imaging already done. Even though, based on our discussion, I don't necessarily think that imaging would be indicated. It's available, we're looking at it and we don't see anything. I definitely don't turn around saying, well, the MRI is clean, there's no way you can have pain. I don't know what you're talking about. [LAUGHTER] That's definitely not true. I think, again, going back to that pain 101, pain is definitely an experience.
42:51
If a person experiences pain, they can experience pain even without the MRI or imaging looking abnormal. Again, that's because there's no imaging modality that can detect pain. Now, what we do do with MRIs is that when there are abnormalities, it helps us explain and understand how one could be experiencing pain because, for example, we see that bulging disc, we see the nerves getting pinch, we see the joints being arthritic that allows us to start to explain what might be causing this pain.
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But if everything is normal, it actually can be helpful because now we know that, hey, this person's spine is stable. It's safe. It's safe to move around. We don't have to be worried that there's some fracture or even though that person is experiencing pain, that moving around is actually going to cause more injury. Perhaps their experience of pain isn't so much that biologic component focusing on the lower back, but perhaps there's an impairment of
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how the brain is processing this sensation as pain. Having a normal image per se, also helps us tailor the therapy as well to focus our efforts on, for example, retraining the brain to not have painful experiences. Yeah. I think that's a good point that even if the imaging looks perfect and the patient does have chronic pain, it is important to focus on function and what we can do to improve daily physical function because that is what matters a lot. Then on the same topic of imaging here,
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we have a question about how does arthritis look like on an image? What is a good treatment approach for that since it's a chronic issue and not something that would easily go away? Yeah. I think arthritis is challenging because arthritis just develops because of age. Our bodies break down over time and degeneration is normal. It's part of aging. Especially as our life expectancies are getting longer and longer, unfortunately, age is not a modifiable risk factor.
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There's nothing you can do about it. It is what it is. However, again, having arthritic findings on MRI doesn't always mean that that person is experiencing pain. That is something that I do see quite often, which is when we do imaging, we may see arthritis, but when the person talks about their pain, it's not presenting like arthritic pain. We just leave those findings aside. A risk factor that is modifiable pain related to arthritis, is weight. Weight is a modifiable risk factor
46:19
for arthritis related pain. When people lose weight, it actually helps with their experience of pain. Even though, on repeated imaging, the arthritis is still there or even progressing because time has passed. But you can change the experience of pain. Speaking about arthritis, how would you describe arthritic pain? What do you hear from your patients when they have arthritic hip pain, and what does that sound like to you? Yeah. For the lower back, arthritis develops at the joint.
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At areas that have motion. If you recall from the slide with the anatomy where the joints of the back are located is actually the back of the vertebrae. Whenever you lean back and put stress and more weight on those joints of the lower back is when one would experience arthritic pain. A classic physical exam maneuver that we have patients do in the clinic to assess for arthritic back pain is to actually lean back and then turn to the right. That puts a lot of stress on
47:39
the joints of the lower back on the right side. Then we have them do it on the left side and assess whether or not those maneuvers exacerbate their pain. Sometimes it's hard to tell if somebody's coming in with low back pain. Is that really due to the spine, to the back or even to the hip or to other joints? How can you differentiate maybe on exam whether it's hip or back causing pain? That's where the challenge is and the reality is, sometimes it's extremely hard to tell.
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That's because all the things that can cause pain is located in a very small area of your body. If you think about the lower back, we've already shown from the previous slides that there is muscles back there, that there's joints, there's nerves, there's ligaments.
