Understanding Spinal Cord Disorders

Spinal cord disorders are common and frequently disabling. Despite advances in our ability to diagnose and treat patients with spinal cord disease, many are underserved by their health care systems due to gaps in knowledge and care.

In this episode, Lyell K. Jones Jr, MD, FAAN, speaks with Shamik Bhattacharyya, MD, FAAN, who served as the guest editor of the Continuum® February 2024 Spinal Cord Disorders issue. They provide a preview of the issue, which publishes on February 8, 2024.

Dr. Jones is the editor-in-chief of Continuum: Lifelong Learning in Neurology® and is a professor of neurology at Mayo Clinic in Rochester, Minnesota.

Dr. Bhattacharyya is the Anne M. Finucane Distinguished Chair in Neurology and chief of the division of spinal cord disorders at Brigham Women's Hospital and an assistant professor of neurology at Harvard Medical School in Boston, Massachusetts.

Additional Resources

Continuum website: ContinuumJournal.com

Subscribe to Continuum: shop.lww.com/Continuum

American Academy of Neurology website: aan.com

Social Media

facebook.com/continuumcme

@ContinuumAAN

Host: @LyellJ

Guest: @shamik_b

Full transcript available here

Transcript

Dr Jones: This is Dr. Lyell Jones, Editor-in-Chief of Continuum, the premier topic-based neurology clinical review and CME journal from the American Academy of Neurology. Thank you for joining us on Continuum Audio, a companion podcast to the journal. Continuum Audio features conversations with the guest editors and authors of Continuum, who are the leading experts in their fields. Subscribers to the Continuum journal can read the full article or listen to verbatim recordings of the article by visiting the link in the show notes. Subscribers also have access to exclusive audio content not featured on the podcast. As an ad-free journal entirely supported by subscriptions, if you're not already a subscriber, we encourage you to become one. For more information on subscribing, please visit the link in the show notes.

Dr Jones: This is Dr. Lyell Jones, Editor-in-Chief of Continuum: Lifelong Learning in Neurology. Today I'm interviewing Dr. Shamik Bhattacharyya, who recently served as Continuum's Guest Editor for our latest issue, on spinal cord disorders. Dr. Bhattacharyya is a neurologist at Brigham and Women's Hospital, where he serves as Chief of the Division of Spinal Cord Disorders and as an Assistant Professor of Neurology at Harvard Medical School, in Boston, Massachusetts. Dr. Bhattacharyya, it's great to see you - welcome. Thank you for joining us today.

Dr Bhattacharyya: Good to see you, Dr. Jones. I look forward to speaking.

Dr Jones: So, for our listeners who are new to Continuum, Continuum is a journal dedicated to helping clinicians deliver the highest neurologic care to their patients. We do so with high-quality clinical reviews and content in our journal and in our audio format. For our long-time listeners to Continuum Audio, you'll notice a few different things with our latest issue and our latest author interviews. For many years, Continuum Audio has been a great way to learn about Continuum articles. Starting with this issue on spinal cord disorders, I'm happy to announce that our Continuum Audio interviews will now be available to all on your favorite open podcast platforms. We'll hear some exciting new content in our interviews, and we're also going to introduce interviews with our guest editors, like Dr Bhattacharyya, who are really indispensable in putting these issues together. In this issue, specifically, Dr. Bhattacharyya is full of extremely helpful clinical descriptions and treatment strategies for patients with spinal cord disorders. As the editor, you got really a broad view of the whole range of spinal cord disease. What was the most surprising thing when you were reviewing these articles?

Dr Bhattacharyya: I think as a field, neurology - the knowledge base in neurology - grows bigger and bigger and bigger each day and in fields hard to keep up and how to integrate all of it together, right? I think all of us deal with it. And that's the hope of Continuum, is that you can provide these periodic refreshers. I got refreshed myself! Even though I see the patients day in and day out, when you actually read about the advances, for example, in hereditary spastic paraplegias, or the nuances of how neoplasms in the spinal cord are now classified- you say "wow", I didn't actually know that. The knowledge spreads and grows, and I think that's the beauty of being an editor of some of these issues - is that you get to learn yourself and maybe perhaps even apply them in the clinical situation.

Dr Jones: You and I are both educators. And that's, I think, one of the secret joys of teaching is that you end up learning a lot, sometimes from the people you're teaching, right? I guess maybe that's not a surprise - that you learn something by reading it. I guess it was probably pretty nice, huh?

