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Novel MRI biomarkers, including cortical lesions, the central vein sign, and paramagnetic rim lesions, are highly specific for MS and can aid diagnosis in select clinical scenarios, particularly early in the disease course or in atypical presentations. When used with appropriate MRI sequences, these markers can improve diagnostic sensitivity while helping prevent misdiagnosis.
In this episode, Casey Albin, MD, speaks with Jiwon Oh, MD, PhD, FRCPC, FAAN, author of the article "Diagnostic Neuroimaging Biomarkers for Multiple Sclerosis" in the Continuum® April 2026 Multiple Sclerosis and Related Disorders issue.
Dr. Albin is a Continuum® Audio interviewer, associate editor of media engagement, and an assistant professor of neurology and neurosurgery at Emory University School of Medicine in Atlanta, Georgia.
Dr. Oh is the medical director of the Barlo Multiple Sclerosis Program at St. Michael's Hospital and an associate professor at the University of Toronto in Toronto, Ontario, Canada.
Additional Resources
Read the article: Diagnostic Neuroimaging Biomarkers for Multiple Sclerosis
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Host: @caseyalbin
Full episode transcript available here
Dr Albin: Spend any time in a neurology conference, and you are certain to hear about the new central vein sign, which, as I learn, is not actually all that new. But have you heard about cortical lesions or these paramagnetic rim lesions? Because today I have the privilege of talking to Dr Jiwon Oh about her article, and we're going to unpack all these new biomarkers in MS.
Dr Jones: This is Dr Lyell Jones, editor in chief of Continuum. Thank you for listening to Continuum Audio. Be sure to visit the links in the episode notes for information about earning CME, subscribing to the journal, and exclusive access to interviews not featured on the podcast.
Dr Albin: Hello, this is Dr Casey Albin. Today I'm interviewing Dr Jiwon Oh about her article on diagnostic neuroimaging biomarkers for Multiple Sclerosis, which appears in the April 2026 Continuum issue on multiple sclerosis. Welcome to the podcast. Thank you so much for being here. I'd love to start by having you introduce yourself to our listeners. 
Dr Oh: Thanks, Casey. Hi, everybody. My name is Jiwon Oh and I'm a neurologist, mainly an MS specialist at Saint Michael's Hospital at the University of Toronto, and I'm the medical director of our MS program.
Dr Albin: And you have written a really fantastic article that dives deep into some of the nitty gritty about these new diagnostic biomarkers that we find on the MRI that we're getting for our patients with multiple sclerosis. And I think we are going to get into a lot of that nitty gritty. How do we look for them? How do they improve our diagnostic specificity? This is really come a long way in shaping the advances for multiple sclerosis. And I'd kind of like to just start with the big picture. Like why do we need these more specific biomarkers? 
Dr Oh: This set of diagnostic criteria in MS, it's actually a huge change in the field, and particularly for people like me who are really interested in developing new MRI measures, we're really, really excited because it's actually the first time since MRI was officially incorporated into the MS Diagnostic criteria, which was way back in 2001. It's the first time that we've actually been able to get newer, more advanced imaging measures beyond just simply detecting, new T2 lesions in the MS diagnostic criteria. So, it's a big moment in the field, and many of us are really excited about it in terms of why we need some of these newer, more specific imaging measures. Well, you know, diagnostic criteria always evolve over time for any disease state, and MS is one that we've recognized over the years. By the time someone actually presents with typical clinical symptoms and has diagnosed, whatever has been happening from a patho-biological standpoint has been happening probably for almost 5 to 10 years before that individual actually presents. And so, because of this recognition in the field and the fact that we're recognizing how important it is to first diagnose MS and then treat MS earlier and earlier, because we know that early treatment helps prevent more clinical outcomes. Diagnostic criteria over time have become much more permissive, meaning that we're doing everything that we can to try to facilitate a diagnosis of MS when we know that someone biologically has MS. But the problem with making diagnostic criteria more permissive, and it's obviously a good thing because you want to capture as many people with MS as early on as possible. The problem with making it permissive is there is this terrible risk of misdiagnosis. As clinicians, we all think we never make mistakes. But it turns out when you actually do studies, you do. And even at MS specialty centers, when studies have been done, 10% to 20% of people with MS are misdiagnosed. So, this is exactly why we need in diagnostic criteria that really help to facilitate a diagnosis. We need things that help us prevent misdiagnosis as well. And these are these specific imaging measures that have now been incorporated into the diagnostic criteria in many settings that will help to facilitate a diagnosis. But the really big perk is if you use them, you can help to prevent misdiagnosis as well. 
Dr Albin: Yeah, that really shone through in your article that this was such a big step in towards being more specific about who were diagnosing. Also capturing more people, right? Trying to get those people that we, we don't want to miss because of all the things you say, you know, that allows them to accumulate more disability, have worse outcomes. Early diagnosis is so important. But I really did take away from your article just how critical these are and sharping our diagnostic acumen. And so just to jump right in, and you describe these three new biomarkers, these cortical lesions the central vein sign and paramagnetic rim lesions. And so just to kick things off let's start with cortical lesions I sort of conceptualize multiple sclerosis a disease of white matter. So, what's going on here? 
Dr Oh: Yes. MS classically has always been described as a white matter disease. But it turns out when you look at brain and spinal cord tissue, as well as when you use kind of better sequences to actually look for lesions in the gray matter, it actually turns out there's a ton of lesions in the gray matter as well. And in fact, what's interesting is that regardless of whether it's the cortex or the deep gray matter, it's lesions within these areas that seem to have the highest relevance for clinical disability in MS. So, all this to say, of course, MS is a lesion that does affect white matter, but it also affects gray matter a lot. And maybe pathology within the gray matter is even more relevant to clinical disability. So, this is why we're really interested in being able to develop methods using MRI to more accurately visualize the gray matter, particularly the cortex, as well as deep gray matter structures like the thalamus. I should add the caveat that cortical lesions were actually included in the 2017 diagnostic criteria revisions, but they were included together with juxtacortical lesions, which are a typical area that MS lesions form. And so, this imaging measure, despite the fact that it is relatively novel and we consider it advanced, it hasn't been used that much only because it's not that easy to detect lesions within the cortex. And reasons for this include that you usually need higher field magnet platforms. And so, the typical clinical MRI scanners that are available kind of widely, regardless of whether you're at an academic center or a community center, are 1.5 Tesla magnets. And cortical lesions are actually really difficult to detect on those typical scanners. But when you get to like, say, three Tesla or seven Tesla, they're a lot easier to detect. But obviously that's a big hindrance to widespread use. And then you actually need very specialized sequences to adequately visualize cortical lesions. And these are not sequences that are usually collected for clinical purposes. So, it kind of requires convincing your radiologists that you need this additional sequence. And then it actually takes a lot of time and training to be able to adequately, accurately detect cortical lesions. So, despite the fact that it's actually very useful when you do have the appropriate MRI sequences and scanners to detect cortical lesions, even though they were incorporated into the 2017 criteria outside of specialty centers, they're not actually widely used. But when you do have the appropriate sequences, cortical lesions are actually pretty specific for MS. So, very helpful for a diagnosis in certain settings. But there's all these practical limitations that have really limited its widespread use.
Dr Albin: That is a beautiful summary. So, it sounds like once we kind of get up to speed in terms of like the protocols for this, having the magnet strength for this, this will be really a game changer in terms of increasing the specificity and also maybe finding things that impact patient's clinical presentation and therefore quite meaningful. But it sounds like for most of us, this is probably not something that they're going to be adopting right away. Is that a fair assessment? 
Dr Oh: Yes. And you know, they were included in the last diagnostic criteria revisions. And it really hasn't changed things very much, only because of these difficulties with, you know, requiring higher field magnet strengths and these specialized sequences and then needing training to kind of figure out how you can adequately detect cortical lesions.
Dr Albin: Totally. So, the other thing we've heard a lot about, and I have to say, I was in the AAN fall conference not too long ago, and this came up quite a bit, was the central vein sign and the fascination with that, because it tells us a lot about the MS pathophysiology and again, increasing that specificity. And it seems like maybe this is one that we can more easily adopt in clinical practice. So, tell our listeners about what that is, how they detect it. How many do you need to find? 
Dr Oh: Sure. And so, this is one of the imaging measures I'm really excited about. So, the central vein sign heard about it recently. And probably in the last ten years particularly in the MS field we're talking about it all the time. But just wanted to emphasize that the central vein sign is not something that is new. Even back in the 1800s, when Charcot described MS lesions in these ancient textbooks, he actually very clearly described that MS lesions form around the central vein. And that makes sense, because we know that these waves of peripherally mediated inflammation somehow get through the blood-brain barrier and cause this cascade of events leading to inflammation in the brain and spinal cord, which is what MS is. But we know that B cells in T cells require veins to get into the central nervous system. And so, it's no surprise, really, that MS lesions form around veins. And so, this is something that's been known pathologically. But the reason we're so excited about it now is because we actually have good enough iron-sensitive MRI sequences that allow us to see a central vein when it is present within a white matter lesion. As a neurologist, we know that there's probably hundreds and hundreds of different things that can cause white matter lesions in the brain. But when you use an appropriate iron-sensitive sequence and you see that many of them, if not most of them, actually have visible central veins, that tells you that this person very likely has MS. And so that's why we're so excited about it, because there have been many studies done in the last ten years. In fact, so much evidence generated in the last ten years that there have been I think it's now four systematic reviews and meta analyzes. Looking at the diagnostic properties of the central vein sign. And, you know, it turns out that when you look at people with MS, most of them have a pretty high proportion of white matter lesions that have visible central veins. And there's a lot of questions about, you know, how to best use the central vein sign. But when 40% or more of the white matter lesions that you see have visible central veins, then the likelihood of a diagnosis of MS is very high. So, this is why we're so excited about it in the MS field because it's a really useful diagnostic tool. You know, again when you have appropriate ion sensitive sequences, if you see someone with white matter lesions and you see that 40% or more of them have visible central veins, this tells you that this person very likely has MS. 
