So good morning, everyone, and welcome to our session, A Game of Clue, where we hope you can help us diagnose the causes of these presenting back and lower extremity symptoms. I'm lucky to be working with some awesome group of presenters that I've worked with in past AAPMR conferences. And our goal here is really to bring you some clinically focused spine talks that can cover relevant topics that you will see in your everyday physiatry pain practice. And so this year, we've really tried to gamify our approach, inspired by the board game Clue, which is a huge hit in my household. And we want you to put on your detective caps while we try to sleuth out the causes of these mysterious symptoms. And so on the agenda, we have Dr. Zach McCormick, who's gonna be helping us figure out possible causes of painful feet. Dr. Adrian Profesco, who's gonna be diagnosing the etiology of numb thigh. Dr. Byron Schneider, who's gonna help us understand what can cause urinary urgency. And then wrapping up with Dr. Matt Smoot, who's gonna help us all figure out what to do with these patients with night back pain. And first, let me start off by presenting to you a case of acute foot drop. My name is Patricia Zhang. I am a clinical assistant professor in the division of PMNR at the University of California, San Francisco. And I have no relevant financial disclosures. So my case starts on a windy day in San Francisco. I walk into my exam room and I find an 80 year old female who's complaining of left foot drop. She just returned overseas. It's been honestly a little bit of a longer than expected trip. Her husband ended up falling and breaking his hip. So she spent a lot of time kind of going in and out of the hospital, spending time seated in a waiting room and just kind of finally got back after a long plane ride. And since she's been back, she's actually noticed that she has been dragging her left foot. And there's definitely a new numbness that's over the dorsum of her foot. Looking through the records, you're like, ah, she does have a long history of back pain. I really wanna keep the session interactive. So I'm gonna take advantage of the polling feature that we have at AAPNR this year. You know, at this point, there really is no right or wrong answer, but what are you thinking at this point hearing her history so far? So use that pop-up window and click your answer. Do you think the reason why my 80 year old female is having a left foot drop, perhaps because she is having a stroke? She does have a history of back pain. So maybe something like a lumbar radiculopathy. She did, you know, she was like seated for a while, perhaps a corneal neuropathy. Could be something like a compartment syndrome. Just gonna give you a couple more seconds here. Yeah, and then, you know, we can release the answers so that you can kind of see what, where we are at. So it looks like we're kind of split between lumbar radiculopathy and corneal neuropathy. Totally fair. You know, I do like to keep my differential really broad when I'm looking at these things, like something central, maybe a lumbar radiculopathy, a plexopathy, some sort of peripheral entrapment, sciatic, maybe even corneal nerve. But I totally agree with you. When I heard this case, I will be thinking about a lumbar radiculopathy, right? She does have a history of longstanding back pain and things being common, a lumbar radiculopathy is definitely high up there. And then, yeah, like, I mean, I'm kind of swayed by the fact that she's been sitting around a lot. She had a long plane ride. There'd be some sort of peripheral entrapment. And most commonly, that would be a corneal neuropathy at the fibular head causing acute foot drop. So let's gather more information. Let's talk to the patient, do an exam. So you find that she does have four out of five left dorsiflexion and great toe extension weakness. And yeah, like the top of her foot kind of feels numb. So she can't really define exactly where. Her low back pain has worsened. It's definitely noticeable now, but she doesn't have much buttock or leg pain, just kind of further down. She did have a left straight leg brace. So that would definitely change things, right? So if I asked you the question again, you would have thought maybe this is a lumbar radiculopathy and jumping straight to the MRI, which I think is probably the most helpful. We have a T2 sagittal, a T1 sagittal, and an axial T2. And I'm gonna start scrolling down more inferiorly on the axial T2 and maybe here at L4-5, a little bit, tiny bit of subarticular stenosis there. But I think what really stood out to me is that she has a left-sided L5-S1 bulge or maybe protrusion that's going into the neurofibromina. I like to evaluate these things better on a T1 sagittal. So you're gonna see me scroll more progressively to the left here. And so right there, you really can't make out that foramina at left L5, whereas you can a little bit better at the upper nerve roots. And so, yeah, really strongly thinking now about a left L5 radiculopathy causing her drop foot. You can do an EMG and this would probably be a very definitive EMG and not all of them are, right? If you could see denervation in the tibias anterior, the pronius longus. If you tested kind of above the knee and found something that's in my tendinitis, the gluteus medius, which I like to test, superior gluteal nerve. And of course, in the lumbar paraspinus, that would strongly make you think this is a radiculopathy, especially if your screen for other nerve roots were negative. And so what would you do here? And this is another polling question. So this is a patient that we now have found to have acute left L5 radiculopathy. You know, you're a little bit concerned. She's four out of five weakness. Would you, A, send her to the emergency room? B, kind of go around, send her home, but talk to your surgical colleagues and plan for expedited outpatient consultation. Or are you like, okay, well, let's give it some time and continue to monitor. Let's kind of see how things go. So let me give you a couple more seconds while you think this through a little bit. Yeah, and let's just go ahead and review the answers. Yeah, so not a lot going to the emergency room, and I agree, right? It's four out of five weakness. It's been going on, and she is 80 years old, so she really doesn't want to go to the emergency room. But yeah, kind of split here. And you know, you could do more than one thing, right? You can monitor while making sure there's a surgical consultation, maybe not so expeditedly. And so the things I think about while I'm determining when to send my patient for a surgical consultation would be these three factors, right? Like we're thinking about degree of weakness. I mean, four out of five weakness is concerning, but I would be a lot more concerned if she had one out of five weakness. I would consider the clinical trajectory. So we haven't really talked about, like I would definitely ask, did the pain and the weakness, are they getting better, or are they getting worse, or staying the same? Because that would influence things. And of course, patient factors, right? Like if this had instead be a 25-year-old