Continuum Audio

• Optic Neuritis With Dr. Eric Eggenberger

  The inflammatory and infectious optic neuropathies are a broad, heterogeneous, and common group of diseases producing visual loss. Although many now-distinct syndromes have been previously combined as “typical or atypical optic neuritis,” recent developments highlight the importance of precision terminology as well as an individualized evaluation and treatment approach. In this episode, Gordon Smith, MD, FAAN speaks with Eric Eggenberger, DO, MS, FAAN, author of the article “Optic Neuritis” in the Continuum® April 2025 Neuro-ophthalmology issue. Dr. Smith is a Continuum® Audio interviewer and a professor and chair of neurology at Kenneth and Dianne Wright Distinguished Chair in Clinical and Translational Research at Virginia Commonwealth University in Richmond, Virginia. Dr. Eggenberger is a professor of ophthalmology, neurology, and neurosurgery at the Mayo Clinic in Jacksonville, Florida. Additional Resources Read the article: Optic Neuritis 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: @gordonsmithMD Full episode transcript available here 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 Smith: This is Dr Gordon Smith. Today I'm interviewing someone who really needs no introduction, Dr Eric Eggenberger, about his article on optic neuritis, which appears in the April 2025 Continuum issue on neuro-ophthalmology. Eric, welcome to the podcast, and maybe you can introduce yourself to our audience. Dr Eggenberger: Thank you. Thanks for having me. So, my name is Eric Eggenberger. I work at Mayo Clinic Florida, and I am involved exclusively in neuro-ophthalmology. Dr Smith: I just had the pleasure, Eric, of talking yesterday with Lindsey De Lott about non-optic neuritis causes of optic neuropathy. And so, I'm going to kind of reference a little bit what I learned yesterday. She was great. I wonder if you might begin by talking a little bit about nomenclature. You talk about the need for use of precise terminology in your article. And yesterday she taught me a lot about the risk of misdiagnosis and other causes of optic neuropathy, and the two seem related. So, I wonder if you can maybe lay the foundation for our conversation by talking about terminology? Dr Eggenberger: I think that's a great point. So, we are in an era now where, instead of lumping all these different diagnoses together, we have learned to split apart some of these clinical entities. And so, I think it's really important that we focus on precise terminology and recognize that all optic neuritis is not the same. And we have very different, distinct clinical pathways for these imaging pathways, treatment pathways, for these different types of optic neuritis, whether that's MS related, whether it's MOG related or aquaporin-4 related. Dr Smith: So, I wonder maybe we can begin by just, you know, giving our listeners wisdom, pearls, and pitfalls about, how do you recognize when someone with a suspected optic neuropathy has optic neuritis versus a noninflammatory optic neuropathy? Dr Eggenberger: So, that's a really important issue because there's a lot of clinical overlap in terms of exam findings. So, for instance, in any optic neuropathy, let's say it's unilateral, you typically are going to see decreases in acuity and field and color, and you're going to see a relative afferent pupillary defect. And then it's really the context that that occurs in that helps us distinguish different disease entities. So, with optic neuritis, typically you're going to have pain. And that's oftentimes going to be in the younger populations compared to some of the other common optic neuropathies we see, like ischemic optic neuropathy, for instance. Dr Smith: Right. So maybe we can talk a little bit about, kind of, your overall diagnostic approach, right? A lot of this is, of course, based on age and context, but young people get ischemic lesions and older people can have inflammatory lesions. So, what's your overall approach to the patient you just described? Let's say it's a forty-eight-year-old woman who comes to the emergency department with subacute unilateral vision loss and there's dyschromatopsia, APD, reduced acuity. And, you know, let's just say a fairly, you know, benign-looking fundoscopic exam. What do you do to evaluate that patient? Dr Eggenberger: In that particular context, I think we're looking at other contextual clues. Is there other vascular risk factors or other things to point you in one direction or the other? One of the important parts you mentioned was the fundus exam. So, we know with ischemic optic neuropathy, 100% of the time with AIOM, you're going to see disc edema. And so, in the context of that story, we want to confirm on our exam an optic neuropathy, and then we can kind of focus on the retrobulbar courses or different types of optic neuropathies. From an exam perspective, in that particular patient we’d be looking to measure the acuity, quantify that. And in the ER, you're not going to be able to do a perfect field, but you'll get some sense of the field and how much field loss there is. And then as you mentioned, the afferent pupillary defect is critical. And we're going to get a little bit of the historical features in terms of pain. With typical retrobulbar optic neuritis, most of those patients are going to experience some pain, and usually it's pain on eye movements. And those would be the clinical things to focus on. Other exposures the patient may or may not have had, any other concomitant conditions, would all help point you in different directions, perhaps, and then we're probably on towards imaging. Dr Smith: Yeah, maybe you can talk a little bit about that? What's the appropriate use of imaging? I mean, presumably the patients, like the one I just threw out there, are pretty much all going to get neuroimaging. What's your approach to that? How do you protocol the study? What should we be looking for? Dr Eggenberger: In our clinic, we would typically be ordering an MRI orbit and brain, and each of those has a specific purpose. The orbit is going to show us the extent of the optic neuropathy. So, we're particularly looking for a longitudinally extensive optic nerve lesion or more than half of the optic nerve involved. And most patients acutely, if it isn't an “itis" situation, we'll see enhancement. And then the MR brain is going to be useful for looking for other evidence of demyelination within the central nervous system. We may at some point get down to doing an MR cord, but I think acutely it's going to be