Dr Albin: So, Dr Oh, I hear you say, you know, 40% of the lesions. Does that mean the neuro radiologist needs to look at every single lesion and then count how many have the central veins, or is there an easier way to do this?
Dr Oh: Great question. Casey, there is definitely an easier way because our neuro radiologists would not be our friends anymore if we made them look at every white matter lesion and make sure that 40% of them had the central vein sign. So, because it's so time-consuming to use that 40% threshold, there's an easier criterion that has actually made it into the diagnostic criteria. And it's called Select Six. And what this means is when you have more than ten lesions, as long as you show that six of them have a visible central vein, you just have to count six with the central vein. Then you're done. So that means you're Select Six positive or central veins nine positive. However, if you have ten or fewer lesions, as long as you show that more than 50% of them show a visible central vein, then you are select six positive, and then you're done. So, as you can see, it's a much simpler criterion to apply, and it seems to perform almost as well as that 40% threshold, which is why that is the criterion that's made it into the new diagnostic criteria. 
Dr Albin: Perfect. I love that we definitely do not want to make enemies with our neuro radiology colleagues, but yet they do so much for us. So perfect. I'm glad that we can, make their jobs a little easier without losing any specificity there, or just losing a touch of specificity there. All right. If I am working with a, you know, in a center that maybe doesn't do this all the time, am I just getting a run of the mill SWI sequence? Do I need to ask my radiologist for a special sequence? Or is this just, you know, you can get it from the typical array of what our patients are getting. 
Dr Oh: You know, SWI is a widely available commercial sequence that's iron-sensitive, the ones that are typically commercially available, they can detect central veins, but there actually are little tweaks that you can do to make it a little more optimal. With the recent diagnostic criteria publication, which was, led by Xavier Montalban and recently published in Lancet Neurology. There's actually a companion MRI paper that was led by Frederick Barkov and Danny Wright. And the reason I'm specifically citing those papers is in that companion MRI paper, there's a table that has kind of optimal sequence parameters that you can use even with a conventional SWI sequence, to try to best detect the central vein sign. And then there's a wide range of different iron-sensitive sequences, and SWI is one of them, but the one that seems to have emerged as most sensitive to detect the central vein sign is something called the 3D T2*-EPI sequence. But the bottom line is there's a whole bunch of different iron-sensitive sequences that you can use, little tweaks that you can do to make them optimal, to be able to visualize central veins when they're present within white matter lesions.
Dr Albin: Incredible. So like partner with your neuro radiologist, there is a great sounds like a field guide almost to this. So, it makes it easy to pick up in your standard of care so that you can make sure that you are detecting them at the optimal level to see that more specific diagnostic biomarker. 
Dr Oh: Yes. And you know, in contrast to what we were talking about with cortical lesions, you can actually detect central veins when you use these iron-sensitive sequences at any field magnet. So even at 1.5 Tesla, particularly when you use contrast, which is often given with the diagnostic scan anyway, you can very easily detect a central vein. So that's a huge benefit because it allows for widespread use. As long as you work with your radiologist to get the right iron-sensitive sequences in. 
Dr Albin: Yeah, that's incredible. I mean, I think that it really will be practice-changing. And then the last one that I think was honestly new to me, I feel like I had heard a lot about the central vein sign, but the whole new to me term was this paramagnetic rim lesion. So, what does that tell us about the underlying biology of MS? And are there any other things that might also have this finding that we should sort of be aware of? And how specific is it? 
Dr Oh: You know, the central vein sign is kind of the main, really new imaging measure that's made it into every part of the MS diagnostic criteria. And then together with that paramagnetic rim lesions or we call them PRL or pearls for short, they've made it as well, but in a much more limited way only because there's not as much evidence that has accumulated over time to support the diagnostic utility of pearls. But first of all, what are pearls? So, people in the MS field are really excited about pearls, because we know that they capture a subset of what we call chronic active lesions. So, MS lesions will form acutely and over time, some of them will become inactive. And then some of them are chronic active lesions, meaning that they have this rim of activated microglia around them. Over time, they continue to slowly expand. And it's almost like this slow burn. And the reason why we focus a lot on chronic active lesions is because we know that they're a driver of progressive disease biology and MS, meaning that in people who have progressive MS or who have pretty severe disability, global disability or cognitive disability, we know that they have a high burden of pearls. And so that's why there's so much excitement in MS about being able to image chronic active lesions. It's because we're always looking for an imaging measure that allows us to accurately predict progression or to, measure progression over time. So that's why there's so much excitement in MS about pearls. But as kind of an added bonus, it turns out pearls are also really specific for MS. And so, when you use the same iron-sensitive sequences, by the way, that's used to detect the central vein sign when you use appropriate iron‑sensitive sequence. And if you see that someone has a pearl, the likelihood of a diagnosis of MS is very high. The one exception to that is Susac syndrome, where pearls have been observed. But other than that, with many other white matter diseases like neuro rheumatology disease, NMOSD, MOGAD, you really don't see pearls. And so, this is why it's made it into the new diagnostic criteria. In contrast to the central vein sign, though, not everybody with MS has a pearl, so the sensitivity isn't as high. However, it's really, really specific in the range of, you know, 90 to 95%. So, this is why it's been added as, an imaging measure in certain settings. It can help facilitate a diagnosis. But the real utility, again, is when you use it, it helps you to prevent misdiagnosis. 
Dr Albin: It's fantastic. And hearing you talk about that, this one stands out to me as a biomarker that not only helps increase our diagnostic specificity, but also may really inform if the patient has having progression despite the treatment they're on, that this could play a role in helping you say, look, there probably is something that we need to switch because we can still see this ongoing progression.
Dr Oh: Yes. And especially in this new era of treatment in MS. I think, you know, MS as a field, we've been so fortunate to have so many treatments emerge over the years that mainly target relapsing disease. But we hopefully, in the next little while, in short order, I hope we'll have treatments that target these progressive disease biologies. And so, not only is it helpful as a diagnostic marker, but there's a lot of evidence accumulating, showing that it may have a lot of prognostic value and will also help guide treatment decisions, exactly as you said. 
Dr Albin: It truly does sound like it's a great time to be an MS doctor there. So, so many new advances in the field. There is so much more that we can do for these patients in our limited time left. I'd love to ask you, what is it that you're most excited about now with the change in the biomarkers, the change in the treatment, what makes you really excited to be a doctor specializing in MS right now?
Dr Oh: I feel like we're on the brink of a new era of treatment. I think, you know, in the last two decades, MS care has changed so dramatically. I remember, you know, way back when, as a medical student, when I did my first neurology elective, this was when the first treatments for MS were emerging. And the prognosis that we were talking to patients about at that time is like night and day compared to what we talk to them about now. But we're going to do even better in the next couple of years. And so, there's a number of new treatments that hopefully will be approved soon that, for the first time, have shown an effect in clinical trials where it seems to be decreasing progression that is independent of relapsing activity. And that's really the greatest unmet treatment need that we have. And it seems like we might have some therapies on the horizon that can actually target that aspect of progression. It's really exciting, and even more that we're going to be able to do for our patients to completely change the way, we look at and the way we treat MS in the years to come. 
Dr Albin: Dr Oh, this has just been fantastic. To all of our listeners, I really want to point you to the article because obviously, as an imaging biomarker article, there are so many beautiful images. There are great examples. There are some fantastic cases that show how applying these new biomarkers can help get you to the right diagnosis. This is truly a tour de force of how imaging has really shifted the care that we provide patients with MS, and so please go and check it out. It is one that you do not want to miss. And again, today I've been interviewing Dr Jiwon Oh about her article on diagnostic neuroimaging biomarkers for multiple sclerosis, which appears in the April 2026 Continuum issue on multiple sclerosis. Thank you again, Dr Oh, this has just been such a delight. 
Dr Oh: Thank you for having me on the show, Casey, and look forward to people reading the article.
Dr Monteith: This is Dr Teshamae Monteith, associate editor of Continuum Audio. If you've enjoyed this episode, you'll love the journal, which is full of in-depth and clinically relevant information important for neurology practitioners. Use the link in the episode notes to learn more and subscribe. AAN members, you can get CME for listening to this interview by completing the evaluation at continpub.com/audioCME. Thank you for listening to Continuum Audio.

In this episode, Lyell K. Jones Jr, MD, FAAN, speaks with Andrew J. Solomon, MD, FAAN, who served as the guest editor of the April 2026 Multiple Sclerosis and Related Disorders issue. They provide a preview of the issue, which publishes on April 2, 2026.
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. Solomon is the Division Chief of Multiple Sclerosis and a Professor in the Larner College of Medicine at the University of Vermont in Burlington, Vermont.
Additional Resources
Read the issue: continuum.aan.com
Subscribe to Continuum®: shop.lww.com/Continuum
Continuum® Aloud (verbatim audio-book style recordings of articles available only to Continuum® subscribers): continpub.com/Aloud
More about the American Academy of Neurology: aan.com
Social Media
facebook.com/continuumcme
@ContinuumAAN
Host: @LyellJ
Full episode transcript available here
Dr Jones: It's been more than 150 years since Jean-Martin Charcot first described the disease that we now know as multiple sclerosis. Since then, the tools we have to diagnose and treat this disorder have expanded enormously. So why are the diagnostic criteria for MS. still evolving? Today we're speaking with Dr Andrew Solomon, guest editor of our latest issue of Continuum on MS and related disorders. To learn more about this question and much more.
Dr Jones: This is Dr Lyell Jones, editor in chief of Continuum. Thank you for listening to Continuum Audio. Be sure to visit the links in the episode notes for information about subscribing to the journal, listening to verbatim recordings of the articles, and exclusive access to interviews not featured on the podcast.
Dr Jones: This is Dr Lyell Jones, editor in chief of Continuum, Lifelong Learning in Neurology. Today I'm interviewing Dr Andrew Solomon, who is Continuums guest editor for our latest issue of Continuum on multiple sclerosis and related disorders. Dr Solomon is a professor of neurological sciences at the University of Vermont, where he also serves as the division chief of multiple sclerosis. Dr Solomon is an internationally recognized authority on MS, particularly on the diagnostic approach to this complex disorder. Dr Solomon, welcome. Thank you for joining us today. Why don't you introduce yourself to our listeners? 