male who's really active and runs and enjoys that, I would be much more likely to send that patient to surgery, a surgical consultation, sooner than someone who's 80 and who's frankly a little bit against surgery. And studies have shown that these are kind of the things we want to keep in our mind, right? So there are three studies. They all looked at lumbar radiculopathy causing foot drop. And so this one by Liu, they specifically looked at 135 patients with foot drop due to lumbar degenerative disease. And they were looking for clinical features that are able to prognosticate outcome after lumbar spine surgery for drop foot. And so, you know, these are the three significant factors. So one of them is going to be the duration of the weakness. So in the group that recovered, or recovered well, they had duration of sometimes less than three months, as compared to much longer duration in the group that didn't have good recovery. And of course, pre-optive muscle strength also matters. So people who were less weak tended to have better recovery, right? And people who were much more weaker at presentation. And there actually seemed to be some row of age. So people who are younger tended to recover better as compared to ones who were more elderly. But let's just say instead, the presentation had been very, very different, right? So you talk to your 80-year-old female, she actually doesn't have that much back pain. There is a positive now, so the left fibular head. And when you kind of do your sensory exam, she actually has lost sensation over the superficial peroneal distribution right there, kind of in yellow. That presentation would really make you think about a peroneal neuropathy. And so, the EMG nerve tension study would be super helpful here. And let's just say you had a slam dunk EMG here with focal slowing across the fibular head and denervation only in the peroneal supplied muscles. So the pibialis anterior, which is the deep branch, and the peroneus longus, which is a superficial branch. So you're really localizing this to likely the common peroneal nerve. This is a neurogram. And so, I really want you to pay attention here. This is a common peroneal nerve. And as it's kind of starting to wrap around the fibular head here, you can see there's increased T2 hyperintensity. The radiologist thought that actually could be consistent with an injury to the peroneal nerve right there. And the most frequent site of injury to the common peroneal nerve, it's right there just below the knee as it wraps around. And compression at this site is the most frequent cause of a peroneal neuropathy. And so, one thing that I thought was interesting is that in one study of 103 patients, 79% of them with common peroneal neuropathy did note sensory loss, but only 17% actually reported pain. So that's actually less frequent. I do think overall the prognosis is good. So in this Pigot study where they looked at 13 cases of idiopathic common peroneal nerve palsy, you would see that except for when there was a complete palsy, almost all of them recovered in full. So some of that did take up to as long as 14 to 18 months. And so for us, we really tried to support these individuals non-operatively with physical therapy to keep up the range of motion, splinting like an AFO to help with function, and really reserving surgery for those patients who are not improving after months and in whom we see a compressive lesion on the MRI. So wrapping up kind of my presentation here, take home points if you're faced with acute foot drop. So if this is from rheumatic neuropathy, it's most likely L5, MRI would be helpful. Keep in kind of mind some of these factors that may make you think about surgery sooner or later, severity, duration, age, trajectory. And then if this is from a proneuropathy, keep in mind that maybe pain is not always present, right? 70% of them actually only repaired at pain. EMG will be really helpful. And there's actually generally favorable outcome. So with that, I want to remind you that to hold any questions you may have and put them in the chat box, because we are all going to take questions at the end of the Q&A. And with that, I want to turn over the Zoom spotlight to the next presenter, Dr. Zach McCormick. Good morning, everyone. Thanks, Dr. Zhang. And I will just say much appreciation for the invitation. You've put together fantastic sessions for the past, I don't know how many years, several years in APM&R. So I'm going to move on to a new case. So we'll talk about the painful foot. These are my disclosures, nothing relevant to what I'm going to speak about today. So this is a middle-aged man, a recreational runner, essentially no real meaningful past medical history who came into our clinic with about a five-year history of right paramedial low back pain, and then about a three-year history of right forefoot pain. And as we elicited his history, he described that both his low back and his right foot pain were both worse with running, particularly downhill. And there was kind of a vague history of an electric quality to that pain. He mentioned that his foot pain was worse with tight shoes and also walking on hard surfaces. And he did mention more back pain with coughing. So exam was fairly unremarkable overall. Lumbar spine, hips, sacroiliac joint, provocation maneuvers, the sensory neuro exam, all essentially unremarkable. Notably had a negative seated slump. One helpful clue was a bit of forefoot pain with a tarsal squeeze. So as we start to sort through what we're thinking here, it's always attractive to find a unifying diagnosis. So could this be an L5 and or S1 radicular pain syndrome, both back and foot? Little bit of a uncommon presentation to kind of skip the thigh and the calf and just have back and foot, but possible. Probably unlikely to have a somatic referral all the way down to the foot from a lot of the other axial structures, disc, vertebral body, the set SI joint myofascial, but possible. And then of course we have to consider two distinct diagnoses. So can you have an axial pain generator and as well as an issue going on with the foot, stress reaction or fracture, turf toe or plantar plate disruption, sesamoiditis, potentially intermittent tarsal bursitis, et cetera, longer differential than that, of course. So these are x-rays that he came to us with. So they're not very good. You can see they're a bit underexposed, but in the AP view on the left panel, maybe a little bit of increased opacity at the L5 S1 facets, no evidence of a Bertolotti's segment, which could rarely but possibly impinge the L5 nerve after it's exited the canal. On that lateral view, pretty good alignment. Obviously we don't have flexion extension bones here, but perhaps just a bit of L5 S1 disc height loss. And again, that maybe a little bit of increased opacity at the facets of that L5 S1 level right here. Here's his MRI. So you're looking at axial T2s in the left-hand panel, sagittal T2s in the middle, and then sagittal T1s on the right side. And as we just scroll our way down towards the L5 S1 disc and segmental level, you can note the modic changes at the end plates around that L5 S1 disc. So these are probably