Continuum Audio Traumatic Brain Injury and Traumatic Spinal Cord Injury With Dr. Jamie Podell
Despite validated models, predicting outcomes after traumatic brain injury remains challenging, requiring prognostic humility and a model of shared decision making with surrogate decision makers to establish care goals.
In this episode, Lyell Jones, MD, FAAN, speaks with Jamie E. Podell, MD, an author of the article “Traumatic Brain Injury and Traumatic Spinal Cord Injury,” in the Continuum June 2024 Neurocritical Care issue.
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. Podell is an assistant professor in the department of neurology, program in trauma at the University of Maryland School of Medicine in Baltimore, Maryland.
Additional Resources
Read the article: Traumatic Brain Injury and Traumatic Spinal Cord Injury
Subscribe to Continuum: shop.lww.com/Continuum
Earn CME (available only to AAN members): continpub.com/AudioCME
Continuum® Aloud (verbatim audio-book style recordings of articles available only to Continuum® subscribers): continpub.com/Aloud
More about the Academy of Neurology: aan.com
Social Media
Host: @LyellJ
Guest: @jepodell
Transcript
Full transcript available here
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. AAN members, stay tuned after the episode to hear how you can get CME for listening.
Dr Jones: This is Dr Lyell Jones, Editor-in-Chief of Continuum: Lifelong Learning in Neurology. Today, I'm interviewing Dr Jamie Podell, who has recently authored an article on traumatic brain injury and traumatic spinal cord injury in the latest issue of Continuum on neurocritical care. Dr Podell, welcome. Thank you for joining us today. Why don't you introduce yourself to our audience and tell us a little bit about yourself?
Dr Podell: Thanks, Dr Jones. It's great to be here. As you mentioned, I'm Dr Podell. I'm neurocritical care faculty at University of Maryland Shock Trauma. I have a primary interest in traumatic brain injury, both from a research and clinical perspective. I previously have more of a cognitive neuroscience background, but I think it kind of ties into how I think about TBI and outcomes from traumatic brain injury. But what I really like doing is managing acutely ill patients in the ICU, and I think TBI really affords those kinds of interventions, and it's a really rewarding kind of setting to take care of patients.
Dr Jones: Yeah, and I really can't wait to talk to you about your article here, which is fantastic. For our listeners who might be new to Continuum, Continuum is a journal dedicated to helping clinicians deliver the best possible neurologic care to their patients, just like Dr Podell was talking about. We do that with high quality and current clinical reviews, and Dr Podell's article - it's a massive topic - traumatic brain injury and traumatic spinal cord injury. And, you know, as we start off here, Dr Podell, we have the attention now of a massive audience of neurologists. If you had one most important practice change that you would like to see in the care of these patients who have trauma, what would that practice change be? And, I think, maybe, we'll give you two answers, because you cover TBI and you cover spinal cord injury. What would be the most important practice changes you'd like to see?
Dr Podell: So, this isn't that specific, but I think it's really important. I think we need more neurologists, and specifically neurointensivists, managing these patients. I think there's a lot of variability across institutions and how acute severe TBI and spinal cord injury patients are managed. They're often in surgical ICUs, and neurology may be involved in consultation but not in the day-to-day management. But I think what we're seeing is that, you know, there's a lot of multisystem organ dysfunction that happens in these patients, and that has a really strong interplay with neurologic recovery and brain function. And I think, you know, neurointensivists are very well equipped to think about the whole body and how we can kind of manipulate and really aggressively support the body to help heal the brain with special attention to, kind of, the nuance of any individual patient's brain injury. Because TBI is extremely heterogeneous and there's not just a cookie-cutter script for how these patients can be managed, I think, you know, people like neurologists, neurointensivists who have a lot of attention to the nuance - that's really helpful in their management.
Dr Jones: I'm so glad you said that, and not just because I'm a neurologist who's a fan of neurologists, but I do think there are some corners of neuroscience care where neurologists could be a little more present - and trauma definitely seems like one of those, doesn't it?