Dr Bhattacharyya: It was very good. I think the authors all come from different geographic backgrounds, even from different training backgrounds. In spinal cord disorders, there are trials in some aspects, but in other aspects it's really opinion-based practice, right? So, it was good to also see how other institutions do it. And I imagine it's the same for readers when they see how they do it at their institution and also get a viewpoint of how it's done at other places. That's the valuable perspective piece for putting together a different of authors and see how people do it at different places.

Dr Jones: Always nice to learn from others. And speaking of learning - for our clinicians who are listening to our interview today, Shamik, tell us a little bit about the basics of how spinal cord disorders present. I know as an educator, sometimes for, especially junior learners, it's a little mysterious and I'm not really sure why that is, but what are some of the basic clinical tenets of how spinal cord disorders present?

Dr Bhattacharyya: I'm glad you brought this up, because in some ways, spinal cord is the orphan child of neurology, right? I think for most neurology trainees, the nervous system stops at the brainstem and then progresses again at the nerves. The spinal cord is really just viewed as this conduit of tracts up and down, and that's all it does is a big set of wires, which is not true, right? A lot of primary neurological processing happens at the level of the spinal cord, and it really is a continuation of the central nervous system. And I hope, with this issue, people get a sense of that. For spinal cord disorders (also called myelopathy; the name goes, synonymously, hand in hand), I think one of the principal functions of the spinal cord is balance. A lot of the program - the neural programming of balance on postural reflexes are hard wired into the spinal cord. I think one of the key aspects of spinal cord disorders is imbalance. I think that people should think of this as a core feature of myelopathy. If you take an example for cervical spondylotic disease, people think, is it going to be off your hands? Well, I think most patients with cervical spondylotic myelopathy actually complain of gait imbalance as one of the early features of the disease. So, imbalance, bilateral weakness, and/or bilateral numbness, tingling, paresthesia - those aspects are suggestive of spinal cord disorder. Bowel and bladder dysfunction can be, but it's not universally true. Now, there's some specific symptoms that I think are especially suggestive of spinal cord disorders I think that are kind of fun to ask about, and if true, can help you localize. One is the Lhermitte sign; you ask people to flex their neck and say, like, "Do you feel sharp, shooting thing, like, down your hands or your back?" In your legs? If true, you have something, right? That's a spinal cord disorder. The other sign that I think is clinically helpful is weakness on one leg and numbness on the other, like Brown-Séquard syndrome or hemicord syndrome. If you find that to be true - and you often see that with multiple sclerosis lesions or other traumatic lesions - that is a spinal cord disorder. I think those clues can come out in history and on exam, and can help you localize it better.

Dr Jones: It's nice to know those specific features - in other words, those things that, when you do see or hear them, really should make us think about spinal cord disorders, right? Again, they might not be the most common way they present, but it's good to have those in your pocket, right?

Dr Bhattacharyya: Right.

Dr Jones: You mentioned this - spinal cord pathology occupies kind of an interesting place in the neurological world, right? There really aren't "myelopathists," but you direct a division on spinal cord disorders, which is - I think is pretty uncommon. Tell us a little about that. How does that work at your institution?

Dr Bhattacharyya: Maybe I can start with the history of this, right - of how this actually came about. I was graduating as a fellow and entering as a faculty in our neurology department. Initially, my interest was in autoimmune neurological disorder - it still is in autoimmune neurological disorders. And yet, when they saw patients who came in for myelitis and turned out they didn't have an inflammatory myelopathy, there really was no home for them, right? - it's a strange space. And that includes even for garden-variety, cervical spondylotic disease that's causing myelopathy - there is no good neurology home for those patients. After the first year of seeing patients, I felt that we need to do better for that. That's why we ended up opening the spinal cord disorders clinic, which was actually the only neurology-based one in our system. There are plenty run by physiatry, surgery, pain management, and other services. But the only neurology one in our system focused specifically on neurologic management of patients with any type of spinal cord pathology.

Dr Jones: That's a distinctive way that it came about at your institution and in your own career. It sounds like this does need to be a team effort. Who are the other disciplines or specialists who need to be involved in the care of these patients?

Dr Bhattacharyya: Our spinal cord clinic itself is a part of the comprehensive spine center in our hospital. In that center are pain management doctors, physiatry, as well as different spine specialties, including orthopedics and neurosurgeons and interventional radiologists. So, it's kind of a multidisciplinary group effort to take care of these patients.

Dr Jones: I know it'll vary according to the problem with the spinal cord, right? There's dozens or hundreds of different diseases that can affect the spinal cord. So, treatments are different for different diseases, right? But what do you see, therapeutically, as being some of the next big things on the horizon for patients with spinal cord disease?