Dr Solomon: Hi, everyone. This is Andy Solomon. It's a pleasure to be here with you. And I feel honored to have helped this collaborative effort that created this important tool for trainees and clinicians in practice, the Continuum issue on multiple sclerosis and related disorders. 
Dr Jones: Obviously, we're grateful that you've taken us on. A lot has happened in the world of MS and other neuroinflammatory disorders in the last few years, so lots to update. But as we've done over the last few podcasts, I'm going to start off the interview today, Dr Solomon, with a trivia question. And then we'll come back at the end of the podcast and give the answer. So, the trivia question is this. There are now more than 20 drugs approved by the FDA for the treatment of MS. What was the first disease-modifying therapy approved for MS? And when was it approved? So, don't answer because I know you know the answer. But we'll come back to it at the end of the interview. And our listeners can think about that question. So, let's get right to it. As many of our listeners know, the diagnostic criteria for MS. were recently revised. And you were involved with that revision. So, you're the perfect person to ask what were the major changes in the 2024 McDonald criteria, and why did we need to update them in the first place?
Dr Solomon: I'm very excited about the 2024 McDonald criteria, and it was an honor to be part of that process that resulted in that manuscript. When we revise the diagnostic criteria for MS usually it's driven by accumulating data that suggests some changes or revisions might help us diagnose patients either earlier or with more accuracy. And that's certainly the case with this criteria. There was accumulating data that suggested some particular changes were important. You know, there's a lot of expert opinion involved as well. You know, there's many experts who are involved in the collaborative decisions that go into these revisions. And some of the changes in our field also pushed some of the revisions to where maybe there's not as much evidence, but where we felt it would improve care for patients with MS. This criteria, I would argue, is probably one of the most substantial revisions in over 20 years. There's multiple changes that are potentially impactful for the diagnosis of MS. Some very important changes involve the incorporation of new paraclinical tools that we can use to assess the visual pathway, as well as, imaging tools that provide high specificity for MS that we can use to substitute or dissemination in time, for instance, as well as other tools that may allow us to diagnose patients earlier than we would have in prior criteria.  There's also some opportunities with the new criteria to potentially provide access in regions where some tools are more available than others. For instance, the incorporation of Kappa Free Light Chains as a substitute for oligoclonal bands may open up opportunities in regions where expertise for oligoclonal band testing are not available. That's a very qualitative test, whereas Kappa Free Light Chain index is more quantitative, less expensive and may allow CSF testing to be performed to aid the diagnosis of MS in some regions where it wasn't available previously. This criteria provides multiple pathways to the diagnosis of MS, many more than we've had in prior criteria. So, it's important to emphasize that while there's all these new tools and changes that have been incorporated, not every pathway needs to be available where you practice. What it incorporates as flexibility. It is a bit more complex looking at all of these different possibilities, but the point is this flexibility allows clinicians or providers to diagnose MS early with high accuracy based on the tools they have available.
Dr Jones: I think it will be a learning curve, right? I think any time we make a change in how clinicians get accustomed to approaching a diagnosis of a disorder, it will take some time for folks to incorporate it. And I see what you mean about the complexity, but I think that's a really great point, that emphasizing the different pathways to the diagnosis is really a strength of the revision, right?
Dr Solomon: I agree, I think, you know, in other disorders, particularly if you think about rheumatologic disorders, systemic rheumatologic disorders or inflammatory disorders, where over time we've not had very highly specific and sensitive biomarkers. And we've incorporated a variety of clinical and prior clinical findings, testing, laboratory testing and biopsy and other things to confirm a diagnosis. These approaches to these disorders are sort of a checklist. And I think that clinicians became familiar with that approach and were able to make diagnoses accurately this way. And I think of the new criteria in a similar way. It's not quite amenable to a checklist, but the pathways are sort of simplified with multiple options. Hopefully, using the figures, clinicians can look at the paper and see what tools they have available to help them confirm a diagnosis of MS. I think it's really important to emphasize that the diagnostic criteria for MS still does not discriminate MS from other disorders. Everyone who's listening here, you do, the clinicians do. So, to enter the diagnostic criteria and these pathways, we first have to feel confident that the patient has a clinical presentation and an MRI presentation or MRI findings that are highly suggestive of MS. That aspect of the criteria hasn't changed since, the Schumacher criteria in the 1960s. This concept of no better explanation. So, we still need to know what's typical for MS. And we need to know what signs or symptoms or findings are that might suggest another disorder, because the criteria are really only validated and tested in patients who have these presentations to start with that are typical for MS. A major change in this particular criteria is that we can now diagnose patients who are asymptomatic. Previously just called radiological isolated syndrome. Not every patient with an MRI finding concerning for MS and now being diagnosed with MS. There's other features that, must be present, but even more than before, knowing what the typical appearance of MRI lesions suggestive of MS, it is even more critical now than it was before, because in those patients who have either no symptoms or a nonspecific presentation, if we have an MRI that's highly convincing for MS and some other prior clinical findings, we can make the diagnosis. But we first need to know with some confidence what that MRI should look like. 
Dr Jones: So, there is a little circularity when we do these diagnostic criteria. I think our listeners who see patients will be reassured that the clinician is still in the loop. We haven't been automated out of the process yet. 
Dr Solomon: We need a highly sensitive and specific biomarker or a set of biomarkers for MS.  We're getting closer with some of these advanced imaging findings like central vein sign and paramagnetic rim lesions. But not every patient can be diagnosed with those. And they're not required for the diagnostic criteria. In lieu of a highly sensitive and specific test. Our clinical acumen, for what we find a neurologic exam. And what we see on imaging in particular, is quite critical for ensuring that the criteria perform as well as we hope they will.
Dr Jones: So, you've had the opportunity, the vantage point, to review all of these articles covering a wide variety of topics, MS, other neuroinflammatory disorders like aquaporin‑4–positive neuromyelitis optica spectrum disorder (NMOSD), myelin oligodendrocyte glycoprotein antibody-associated disease, MOGAD. Anything that surprised you in these articles as you were reading through them? 
Dr Solomon: I think maybe for listeners, what may be surprising to some of them is that despite guidelines surrounding the use of some of our disease modifying therapies in pregnancy and breastfeeding that are published by regulatory authorities in the United States or Europe or other places, we are making other decisions for patients based on the data we have, the best data we have. Thinking about family planning is really important for us with patients who are newly diagnosed with MS, as well as through the course of their disease. This is a conversation we should be having shortly after diagnosis, because there are strategies we can take to minimize the risk of exposure of DMT around conception and to make plans for how we're going to think about DMT surrounding breastfeeding, to ensure the health of mom and the baby, and reduce risks as much as we can with the knowledge we have. I think in medicine it's quite common for us to use medications off label, right? I mean, so medications are often FDA approved for one indication. And in neurology, for instance, we find a lot of medications after their approval were quite effective for migraine prophylaxis for instance. Right? And so, it's not unusual for us to prescribe medications beyond the label. And I'm not suggesting that we necessarily ignore the advice of our regulatory authorities. But sometimes the data is accumulating really fast around some of these therapies after they're approved. Sometimes we can look towards experts and how we can navigate pregnancy and breastfeeding in MS.
Dr Jones: I think that's a great point about the importance of family planning and having to use judgment. I do want to highlight to our listeners and our subscribers a fantastic article in the issue on family planning and MS and other neuroinflammatory disorders. This was written by Dr Ruth Dobson and Dr Kersten Hellwig, and I think it covers a lot of that gray area where we have to use our clinical judgment to manage these diseases in the absence of a regulatory approval. And I think, again, that's an important gap that the issue fills. And really, that's just a wonderfully written article that I think is a must-read. So, we cover lots of topics in this issue. And one of them is again a relatively newly characterized disorder, MOGAD. What's the latest in the world of MOGAD, what should our listeners be aware of?
Dr Solomon: I agree, I think we're in an exciting time in CNS inflammatory disease. And this is a recently described disorder. You know, and the diagnostic criteria now is only a few years old. So, I think importantly, readers should be aware of the diagnostic criteria. This is something that, really will help us distinguish this disorder from NO spectrum disorder and MS. There's a key overlap between the MS diagnostic criteria and MOGAD. Two decades ago we saw a pediatric MS included somewhat atypical presentations like bilateral optic neuritis or acute disseminated encephalomyelitis. And we had caveats in our approaches to pediatric presentations of presumed MS, suggesting that there could be something very different than adult MS. Subsequently, we've realized that pediatric MS presents quite similarly to adult MS in terms of its clinical syndromes and MRI appearance, and many of those pediatric patients who had initially been diagnosed with MS and MOGAD. MOGAD is actually probably more common demyelinating syndrome in patients who are under 12 years old. So, the MS diagnostic criteria requires testing for MOG-IgG with a good assay, a cell-based assay, any patient being evaluated under the age of 12 or with a demyelinating syndrome to avoid misdiagnosis. 
Dr Jones: Thanks for that. Obviously, MOGAD is one of several disorders that have been more recently characterized and, something that our readers need to be familiar with, and there's plenty of updates within the issue on that and other topics. Okay. So now back to our Continuum audio trivia question. And just to remind our listeners, there are now more than 20 drugs approved by the FDA for the treatment of MS. What was the first disease-modifying therapy approved for MS? And when was it approved? Dr Solomon, do you want to take the honors and answer the question? 
Dr Solomon: Sure. It was way back in 1993. You had to get on a wait list, I believe, initially to get on it. There was some sort of lottery, and it was Betaseron. 