brain and orbit that most of our patients are getting. Dr Smith: Let's say that we did the scan and, sure enough, there's sort of a shorter segment, so less than half the length of the nerve region of enhancement. What's the rest of your diagnostic evaluation look like for that patient? Dr Eggenberger: So, in that particular case, we would look at the remainder of the brain. So, we're looking for other evidence of demyelination and any other contextual clues, systemically that would point you one direction or another. But with a shorter segment involved, one of the more common things we might encounter would be multiple sclerosis-related optic neuritis. Dr Smith: Would you look for aquaporin-4 and MOG in a patient with what appears to be an isolated, uncomplicated short segment optic neuritis? Dr Eggenberger: So, I think it really depends a bit on the context. I would never fault anybody for looking at MOG or an aquaporin-4 in that context because those are really treatment-altering diagnoses, but the yield in this particular case with a short segment involved and depending on the acuity and other features is probably going to be pretty low. Dr Smith: I really liked as an aside- I wasn't going to go there next, but you kind of got me thinking about it, you have a really nice section in your article. Which, all of it's great, but talking about how to manage low titer MOG antibodies. I wonder if you could talk about that because I think that's a lesson, maybe, that is transferable to a lot of other testing that we do. in terms of pre-prior probability and titer and so forth. Dr Eggenberger: Yeah, that's really an important point. So, we've seen this come up a number of times where the MOG antibody is a very good test, but in low titer it has a relatively low positive predictive value, perhaps 50%. In those cases, particularly without a classic clinical context, you have to be extremely alert for some other diagnosis that could mimic what you think is inflammatory demyelinating optic neuritis, but in fact is infectious or some other cause. Dr Smith: Yeah, super, super important and helpful. In terms of aquaporin-4, how does that compare in terms of predictive values, lower titer positive results? Dr Eggenberger: So aquaporin-4, the test has a very high specificity. So, it's quite useful if positive. You have to keep in mind there can be some false negatives, but the test otherwise is quite specific. And that is a diagnosis, you know, we never want to miss. It's a vicious disease. It tends to be a blinding disease, particularly without treatment. Bad things happen when we miss that, and we want to get on that diagnosis early and do pretty aggressive early and prophylactic treatment. Dr Smith: Your article covers not only the common causes of optic neuritis and, you know, MS, isolated optic neuritis, MOGAD NMO, you talk about a bunch of other things. I wonder, in this patient that we've been discussing, in the absence of any other historical information that seems relevant---or maybe you can define what would seem relevant---would you do other evaluation in that individual, other serologic evaluation and so forth, just in terms of diagnosis? Dr Eggenberger: In that particular case, without other red flags, I don't think I would initially. And follow-up is going to give you a lot of this context. So, you'd be on the lookout for other systemic conditions. So, if the patient had some arthropathy, if the patient had any pulmonary disease hints, if there was anything else that could lead you on a broader expedition. But I think in the context of this case, acutely in the ER, I probably wouldn't do a big lab plug for this. I probably would kind of go down the most likely road and start our treatments, and then follow that patient up. Dr Smith: Yeah, I know your article does a really great job, I think, of outlining when do you need to think about some of these less common causes. Well, can we talk about treatment, Eric? Because I want to move on to some other things. But- so, we've got a patient with isolated optic neuritis, nothing else, you know, in terms of the other antibodies we've talked about. What state-of-the-care- or, state-of-the-art treatment for that patient? Dr Eggenberger: So, the acute treatment for these inflammatory, optic neuritis-type cases is very similar Initially. High dose steroids remains kind of the standard. And then, in MS-related optic neuritis, we may or may not see a taper. So many times it's just an acute treatment of three to five days high dose. Whether that's oral or PO, we could institute either depending on the particular case. And then the taper would depend on the potential cause. So, for instance, with these antibody-driven diseases---so with MOG- or particularly with aquaporin-4---if it's a longitudinally extensive region of optic nerve involved, we tend to use a longitudinally extensive taper. And so, we use prednisone in those cases for several months while we're getting everything else set and deciding what the overall course is going to bring. Dr Smith: What about IV versus oral? There must be something about my practice. I was telling this to Lindsey. Every time on our hospital service, we seem to have at least two patients with optic neuropathies, which I always enjoy, but I find it's a little weird to admit someone who's doing just fine otherwise to the hospital with three days of IV SOLU-MEDROL. So, I'm always trying to figure out, like, how can I get this patient home? And your article had the best term I've heard in a long time, which is “SOLU smoothies.” I mean, are there other strategies that you sometimes use, other than just high-dose IV methylprednisolone? Dr Eggenberger: So, I agree with you. It's sometimes hard to admit somebody for just an IV therapy. And we'll do this as an outpatient, high-dose IV, but we'll also use high-dose orals. And in times in the past when there's been methylprednisolone shortage, we've used high-dose oral or IV dexamethasone as well. I think the IV form, although it's the gold standard, the high-dose oral forms have pretty equivalent bioavailability and are pretty tolerable in my experience. And certainly more convenient. Dr Smith: I wonder if we should switch and maybe talk a little bit about aquaporin-4, I mean, you emphasized that this is a vicious disease---I love the way you describe that---and often blinding. What updates do you have in terms of our therapeutic approach to NMO? That's been rapidly evolving of late. Dr Eggenberger: Right, so these are cases we're always going to share with