Dr Bhattacharyya: I think one of the common, unifying aspects is pain from spinal cord injury. Especially if there's interruption in the spinothalamic tracts, the pain can be a very severe thing that ranges all the way from neuromyelitis optica, the tonic spasms, to spinal cord infarcts, chronic sequelae of pain, to trauma (spinal cord trauma) - pain is such a big aspect. And our both interventional and oral neuropathic pain medicines don't do a good job with it. I think there's a wave of new medications that are in trials for neuropathic pain and I'm hopeful that they will be helpful and that they will improve pain control and quality of life for our patients. The medication approaches to pain also come with side effects that all of the medicines have. Some of our patients are on high doses of multiple medicines and have cognitive impairment, right? I think that was also the motivation behind our getting a specific section in this issue on symptomatic management of spinal cord injury. Because I think no matter where you are in the spectrum of spinal cord disorders, whether you're a vascular doctor or a family doctor, you will be prescribing gabapentin and baclofen, right - as for helping the patient, and it's good to know how to do it. The other aspect that I'm really hopeful about are sort of second-generation prosthetic devices. These are some of the electrostimulation devices where there's intelligence built into the device that detects you moving your leg and then artificially stimulates a peroneal nerve. This is much better than foot braces, for example, for foot drops. And there are now multiple companies who make these devices, and for some of our patients who have had spinal cord disorders and had difficulty walking or tripping, these have actually made a big difference. I think prosthetic and electric stimulation also has potential of helping a broad range of patients with spinal cord disorders.

Dr Jones: And I'm glad you mentioned that article on the symptomatic management of the problems with spinal cord disease, regardless of the cause. And it's a wonderful article that will encourage our listeners to seek out. To go back to the pain, this is something that - many of us who care for patients with spinal cord problems - we encounter is this. And I think it's underrecognized (the pain complications of spinal cord disease). Medications on the horizon - what about devices and neuromodulation? This is another thing I get asked about a lot.

Dr Bhattacharyya: Exactly. I think the - for example, spinal cord stimulators for pain management - I think it's been controversial in the sense of who are the best people for it. The history of neuromodulation in spinal pain in some senses has been unfortunate because it was first approved for so-called "failed back syndrome," right? And the name is terrible. The patient population is heterogeneous. And it has come to a point where it was unclear who it was helping and what the right indications were. I think for neuropathic pain and, in particular, for spinal cord injury pain, I think there is now a renewed push to study neuromodulation, both implantable devices and external devices, to see if those aspects can help. I think they're part of the new wave of things. I think the question patients often ask me is, "Can you regrow my spinal cord?" - right? "Is there something on the horizon yet?" As far as I know, right at this moment, there is not, that's clinically applicable, but perhaps in the future that might be true. But I think, short of regrowing the spinal cord, we can help function and help pain in meaningful ways.

Dr Jones: We'll be hopeful about cell therapies and other regenerative therapies down the road. I don't think it's in our immediate future, but we maintain hope. You know, I know this is an area that, again - spinal cord problems are common, spine disease is common - but it does kind of fall between the cracks clinically. If there were one point, Dr Bhattacharyya, that you would want to make to our listeners about the one thing not to miss, or the thing that you most commonly see being missed in the clinical evaluation and/or care of these patients, what would that one thing be?

Dr Bhattacharyya: I think the time to clinical evolution of myelopathy probably has the biggest value in determining the cause of it. I think this was beautifully brought out by the article by Dr. Pardo, where he talks about an integrative approach to myelopathy, and in contrast to prior conceptions of whether it's inflammatory based on your CSF cell count or your MRI features, it's actually based on time - time from onset of symptom to nadir of symptom. Is it a few hours, is it days, is it months, right? And having that diagnostic framework is, I think - I go back to it time and time again - is key in trying to figure out, because none of the measures we use, both on imaging or CSF or laboratories, are very sensitive or specific, and actually do not outperform just categorizing by time alone, right? So, I think the one take-home message is, if you have sudden, rapid-onset myelopathy that evolves over minutes, it's probably a vascular process. Even if you find ten cells in the CSF, it's still vascular, right? If it's something that evolves over days, maybe 7, 8, 9 days, and then you find diffusion restriction in the spinal cord on imaging, it's probably still an inflammatory process rather than a sudden spinal cord infarct, right? So, I think that the time aspect cannot be ignored and should play a central role in decision making.