Dr Jones: Betaseron in 1993, was the first disease-modifying therapy approved by the FDA for the treatment of MS. It just shows how much water under the bridge we've had since then. 1993 was also the first year of the Jurassic Park series of movies. It was the biggest movie of the year, the song of the year in 1993 was "I Will Always Love You" by Whitney Houston. It was also the year you can tell that I look back into 1993 to see what else happened. It was also the first year the World Wide Web became publicly available, which is it kind of puts brackets on the era or the epoch of MS disease modifying therapy. And finally, the Super Bowl champs that year were the Dallas Cowboys, who unfortunately, have not had much luck in Super Bowls since the 1990s. Maybe they will have more opportunities like we've seen with MS therapeutics. So, Dr Solomon, I want to thank you for joining us today. I want to thank you for such a wonderful discussion of the latest in MS. I think the updated diagnostic criteria are really going to be critical for our listeners to understand and incorporate into their practice. Really grateful for your leadership of the issue, putting together a really stellar group of experts for all of our articles and grateful for your time today. Thank you for joining us. 
Dr Solomon: Thanks so much for having me. Thank all the other listeners out there for joining us as well. I'm really excited about this issue of Continuum. 
Dr Jones: Again, we've been speaking with Dr Andrew Solomon, guest editor of Continuums most recent issue on multiple sclerosis and related disorders. 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, you'll love the Journal, which is full of in-depth and clinically relevant information important for neurology practitioners. Use the link in the episode notes to learn more and subscribe. Thank you for listening to Continuum Audio.

Neurologic complications of substance use may be the first symptoms that lead patients with substance use disorders to seek care. Neurologists have a key role in identifying patients with substance use disorders and connecting them to treatment.
In this episode, Lyell K. Jones Jr, MD, FAAN, speaks with Adeline L. Goss, MD, author of the article "Neurologic Complications of Drug and Alcohol Use" in the Continuum® February 2026 Neurology of Systemic Disease 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. Goss is a neurohospitalist and associate chief of neurology for Highland Hospital in Oakland, California.
Additional Resources
Read the article: Neurologic Complications of Drug and Alcohol Use
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 American Academy of Neurology: aan.com
Social Media
facebook.com/continuumcme
@ContinuumAAN
Host: @LyellJ
Full episode transcript available here
Dr Jones: A big part of neurology is solving mysteries. Patients can show up with all kinds of mysterious symptoms. Sometimes the diagnosis comes from within, some internal disruption of neurophysiology. But sometimes the problem is a complication of drug or alcohol use. Today we have the pleasure of speaking with Dr Adeline Goss, who recently authored an article for Continuum on this exact problem, a topic all neurologists need to be familiar with.
Dr Jones: This is Dr Lyell Jones, Editor-in-Chief of Continuum. Thank you for listening to Continuum Audio. Be sure to visit the links in the episode notes for information about earning CME, subscribing to the journal, and exclusive access to interviews not featured on the podcast.
Dr Jones: This is Dr Lyell Jones, Editor-in-Chief of Continuum: Lifelong Learning in Neurology. Today I'm interviewing Dr Adeline Goss, who recently authored an article on the neurologic complications of drug and alcohol use for our latest issue of Continuum on the neurology of systemic disease. Dr Goss is a neurohospitalist and the associate chief of neurology at Highland Hospital in Oakland, California. She's also an accomplished writer, broadcaster and podcaster. Dr Goss, welcome, and thank you for joining us today. Why don't you introduce yourself to our listeners?
Dr Goss: Great to speak with you, Dr Jones. Yes, I'm Adeline. I also go by Addie Goss.
Dr Jones: So, before we get into the discussion, we're going to start off today with something fairly new to the podcast, the Continuum Audio trivia question. So, we all know that alcohol and other substances have many potential complications in that use of these substances fluctuates over time. But this one stood out to me from your article, Dr Goss, just for the sheer size of the change. So, for our listeners, here's the question. Accidental exposures to what substance increased a whopping 1,375% between 2017 and 2021? I'll read that again. Accidental exposures to what substance increased 1,375% between 2017 and 2021? So, stick around to the end of our interview for the answer. And let's get right to it, Dr Goss. If you had a single most important message to our listeners from your article, what would it be?
Dr Goss: Well, I mean, many of us went into neurology because of the way that neurologic illnesses can be life-changing for patients. And I work as a neurohospitalist at a public hospital in Oakland, California. Many of my patients are admitted for neurologic conditions related to substance use. And when I see my patients later in the discharge clinic, many tell me that the last day that they used meth or the last day they used cocaine, the last day they smoked, was the day they had their stroke or whatever they came into the hospital for. I think the most important message is that hospitalization for a neurologic condition related to substance use can interrupt use patterns, can motivate change. And therefore, as neurologists, we really have an opportunity to connect to our patients and connect our patients to substance use treatment and make a dramatic difference in people's lives in this regard.
Dr Jones: I think that's a fantastic point. I enjoyed a point you made in your article---and I can't remember exactly how you phrased it, I won't say it as well---that you think of the syndromes through which alcohol and drug exposures can present. Those syndromes almost always could end up of other primary neurologic disorders. So, put a different way, when a patient presents with a neurologic problem, most of the time an exposure could be on the differential.  And so, we really do have a responsibility as neurologists to be familiar with these.
Dr Goss: To be familiar with these and to know how to connect patients to resources to try to get treatment.
Dr Jones: Totally agree. And you touched on the public health aspect of this. It's really hard to talk about drug or alcohol use without acknowledging the public health impact particularly of opioids, which has been a crisis for most of this century. Right? And I think most of our listeners will be familiar with the rapid rise in opioid-related deaths. But there might be a glimmer of optimism there. Is what I've seen true, that opioid-related deaths may have plateaued?
Dr Goss: So, yes, it's true that opioid-related deaths, overdose deaths in general, have begun to decline, actually, since 2023. And that's in part because overdose deaths really surged early on in the Covid-19 pandemic, in the setting of all of the social disruption, reduced access to services, and social isolation that occurred with the pandemic. But there were really multiple factors there. So, as you mentioned, there was this really rapid rise in illicitly manufactured fentanyl. Fentanyl became a major driver in overdose deaths starting in the mid-2010s. And by the late 2010s, it overtook heroin and prescription opioids as drivers of overdose deaths. And then this just collided with the pandemic in 2020, causing skyrocketing deaths. So, as we know as neurologists, fentanyl is more potent, it's shorter-acting, and it's also cheaper than heroin. It can cost as little as 50 cents or a dollar a pill. Thankfully, as services have rebooted and also as naloxone has become more widely distributed, there has begun to be a decline in opioid overdose-related deaths. So, we're relying on provisional data from the CDC for the most recent years, but that shows about a 24% decline in annual overdose deaths, comparing late 2023 to late 2024. And that's real. That comes out to 70 lives saved per day. Unfortunately, deaths still remain above prepandemic levels, and we're still talking about 87,000 drug overdoses per year. So, I would agree, a glimmer of hope. But we're still seeing overdose as the leading cause of death among young Americans aged 18 to 44. And there's a very long way to go.
Dr Jones: 23% is a big number, and that is certainly exciting to think about, but we're still above that long-term secular trend. So, hopefully whatever is happening to bring that down, hopefully it continues. And we talk a lot about- appropriately, we talk a lot about opioid exposures and some of the neurologic presentations of opioid use and toxicity, but alcohol use disorder is the most common substance use disorder, correct? I learned that from your article. And it has been for some time, and it has well-known acute and chronic toxicities. But I think many of us have been taught something of a myth in the acute treatment of patients who may have thiamin deficiency or Wernicke's encephalopathy. Can you tell us a little more about that?
Dr Goss: Yeah, sure. So, boy, what is my favorite vitamin? As a neurologist, I think thiamin is my favorite vitamin. Thiamin is a cofactor in- for several enzymes that are involved in glucose catabolism. And it's necessary to synthesize myelin and several neurotransmitters. And as we know, alcohol use disorder leads to reduced nutritional intake and impaired digestion and absorption of nutrients. And this can lead to deficiencies in water-soluble B vitamins, including thiamin, as well as trace elements. The thing about thiamin is that thiamin deficiency often appears first, because the body's stores of thiamin deplete in about 4 to 6 weeks. You know, we're traditionally taught if a patient presents with symptoms concerning for Wernicke's encephalopathy, that if they're also hypoglycemic or just in general, we have to get glucose into them first, because we don't want to tax these thiamin-dependent glucose catabolism pathways. But really, there's no reported case of a single glucose bolus precipitating some dramatic symptomatic thiamin deficiency. It's thought that harm would come potentially from prolonged carbohydrate administration without thiamin. And so, if a patient in front of you is both thiamin deficient and hypoglycemic, you just treat both. You treat both emergently. But it doesn't really matter in what order you do so.
Dr Jones: That's good to know that doing the right thing for the patient can involve using either of those in whatever order. And I agree with you, I don't think I've ever hurt anybody by giving them thiamin. It's an easy one to miss and an important one to remember in the right context. And speaking of, and I think a lot about in your article, Dr Goss, I can see a neurologist seeing a patient in the emergency department or in the hospital or even in the clinic thinking about the wonderful points in your article. But we know that when alcohol or substance use enters our mind on the differential, the next impulse is to test for it. And we also know there are pitfalls of drug screening, doing urine drug screens, etc. How do you approach testing when you think about a potential drug-related complication in their differential?
Dr Goss: So, like most people, I would start with a urine drug screen for any patient who's presenting with a possible toxidrome or some substance-related neurological presentation. These urine drug screens, they're rapid, they're inexpensive, they're immunoassays for traditional drugs and their metabolites. So, usually amphetamines, cocaine, opiates, plus/minus cannabis. But I think the first thing to note is that they miss entire categories of drugs, and not just drugs that are not in that list. They miss synthetic opioids, including fentanyl. One group is keeping track of this number. So, I have an update for mid-2025. And that's that 30% of U.S. ED overdose encounters as of mid-2025 included fentanyl testing. Only 30% for patients who are presenting with an overdose syndrome.
Dr Jones: And that's for one of the most widely used synthetic opioids. So that's really a striking number.