neuroimmunology. And it requires kind of a multidisciplinary approach, in my opinion, for ideal or for best outcomes. And so, all of these patients are going to get put on prophylactic medications. So, this is a disease you just can't leave untreated. Bad stuff will happen for sure. And we now, fortunately, have some approved, FDA-approved medications that can positively impact the course of this disease. So, that's been a welcome addition. Dr Smith: What are the FDA-approved medications at this point for NMO? Dr Eggenberger: So, there are several at this point, and this is an area that's in growth, fortunately. And again, these are cases we're going to be sharing with our neuroimmunology colleagues. So, these are IV medications typically aimed at complement or CD19. And they all are relatively effective at quieting the course of the disease. Dr Smith: Maybe we can talk a little bit about MOG? I think that most of our listeners are probably pretty familiar with aquaporin-4 and NMO, what- maybe you could describe MOG a little bit and the therapeutic approach for patients with MOG-associated disease? Dr Eggenberger: So, MOG has been a real interesting kind of condition to learn more about. We certainly see a lot of MOG, and I'm sure we saw MOG before it was formally described, but I think we just thought it was kind of a benign, maybe monophasic MS type of presentation. But MOG tends to come in with a loss of acuity that kind of rivals aquaporin-4. So, the acuity tends to be pretty, pretty depressed, but it's very steroid-responsive. So, a lot of times these are the patients, you'll see that their vision will start to improve even when they're on the initial few days of the high-dose steroids. And many times we can get their vision back to 20/20 or very close to that. Dr Smith: And do these patients need chronic management? Dr Eggenberger: So, that's an area of controversy to some degree. About 50% of the optic neuritis MOG-related cases are going to have a relapsing course. And because the disease is steroid-responsive, many times we'll follow these patients after a first attack to see if this is the condition that’s going to declare itself to be relapsing or if this is just going to be a monophasic kind of presentation of optic neuritis. We don't have great biomarkers to separate patients who are going to be in that 50% monophasic course versus the other half. It'll be relapsing. And so, it depends on the patient. If there's somebody that's, as many of these patients are, been very steroid responsive, they get back to 20/20, we can teach them about the disease so that if they do have a relapse, we can get them high-dose steroids in a relatively rapid fashion and they're otherwise healthy, we're probably going to watch that patient. And if it's somebody that doesn't recover 100%, there's other issues with treating them with high-dose steroids potentially in the future, then we may learn more towards an earlier prophylactic approach in that patient. Dr Smith: And what would that approach look like? Is it different from NMO or using more IVIG or B cell depletion as opposed to complement inhibition, for instance? Dr Eggenberger: In MOG, we know that the B cell depletion strategies don't work as well. And so most times we're turning to IVIG, and we found that pretty effective. That's kind of our go-to at this point. Dr Smith: Eric, it's a joy talking to you and I'd love to keep going about content, but I'll refer our listeners to your outstanding article. I mean, you're such a highly regarded neuro-ophthalmologist and educator. I wonder if you could talk to us about why you've done neuro-ophthalmology, and maybe this is an opportunity for you to convince all of our great residents that are listening or students what's great about being a neuro-ophthalmologist. Dr Eggenberger: I think neuro-ophthalmology is by far the most interesting part of neurology. So, it's an area that I think a lot of general neurologists, in my view, don't get enough of in their residency. But it's kind of the essence of neurology, where in neurology you're localizing down to the millimeter and in neuro-ophthalmology,  we're localizing down to the micron level. We have several new emerging diseases like these varieties of optic neuritis we're focused on. We're learning lots about those. You get to be involved in lots of different areas of neurology. So, we'll see not just demyelinating conditions, we'll see trauma as it relates to the visual system. And we'll see tumor, and we see all different flavors, stroke, and in any piece of neurology, commonly we'll have some vision aspect that we that we get involved in. So, we see a wide variety of conditions. So, I think it's been a really exciting place to be within neurology. And it's rapidly changing at this point. We're getting new therapeutics. So, it's, I think it's a great time to be a neuro-ophthalmologist. Dr Smith: Yeah, listening to you talk and just reflecting on it, it's really true. Neuro-ophthalmology does cover the entire span of neurology, right? I'm a neuromuscular guy and we see a lot of ocular myasthenia, which is another super exciting area. But we've been talking about optic neuritis, and your article talks about infectious causes and the paraneoplastic and a whole host of things. So, you're a great advocate and salesperson for your field. You convinced me. Dr Eggenberger: Efferent neuro-ophthalmology we love, we could talk about ocular myasthenia and other aspects for another hour. And we get involved in all kinds of cases: third nerve palsies, ocular myasthenia, trauma that involves the efferent system, all different aspects. It's really a great subspecialty, and you get to see a bit of all of neurology. Dr Smith: I'm trying to remember who it was, Eric. It was an attending of mine at medical school. I went to medical school at the Mayo Clinic in Rochester, and I want to say it was Manny Gomez, who was a very famous tuberous sclerosis person, who told me that neuro-ophthalmology was the most elegant specialty within neurology. That stuck with me. Thank you so much for joining me today. I really appreciate it. Dr Eggenberger: Thank you. I appreciate it as well. Dr Smith: So again, today I've been interviewing Dr Eric Eggenberger about his really wonderful article on optic neuritis, which appears in the most recent issue of Continuum on neuro-ophthalmology. Be sure to check out Continuum audio episodes from the neuro-ophthalmology and other issues. And listeners, thank you very much 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.