Dr Podell: Yeah, I think it's tough, because some patients with severe TBI and spinal cord injury can have a lot of multisystemic trauma with, you know, pulmonary contusions, intraabdominal pathology - you need to go to the OR for their other injuries, and so I think it really makes sense to have kind of a collaborative multidisciplinary approach to these patients, but I think neurologists should play a very big role in that approach, however that's done (there are lots of different ways that it's done). But I think having a primary neurology-trained neurointensivist – I know I’m biased, but I think that’s where I’d like to see the field moving.
Dr Jones: And, obviously, neurocritical care is an intuitive place for neurological trauma care to start, and even with the sequelae of downstream things, I think neurologists could be more engaged. I wonder if neurology hasn't historically been as involved because it's sort of gravitated to surgical specialists. And I think part of it is, you know, trauma is not usually a diagnostic mystery, right? The neurologist can't pretend to be Sherlock Holmes and try to figure out what's going on when it was pretty clear what the event was, right?
Dr Podell: Right. Yeah, I agree with both of those points. I think, for one, I think postacute care is also a big area where neurologists can be involved more - and patients kind of fall through the cracks. A lot of times, these patients will just follow up with a neurosurgeon and get a repeat head CT and it’ll look stable. We started implementing post-TBI neural recovery clinics, which I think other places are starting to do as well, and I think that's kind of a good model for getting neurologists involved - but also, rehab specialists are involved in that. But in terms of, yeah, the diagnostic mysteries and stuff, I think there still can be some, though, with TBI. Yes, obviously, the initial primary insult is obvious, but the secondary pathology that can happen in patients is really nuanced, and it is so variable, and, sometimes, it does take that detective eye to see, “Oh, this patient has one cerebrovascular injury, their risk of stroke to this territory? How are we going to manage it? and thinking about all the kind of sources of secondary decline that are possible. I think it takes that neurology detective sometimes to think about, too.
Dr Jones: Yeah. We never stop pretending to be detectives, right?
Dr Podell: Yeah.
Dr Jones: And on a related note, you know, in your article, you mentioned some of the novel serum and electrophysiologic and imaging biomarkers that are being used to care for these patients. How are you using those in your practice, Dr Podell?
Dr Podell: That's a good question. I think, unfortunately, as with a lot of clinical care, the clinical care does kind of lag behind the research and what we know what we can learn about these patients and their outcomes through retrospective studies. So, to be completely honest, you know, even the serum studies that I mentioned in the article (like GFAP, UCH-L1) - those kind of things, that's not clinically available at our institution. We don't use those. I think a lot of the imaging biomarkers that we see, some of them are coming from more advanced imaging – like, we're talking about FMRI - that requires a lot of post processing (so, again, we're not necessarily using that clinically). But what I would say is that we use imaging to kind of try to predict what complications patients might be at risk of and to try to predict their clinical course. And I think it comes down to trying to break down the heterogeneity of these patients and to try to kind of lump them into different bins of, “What's this patient at risk for?”, “What's their trajectory going to be like?”, “When can I start peeling back how aggressive I am with this patient?”. And, so far, I don't think any of the markers that we have are really clear black-white prescriptive indicators of what to do (I don't think we're quite there yet). So, again, I think we just kind of use all of the data in combination to come up with a management plan for these patients. I think some of the markers, (like some of the electrophysiologic markers), looking at EEG for things like background can provide prognostic information, especially in patients who are comatose that you're wondering about if they're going to wake up (so a lot of this can inform family discussions). But, you know, we used to think that grade three diffuse axonal injury on MRI portended a very poor prognosis (and in the past, some surgeons and ICUs might use that to limit care in patients), but more and more, we're finding that even that is quite nuanced and we're detecting more and more diffuse axonal injury on images in patients who then wake up, or have already woken up and they have the MRI later, and you're like, “Hmm, they had DAI. It's a good thing you didn't get the MRI early and decide not to move forward with aggressive care”. But, I think, in a patient who's comatose and you don't have a good explanation, sometimes, looking for those additional biomarkers to explain what kind of injury pathology you have can just provide more information for families.