Dr Goss: Yeah, one of the most widely used and one with the greatest rate of complications. So, states can make a difference here. In 2022, California passed a law requiring fentanyl testing on hospital urine drug screens and several states have followed. And so that number is rising, the rate of testing for fentanyl. But that's just a really key thing to know, that that one is often missed. Other just important pitfalls, the timing of the urine drug screen matters because for most substances, it only picks up the drug within 24 to 72 hours after the last use. With amphetamines and cocaine going out a couple more days after that, especially in patients who use repeatedly. And then also, notably, there's a risk of false positives. This is especially true with amphetamine use, and beta blockers are one of the drugs that can lead to false positives on an amphetamine test, on a urine drug screen. So, I'll share that I've had several patients who have presented with intracerebral hemorrhage and who tested positive on the emergency department's urine drug screen and who adamantly stated that they do not use amphetamines, they've never used amphetamines, and they didn't ingest anything that could have contained amphetamines. And when we did serum confirmatory testing, in fact, their amphetamine testing was negative, and all those patients had received esmelol or the labetalol in the ED to treat their blood pressure related to their ICH. So false positives can occur with, you know, other medications like decongestants and certain antidepressants. But beta blockers are a key one to know. And then finally, there are just a number of things outside of that short list of substances that I mentioned, including a huge range of novel psychoactive substances that would not be tested for on a standard urine drug screen. And for those, you'd require serum testing, or at some large academic centers or specialty toxicology labs, you can actually do liquid chromatography high-resolution mass spectrometry, with- which is basically unbiased testing for any substance that's present in the patient sample. So, I guess, you know, you asked about my approach. Start with the urine drug screen, but there's no substitute for good history-taking and close examination of your patient's general examination, not just their neurologic presentation. And if patients are presenting with a toxidrome that I would expect would show up on a urine drug screen but it's negative, there are other confirmatory tests that can be sent, although they're often send-out labs and come back in a very delayed fashion.
Dr Jones: So, in other words, it's complicated, which usually means it's humbling. And if I'm understanding it correctly, there's the risk of the false positive on the urine drug screen. And then there's the risk of the false negative if we think we're screening for something that might not even be on that initial screen. So, that's a wonderful reminder that these are clinical diagnoses and we have to keep our clinician hats on while we're thinking about how to establish these diagnoses or exclude them. So, back to opioids, Dr Gross. There are some really peculiar neurologic syndromes associated with opioid overdose. Tell us a little about those.
Dr Goss: Well, I mean, some of these were described first with heroin. So, we can start with the one that almost anybody has heard of, heroin-associated spongiform leukoencephalopathy, which we know is associated with a practice known as "chasing the dragon," which is inhaling vapors of heroin heated on foil. But we know now that this syndrome can occur with other opioids, including fentanyl. The clinical features are, you know, apathy, cerebellar signs, quadriparesis, parkinsonism, myoclonus, and some patients progress to coma or even death. But on MRI you're seeing, you know, these confluence symmetric white matter diffusion restriction and T2 hyperintensities in the cerebellar white matter and the posterior limb of the internal capsule that spare the subcortical U-fibers. So, you know, I think this is kind of the classic example of something that's symmetric, that has a very obvious and interesting MRI pattern. But as time is passing, we're seeing more and more similar types of syndromes of leukoencephalopathies, but with different clinical presentations and MRI characteristics. So, another of these is CHANTER syndrome. This is an opioid overdose-related presentation where people have stupor and coma. And on the MRI there, you see bilateral symmetric diffusion restriction in the cerebellar cortex, in the hippocampi, in the basal ganglia. And it spares the cerebral cortex. And notably in these cases, patients can progress to cerebellar edema, to obstructive hydrocephalus. And some require suboccipital craniotomy. I had a week recently at Highland Hospital, where I work, where we had two of these cases in the same week, in just a community hospital. And there's a similar syndrome in children known as POUNCE syndrome with profound cerebellar edema, and many patients require posterior decompression. So that's another different distribution of findings with a different outcome. Fortunately, there's a milder sort of phenotype of opioid-associated amnestic syndrome, is what it's been described, where there's primarily DWI changes in the hippocampi and the globus pallidus. So, patients primarily present with an amnestic syndrome, mostly anterograde amnesia. Seeing these in practice, I'm not sure that patients always fall into one bucket or another. But in general, you'll see some degree of symmetric diffusion restriction or symmetric white matter changes that clearly point to a toxic presentation, a toxic syndrome, as opposed to pure anoxia, for example. And it's important to know that because from a prognostic standpoint, anoxic brain injury, which can occur after cardiac arrest and after opioid overdose, can look different than some of these syndromes. Finally, heroin has been associated with myelopathy, but also that's been reported on with fentanyl. So, I think some of these conditions got their reputation from heroin. But as fentanyl has proliferated---and prior to that as prescription opioid, you know, misuse had proliferated---we're seeing similar syndromes with all of the opiates.
Dr Jones: And I think it's a good case in point that you can have multifocal disease and it be a manifestation of an intoxication, and I think that's a really good reminder that we have to have many of these syndromes in our differential, we have to be aware of them, otherwise we might miss them or attribute them to another mechanism. Dr Goss, our last issue of Continuum that was dedicated to the neurology of systemic disease came out in 2023, and here we are in 2026 publishing our latest issue, including your article and this podcast. Since 2023, have there been any emerging patterns or novel agents of abuse or misuse out there?
Dr Goss: The short answer is yes, and I would say the reason is just the supply is moving at more and more rapid speed. The relationship between the internet and drug supply has really informed what's out there at any given moment. So, the turnover in the market can change in weeks, not in years. And there's all of this distribution through social media and encrypted apps. And then manufacturers are kind of continuously tweaking chemical structures to evade law enforcement. In the process of researching this article, I came across some, I mean, really wild examples. To be clear, these are not- not all these are common substances, but I think the general phenomenon should be known that people can walk into a vape shop or walk into a gas station or meander around online and buy some really weird stuff. So, in 2024, there was this nationwide recall of a product called Diamond Shrooms that was sold online and in smoke and vape shops, and this was billed as, like, a hemp and mushroom mixture. But it led to multiple- I mean, over 100 cases of seizures and agitation and depressed consciousness and a few possible deaths. And when the contents were analyzed, they included psilocybin analogs and pregabalin. I mean, some weird stuff. And so, those have been pulled. But people are constantly inventing and marketing these different substances. I think another example… we all know about nitrous oxide and its association with B12 myopathy. But the use of nitrous oxide has really changed. Companies are selling large canisters online and in vape shops, and they're flavored, like, in blue raspberry flavor. And unfortunately, there's been a rise of nitrous among youth. So, we're seeing not just increased cases of myelopathy, but also a 2025 study in JAMA found a spike in deaths attributed to actual nitrous oxide overdose. And so nitrous, I think, had not been that commonly used a few years ago, but has become more common in the last couple of years.
A final one I'll just mention is ketamine. So, ketamine has certainly appeared in reviews of neurological syndromes related to substance use for a long time, and it's also been studied and used off-label for mood disorders in outpatient infusion clinics for some time. But in the pandemic, there was an expansion in telemedicine, as we know, and an associated proliferation of teleclinics that were prescribing very frequent, even daily oral and lozenge and nasal formulations of ketamine, which has led to increased rates of misuse. So, you know, acutely, the syndrome associated with ketamine intoxication is very brief. And often by the time people come to the emergency department, their symptoms have already worn off. But long-term, frequent use of ketamine is really still being studied. There seems to be an association with persistent neuropsychiatric effects like cognitive impairment, psychosis, persistent depressive symptoms. And so, you know, I think it's just important to realize that while the list of substances may look pretty similar to 2023, the use patterns, the distribution patterns are continuing to change. It's hard to keep up. And while alcohol and opioids and stimulants are by far the most common substances that a neurologist is going to encounter in daily practice, there's this ever-expanding range of possible substances that can trigger neurologic syndromes, both acute and chronic.
Dr Jones: And I think that might be the best possible plug to read your article, because it is evolving and we have to stay on top of it. And we really can't be complacent with it. So, thank you for that update. Okay, back to our trivia question. Accidental exposures to what substance increased a whopping 1,375% between 2017 and 2021? Dr Goss, what do you think?
Dr Goss: That was THC-infused edibles. Specifically, these would be THC-infused substances that are often marketed as looking like candy or snacks or cereal. Exactly what a kid might want to get their hands on. And unfortunately, accidental cannabis exposures in children under age five went up by 1,375% between 2017 and 2021, and 600 of those patients required critical care admission.
Dr Jones: Yeah. So, just a mind-blowing number, and obviously something for us to be on the lookout for, especially if you see children in your practice and someone comes in with CNS depression or stupor, it's one to not miss. So that was something I learned in reading your article, among many other things. And Dr Goss, I want to thank you for joining us. I want to thank you for such a great discussion. I learned a lot from reading your article, I learned a lot just from our conversation today, and I suspect our readers and our listeners will too.
Dr Goss: What a pleasure. Thank you so much, Dr Jones.
Dr Jones: Again, we've been speaking with Dr Adeline Gross, author of a fantastic article on neurologic complications of drug and alcohol use in our latest issue of Continuum on the neurology of systemic disease. Please check it out, and thank you to our listeners for joining us today.
Dr Monteith: This is Dr Teshamae Monteith, Associate Editor of Continuum Audio. If you've enjoyed this episode, you'll love the journal, which is full of in-depth and clinically relevant information important for neurology practitioners. Use the link in the episode notes to learn more and subscribe. AAN members, you can get CME for listening to this interview by completing the evaluation at continpub.com/audioCME. Thank you for listening to Continuum Audio.

Neurologic care during pregnancy and menopause requires careful attention to the dynamic interplay between hormonal transitions, evolving evidence on diagnostic and treatment safety, and the lifelong risks associated with neurologic complications of pregnancy.
In this episode, Katie Grouse, MD, FAAN, speaks with Sara C. LaHue, MD, author of the article "Neurologic Complications of Pregnancy and Menopause" in the Continuum® February 2026 Neurology of Systemic Disease issue.