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  21:36
• Optic Neuropathies With Dr. Lindsey De Lott

  Optic neuropathies encompass all congenital or acquired conditions affecting the optic nerve and are often a harbinger of systemic and central nervous system disorders. A systematic approach to identifying the clinical manifestations of specific optic neuropathies is imperative for directing diagnostic assessments, formulating tailored treatment regimens, and identifying broader central nervous system and systemic disorders. In this episode, Gordon Smith, MD, FAAN speaks with Lindsey De Lott, MD, MS, author of the article “Optic Neuropathies” in the Continuum® April 2025 Neuro-ophthalmology issue. Dr. Smith is a Continuum® Audio interviewer and a professor and chair of neurology at Kenneth and Dianne Wright Distinguished Chair in Clinical and Translational Research at Virginia Commonwealth University in Richmond, Virginia. Dr. De Lott is an assistant professor of neurology and ophthalmology at the University of Michigan in Ann Arbor, Michigan. Additional Resources Read the article: Optic Neuropathies 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: @gordonsmithMD Guest: @lindseydelott Full episode transcript available here 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 Smith: Hello, this is Dr Gordon Smith. Today I'm interviewing Dr Lindsey De Lott about her article on optic neuropathies, which appears in the April 2025 Continuum issue on neuro-ophthalmology. Lindsey, welcome to the podcast, and perhaps you can introduce yourself to our audience. Dr De Lott: Thank you, Dr Smith. My name is Lindsey De Lott and I am a neurologist and a neuro-ophthalmologist at the University of Michigan. I also serve as the section lead for the Division of Neuro-Ophthalmology, which is actually part of the ophthalmology department rather than the neurology department. And I spend a good portion of my time as a researcher in health services research, and that's now about 60% of my practice or so. Dr Smith: I'm super excited to spend some time talking with you. One, I'm a Michigan person. As we were chatting before this, I trained with Wayne Cornblath and John Trobe, and it's great to have you. I wonder if we maybe can begin- and by the way, your article is outstanding. It is such a huge topic and it was actually really fun to read, so I encourage our listeners to check it out. But you begin by talking about misdiagnosis as being a common problem in this patient population. I wonder if you can talk through why that is and if you have any pearls or pitfalls in avoiding it? Dr De Lott: Yeah, I think there's been a lot of great research looking at misdiagnosis in specific types of optic neuropathies; in particular, compressive optic neuropathies and optic neuritis. A lot of that work has come out of the group at Emory and the group at Washington University. But a lot of neuro-ophthalmologists across the country really contributed to those data. And one of the statistics that always strikes me is that, you know, for example, in patients with optic nerve sheath meningiomas, something like 70% of them are actually misdiagnosed. And a lot of those errors in diagnosis, whether it's for compressive optic neuropathy or some other type of optic neuropathy, really comes down to the way that physicians are really incorporating elements of the history in the physical. For example, in optic neuritis, we know that physicians tend to anchor pretty heavily on pain in general. And that often tends to lead them astray when optic neuritis was never the diagnosis to begin with. So, it's really overindexing on certain things and not paying attention to other features of the physical exam; for example, say presence of an afferent pupillary defect. So, I think it just really highlights the need to have a really relatively structured approach to patients that you think have an optic neuropathy when you're trying to sort of plan your diagnostic testing and your treatment. Dr Smith: I do maybe five or six weeks on our hospital service each year, and I don't know if it's just a Richmond thing, but there's always at least two people in my week who come in with an optic neuropathy or acute vision loss. How common is this in medical practice? Or neurologic practice, I should say? Dr De Lott: Optic neuropathies themselves… if you look across, unfortunately we don't have any great data that puts together all optic neuropathies and gives us an actual sort of prevalence estimate or an incidence estimate from year to year. We do have some of those data for specific types of optic neuropathies like optic neuritis and NAION, and you're probably looking around five-ish per one hundred thousand. So, these aren't that common, but at the same time they do get funneled to- often to emergency rooms and to neurologists from our ophthalmology colleagues and optometry colleagues in particular. Dr Smith: So, one other question I had before kind of diving into the topic at hand is how facile neurologists need to be in recognizing other causes of acute visual loss. I mean, we see acute visual loss as neurologists, we think optic neuropathy, right? Optic neuritis is sort of the go-to in a younger patient, and NAION in someone older. But what do neurologists need to know about other ophthalmologic causes? So, glaucoma or acute retinal disorders, for instance? Dr De Lott: Yeah, I think it's really important that neurologists are able to distinguish optic neuropathies from other causes of vision loss. And so, I would really encourage the listeners to take a look at the excellent article by Nancy Newman about vision loss in this issue where she really kind of breaks it down into vision loss that is acute and chronic and how you really think through distinguishing optic neuropathies from other causes of vision loss. But it is really important. For example, a patient with a central retinal artery occlusion may potentially be eligible for treatments. And that's very different from a patient with optic neuritis and acute vision loss. So, we want to be able to distinguish these things.  