characterized as a type one changes. They're brighter on T2, darker on T1. And you can perhaps appreciate a little bit of a kind of focal central protrusion there. Maybe the hint of a small high intensity zone, perhaps. But otherwise, as we continue to scroll down, actually, I'm gonna go back up for one moment. We're taking a look carefully, obviously, at the L5 S1 neural foramen. L5 nerve exiting here. We'll come down a cut, perhaps some subarticular zone narrowing where the S1 nerve is traversing. And as we look at more lateral cuts to the right side, you can see the neural foramen here, that L5 nerve root seems to exit with room to spare. But if anything, maybe there's a bit of that subarticular zone narrowing at the disc level. Again, here, perhaps tickling that exit, the descending S1 nerve root. So no strongly convincing evidence for radiculopathy. However, perhaps some evidence for disc pain with the protrusion, maybe a hint of a possible small annular HIZ or potential annular fissure. Vertebra end plate pain. So those modic changes, there isn't really time to go in this today, but if you do spine care, this is definitely something to read up on if you're not familiar with it yet. A lot of emerging evidence, actually a lot of good basic science coming from Dr. Zhang and her institution, UCSF, and Dr. Lotz and his team, that the end plates in the context of type 1 or type 2 modic changes, that probably is clinically meaningful. Not that you can't have incidental findings, but emerging evidence that there's probably breakdown of the cartilagin plate. You have transfer of pro-inflammatory factors through the cartilagin plate, and then sensitization of the end plate. We see increased expression of pain receptors, increased nociceptive capacity of the nerves there, and increased growth of nerves that carry substance P, calcitonin, gene-related peptide, histologic evidence that there is some, essentially nociceptive hypersensitization that's probably developing in these end plates when we see type 1 or type 2 modic changes in the context of back pain. So foot x-rays, fairly unremarkable. We really don't see any evidence of a fracture, old fracture, displacement. So what next? So we ultimately, I didn't do this myself, but a sports medicine colleague did an ultrasound diagnostic, ultrasound of the right foot, found this in the third web space. So this is a Morton's neuroma, and not uncommon. Classically, you do find it in the third web space, most commonly, usually most common in women, fifth to sixth decade of life. And ultimately, it's an interdigital nerve compression between the metatarsal heads, or potentially a bit of an entrapment at the level of the intermetatarsal ligament. So usually does present with pain in the toes, paresthesias, numbness, and potentially tighter shoes, high heels, where you're essentially loading the toes into the forefoot, putting body weight forward, and then creating a squeeze, much like you would with one of the exam maneuvers that helps elucidate this pathology. So on exam, you might find a positive metatarsal compression test or squeeze. As well as localized tenderness. So in this gentleman, we ultimately had success with just conservative measures. So recommended that he get wider toe box shoes for running, gave him a plantar metatarsal padding, and he ultimately ended up getting an orthotic. He had a couple injections, corticosteroid injections with one of my colleagues, essentially pain resolved. And ultimately when his foot pain resolved, interestingly his back pain resolved. So probably something compensatory going on. Disc and perhaps possibly end plate as well were unhappy. Once his foot was doing better, he ultimately was a happy camper. So there was not a unifying diagnosis in this case. And obviously don't forget about the possibility of dual pathology when you're, if you're like me, you mostly see spine patients all day. All right. Thank you very much. That's our foot pain case, and I will turn it over to Dr. Kupescu from the University of Pennsylvania. Thank you, Dr. Zag, Dr. McCormick, and my co-presenters. I will share my screen, and we'll go over the numb thigh and the clue associated. This is just a clue in our diagnostic algorithm, and we need to take it as such. I have no disclosures. This is dull pain or numb thigh, and I hope we're going to avoid worrying. These are some prerequisites that we all need to have prior to go and formulate a differential diagnosis for a patient with a numb thigh. As we all know, that mystery is in the history, and not very frequent. We forget about chief complaint, we forget about getting a good history, what is the patient's preferential direction, what worsens the symptoms, any associated weakness, and we need to make sure that our clue makes sense, or our physical exam clues make sense. I chose to present a real-life case of a 38, 39-year-old neurologist at Penn who had numbness in the right thigh anterior lateral, no improvement with pain. His wife is a physical therapist, a normal body habit is some intermittent pain in the thigh, mostly outer thigh, very rarely inner thigh, and very, very rarely a brief sharp shooting pain to the right would go into the groin, exacerbated with valsalva, and rarely with lumbar extension. So, yeah, we need to find some clues here that would make us go to the next step. Again, intermittent, symptoms worse with extension, no improvement with PT, and no bowel, bladder incontinence or urgency. Differential diagnosis, of course, your differential diagnosis might be different than ours, but put down what you think is going on, is it myrology or parasitica, radiculopathy, plexopathy, permanent neuropathy. And as we all know, the acute lumbar radiculopathy clearly shows that you can have these conditions occurring through lumbar dystatology, due to a space-occupying lesion, can be associated with weakness, you know, three or four mild ones. And again, stellar muscle stretch reflex usually is impaired, and if you compare that with myrology or parasitica, that is normal, the stellar muscle stretch reflex. Again, most common is a nervous compression, you can have weakness of the deflection of the knee, the deflection, the extension, the pain reduction, none of those were present for our patient, except for a ankle dorsiflexion. Myrology or parasitica is a condition, it's a pure sensory nerve that is affected, the lateral pericardial nerve that goes under the inguinal ligament, the L2 and L3 segments are involved, susceptible to compression, any of the four sides from the lumbar plexus, lateral to the psoas muscle, under the ring ligament. Causes, idiopathic, local or abdominal surgery, external compression, all of those can be causes for myrology or parasitica. For those of you that are really interested in ultrasound and injections, I want you to memorize this slide and see the anatomical variations and how accurate you are when you do this plot for diagnostic purposes. So, the lateral pericardial nerve can be anywhere between 6.5 centimeters medial to 6 centimeters lateral to 8.5, and sometimes can arise from the femoral nerve, and this study was done on 20 cadavers by a