Dr Jones: That's very helpful. And I think maybe the corollary to that is - there are chronic spinal cord disorders, right? And I think clinicians, especially if you're not familiar with spinal cord disease, it's terrifying, right? As soon as you start to think, "Wow, this patient's telling me a story and I'm worried this could be a spinal cord problem - should I send them to the emergency department?" - right? They have some bladder dysfunction; they have some gait disorder. But if it has been going on for years, the emergency department is probably not the best place to evaluate that, is it?

Dr Bhattacharyya: I'm glad you mentioned it because we see that in the emergency room, right? Someone clearly has a myelopathy; you asked him how long it's going on – it going for months or even years sometimes, right? And it was first noticed and sent out. So, yes - there are multiple causes of chronic myelopathies. They range all the way from structural causes, where you can have things like, for instance, webs, of arachnoid webs, that cause slow progressive myelopathies, to vascular malformations of myelopathies, to nutritional causes (even that can cause a slow, progressive myelopathy), Not to speak of infections; I think we often think of infections as causing fast myelopathies, but especially with HTLV-1-associated myelopathy, the usual clinical progression is slow and progressive. I think across all categories of disease, there are instances of slow, progressive myelopathies that really require thoughtful workup but doesn't require an emergency workup.

Dr Jones: Yeah, it's good to know that not every spinal cord problem is an emergency. I think it does terrify clinicians, right? I mean, this is the broadband connection between the brain and the body, and it's fragile, and it's unforgiving, and it's every command sent to the body - every piece of information sent back to the brain, all traveling through a billion neurons with a maximum diameter slightly larger than a dime, right? I think that's why it creates consternation. But I imagine it's also - on the clinical side - it's probably in part challenging and in part rewarding to care for these patients. When you think about what's most rewarding about the care of patients with spinal cord disorders, what comes to mind for you?

Dr Bhattacharyya: I think, a couple of aspects. And just thinking back to my last clinic - I put it on Fridays, just because I get the most joy out of this clinic, right? The first is that there's no single piece of test that gives you the answer totally, right? It's usually about putting the history together, the labs, the imaging, and talking about it together, right? And I think it's that integrated piece that, as clinicians, I think that brings us joy; it's that figuring something out, that's more than saying, "Is there diffusion restriction or not on the brain MRI?" – right? The second piece that I think is helpful is that, that patients really want to learn, and for spinal cord disorders in particular, there's easy anatomic things that you can point to patients and say, like, "This is why you are weak in the arm and maybe numb in the leg, and that's causing your problem, and this is what we're going to do about it." And I think, the ability to communicate that with the patient through images is, I think, unique in the sense that patients understand it - that this is the connection and there's something wrong here and that's why I'm having these symptoms. I think those are aspects of spinal cord disorders that I think are really neat. I will say that I also hope that, for our trainees, right, - I think their comfort with imaging stops at the brainstem, right? The moment it gets below the spine, whether looking at foraminal narrowing or canal stenosis, it's about, "Do they have a T2-hyperintense lesion or not?" And beyond that, people are hesitant. I hope that if this issue can give a different categories of spinal cord disorders, our trainees also become a little bit more facile with different aspects of spinal pathology.

Dr Jones: I think a lot of neurologists are drawn to our field because of the problem-solving nature, right? Which is what you have to do before you start helping the patient. And you clearly have a lot of enthusiasm for this - I mean, it's contagious, right? There aren't a lot of myelopathists right now, but maybe after listening to your interview, Dr Bhattacharyya, reading your issue in Continuum, maybe you've created some myelopathists.

Dr Bhattacharyya: And just remind, there's an AAN spine section that exists in the American Academy of Neurology, and it's very small and can use more members. Certainly, you're welcome to join.

Dr Jones: Well, that's a great plug and, Dr Bhattacharyya, once again, I want to thank you for joining us and thank you for such a thorough, fascinating, engaging discussion on spinal cord disorders. Thank you for guest editing a really phenomenally well-done issue that I think is going to be really informative to our readers and our listeners. Again, we've been speaking with Dr Shamik Bhattacharyya, Guest Editor for Continuum's most recent issue, on spinal cord disease. Please check it out, and thank you to our listeners for joining today.

Dr. Monteith: This is Dr. Teshamae Monteith, Associate Editor of Continuum Audio. If you've enjoyed this episode, please consider subscribing to the journal. There's a link in the episode notes. We'd also appreciate you following the podcast and rating or reviewing it. Thank you for listening to Continuum Audio.