Dr Smith: So maybe we can pivot to that a little bit. Just for our listeners, our focus today is going to be on- not so much on optic neuritis, although obviously we need to talk a little bit about how we differentiate optic neuritis from non-neuritis optic neuropathies. It seems like the two most common situations we encounter are ischemic optic neuropathies and optic neuritis. Maybe you can talk a little bit about how you distinguish these two? I mean, some of it’s age, some of it’s risk factors, some of it’s exam. What's the framework, of let's say, a fifty-year-old person comes into the emergency room with acute vision loss and you're worried about an optic neuropathy? Dr De Lott: The first step whenever you are considering an optic neuropathy is just making sure that the features are present. I think, really going back to your earlier question, making sure that the patient has the features of an optic neuropathy that we expect. So, it's not only vision loss, but it's also the presence of an apparent pupillary defect in a patient with a unilateral optic neuropathy. In a person who has a bilateral optic neuropathy, that apparent pupillary defect may not be present because it is relative. So, you really would have to have asymmetric vision loss between the two eyes. They should also have impairment of their color vision, and they're probably going to have some kind of visual field defect, whether that's central scotoma or an arcuate scotoma or an altitudinal defect that really respects the horizontal meridian. So, you want to make sure that, first and foremost, you've got a patient that really meets most of those- most of those features. And then from there, we're looking at the other features on their history. How acute is the onset of the vision loss? What is the progression over time? Is there pain associated or not associated with the vision loss? What other medical issues does the patient have? And you know, one of the things you already brought up, for example, is, what's the age of the patient? So, I'm going to be much more hesitant to make a diagnosis of optic neuritis in a much older patient or a diagnosis on the other side, of ischemic optic neuropathy, in a much younger patient, unless they have really clear features that push me in that direction. Dr Smith: I wonder if maybe you could talk a little bit about features that would push you away from optic neuritis, because, I mean, people who are over fifty do get optic neuritis- Dr De Lott: They do. Dr Smith: -and people who get ischemic optic neuropathies who are younger. So, what features would push you away from optic neuritis and towards… let's be broad, just a different type of optic neuropathy? Dr De Lott: Sure. We know that most patients with optic neuritis do have pain, but that pain is accompanied---within a few days, typically---with vision loss. So, pain alone going on for a number of days without any visual symptoms or any of those other things I listed, like the afferent papillary defect, the visual field defect, would push me away from optic neuritis. But in general, yes, most optic neuritis is indeed painful. So, the presence of optic disc edema is unfortunately one of those things that an optic neuritis may be present, may not be present, but in somebody with ischemia that is anterior---and that's the most common type of ischemic optic neuropathy, would be anterior ischemic optic neuropathy---they have to have optic disc edema for us to be able to make that diagnosis, and that is a diagnosis of NAION, or nonarteritic ischemic optic neuropathy. An APD in this case, again, that's just a feature of an optic neuropathy. It doesn't really help you to distinguish, individual field defects are going to be relatively similar between them. So then in patients, I'm also looking, like I said, at their history. So, in a patient where I'm entertaining a diagnosis of ischemic optic neuropathy, I want to make sure that they have vascular risk factors or that I'm actually doing things like measuring their blood pressure in the office if they haven't seen a physician recently or checking a lipid panel, hemoglobin A1c, those kinds of things, to look for vascular risk factors. One of the other features on exam that might push me more- again, in a patient with ischemic optic neuropathy, where it might suggest ischemia over optic neuritis, would be some other features on exam like a crowded optic disc that we sometimes will see in patients with ischemic optic neuropathy. I feel like that was a bit of a convoluted answer. Dr Smith: I thought that was a great answer. And when you say crowded optic disc, that's the- is that the “disc at risk”? Dr De Lott: That is the “disk at risk,” yes. So, crowded optic disk is really a disk that is smaller than what we see in the average population, and the average cup to disk ratio is 0.3. So, I think that's where 30% of the disk should be. So, this extra wiggle room, as I sometimes will explain to my patients. Dr Smith: And then, I wonder if you could talk a little bit about more- just more about exam, right? You raised the importance of recognizing optic disc edema. Are there aspects of that disc edema that really steer you away from optic neuritis and towards ischemia-like hemorrhages or whatnot? And then a similar question about the importance of careful visual field testing? Dr De Lott: So, on the whole, optic disc edema is optic disc edema. And you can have very severe optic neuritis with hemorrhages, cotton wool spots, which is essentially just an infarction of the retinal nerve fiber layer either overlying the disc or other parts of the retina. And ischemia, you can have some of the same features. In patients who have giant cell arteritis, which is just one form of anterior ischemic optic neuropathy, patients can have a pallid optic disc edema where the optic disc is swollen and white-looking. But on the whole, swelling is swelling. So, I would caution anyone against using the features of the optic nerve swelling to make any type of, sort of, definitive kind of diagnosis. It's worth keeping in mind, but I just- I would caution against using specific features, optic nerve swelling. And then for visual field testing, there are certain patterns that sometimes can be helpful. I think as I mentioned earlier, in patients with ischemic optic neuropathy, we’ll often see an altitudinal defect where either the top half or, more commonly, the bottom half of the vision is lost. And that vision loss in the field corresponds to the area of swelling on the disk, which is really rewarding when you're actually able to see sectoral swelling of the disk. So, say the top half of the disk is swollen and you see a really dense inferior defect. And other types of optic neuropathy such as hereditary optic neuropathies, toxic and nutritional optic neuropathies, they often cause more central field loss. And in patients who have optic neuropathies from elevated intracranial pressure, so papilladema, those folks often have more subtle visual field loss in an arcuate pattern. And it's only once the optic nerves have sustained a pretty significant injury that you start to see other patterns of field loss and actual decline in visual acuity in those patients. I do think a detailed visual field assessment can often be pretty helpful as an adjunct to the rest of the exam. Dr Smith: So, we haven't talked a lot about neuroimaging, and obviously, neuroimaging is really important in patients who have optic neuritis. But how about an older patient in whom you suspect ischemic optic neuropathy? Do those patients all need a MRI scan? And if so, is it orbits and brain? How do you- how do you protocol it? Dr De Lott: You're asking such a good question, totally controversial in in some ways. And so, in patients with ischemic optic neuropathy, if you are confident in your diagnosis: the patient is over the age of fifty, they have all the vascular, you know, they have vascular risk factors. And those vascular risk factors are things like diabetes, hypertension, high blood pressure, hyperlipidemia, obstructive sleep apnea. They