neurosurgeon that was published in Journal of Neurosurgery. Lumbar sacroplexopathy, it's another differential diagnosis that can be clearly diagnosed with imaging, EMG, usually absence or disturbances, anterior medial thigh, causes being diabetic amyotrophy, or you can have a pelvic tumor, retroperitoneal hematoma, femoral neuropathy. You can have sensory changes in the anterior medial skin of the thigh, you can have motor changes, the quad muscle deflection with sparing of the adduction, remember this, and none in its history would match this. Sensory exam, it's challenging for me and in my clinic usually. Trainees have a hard time with the long exam, it's not a short exam, and their symptoms can overlap. It's not always very, very accurate. Ordering studies for a case like this, tell the consultant what you're looking for. Primarily, it's good enough for Lumbar pericardial necrosis, Lumbar sacroplexy, Lumbar spine imaging, at an abdomen, perceptual studies are important. Nerve conduction studies always compare side to side, where you have decreased amplitude in your pericardia, and the needle EMG study, you can order it, but it's normal in all your pericardia, because your sensory nerve is affected. You can get imaging to check for trajectory of the nerves and any external compression, abdominal pelvis, or ultrasound of the abdominal wall or inguinal area. What do we do for our patient? Again, this is our patient, has thigh numbness and left ADF, ankle dorsiflexion weakness, the right thigh numbness and left ADF. You can tell them what you want or want. He's a neurologist. He's a colleague. What are your next steps? You can write down what are your next steps. I can tell you what were our next steps with imaging. Why? Because things didn't make sense. We didn't have enough clues. And I did not have my x-ray vision with me or any other possibility to explain this. You know, very reliable history with no other explanation. And this was our surprise. We're not here to discuss schwannomas or tumors of the spine, but this was a fairly large schwannoma. And he was told, actually, while taking the MRI without contrast, that they need to put contrast. So you know that as a neurologist on the table, when you hear that, you know something is up. These are a couple of clues for you to remember after this session. Neurology of parastatica is a self-limiting, benign disease in most patients. Spontaneous remission is frequent. Seven times more frequent in patients with diabetes. Acute lumbar radiculopathy, monitor for weakness. Flexopathy, neurodifferential, and femoral neuropathy about external compression and recent procedures. Remember this, neurology of parastatica is a purely sensory condition. Thank you very much. And I want to introduce Dr. Schneider. He's a professor at Vanderbilt University. And if you like evidence-based and you follow evidence-based, listen to his lectures at any conference. Thank you. All right. Thanks for the nice introduction. And thank you everybody for joining us today. So the topic I was asked to present on was urinary urgency. Should I be concerned? And I am in a spine clinic. So I approached this from a spine perspective. And in trying to stay in line with the theme of clue, mine's a little different because we're not going to talk about a patient. We're actually going to play a game of clue on what does this mean in your clinic even. I wouldn't say I have any relevant disclosures, though I do get some advising money. So when we think about this, if you're in a spine clinic, these are all clinical scenarios that may or may not involve cauda equina or back problems or urinary urgency. But I don't think these would give us a lot of consternation, right? If you have a patient that wakes up with severe pain down their legs and saddle anesthesia and urinary incontinence, well, they have cauda equina. And if someone has a long, short subacute history of bad radicular pain, you already have an MRI, you know they have a large disc extrusion, and then they call you and overnight they developed urinary incontinence. Again, that's going to be high on your list or you're going to know what it is. If you see someone that just has radicular pain, you're probably not worried about neurologic deficits like urinary incontinence or cauda equina. One we might see frequently, right, is a young person who has chronic low back pain and they say their symptoms have been stable for years, but I don't know about you, but I have a large percentage of my patients that check off your urinary incontinence on their intake forms or their review of systems, but it probably, you might ask them about it, but it's going to be very easy to sort through that probably, and that probably comes down to a misunderstanding of what incontinence is. Or you can have an elderly lady and, you know, she seems pretty fine otherwise, she might have a little bit of low-grade back pain and she says, yeah, I leak urine when I laugh, and that might be pretty easy to say, oh, it's just probably, you know, an unrelated symptom here. It's a case more like this that may give us a little bit of time to deliberate on what to do, so, and we'll come back to this at the end, but, you know, this patient came to my clinic recently, he was a 75-year-old male, he had a long-standing history of low back pain and neurogenic claudication. He also had a history of prostate issues, though, his walking tolerance has been declining, his work pain, his back pain has been worsening, and he had mentioned something to his PCP that his urinary function had been changing, very vague kind of statement, denied, you know, other neurologic problems subjectively, like saddle anesthesia or bowel incontinence, and then you examine him and you maybe have a little bit of dorsiflexor weakness that he wasn't aware of, so really it's of unknown chronicity, and it's a case like this where you start to wonder if the urinary symptoms, what they are and what they mean. The thing you'd be worried about, at least in a spine clinic, is cauda equina, right, and to understand that we need to define it a little bit, so the first thing to consider is that this stuff is rare, true cauda equina is probably one or two cases per million of the population, or other ways to look at it would be that it is one in about a thousand disc herniations, and given that we have about 15,000 or 1500 disc herniations per million population in the U.S., this you might see it once a year if you're in a city of a million people, well not you, but someone might see that person. There's ways to classify cauda equina syndrome, so type 1, type 2, and type 3 really just have to do with whether the cauda equina symptoms are the presenting symptom of the disc herniation, the endpoint of a long history with low back pain with or without sciatica, or type 3 is this insidious presentation that has a very slow progression of neurologic symptoms irrespective of their back pain. Another way that this is often categorized is actually based on urinary symptoms, so some people will qualify cauda equina based on whether it presents with urinary retention plus or minus overflow incontinence, or a more incomplete