Dr. Grouse is a Continuum® Audio interviewer and a clinical assistant professor at the University of California, San Francisco in San Francisco, California.
Dr. LaHue is an assistant professor of neurology for the Weill Institute for Neurosciences in the Department of Neurology at the University of California, San Francisco School of Medicine in San Francisco, California
Additional Resources
Read the article: Neurologic Complications of Pregnancy and Menopause
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 American Academy of Neurology: aan.com
Social Media
facebook.com/continuumcme
@ContinuumAAN
Full episode transcript available here
Dr Grouse: Despite the high prevalence of neurologic conditions in women, critical gaps remain in training, research, and clinical guidelines on sex and gender specific considerations across the lifespan. Today, I have the opportunity to speak with an expert on neurologic complications of pregnancy and menopause and coauthor of the and women's neurology curriculum core competencies, Dr Sara LaHue about the latest issue of Continuum on neurology of systemic disease.
Dr Jones: This is Dr Jones, editor in chief of Continuum. Thank you for listening to Continuum Audio. Be sure to visit the links in the episode notes for information about earning CME, subscribing to the journal, and exclusive access to interviews not featured on the podcast.
Dr Grouse: This is Dr Katie Grouse. Today I'm interviewing Dr Sara LaHue about her article, Neurologic Complications of Pregnancy and Menopause, which appears in the February 2026 Continuum issue on Neurology of Systemic Disease. Welcome to the podcast and please tell us more about yourself.
Dr LaHue: Well, thanks so much for having me. I'm really excited to talk about this topic. So, I'm Sara LaHue. I'm a neurologist at UCSF, assistant professor of neurology, and a neurohospitalist. So much of my role is taking care of people who are coming into the hospital with urgent and emergent neurologic conditions. And so that's very much a framing that I come to this chapter with.
Dr Grouse: I just want to start by congratulating you on your article, which is such a phenomenal compendium of important neurologic issues related to pregnancy and menopause, which I think I really needed and a lot of us really need and was missing, I think, in all of the literature out there. This article will be such an important clinical resource. I know for me, and I'm sure for many of our listeners, this may be a difficult question to answer because of how comprehensive the article is. But what do you hope will be the main takeaway for those who read your article?
Dr LaHue: So, I really hope that listeners walk away with understanding that pregnancy and menopause are not contraindications to providing excellent neurologic care. I think too often we default to withholding treatment, pseudo-assumed risk, rather than actual evidence of harm. And so, I think that the key message here is that protecting maternal health is protecting fetal health, and that under-treating neurologic conditions during pregnancy can harm both mother and baby.
Dr Grouse: You did say specifically in your article that I thought it was so important that presumption of harm from medications during pregnancy, due to lack of evidence rather than evidence of harm, was something that we really had to be aware of, of that bias. And how do you recommend neurologists listening to this podcast approach situations where diagnostic or management strategies become less certain due to safety considerations in pregnancy?
Dr LaHue: Yeah, that's such an important question. I really frame it as a risk-benefit calculation with a patient, and I'm very transparent about what we know and what we don't know. And I emphasize that untreated disease may also impact fetal health. I use resources like LactMed and pregnancy registries that can help provide some of the more latest data. And then when evidence is limited, I document our discussion thoroughly, and I'll often involve maternal-fetal medicine colleagues for their multidisciplinary input. So, the goal is really to have an informed, shared decision-making process rather than a reflexive avoidance of all treatments.
Dr Grouse: I think that's really important to reiterate, and I think something that we're all I think working on as we try to manage these difficult situations and conditions. Now, I want to switch gears a little bit and ask. Your article was so comprehensive and so helpful, but what isn't in the article that you wanted to put in?
Dr LaHue: There was a fair amount that I ended up having to take out. So, this is a question that's near and dear to my heart. So, I would have liked to include more on the neurodevelopmental outcomes for children who are exposed to various neurologic medications in utero. And I also wanted to discuss more about transgender and non-binary individuals who are experiencing pregnancy and menopause, as they're often underrepresented in research. They've faced unique challenges accessing care.
Dr Grouse: Now, I was really struck by one statistic in your article, specifically that intimate partner violence is a leading cause of head injury during pregnancy, and that actually homicide is a leading cause of death during pregnancy in the postpartum period in the US, which was absolutely a surprising statistic to me. What does this mean for our listeners caring for pregnant patients with concussions and head injuries? What should we be doing differently?
Dr LaHue: This is also something that really struck me when I first encountered it. I think that the statistics should really fundamentally change how we approach head injuries in pregnant patients. I think we need to screen everyone routinely and privately for violence in the home and in the relationships, and to document injuries very carefully. But we also need to be prepared if someone does screen positive. And so, it's important to be familiar with what's available in terms of resources within your community, where you work, and also to remember that that strangulation in particular is something that can cause dissection and stroke. And so, to maintain a high index of suspicion for any kind of vascular injury in these cases. So not just thinking about head injury itself, but also thinking about complications of strangulation as well.
Dr Grouse: Really a great reminder of the role that we can play in our own careers and our own clinical settings when we see cases like this. So, I really appreciate that this point was made, and I hope this will change people's practice. Now switching gears to stroke in pregnancy. Could you walk us through your evaluation and management of a patient who comes in with acute stroke in the peripartum period?
Dr LaHue: This is such an important topic, and I think the first thing I'd like to emphasize is that time is brain. Whether or not you're pregnant. It's important to get whatever imaging modality is going to be fastest. Get the CT or get the MRI as soon as you can. Don't delay for fetal concerns. The radiation risk is minimal compared to missing a treatable, disabling stroke. In terms of treatment, thrombolysis and mechanical thrombectomy should be considered just as in a non-pregnant person, when the benefits outweigh the risks. And so, I think the key is involving obstetrics early for shared decision making, and being very transparent with what treatment options are available for the individual, and to not let pregnancy alone stop you from offering standard stroke therapies.
Dr Grouse: Definitely a helpful resource, and I think the resources that you put in specifically around the considerations and differentials in these various populations. Postpartum, while still pregnant during the period of period, I think is all just so helpful and a great review. So, I encourage our listeners to check that out. Now switching over to the topic of menopause. I have to say, I really appreciated your coverage of neurologic issues related to the perimenopause period. What do you think is the biggest debate or controversy in this area?
Dr LaHue: I think this has to be our understanding of the use of menopausal hormone therapy. The pendulum, when using menopausal hormone therapy, has really swung dramatically. So, we went from routine use to predominantly avoidance. After the Women's Health Initiative was published in 2002, and now we're finding that we're starting to come more to a middle ground. I think there's still great debate when it comes around timing of initiation, formulation of the different therapies, a route of administration and also the dosing, as well as just including how to individualize therapy for individuals with neurologic conditions.
Dr Grouse: Well, going into that a little further, I know I get a lot of questions about the use of hormone therapy as it relates to stroke risk and particularly in higher risk patients such as patients who've had prior strokes, dissections, a history of migraine with aura. And I find it hard to get the answers in the literature that's out there. How are you counseling these patients?
Dr LaHue: So, I think this is where discussions around the route of administration and dosing become especially important. And this is where there's emerging literature that I think is helping to guide some of these discussions. So, for higher risk patients, I discuss how low dose transdermal formulations which can bypass hepatic metabolism and reduce clotting risk. These are medications that can appear safer in those higher risk individuals. I think the key is really individualizing the risk-benefit discussion with the patient. For a woman with severe vasomotor symptoms that are affecting sleep and cognition, who had a remote stroke. I think this is a person for whom low dose transdermal patch might be a reasonable option. All of these factors end up being considerations for that shared decision-making.
Dr Grouse: Now your article covers another topic that I often get questions about, and that's specifically regarding safety of vaginal delivery for patients with neurologic conditions that are sensitive to increased intracranial pressure. Could you summarize your advice for these types of questions when they come up?
Dr LaHue: So broadly speaking, most neurologic conditions don't require C-section delivery. And this is a procedure that, just globally speaking, as has been increasing dramatically. And so, I think that's the key message that really, most neurologic conditions don't require a C-section as a main indication. And really, the indication should be based on obstetric considerations. For most conditions, like controlled idiopathic intracranial hypertension, a vaginal delivery is fine. But for patients with mass effect or obstruction at the foramen magnum, a C-section with general anesthesia, it's probably going to be safer. The transient increase in intracerebral pressure that can come with pushing. It hasn't really been shown to harm patients who have stable, treated neurologic conditions.
Dr Grouse: I really appreciated the advice that you given in the article, which was that if generally you feel like this would be a patient who would be safe to get a lumbar puncture, you have a little less concern about vaginal delivery versus those that you feel would not be safe to get a lumbar puncture, that you'd be more leaning towards a C-section.
Dr LaHue: Yeah, that's exactly right.
Dr Grouse: Now, why do you think we have so many gaps in our understanding of how pregnancy and menopause affect neurologic conditions?
Dr LaHue: So, I think it really comes down to a perfect storm of factors. So, in 1977, the USFDA came down with the recommendation, stating that it was best to exclude all women of reproductive potential from both phase one and phase two studies. And this recommendation wasn't reversed until 1993. And there are also concerns around liability and also the fact that pregnancy is a temporary state is something that may falsely minimize the potential for delays. The potential for harms that come with delays in treatment. And I think that the fact of menopause is also historically been dismissed, despite this is something that is affecting half of the population. I think we need systemic change. We need to mandate inclusion in research. We need funding for dedicated studies. We also need to recognize women's health as a core competency and not just a special interest.
Dr Grouse: That all sounds like a great roadmap for improving our knowledge. And I really hope we get there. But hearing you talk about it really does give me hope that we can improve how we are understanding and treating these conditions. Now, your article included a really helpful overview of headaches in pregnancy, and that's certainly something I think many of our listeners are very familiar with. We do have a lot of questions around that, and I think there's a lot of areas where we don't really always know what the best thing to do is. I think that your article really gave a lot of great information and a really great framework to think about. It would be wonderful to hear you walk through your approach to evaluation of a patient who was pregnant with a new onset headache.