have a “disc at risk” in the fellow eye. They don't have pain, they don't have a cancer history. Then doing an MRI of the orbits is probably not necessary to rule out another cause. But if you aren't confident that you have all of those features, then you should absolutely do an MRI of the orbit. The MRI of the brain probably doesn't provide you with much additional information. However, if you are trying to distinguish between an ischemic optic neuropathy and, say, maybe an optic neuritis, in those patients we do recommend MRI orbits and brain imaging because the brain does provide additional information about other CNS demyelinating disorders that might be actually the cause of a patient's optic neuritis. Dr Smith: I wonder if you could talk a little bit about posterior ischemic optic neuropathy. That's much less common, and you mentioned earlier that those patients don't have optic disk edema. So, if there's a patient who has vision loss that- in a similar sort of clinical scenario that you talked about, how do you approach that and under what circumstances do we see patients who have posterior ischemic optic neuropathy? Dr De Lott: So, you're going to most often see patients with posterior ischemic optic neuropathy who, for example, have undergone a recent surgery. These are often associated with things like spinal surgeries, cardiac surgeries. And there are a number of risk factors that are associated with it. Things like blood pressure, drain surgery, the amount of blood loss, positioning of patient. And this is something that the surgeons and anesthesiologists are very sensitive to at this point in time, and many patients are often- this can be part of the normal informed consent process at this point in time since this is something that is well-recognized for specific surgeries. In those patients, though… again, unless you're really certain, for example, maybe the inpatient neurology attending and you've been asked to consult on a patient and it's very clear that they went into surgery normal, they came out of surgery with vision loss, and all the rest of the features really seem to be present. I would recommend that in those cases you think about orbital imaging, making sure you're not missing anything else. Again, unless all of the features really are present- and I think that's one of the themes, definitely, throughout this article, is really the importance of neuroimaging in helping us to distinguish between different types of optic neuropathy. Dr Smith: Yeah, I think one of the things that Eric Eggenberger talks about in his article is the need to use precise nomenclature too, which I plan on talking to him about. But I think having this very structured approach- and your article does it very well, I’ll tell our listeners who haven't seen it there's a series of really great tables in the article that outline a lot of these. I wonder, Lindsey, if we can switch to talk about arteritic optic neuropathy. Is that okay? Dr De Lott: Sure. Yeah, absolutely. Dr Smith: How do you sort that out in an older patient who comes in with an ischemic optic neuropathy? Dr De Lott: Yeah. In patients who are over the age of fifty with an ischemic optic neuropathy, we always need to be thinking about giant cell arteritis. It is really a diagnosis we cannot afford to miss. If we do miss it, unfortunately, patients are likely to lose vision in their fellow eye about 1/3 to 1/2 the time. So, it is really one of those emergencies in neuro-ophthalmology and neurology. And so you want to do a thorough review systems for giant cell arteritis symptoms, things like headache, jaw claudication, myalgias, unintentional weight loss, fevers, things of that nature. You also want to check their inflammatory markers to look for evidence of an elevated ESR, elevated C-reactive protein. And then on exam, what you're going to find is that it can cause an anterior ischemic optic neuropathy, as I mentioned earlier. It can cause palette optic disc swelling. But giant cell arteritis can also cause posterior ischemic optic neuropathy. And so, it can be present without any swelling of the optic disc. And in fact, you know, you mentioned one of my mentors, John Trobe, who used to say that in a patient where you're entertaining the idea of posterior ischemic optic neuropathy, who is over the age of fifty with no optic disc swelling, you should be thinking about number one, giant cell arteritis; number two, giant cell arteritis; number three, giant cell arteritis. And so, I think that is a real take-home point is making sure that you're thinking of this diagnosis often in our patients who are over the age of fifty, have to rule it out. Dr Smith: I'll ask maybe a simple question. And presumably just about everyone who you see with a presumed ischemic optic neuropathy, even if they don't have clinical features, you at least check a sed rate. Is that true? Dr De Lott: I do. So, I do routinely check sedimentation rate and C-reactive protein. So, you need to check both. And the reason is that there are some patients who have a positive C-reactive protein but a normal sedimentation rate, so. And vice versa, although that is less common. And so both need to be checked. One other lab that sometimes can be helpful is looking at their CBC. You'll often find these patients with giant cell arteritis have elevated platelet counts. And if you can trend them over time, if you happen to have a patient that's had multiple, you'll see it sort of increasing over time. Dr Smith: I'm just thinking about how you sort things out in the middle, right? I mean, so that not all patients with GCF, sky-high sed rate and CRP…. And I'm just thinking of Dr Trobe's wisdom. So, when you're in an uncertain situation, presumably you go ahead and treat with steroids and move to biopsy. Maybe you can talk a bit about that pathway? Dr De Lott: Yeah, sure. Dr Smith: What's the definitive diagnostic process? Do you- for instance, the sed rate is sky-high, do you still get a biopsy? Dr De Lott: Yes. So, biopsy is still our gold-standard diagnosis here in the United States. I will say that is not the case in all parts of the world. In fact, many parts of Europe are moving toward using other ancillary tests in combination with labs and exam, the history, to make a definitive diagnosis of giant cell arteritis. And those tests are things like temporal artery ultrasound. We also, even though we call it temporal artery ultrasound, we actually need to image not only the temporal arteries but also the axillary arteries. The sensitivity and specificity is actually greater in those cases. And then there's high-resolution imaging of the vessels and the- both the intracranial and extracranial distributions. And both of those have shown some promise in their predictive values of patients actually having giant cell arteritis. One caution I would give to our listeners, though, is that, you know, currently in the US, temporal artery biopsy is still the gold standard. And reading the ultrasounds and the MRIs takes a really experienced radiologist. So, unless you really know the diagnostic accuracy at