cauda equina picture in which there may be some urinary symptoms such as a loss of desire to void or poor stream, and this you know again to our case that we're talking about is after the slower presentation to the patient, so they tolerate it better and they're less likely to be alarmed, so that can be problematic. So we've said how frequently it may occur, we've said how it's classified, but we haven't really defined it yet, and so to find a definition I found this article that was a systematic review, it's a few years old but it's still very pertinent, and they looked at 105 articles that all describe cauda equina, and I mention it because they noted defining it was problematic even in their systematic review, and that's because of all the articles they looked at they found at least 17 different definitions of cauda equina. So maybe if we can't define it, we can start to look at symptoms, and in this systematic review they didn't comment on prevalence within the population, but just prevalence within the literature on how often these symptoms were considered, and as you can see here that as it is reported in the literature or defined in the literature, these symptoms aren't even universally acclaimed to all be part of cauda equina, or at least not be required, or universally present, and so things like abnormal sensation, bladder dysfunction, bowel dysfunction, pain, and power, all of these really were present in the majority, but not the vast majority of literature talking about this. If we think about what causes cauda equina, most often it's a disc, there can be other nefarious causes of back pain with urinary symptoms such as tumor infection, but a more spondylitic picture with degenerative stenosis is actually a pretty rare cause of cauda equina. This article had some, I like to do evidence-based review, but this article had some expert opinions, and it was challenging to find evidence bases or an evidence base to comment on theories behind this, but there was clear consensus that bladder involvement is not always present with cauda equina, that cauda equina can present with lower limb weakness and sexual dysfunction in an absence of urinary dysfunction. Oops, sorry, I got distracted by a question. While it's often taught that bowel and bladder dysfunction are concurrent, this was actually only present in about half of the definitions of cauda equina, and there was clear, clear agreement that many patients deny urinary incontinence, but they still may have urinary symptoms if you do something like check a postpoidal residual. So why is there this variability? Well, some people have suggested that central disc herniations may selectively spare the lateral lumbar roots, and so in that case, maybe only the lower sacral roots are affected as they settle midline and posteriorly within the spinal canal as they traverse the upper or mid lumbar segments, and it's also been suggested that various parts of the cauda equina in the spine itself have varying vascularity, so that in the upper lumbar spine, there may be hypovascularity, and this may selectively, again, knock out certain nerve roots. So we've been talking about cauda equina, but that's really just one side of the coin. The talk is supposed to be about urinary urgency, right? So we need to have an understanding of that as well. If you just pull up like primary care or internal medicine literature, you can find a differential for chronic urinary incontinence, and if you had cauda equina, that would be the overflow type of incontinence here, so we can unpack that, and really only 5% of patients with chronic urinary incontinence have it due to this overflow picture. So most picture, most, if you just take that at face value, most patients in your clinic that tell you they have urinary incontinence probably don't even have the type of urinary incontinence that would be cauda equina, but if you do have this type of incontinence, it's due to overdistension of the bladder, you have impaired detrusor contractility, patients may just report dribbling of urinary, inability to empty, hesitancy, they may have loss of urine without recognizable urge, and consistently, these patients will have elevated post-void residuals. If you unpack the differential of chronic overflow incontinence, then you see here that there can be anticholinergic medications that cause it, and I would add opioid medications to that list, BPH, pelvic organ prolapse, diabetes, multiple sclerosis, and spinal cord injuries, and so this now, spinal cord injury or cauda equina, is one less common cause of an uncommon cause of urinary incontinence, so now we can see why it might be so rare. Patients don't know what kind of urinary incontinence they have, though, so we have to have a somewhat broad understanding of other causes of urinary urgency or overactive bladder, even if it's not overflowing incontinence, and as you see here, most of these things on the differential have to do with the GU system themselves and not the neurologic system, and it should be easy to look in their chart and see if they have these things or ask questions about the presence of other symptoms. One thing that can be particularly challenging is, you know, I have patients that they say they are transient incontinence, like, yeah, I wet, you know, I wet myself a few times a month, and that really doesn't seem like a neurologic picture, right, and in fact, if you look up this differential of transient incontinence, it really doesn't have to do with the spinal problem. It's delirium, it's infection, it's atrophic vaginitis, it may be pharmaceutical-related, related to their urine output itself, or even just poor mobility or stool impaction, but I think we can be confident that if it's intermittent incontinence, it's most likely not spine, so my conclusion on that would be that most urinary symptoms in our spine clinics, at least as a physiatrist, are not cauda equina, but this question, you know, is what do you do with a patient with urinary incontinence? You got to work it up or you have to know what to do, so to do that, I think we'd all agree that cauda equina is a surgical condition, so we have to look at some of that literature as well, so we'll go over two quick papers here. So, the first was a retrospective review of 75 patients that were operated on for cauda equina, and this represented about 10% of the discectomies they did over a 15-year period, and they looked at the baseline characteristic and outcomes of these patients, and as you see here, the symptom incidence of the cases they operated on were actually sciatic pain, altered sensation in the saddle region, and micturation dysfunction, so this triad of symptoms here are actually very, very common, and if you see the three of these, you probably know what you're dealing with, and all the other symptoms are either much less prevalent or at least much less reported. Another emergency room paper looked at this in terms of patients presenting with cauda equina to the emergency room, and we see a very similar picture here in terms of neurologic symptoms, and that is that up to 90% or 85% of patients will have sensory loss or urinary