Dr Jones: Yeah, and that's a great point that comes up in a lot of our articles and interviews (that the biomarkers really do have to be in a clinical context). So, if I understand you correctly, really, no individual biomarker that has emerged as a precise predictor or prognosticator for outcomes - but you do talk a lot about recent advances in the care of these patients. What would you want to point out to our listeners that's come up recently in the care of trauma?
Dr Podell: Yeah. I think the evidence basis for severe TBI is limited because, again, there's so much heterogeneity and different things going on with different patients, but some of the evidence that has come out more recently involves, kind of, indications for surgical procedures and the timing of those procedures. Some of that is still kind of expert consensus-based. But, for example, doing a secondary decompression for elevated ICP with the DECRA and RESCUEicp trials. We do have better high-quality evidence that doing a secondary decompression for more refractory, elevated ICP can improve both mortality and functional outcomes in patients, so that has kind of become more standard of care. Additionally, I think timing for spinal cord injury, neurosurgical procedures - that's been a topic that's been studied in more evidence-based to perform earlier decompressive surgeries. And then, I think, you know, more and more is emerging just about the pathophysiology of secondary injury - and some of those things haven't necessarily translated to what to do about it - but we've learned about things like cortical spreading depolarizations being associated with worse outcomes in traumatic brain injury, and we've also identified that ketamine or memantine can both actually stop those cortical spreading depolarizations. But the overall impact of managing them is still unknown, and the way that we detect those, it requires an invasive electrocorticography monitor which not all centers have. So, I think, one of the important things as we move forward in TBI care is, as we get this better mechanistic understanding of some of the pathophysiology that's happening in these TBI patients, figuring out a way to be able to translate that across all clinical settings where you can actually do the monitoring invasively - that's also an issue we see. Even intracranial pressure monitoring is pretty standard of care, but not all centers do that, and we have to be able to apply practice recommendations to centers where there isn't necessarily access to the same things that we have at large academic trauma centers.
Dr Jones: Got it. Obviously, there's a lot of research in this area, a lot of clinical research, and I'm glad you mentioned the secondary injury - things that are happening at the tissue level are important for us to think about. As the care of patients with trauma has evolved (and I'm thinking now of patients with spinal cord injury), we still see patients who receive high-dose corticosteroids in the setting of acute spinal cord injury - and obviously, that's something that's evolved. Can you tell our listeners a little bit more about what they should be doing when they're seeing a patient with a traumatic spinal cord injury?
Dr Podell: Yes. So, the steroids story for spinal cord injury is kind of interesting. There were a series of trials called the NASCIS trials that looked at corticosteroids and spinal cord injury, and they were initially interpreted that high-dose steroids had a beneficial effect on spinal cord injury recovery - but then, kind of in relooking at the data and recognizing that these were kind of unplanned subgroup analyses that showed benefit, and then looking at kind of pooled reanalysis and meta-analysis of all the data out there, it was determined that there actually was no clear benefit from steroids and that there was a clear incidence of more complications from high-dose steroids. So, in general, corticosteroids are not recommended for spinal cord injury. Same for traumatic brain injury, too (even though some people will still give steroids for that) - there was a CRASH study that looked at corticosteroids in TBI and found worse outcomes in TBI (so there actually is high-level evidence not to use steroids in that case). That's not to say that there's not an inflammatory process that's going on that could be causing secondary injury - I think that's still, really, you know, an area of active research is to try to figure out what is the balance between potential adaptive mechanisms of inflammation that are happening versus more maladaptive sources of secondary injury from inflammation and how and when do we target that inflammation to improve outcomes. So, there's still, I think, more to come on that.
Dr Jones: And, you know, we are guided by evidence, obviously, but also, we learn from our experience as clinicians. You work in the neurocritical care unit. You take care of all patients with critical neurologic problems. When it comes to TBI and spinal cord injury, what kind of management tips or tricks have you learned that would be good for our audience to hear?