your institution, again, temporal artery biopsy remains the gold standard here. So, when you are considering giant cell arteritis, start the patient on steroids and- that's high dose, high dose steroids. In patients with vision loss, we use high dose intravenous methylprednisolone and then go ahead and get the biopsy. Dr Smith: Super helpful. And are there other treatments, other than steroids? Maybe how long do you keep people on steroids? And let's say you've got a patient who's, you know, diabetic or has other factors that make you want to avoid the course of steroids. Are there other options available? Dr De Lott: So, in the acute phase steroids are the only option. There is no other option. However, long term, yes, we do pretty quickly put patients on tocilizumab, which is really our first-line treatment. And I do that in conjunction with our rheumatology colleagues, who are incredibly helpful in managing and monitoring the tocilizumab for our patients. But when you're seeing the patients, you know, whether it's in the emergency room or in the hospital, those patients need steroids immediately. There are other steroid-sparing agents that have been tried, but the efficacy is not as good as tocilizumab. So, the American College of Rheumatology is really recommending tocilizumab as our first line steroid-sparing agent at this point. Dr Smith: Outstanding. So again, I will refer our listeners to your article. It's just chock-full of great stuff. This has been a great conversation. Thank you so much for joining me today. Dr De Lott: Thank you, Dr Smith. I really appreciate it.  Dr Smith: The pleasure has been all mine, and I know our listeners will be enjoying this as well. Again, today I've been interviewing Dr Lindsey De Lott about her article on optic neuropathies, which appears in the most recent issue of Continuum on neuro-ophthalmology. Be sure to check out Continuum Audio episodes from this and other issues. I already mentioned Dr Eggenberger and I will be talking about optic neuritis, which will be a great companion to this discussion. Listeners, thank you 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.

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  25:28
• Approach to Vision Loss With Dr. Nancy Newman

  Diagnosing and differentiating among the many possible localizations and causes of vision loss is an essential skill for neurologists. The approach to vision loss should include a history and examination geared toward localization, followed by a differential diagnosis based on the likely location of the pathophysiologic process.  In this episode, Aaron Berkowitz, MD, PhD, FAAN speaks with Nancy J. Newman, MD, FAAN, author of the article “Approach to Vision Loss” in the Continuum® April 2025 Neuro-ophthalmology issue.  Dr. Berkowitz is a Continuum® Audio interviewer and a professor of neurology at the University of California San Francisco in the Department of Neurology and a neurohospitalist, general neurologist, and clinician educator at the San Francisco VA Medical Center at the San Francisco General Hospital in San Francisco, California.  Dr. Newman is a professor of ophthalmology and neurology at the Emory University School of Medicine in Atlanta, Georgia.  Additional Resources Read the article: Approach to Vision Loss 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: @AaronLBerkowitz  Full episode transcript available here 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 Berkowitz: This is Dr Aaron Berkowitz, and today I'm interviewing Dr Nancy Newman about her article on the approach to visual loss, which she wrote with Dr Valerie Biousse. This article appears in the April 2025 Continuum issue on neuro-ophthalmology. Welcome to the podcast, Dr Newman. I know you need no introduction, but if you wouldn't mind introducing yourself to our listeners. Dr Newman: Sure. My name's Nancy Newman. I am a neurologist and neuro-ophthalmologist, professor of ophthalmology and neurology at the Emory University School of Medicine in Atlanta, Georgia. Dr Berkowitz: You and your colleague Dr Biousse have written a comprehensive and practical article on the approach to visual loss here. It's fantastic to have this article by two of the world's leading experts and best-known teachers in neuro-ophthalmology. And so, readers of this article will find extremely helpful flow charts, tables and very nuanced clinical discussion about how to make a bedside diagnosis of the cause of visual loss based on the history exam and ancillary testing. We'll talk today about that important topic, and excited to learn from you and for our listeners to learn from you. To begin, let's start broad. Let's say you have a patient presenting with visual loss. What's your framework for the approach to this common chief concern that has such a broad differential diagnosis of localizations and of causes? Where do you start when you hear of visual loss? How do you think about this chief concern? Dr Newman: Well, it's very fun because this is the heart of being a neurologist, isn't it? Nowhere in the nervous system is localization as important as the complaint of vision loss. And so, the key, as any neurologist knows, is to first of all figure out where the problem is. And then you can figure out what it is based on the where, because that will limit the number of possibilities. So, the visual system is quite beautiful in that regard because you really can exquisitely localize based on figuring out where things are. And that starts with the history and then goes to the exam, in particular the first localization. So, you can whittle it down to the more power-for-your-buck question is, is the vision lost in one eye or in two eyes? Because if the vision loss clearly, whether it's transient or persistent, is in only one eye, then you only have to think about the eyeball and the optic nerve on that side. So, think about that. Why would you ever get a brain MRI? I know I'm jumping ahead here, but this is the importance of localization. Because what you really want to know, once you know for sure it's in one eye, is, is it an eyeball problem---which could be anything from the cornea, the lens, the vitreous, the retina---or is it an optic nerve problem? The only caveat is that every once in a while, although we trust our patients, a patient may insist that a homonymous hemianopia, especially when it's transient, is only in the eye with the temporal defect. So that's the only caveat. But if it's in only one eye, it has to be in that side eyeball or optic nerve. And if it's in two eyes, it's either in both eyeballs or optic nerves, or it's chiasmal or retrochiasmal. So that's the initial approach and everything about the history should first be guided by that. Then you can move on to the more nuanced questions that help you with the whats. Once you have your where, you can then figure out what the whats are that fit that particular where. Dr Berkowitz: Fantastic. And your article with Dr Biousse has this very helpful framework, which you alluded to there, that first we figure out, is it monocular or binocular? And we figure