symptoms. Now, this makes it even trickier, though, because I keep saying they have urinary dysfunction, and we haven't even really defined what that is, so in these studies, when they talk about urinary dysfunction as part of cauda equina, a lot of times they're seeing them, they already have a catheter in, and that means someone figured out they had retained urine, but if they have not been diagnosed and treated, the patients actually subjectively will just complain most often of a reduced feeling of passing of urine or mild incontinence, and that speaks to the case I presented at the beginning. This isn't really about outcomes, but I think we should understand what happens to these patients if we diagnose them and treat them, and as you see here, while many patients will present with urinary symptoms, unfortunately, even despite definitive treatment, many of them still have residual symptoms post-operatively. Despite that, you could say relatively poor outcome, there's a consensus in the surgical world that you want to urgently decompress these, and that's really the 48-hour mark is considered something that you want to shoot for, and so then you have to ask, again, we're asking what do we do in clinic, what are we worried about, and one study looked at what happens when cases are missed and when there's delay in treatment and unfortunately the majority of cases where there's delay in treatment weren't patient factors and they were physician factors and essentially missed diagnoses. The patient or the physician didn't know what was going on or they didn't catch it immediately. It may not be fair to always blame the physician but another study looked at this from a slightly different perspective and again physicians were often noted to miss the diagnosis but their conclusion was that it was missed because patients don't present with the classic or all of the characteristic features of cauda equina and this paper at least here noted that sacral sensory loss is sensitive and specific for cauda equina which is consistent with the other data I've presented. In that same paper though four of the missed cases which was a minority but still a significant percentage were essentially because cauda equina wasn't considered on the differential when the patient presented and I would assume everyone's listening to this because we don't want to be that physician that misses this or in another way of looking at this graphically this is a chart of patients who are operated on their time to operation and their clinical findings and what we certainly don't want to be is have a significant delay in diagnosis or treatment when they have a pretty significant constellation of symptoms but I'm guessing Dr. Zhang asked me to speak on urinary symptoms alone because sometimes that might be the only presenting symptom and what we're all trying to be is not be this person where they have a few symptoms we would like to catch that earlier so we don't want to be the red and we may be the yellow but we may have tools to correct for that. Unfortunately there are medical negligence cases that occur due to delayed diagnosis and those cases essentially occur when the delay in diagnosis or the diagnosis itself was made in six days only so missing this by just two or three days can be catastrophic. My summary points for the literature at least would be that most of the cases of incontinence in a spine clinic are not likely spine related. Most causes of cauda equina do not present classically. Be wary of vague urinary symptoms because that's probably the most common presentation of urinary symptoms and that research shows that there may be some abnormalities in rectal tone that we didn't talk about but there's a significant body of literature that shows these patients have retained urine so a reasonable first test may be a bladder scan and it's generally accepted that early decompression results in better outcomes so we do want to stay on guard. So if we go back to this case example I presented these were his presenting symptoms um because of the urinary symptoms and imaging which I was fortunate to have you can see there's quite significant compromise of the central canal there he was referred to the spine surgery team the same day that he presented to me and they elected to surgically decompress but not urgently because the symptoms had been going on for weeks so they did it in a controlled manner and did it within a day or two and the outcome of that case is still pending and those are my summary points again again be wary of vague urinary symptoms consider checking PVRs and realize that most patients present with urinary symptoms as well as some sort of sensory abnormalities but this constellation of symptoms may not always be there. Thank you very much next up is Dr. Matthew Smoot who is a professor at Stanford University. Thank you Byron. I'm going to pull my slides up and get started. So my discussion today is on night pain and let's jump right in. First I'd just like to point out that these are all of my potential conflicts and I don't believe any of them have any relationship to things discussed in this lecture. So Dr. Day has done a lot of good work in the primary care setting on back pain and he produced data on the prevalence of malignant causes of back pain and keep in mind that this data relates to all malignant causes which he considered to be infection, fracture, tumors, you know bad things and in the primary care setting you can see that you know patients that present with back pain as their primary symptom the the prevalence of malignant causes including all of those things I mentioned is is pretty small but you know given how common back pain is you know even at at one percent or half a percentage point that's going to turn out to be a fair number of people over time. Something to keep in your back pocket is that Dr. Day also showed that 95 percent of those cases can be uncovered by these three simple tests an x-ray a cbc and a sed rate and and I like this data because I use this uh sometimes to screen uh when I have some concerns. Now it's also important to keep in mind what things this won't pick up so one of the things that wouldn't be picked up on Dr. Dayo's list is a sacral insufficiency fracture. Oftentimes those are missed by x-ray. Also myelodysplastic disease will not be discovered unless it's severe enough to cause an abnormality in the cbc which can happen but happens typically later in the disease when you'd like to pick it up sooner. So 95 percent is pretty good number but you have to be wary of the things that aren't uncovered by these tests and know when to look for them in more detail. Dr. Slipman looked at PM&R clinics and provided good prevalence data there and specific to neoplasia in the spine he showed that that in a private practice setting a little more than 0.1 percent and in an academic setting almost 0.7 percent of patients that present to spine centers with with complaints of back pain are found to have a neoplastic cause. So this just gives you some idea of the rates that you'll encounter these things and it should be relatively you know anybody who's been in practice for years has probably