Dr Podell: I think the way that I would sum it up is that you should be very aggressive - supportive care early on, and then thoughtfully pull back and let the brain and spinal cord heal itself. And, you know, the patients come in with TBI (for example) very sympathetically aroused. They do need sedation, they need blood pressure support, they need mechanical ventilation - they need help kind of maintaining homeostasis. And other autonomic effects with spinal cord injury happen, too - you get neurogenic shock (you need very aggressive management of blood pressure, volume assessments), you know, in both cases in trauma patients, managing things like coagulopathy - but, you know, over time, usually, these things start to, kind of, heal themselves to some degree. And then, kind of thoughtfully figuring out when you can peel back on the different measures that you're doing to support them through their acute injuries. Different protocols have been developed, and the Brain Trauma Foundation has developed evidence-based guidelines that have improved (just having a protocol, we know, improves) trauma outcomes overall at centers - but I think those protocols are just guidelines, and you really have to pay attention to the individual patient in front of you. For TBI, for example, our guideline will say to aggressively manage fever within the first seven days with surface cooling. But in a patient that, for example, developed kind of a stroke or progressive cerebral edema even on day five (or something) you're looking at them, and on day seven, they're still having a lot of swelling in their brain, I'm not going to peel off the temperature management. So, there is nuance - you can't just kind follow a rule book in these patients.
Dr Jones: Got it. And I think that point about aggressive support early is a good takeaway for any listeners who might be engaged in the care of these patients. You know, I imagine working in that setting and taking care of patients who are in the midst of a devastating injury - I imagine that can be pretty challenging, but I imagine it could be pretty rewarding as well. What drew you to this particular area of interest, Dr Podell, and what do you find most exciting about it?
Dr Podell: A lot kind of converged for me in this area. I went into neurology thinking I would be a cognitive neurologist. I had more of a neuroimaging background and an interest in neural network pathology that certainly happens to patients with TBI (and patients with TBI often will have neuropsychiatric and neurocognitive problems after injury). But then, during residency, I found myself. My personality clicked in the ICU, and I just liked managing sick patients - I liked the pace of it, I also really liked it. It's kind of a team sport in the ICU with multiple people involved - the bedside nurses, respiratory therapists, neurosurgeons, trauma surgeons - all working together to figure out the best management plan for these patients, so you don't feel alone in managing them. And not all outcomes are good, obviously, but you can see people get better even during their course of their ICU stay - and that's really, really rewarding. And I think what we're seeing even in the literature following patients out longer and longer, the recovery trajectory for TBI is different than what we see in other neurologic injuries (like stroke, where the longer you go - up to ten, twenty years, even - people are still improving). I think the idea that you can keep hope alive for a lot of these patients and try to combat any kind of nihilism - obviously, there's a time and place for that after a really devastating injury, but I've seen a lot of patients who are really, really sick, needing therapeutic hypothermia, barbiturate coma, decompression, still then recovering and being able to come back into the ICU and talk to us.
Dr Jones: We might have some junior listeners who are thinking about behavioral neurology or neurocritical care, and it's probably - I don't know if it's reassuring, or maybe concerning, to them to know that they might swing completely to the other end of the spectrum of acuity, which is kind of what you did.
Dr Podell: Yeah, and what I'm trying to do now is, I'm very interested in autonomic dysfunction that happens in these patients. It's related a lot to multisystem organ dysfunction and, I think, may contribute to secondary injury, too, with changes in cerebral perfusion, especially in patients who have storming or even just the early autonomic dysregulation that happens early on. I think it's induced by neural network dysfunction from the brain injury, kind of similar to the way that there are other phenotypes that would be induced by neural network dysfunction (like coma). So, we're trying to look at MRIs of acute TBI patients and trying to identify what structural imaging pathology then gives rise to these different kinds of clinical phenotypes - trying to bring it back to this neuroscience focus.
Dr Jones: Well, that gives us and our listeners something to look forward to, Dr Podell. And again, I just want to thank you for joining us, and thank you for such a great discussion on the care of patients with TBI, and spinal cord disorders and thank you for such a wonderful article.
Dr Podell: Thank you very much. It is my pleasure.
Dr Jones: Again, we've been speaking with Dr Jamie Podell, author of an article on traumatic brain injury and traumatic spinal cord injury in Continuum’s latest issue on neurocritical care. 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. AAN members, go to the link in the episode notes and complete the evaluation to get CME for this article. Thank you for listening to Continuum Audio.