Dr LaHue: You'll see in this chapter that I introduce a mnemonic that's spelled out pericardium as a framework for thinking about headache and pregnancy. And here are the you specifically points to an unusual headache, referring to a new or atypical presentation of headache for the patient. I think this is an important place to start, because one of the initial considerations should be this is a new headache, or is this an old headache? If this is a patient who already has a preexisting diagnosis of migraine or some other primary headache disorder, then it's certainly possible that the headache that they're experiencing during pregnancy is also a continuation of their primary headache disorder. But certainly, our role is to make sure that we're not missing a scary complication, a secondary headache that could be dangerous to the patient. And so, then this is where I also think about, well, where are they in the course of their pregnancy. Is this person currently pregnant or are we in the postpartum period? When someone is after 20 weeks gestation, one of the first things to consider is going to be preeclampsia. And so, it's important in those individuals to check blood pressure, check urine to rule out preeclampsia, as this is always going to be top of mind after 20 weeks.
I think it's also important to emphasize that preeclampsia is not just a condition that can occur when someone is pregnant. This is also something that can occur postpartum. One needs to be vigilant for looking out for this complication during both time periods. And then I think for new headaches, I really want to focus on what the timing is and any other red flags. For example, if it's a thunderclap headache and onset, then I might be worried about something like RCBS or cerebral venous sinus thrombosis. If the headache itself is orthostatic and patient may have had an epidural, then I might think about a post-dural puncture headache, which is a, unfortunately very common complication and reason for headache in the postpartum period. I think the key is that most dangerous headaches often will occur late in the third trimester or early postpartum. And I think it's also important to remember that if you need imaging to make the diagnosis, and you should get it. The risks of missing something serious far outweigh concerns that one might have around imaging. And when possible, it's certainly preferred to get an MRI if that's available.
Dr Grouse: I really did appreciate articles, overview of the various imaging modalities out there and the overview of risk versus benefits and times where they may or may not be needed. So, yet another very useful piece of information that I think that our listeners will appreciate in your article. Now, I'm curious how did you get interested in this area of neurology?
Dr LaHue: So, it really was my interest in both reproductive health and neurology that led me to go to medical school in the first place. I knew early on at the beginning of medical school that I was interested in neurology, but I also was very drawn to obstetrics, and I recognized in medical school and then further on as, as a resident, just how vast the knowledge gaps were. When I was counseling my own patients and I found this to be just a very frequent source of frustration as both a clinician and a researcher, I very much feel an obligation to try to help fill these gaps. And I've also just been very encouraged by an outstanding community of other neurologists that I've been able to meet in this space. It's been a just a wonderful collaborative network that we've been able to grow, both within United States and even more globally, when it comes to other neurologists who are interested in this topic. And I'm just very excited to see the direction that this field is going in.
Dr Grouse: Well, we can't wait to learn more as this field develops and more is understood about the right way to approach these types of diagnostics and treatments. So, thank you for all your work in this space. And it's been absolutely fascinating reading your article and talking with you today.
Dr LaHue: Well, thank you so much for having me, and I'm just so thrilled that these important topics are going to be part of this issue of Continuum.
Dr Grouse: Again, today, I've been interviewing Dr Sara LaHue about her article and Neurologic Complications of Pregnancy and Menopause, which appears in the February 2026 Continuum issue on Neurology of systemic disease. Be sure to check out Continuum Audio episodes from this and other issues. 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, you'll love the Journal, which is full of in-depth and clinically relevant information important for neurology practitioners. Use the link in the episode notes to learn more and subscribe AA and members. You can get to me for listening to this interview by completing the evaluation at continpub.com/audioCME. Thank you for listening to Continuum Audio.

Prompt recognition of direct and indirect neurologic complications of systemic cancers and their evolving treatments is essential. Neurologists should be familiar with common and rare neurologic toxicities of conventional chemotherapy, immune checkpoint inhibitors, and CAR T-cell therapy.
In this episode, Teshamae Monteith, MD, FAAN, speaks with Amy A. Pruitt, MD, FAAN, author of the article "Neurologic Complications of Cancer and Its Treatment" in the Continuum® February 2026 Neurology of Systemic Disease issue.
Dr. Monteith is the associate editor of Continuum® Audio and an associate professor of clinical neurology at the University of Miami Miller School of Medicine in Miami, Florida.
Dr. Pruitt is the William N. Kelley Professor of Neurology, Vice Chair for Education, and Division Chief in the Department of General Neurology for the Perelman School of Medicine at the University of Pennsylvania in Philadelphia, Pennsylvania.
Additional Resources
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Host: @headacheMD
Full episode transcript available here
Dr Monteith: As neurologists, we have a critical role in diagnosing neurologic complications of cancer from metastatic disease, seizures to neuropathies. Increasingly, the rapid development of novel treatments themselves, like immunotherapies, Car-T cells, and targeted drugs are causing new neurologic side effects, which we need to recognize, manage and anticipate as therapeutic developments evolve.
Dr Jones: This is Dr Jones, editor in chief of Continuum. Thank you for listening to Continuum Audio. Be sure to visit the links in the episode notes for information about earning CME, subscribing to the journal, and exclusive access to interviews not featured on the podcast.
Dr Monteith: Hi, this is Dr Teshamae Monteith. Today I'm interviewing Dr Amy Pruitt about her article on neurologic complications of cancer and its treatment, which appears in the February 2026 issue on neurology of systemic disease. Welcome to our podcast. How are you?
Dr Pruitt: Thanks for having me.
Dr Monteith: Absolutely. Why don't you introduce yourself?
Dr Pruitt: As you said, my name is Dr Amy Pruitt. I'm a professor of neurology at the University of Pennsylvania, where I am also the clerkship director and have been for a long time. I'm the division chief of general neurology and the vice chair for education in my department.
Dr Monteith: You have a lot of hats.
Dr Pruitt: I do.
Dr Monteith: Okay. So, before we dive into all this great work that you did in the article, why don't you just let us know just a little bit about what led you to this career path?
Dr Pruitt: Sure. So, I've always been interested in the intersection between internal medicine and neurology; in fact had I've not been a neurologist. I probably would have been either an oncologist or infectious disease specialist. And that leads to doing neuro oncology and seeing a fair amount of CNS infections. I see both inpatients and outpatients and really enjoy my neuro hospitalist time because, honestly, as all of you who do consults on inpatient services know, there is an incredibly changing landscape of consequences of cancer therapies. And if you haven't been on service for a while, you probably don't even know the name, is much less the adverse effects of these medicines.
Dr Monteith: Okay, so you were just like me to write this article.
Dr Pruitt: Well, I think where it is directed, I think, as I said, that people who are seeing a lot of inpatients and who may not know it's a new consequences of cytotoxic or immunotherapies or T cell therapies and the different appearances and really prognoses, which have changed dramatically in the last few years in the field of systemic cancer.
Dr Monteith: Any other essential points of your article?
Dr Pruitt: So, I think there are certain areas where neurologists are going to intersect with oncologic patients even before oncologists do so, what tumors might present synchronously in the brain and the rest of the body. And those would include things like small cell and non-small cell lung cancer and melanoma, to a lesser extent, women who are surviving much longer now with good therapies for various versions of breast cancers, have one of the solid tumors most likely to present at first relapse in the brain, either in the brain metastases category or in the leptomeninges. So, these are the areas where I think it most likely that our neurologists are going to intersect with oncology. And then there is the burgeoning, thankfully, realm of long-term survivors who have had cancer therapies in young adult lives, sometimes in childhood. And we need to be abreast of the ever-changing spectrum of complications that will plague these people all their lives. And we can do a great deal to improve the quality of survival in these patients.
Dr Monteith: And of course, there has been a lot of great development in cancer research, which has led to novel therapeutics. So, can you tell us about a few of these therapeutics and their complications that neurologists need to know about?
Dr Pruitt: Sure. Well, as I said, some of the cancers you're most likely to encounter are lung cancer and melanoma. And here the prognosis has changed dramatically. A few years ago, someone with metastatic melanoma might have had a couple months prognosis. And now we're talking honestly about long term survivors, complete responses in lung cancer and melanoma, and really good responses in the breast cancer realm as well. So, these are dramatic changes. And these are ways neurologists need to know what the actual nuanced and much more variable prognosis is among patients with brain metastases. In order to give the patients good advice and also to give the radiation oncologist and the oncologist, the medical oncologist, good advice. So, for example, just in the realm of brain metastases, a stage change has been that people with asymptomatic metastases for, let's say, non-small cell lung cancer or melanoma might have systemic therapy rather than local therapy, local therapy being gamma knife radiation or less likely, whole brain radiation therapy, but really systemic therapy with responses and the brands that are nearly as good as those in the rest of the body. And sustained, durable responses. The article goes into great detail about what's available in the way of therapies for these cancers, like breast, HER2-positive breast cancer, like EGFR‑positive lung cancer and melanoma of various types. It's really quite amazing actually, to have anybody quote a seven-year survival of little over 40% in people who presented with non-symptomatic melanoma metastases. Unheard of, really. So, I think if you're still practicing, quote unquote old school neuro-oncology, you need to get up to date because you're giving patients and their caregivers good advice that will lead them to the very important therapies. You mentioned some of the immunotherapies. If we have time, I'm happy to go into those because those are really important for neurologic consultants in the hospital.
Dr Monteith: Yeah. Let's talk about immune checkpoint inhibitors. What do we need to know about them and their complications?
Dr Pruitt: So, they have a novel set of central nervous system and peripheral nervous system complications. These include both acute and subacute presentations. They can arise after the very first dose and usually do so within the first several doses. Importantly, even though the patient may be quite sick, about three quarters will recover entirely. However, the most common ones are actually the peripheral nervous system, and they have the highest morbidity and mortality rate. So, a very unfortunate combination of myasthenia, myocarditis and skeletal myositis has a high mortality rate and is very hard to treat in a group of people who have received these immune checkpoint inhibitors in the central nervous system, there can be cerebellitis, encephalitis. These again can be acute or subacute presentations. And the big discussion with the attending oncologist is, can we continue these therapies after we've withdrawn them, and for instance, treated them with steroids? Because you can imagine that if you knock down the immune system with steroids, you might make the patient temporarily better. But in so doing, you're negating the important consequences of the mechanisms of immune checkpoint inhibitors.