diagnosed somebody with with neoplastic disease. What did Dr. Slipman find that are some of the associated features that go along with this? Well here's the list. The patient characteristics look at the top two. Spontaneous onset of symptoms in 94 percent of these patients but unless somebody has a workman's comp claim or was injured in an automobile collision I find that most patients describe a spontaneous onset of symptoms without a known cause. So it's hard you know while that might be highly sensitive it's not very specific and also no relief with prior conservative treatment is also a very non-specific thing that that is something we see all the time. I can't say how many times I see people that tell me physical therapy doesn't work for them. So the point of this is that good follow-up care is required because none of these symptoms are highly sensitive and specific at the same time. Now look down at the bottom of this list you see pain characteristics and our our topic of the day which is night pain and although we think of that as a red flag and you should think of it in that way it's only present in less than half of patients that were determined to have a neoplastic cause of their pain. So while night pain should raise a red flag the absence of night pain doesn't doesn't put you in the clear. All right so that brings us to our first case. This is a 44 year old female with six months of left back buttock and thigh pain and it's in a pretty clear L3 distribution when she describes it to you. She says the pain started at night about three months ago so here's our night pain but over time it's become persistently painful 24-7. Pain has increased despite oral meds and PT so here we have failure of conservative treatment to help and an outside provider gave her a left L5S1 transpiraminal epidural steroid injection based on her MRI and it really didn't help her at all and so she's coming in looking for a second opinion. On exam you find a positive femoral stretch and signs of left L3 radiculopathy including motor sensory and reflex deficits and you have an outside MRI and the MRI report you have the report and the images the report says there's an L45 disc protrusion that explains the L5S1 transpiraminal epidural steroid injection and a L3 atypical hemangioma and here's the MRI. On the left you see the axial T2 slice through the L3 vertebral body of that atypical hemangioma and on in the middle on the right you see the T1 and T2 sagittal views of that same lesion and L3. Now looking at this when I saw this this is the actual case for my clinic I thought well you know I guess I don't really know what is an atypical hemangioma but I can say this doesn't look like a typical hemangioma and in fact I'm a little concerned because this looks the majority of this looks dark on both T1 and T2. Darkness on T1 and T2 should raise concerns because that's usually solid tissue and because of the fat content of the bone of the vertebral body you should not see dark things growing there and so if it's dark on both T1 and T2 it's replacing the fat and maybe something's growing there. So I was worried about this and I called the you know radiologist to talk about it because number one it was the only thing in the area of her symptoms is she had clear L3 radicular pain but number two you know I wanted to ask them what's an atypical hemangioma and what should I do. So you know what do you do next that's definitely one of the things you want to do is talk to your radiologist if you have that available. But I also started growing gabapentin she hadn't used that medicine and she had radicular pain. I ordered an EMG because the MRI really didn't tell me why she had this L3 radiculopathy and I wanted to make sure that you know I didn't have a diagnosis wrong and EMG turned out to show active denervation in L3 muscles and I ordered a new MRI and this was in part based on the conversation with the radiologist who told me you know well this may be an atypical hemangioma but you can't rule out other things including neoplasm which was my concern and they said yeah maybe you should you know wait a couple of months and get another MRI and see what happens. But you know this woman was in a lot of pain and needed treatment and so I scheduled the EMG rapidly and scheduled another MRI although it was only four months after the previous MRI and you can see here that the lesion is larger. So what do you do now? You know what's next? Obviously this is very concerning hopefully you get this information ahead of the follow-up visit with the patient and the follow-up visit is in the near term because this needs to be addressed and if you have this information as the patient comes into clinic your day is going to be disrupted because you have a lot of coordinating to do. And so what did I do? I had the patient scheduled for follow-up the day after the MRI. I got the MRI results and at the end of clinic the day before the patient was to return to clinic I talked to the spine surgeon and I talked to the oncologist to have the next steps in place and the spine surgeon was already prepared to schedule her for our biopsy and the oncologist was ready to see her in consultation. So when she arrived at clinic the next day to go over the MRI results and I told her of my concern I was also able to provide her with next steps and get things taken care of rapidly. All right case number two. This is a 72 year old male with low back pain on and off for decades. Six months ago he started having more pain and he says his pain's most bothersome at night. You know it's when it bothers him the most during the daytime he's kind of distracted from it and and he gets along okay. His exams unremarkable and his MRI shows age-appropriate degenerative changes and heterogeneous bone marrow signal. All right that's one of my least favorite things in spine care is heterogeneous bone marrow signal. What do you do with that? This is a person with night pain and with this MRI finding. So what do you do next? In my case in in this scenario I order labs and what labs am I going to order? I'm going to order these four tests a CBC, SPEP, UPEP and serum-free light chains and the goal here is to rule out myelodysplastic disease. That's something that you don't want to have come to your clinic and and go unchecked. Now the trouble here is that it's really challenging to know when to be concerned about heterogeneous bone marrow signal, when is it more concerning for myelodysplastic disease and when is it not. I've talked to multiple neuro and MSK radiologists about this you know where's your threshold and they basically give you an answer that is similar to the way I would answer this question now which is well you know it just doesn't look right. I know that's very uh unfulfilling but but to my point let's look at these three patients. Patients A, B and C. All of these are real patients from my own clinic. Which of these patients has myelodysplastic disease? Because I'm going to tell you one of them does but only one of them does. So take a look for a moment here, which do you think? Well here are the answers. Patient A ruled out for myelodysplastic disease just