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It's really hard, and they all feed into the spinal cord at the same location. Our brains and our nervous systems sometimes are just not that good at being able to tell what one pain feels like compared to the other. It's like that game when you have someone touch you on two spots on the back of your hand, and you can tell very distinctly where those two spots are, and you can differentiate the two really vividly. But then if you have someone touch you on two spots on your back,
49:21
I think the response is going to be very different. It's very hard to distinguish the location on the lower back or on your back. That's the same analogy is that our nervous systems don't have the ability to distinguish between different pain generators in that small location. It's important to get that overall evaluation from your primary, or even a pain doctor where sometimes they put together the symptoms, the exam, imaging to help differentiate whether it's fine versus
49:56
your hip causing the low back pain. Exactly. A lot of the times even when try to put together the picture in a unifying way, sometimes it's not absolute. We form essentially educated guess based on everything we know and how patients are presenting, what is most likely. But sometimes what is most likely versus what's second most likely are just right next to each other. This is a question about, again, a little bit more about the anatomy and the back. Do we ever see that
50:35
the low backbones or the vertebrae get out of alignment, which can therefore affect their normal function. In the sense I think one good example is patients who are born with scoliosis is a good example of congenitally the bones of the vertebrae are out of alignment. That's not to say that they always generate pain, but over time the fact that the vertebrates are out of alignment may put unbalanced stress on one joint over the other and over time that might lead to issues
51:15
with arthritis and things like that, for example. Sometimes we can see this listhesis where the vertebrae might slip forward or backward on the other and that can sometimes also lead to some tightening of nerve roots or the spinal canal as well. There's different ways for the bones to be out of alignment. Yeah absolutely. Here's another question, a general question. What is radiculopathy? Radiculopathy sounds a little ridiculous but [LAUGHTER] cringy worthy there but it actually refers to
51:55
the nerve roots when they come out from the spinal canal to connect to the rest of the body, that the area where the nerves come out, it's a small foramen. Now, if those nerves get pinched, the more commonly radiculopathies might be known by things like sciatica or pinched nerve. That's just the medical term for a pinched nerve root; is radiculopathy. What are your thoughts on chronic pain and neuroplastic pain? You mean like Nociplastic pain perhaps I think
52:31
is the new category of pain that's coming about. Chronic pain simply just means that you are experiencing or one is experiencing pain for more than three months. What I've presented here earlier on, are three different mechanisms by which we try, us, we try to explain why people are experiencing pain for more than three months. One way is that there's some tissue damage that's going on and that's activating the nociceptive system and the nociceptive system is functionally totally fine.
53:11
It's doing what it's supposed to do. It's just responding to an area of the body that has injury that's prolonged. Take the example of arthritis, there is joint damage in the knees. The nociceptive system is firing appropriately saying, hey, there's degeneration in the knees. I'm going to pick that up and I'm going to fire. That can happen for more than three months and that's one mechanism of chronic pain. The other mechanism I discussed was when there's
53:41
injury to the system that's supposed to pick up pain. That type of pain is, the word just Neuroplastic. Yeah sorry. Neuroplastic pain. I just blanked. That's pain that comes about when that system that's supposed to detect pain goes haywire or has a disease with it. The example that I gave for that is people with diabetic neuropathy, for example, or peripheral neuropathies, the nerves are injured and they can fire in that way. Then the last category of pain is called nociplastic pain.
54:28
This is that new concept of pain that is being more characterized nowadays. Essentially that means that it's pain that does not involve the nociceptive system. There's no injury in your body, so the nociceptor system should not be firing and there's no injury to the system that's supposed to be working, but you're still experiencing pain. The examples or the stereotypical patients are patients with fibromyalgia, for example. They can actually happen with lower back pain.
55:06
When patients present with back pain, that's nonspecific, it hurts in the lower back area, there's nothing really on imaging that could explain why they're having pain, there isn't any previous injury that occurred in that area, there's no diabetes or other reasons why their nervous system wouldn't be functioning well, but they're still experiencing pain. That invokes this new Nociplastic pain, which we think and we're not fully sure yet, it's an area of active research,
55:46
but we think that it's from impaired pain processing that's up in more of the cortical region. Usually those types of pains are not really isolated to just one body area, because if you think about, if it's something wrong with the CPU or the motherboard processing pain, it's more likely that it's going to spill out into lots of different areas. Those type of patients with Nociplastic pain typically also have anxiety. They also have depression, they have headaches,
56:22
they have difficulty concentrating, they have chronic fatigue syndrome. You can see how the central processing spills over and is dysfunctional for lots of different areas. I think one of our audience members is also talking a little bit about neuroplasticity, which I think there's definitely that thought about training the brain and training our response to pain and changing it over time as well. Yeah definitely. I think the neuroplasticity of the pain is one of the mechanisms,
57:02
it can happen to explain all of the different pain types that we just talked about because, you're right the brain is really good at picking up and learning. What I tell patients is that sometimes if you think about pain like a bad habit, even if you're not trying to learn something just by repeating and doing it multiple times, your brain naturally picks it up. That's how we ride a bike, that's how we learn to play sports or do certain skill, is that you're focusing on it for a couple of times,
57:36
but then the brain rewires itself. Sometimes when the pain signal fires repetitively over and over again, whether we know it or not, we're actually strengthening those type of connections and over time, one of the things that can happen unfortunately, is that you actually don't need that trigger anymore. The brain has picked up so much of it that it can just do it on its own. Thank you so much, Dr. Su, for answering our questions. Any other last words here, Dr. Su?
58:09
No. Thank you, everyone for the great discussion. I think these are all really good questions and I really think that the future lectures are going to be able to answer and address and dive into more detail some of these great points that were brought up today [MUSIC]
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