So, I would say probably in a given week on the inpatient service, I'll see five or so. So nearly a daily event when I see some major complication of immune checkpoint inhibitors. And again, I've already mentioned the histology in which those have been useful, but they're not indicated for a variety of other malignancies as well. And the Car-T cell therapies are a whole different set of side effects. And some of your listeners may know about cytokine release syndrome, which is nearly universal right after the infusion of the car T cells. But a few days later is where we come into action with the immune effector cell-associated neurotoxicity syndrome. Or ICANS can say that I'll refer to it as ICANS since then. These include focal neurologic symptoms and the form of what's often a conduction sort of aphasia, a predictable deterioration, and handwriting along with confusion. As far as the radiology of that syndrome, that's really pretty odd. It can range from a dramatic cerebellitis, just a dramatic basal ganglia syndrome, a dramatic and enhancing leptomeningeal syndrome to an absolutely normal MRI scan. And the important thing for our consultant consultants to remember is that the patient can look really, really ill, and you can turn to the team and say, you know what, there's a very good chance that it's going to get all better. So, supporting people through what are very good diagnostic and therapeutic algorithms that exist in the literature and are quoted in the Continuum chapter to help know when you should be giving steroids, when you should be giving tocilizumab, etc. these are tried and true therapies now, and the Car-T world has improved not only the prognosis of patients. And I remember seeing some of the very first Car-T patients, and we really didn't know what to do to help them, how to turn off the cascade of this immunologic reaction. Now we know how to do that. And it's important to stay up to date on those algorithms because you can make a big difference for these patients.
Dr Monteith: Yeah. So, this is great. We're going to dive back into the diagnostics, which is really related to my follow up question. I think you gave a really great pearl. And it's always can we keep going? Do we stop? So, I want to like dive into that question. And I assume that there are categories. Yes. You can, somewhere in between, and absolutely not. And so, tell me a little bit more about that thinking.
Dr Pruitt: Well that's a very nuanced question. And so, the answer that some oncologists will give you as well, they've had such a dramatic response. So maybe we don't need it anymore. It's never the neurologist's decision. It's always the joint decision with the oncologist. So, for instance, with a Merkel cell cancer patient develops a severe anti‑AChR syndrome on an immune checkpoint inhibitor. And we tell the oncologist maybe you shouldn't go back and do that again. And the person says, never mind, he'll be fine. He's already had the response that we want, but that's a difficult question to answer because, for instance, in a slightly different subset, let's look at multiple myeloma patients. And I spent a fair amount of time on multiple myeloma in the article because it affects the nervous system in so many ways. And we have so many different therapies for these patients, one of which is a Car T-cell. And this is a B-cell maturation antigen, Car-T. It's different from the ones that we know for lymphoma and leukemia. And it has a different set of neurologic problems, which unfortunately do preclude going back to taking a Car-T cell therapy again. And just to make a long story short, this particular complication makes the patient look Parkinsonian.
The consult you're probably going to get from the medical services is patients weak. Well, the patient is not exactly weak. He is Parkinsonian. He has a extrapyramidal rigidity, sometimes a tremor a negative cat scan and a B-cell maturation antigen syndrome occurs not at the sort of 5 to 7 day mark about ICANS that we just discussed, but rather a month or so out and a month or so out. It's not when you're expecting to see Car-T cell therapies. So, patients end up getting worked up extensively for, let's say, some sort of infection, when in fact, what we should be looking at is a newly described complication of Car-T cell therapy. So, the part of my article on multiple myeloma is one that's really important because as you know, it's such a common hematologic problem among older people. And many of these people may have direct complications of multiple myeloma, such as direct tumor infiltration of nerves. POEMS syndrome. So, it's really a wealth of neurological issues for us to contend with for these people.
Dr Monteith: Yeah. And I know you've really done a great job of adding lots of wonderful charts, including understanding the time course of some of these complications, when to anticipate, because I think some of it is about when to anticipate some of these complications.
Dr Pruitt: Well, exactly. Yes. Given the time constraints, I've made a lot of tables because there was a lot of information. And those, I think, are the kinds of things that a consultant should know: what should I be thinking about at this point in time? And that sort of leads us to what are the later complications of these things. And those include many medical things, from failure due to neoplasia, morbidity, radiation, chemotherapy agents, the long-term and medium-term consequences of these things for people. Are going to come back to our office as well. Immunocompromised patients, such as the ones and heavily treated patients that I just mentioned, may lack a robust inflammatory response. And they can have infections really at any time out. Some are predictable, as in our leukemia patients who have had hematopoietic cell transplant. So, we kind of know when to expect viral infections, nosocomial infections, progressive multifocal leukoencephalopathy, many other things down the road. But in this era of COVID, we know that these patients are more susceptible to the dire effects of COVID, and they may not mount a good vaccination response. We have seen types of neurologic complications of all sorts of infections, including babesiosis this year, and persistent enteric viral meningitis. So, the patient can present a very atypical fashion. And the neurologic consultant has to keep a really open mind about the broad differential of what might be happening.
Dr Monteith: And you do have a section under imaging and metastatic disease. Are there any like new sequences or a way to kind of tease out complexities?
Dr Pruitt: So, there is marked variability in the radiographic appearance of brain metastases. And I must confess that I made a very large collage of all the different representative types of things. And I think that's important for neurologic consultants to recognize that some metastases don't enhance. They don't all look like ring-enhancing lesions. Some can be much more diffuse, particularly if the patient has received something like a VEGF inhibitor like bevacizumab therapy can look exceedingly different. They can involve the dura, which should be treated differently. There can be simultaneous leptomeningeal and disease. So as far as I know, sequences perhaps not so much. Although if one is thinking about the differential between radiation-related injury and someone who's already been treated versus tumor recurrence, then we have some pretty good microscopic data, some susceptibility weighted images, other ways of getting whether this is really radiation related change or tumor recurrence, a major problem obviously.
What we also know about radiation is kind of a theme of the article is use it as infrequently as possible, because we just talked about some of the other therapies that we have. We may need to give local therapy for symptomatic patients, but we give as little as possible, and we try never to give whole brain radiation therapy. I'll go on record as saying that it's certainly necessary. Sometimes people have diffuse lymphoma, this disease that's recurred, they have multiple metastases in a sort of miliary fashion may be necessary, but if you can use gamma knife radiation, if you cause any use form of focal radiation, new in the leptomeningeal world is proton therapy for spinal metastases. So quick sparing techniques. And this is something that should always be considered when you're consulting on someone in a place in which you have the option of proton therapy. So, I would say that distinguishing between radiation necrosis and recurrent tumor and the use of protons are the big news in the radiation therapy world. And don't give whole brain radiation therapy if you can avoid it.
Dr Monteith: Yeah. I'm getting a flashback from residency because, you know, that always happens. And the radiologist saying, you know, we need more information when you put in those orders. And so, I think with this whole era of new chemotherapeutic agents and how they could present on imaging and give the radiologists as much information, including the type of chemotherapeutic agent used.
Dr Pruitt: Yeah, I think particularly in the transplant world. So, the leukemia lymphoma patients who have received one of the calcineurin inhibitors, like tacrolimus or cyclosporine, that induces a whole set of complications, some of which are visible radiographically. There's a delayed leukoencephalopathy. There can be stroke. There can be SMART syndrome, stroke like migraine after radiation therapy. And perhaps many of our listeners have been confronted with someone who has a prolonged focal deficit, say, a hemianopia and maybe a hemisensory deficit with or without a subsequent headache. It goes on for days to hours. It looks peculiar on the MRI scan because it's not then a vascular distribution. There's sort of diffuse gyral swelling, flattening of the EEG on that side, the patients getting steroids and valproate and anticoagulation and angiography and all. It doesn't need any of that. The syndrome of stroke, like migraine after radiation therapy, needs to be recognized. And best thing to do is don't just do something. Stand there. You should wait until it goes away. And so, I think that's we are seeing this increasingly, that we first reported this in young adults who had been treated years ago for medulloblastoma. So, it was posterior fossa tumors primarily. But this has now been broadened, as you know, to include supratentorial tumors of many types and adults at various times out from their radiation therapy from a few months to many years.
Dr Monteith: I should ask you in writing this article, clearly you have a wealth of knowledge, but in kind of just putting this together, what surprised you?
Dr Pruitt: I think what surprised me is the increasing range of complications and that virtually anything needs to be thought of central nervous system or peripheral nervous system. With some of these newer therapies. There is a chart in there about the conventional cytotoxic therapies, and we're all familiar with things like methotrexate and that sort of thing. But what surprised me really is the increasing diversity of complications of these newer drugs, and also the fact that I didn't know some of the third and fourth generations of the tyrosine kinase inhibitors too. When you look at even the year of 2020, neurologic drugs were second only to oncologic drugs and FDA approval even at the height of COVID. So, don't feel badly if you don't remember any of the drugs really changing so rapidly. And they're better ideas, they're going to be fancier Car-T cells that attempt to get around some of the adverse effects of these and neurologists will retain really important role in following some of these patients, to be sure that these improvements are actually real and durable.
Dr Monteith: Excellent. Thank you so much for this wonderful conversation.
Dr Pruitt: Well, thank you so much for having me. And I hope people do get information from the article. Thanks.
Dr Monteith: Again, today I've been interviewing Dr Amy Pruitt about her article on neurologic complications of cancer and its treatment, which appears in the February 2026 Continuum issue on neurology of systemic disease. Be sure to check out Continuum Audio episodes from this and other issues. 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, you'll love the journal, which is full of in-depth and clinically relevant information important for neurology practitioners. Use the link in the episode notes to learn more and subscribe, AAN members, you can get CME for listening to this interview by completing the evaluation at continpub.com/audioCME. Thank you for listening to Continuum Audio.