just mild benign heterogeneous bone marrow signal changes. Patient B has confirmed myelodysplastic disease and patient C is somebody I saw just last week and labs are pending and I suspect myelodysplastic disease but I also won't be surprised if it turns out to be benign. So what are things that make me suspicious about these films? It's the darkness of the bone marrow signal. Typically in a vertebrae because of the fat content on both T1 and T2 the the bones should be quite light compared to the discs compared to the muscles and other dark things on the image and each of these there's some dark areas. I'll point out between these two if you just ask me which one's more suspicious I would say the one on the left looks more suspicious than than the one in the middle but the one on the right probably looks most suspicious to me because not only do you have a lot of dark areas on both T1 and T2 but you also have some isolated kind of ovoid structures which look like perhaps more like tumors. So hopefully soon I'll be able to tell you if KC was myelodysplastic disease or not but I order the laboratory test to rule in or out myelodysplastic disease many more times than to come back positive and that is the way any screening test should work and my litmus test in the end for deciding when to order those labs is when I think about whether or not I should order the labs. If that thought occurs to me when I'm looking at the MRI then that tells me that it's time for screening. So what do you do now when the patient has myelodysplastic disease? Well it's probably not quite as much of an emergency as case number one but this is not also something you don't want to sit on you want to get on the phone and talk to your hematologist oncologist colleagues and make sure that this patient has an appointment to be seen and appropriately treated. So in conclusion patients with back pain where there's any suspicion of neoplasia make sure you provide a workup and provide appropriate follow-up care. Night pain has low sensitivity for neoplasia but when it does occur you need to have some suspicion. The most common clinical feature for patients with neoplastic causes of back pain are spontaneous onset and failure to respond to conservative treatment. That's why good follow-up care is necessary for appropriate management and detection of these things and MRI can miss myelodysplasia so if you are concerned about that possibility a laboratory workup is your friend. All right thank you everybody for attending this session. We have a little bit of time for Q&A maybe a minute or so so I will ask the other panelists to come on and and we'll do what we can with the time remaining. So yeah thank you all for participating and for putting in some of the questions you have in the chat box and you know you have all our emails if we're not able to get to your question in our allotted time please feel free to reach out to us directly. Let me just kind of cover some of the questions that I do see in the chat box right now in the very little time we have left. So Dr. Frank King actually asked compared to spinal central causes of foot drop how common is peroneal neuropathy? Great question. There's no direct study that would be able to answer this. You know in my mind lumbar radiculopathy is quite common and I remember working on a grant and the population prevalence is three to five percent. It's one of the most common complaints evaluated by a spine surgeon and the L5 especially the L5 radiculopathy is the most common so it's definitely really high up there especially if there is concurrent back pain and any sort of sciatica sounding symptoms. But peroneal neuropathy I would say may be more common than we give it credit for. It is the most common cause of lower extremity neuropathy. It accounts for 15 percent of compressive lesions and so definitely keep an eye out for that. I do agree with Dr. Michael Dento that you know especially if it's painless foot drop that's really really a lot higher on my differential. Next question is for Dr. Schneider. So Dr. David Judish asked if you do, well I guess commented, I don't know if Dr. Schneider has a comment, that if you do inpatient rehab the estimated incidence of cauda equina seems a little bit higher than what was stated. Dr. Schneider do you have a comment for that? Sure my comment to that would be I would believe the literature I was quoting was looking at patients who present with cauda equina. So you know if someone has cauda equina from an MVC and a major trauma that wouldn't have been captured in those papers and again that's not what we see in our clinics as an outpatient basis. So I believe that's the incidence of patients who present with symptoms that are cauda equina need to be diagnosed as such not with known tumors or with known trauma. Thank you and we have three comments for Dr. Smook in the chat box. So the first is for the case one I believe Dr. Madhu Singh asked what kind of tumor was it in the end? Yeah so it's a very sad case turns out to be a metastatic lung cancer and a patient expired within two years of the diagnosis from my clinic. Oh yeah second question is you know what are the four tests you order when you're thinking of myelodysplasia? SPEP, USPEP, CBC, and serum light chains. I think Dr. Kennedy is also addressing this question to you. You mentioned that day of study on screening being done in a primary care setting which may be different than a pain spine center. Yeah I mean you can expect the prevalence in the spine center to be about double of what you would see in the primary care setting but the screening test should have a similar sensitivity of 95 percent. And Dr. Michael Dento asked Dr. Smook how commonly do you find enlarged lymph nodes on MRI and what do you do with that finding? Oh man that's a great question. I find them rarely and I admit that I'm bad at looking for them. I've tried to do a better job of that but it's also one of those things that's a little nefarious to me just like bone marrow signal changes changes and so when I have some concerns about it I will often talk to the radiology colleagues which I admit is probably a luxury of being in one of the ivory tower institutions like I am but it's very easy for me to call down to the radiology reading room and talk to one of the MSK fellows or one of my colleagues. And last I just want to thank Dr. Josh Schweitler for pointing out yes inversion weakness, ankle inversion weakness can help to tease out alphabetic versus a peroneal neuropathy. The ankle inverters inversion muscles are supplied actually by the tibialis anterior and posterior their tibial innervated muscles that tend to have alpha innervation so thank you for pointing that out. And yeah I think that actually hit all the highlights. Thank you all so much for being here with us today. If you need anything or have further questions feel free to reach out to us and have a great Friday. Stay safe everyone. Bye. Thanks everybody. Take care. Thank you.

spine pain

lumbar radiculopathy

common peroneal neuropathy

Morton's neuroma

diagnosis

treatment options

cauda equina syndrome

urinary urgency

neoplastic causes

follow-up care