out if it's a transient or fixed or permanent deficit. So, you have transient monocular, transient binocular, fixed monocular, fixed binocular. And I encourage our listeners to seek out this article where you have a table for each of those, a flow chart for each of those, that are definitely things people want to have printed out and at their desk or on their phone to use at the bedside. Very helpful. So, we won't be able to go through all of those different clinical presentations in this interview, but let's focus on monocular visual loss. As you just mentioned, this can be an eye problem or an optic nerve problem. So, this could be an ophthalmologic problem or a neurologic problem, right? And sometimes this can be hard to distinguish. So, you mentioned the importance of the history. When you hear a monocular visual loss- and with the caveat, I said you're convinced that this is a monocular visual problem and not a visual field defect that may appear. So, the patient has a monocular deficit, how do you approach the history at trying to get at whether this is an eye problem or an optic nerve problem and what the cause may be? Dr Newman: Absolutely. So, the history at that point tends not to be as helpful as the examination. My mentor used to say if you haven't figured out the answer to the problem after your history, you're in trouble, because that 90% of it is history and 10% is the exam. In the visual system, the exam actually may have even more importance than anywhere else in the neurologic examination. And we need as neurologists to not have too much hubris in this. Because there's a whole specialty on the eyeball. And the ophthalmologists, although a lot of their training is surgical training that that we don't need to have, they also have a lot of expertise in recognizing when it's not a neurologic problem, when it's not an optic neuropathy. And they have all sorts of toys and equipment that can very much help them with that. And as neurologists, we tend not to be as versed in what those toys are and how to use them. So, we have to do what we can do. Your directive thalmoscope, I wouldn't throw it in the garbage, because it's actually helpful to look at the eyeball itself, not just the back of the eye, the optic nerve and retina. And we'll come back to that, but we have in our armamentarium things we can do as neurologists without having an eye doctor's office. These include things like visual acuity and color vision, confrontation, visual fields. Although again, you have to be very humble. Sometimes you're lucky; 30% of the time it's going to show you a defect. It has to be pretty big to pick it up on confrontation fields. And then as we say, looking at the fundus. And you probably know that myself and Dr Biousse have been on somewhat of a crusade to allow the emperor's new clothes to be recognized, which is- most neurologists aren't very comfortable using the direct ophthalmoscope and aren't so comfortable, even if they can use it, seeing what they need to see. It's hard. It's really, really hard. And it's particularly hard without pupillary dilation. And technology has allowed us now with non-mydriatic cameras, cameras that are incredible, even through a small pupil can take magnificent pictures of the back of the eye. And who wouldn't rather have that? And as their cost and availability- the cost goes down and their availability goes up. These cameras should be part of every neurology office and every emergency department. And this isn't futuristic. This is happening already and will continue to happen. But over the next five years or so… well, we're transitioning into that. I think knowing what you can do with the direct ophthalmoscope is important. First of all, if you dial in plus lenses, you can't be an ophthalmologist, but you can see media opacities. If you can't see into the back of the eye, that may be the reason the patient can't see out. And then just seeing if someone has central vision loss in one eye, it's got to be localized either to the media in the axis of vision; or it's in the macula, the very center of the retina; or it's in the optic nerve. So, if you get good at looking at the optic nerve and then try to curb your excitement when you saw it and actually move a little temporally and take a look at the macula, you're looking at the two areas. Again, a lot of ophthalmologists these days don't do much looking with the naked eye. They actually do photography, and they do what's called OCT, optical coherence tomography, which especially for maculopathies, problems in the macula are showing us the pathology so beautifully, things that used to be considered subtle like central serous retinopathy and other macula. So, I think having a real healthy respect for what an eye care provider can do for you to help screen away the ophthalmic causes, it's very, very important to have a patient complaining of central vision loss, even if they have a diagnosis like multiple sclerosis, you expect that they might have an optic neuritis… they can have retinal detachments and other things also. And so, I think every one of these patients should be seen by an eye care provider as well. Dr Berkowitz: Thank you for that overview. And I feel certainly as guilty as charged here as one of many neurologists, I imagine, who wish we were much better and more comfortable with fundoscopy and being confident on what we see. But as you said, it's hard with the direct ophthalmoscope and a non-dilated exam. And it's great that, as you said, these fundus photography techniques and tools are becoming more widely available so that we can get a good look at the fundus. And then we're going to have to learn a lot more about how to interpret those images, right? If we haven't been so confident in our ability to see the fundus and analyze some of the subtle abnormalities that you and your colleagues and our ophthalmology colleagues are more familiar with. So, I appreciate you acknowledging that. And I'm glad to hear that coming down the pipeline, there are going to be some tools to help us there. So, you mentioned some of the things you do at the bedside to try to distinguish between eye and optic nerve. Could you go into those in a little bit more detail here? How do you check the visual fields? For example, some people count fingers, some people wiggle fingers, see when the patient can see. How should we be checking visual fields? And what are some of the other bedside tasks you use to decide this is probably going to end up being in the optic nerve or this seems more like an eye? Dr Newman: Of course. Again, central visual acuity is very important. If somebody is older than fifty, they clearly will need some form of reading glasses. So, keeping a set of plus three glasses from cheapo drugstore in your pocket is very helpful. Have them put on their glasses and have them read an ear card. It's one of the few things you can actually measure and examine. And so that's important. The strongest reflex in the body and I can have it duke it out with the peripheral neurologists if they want to, it's not the knee jerk, it's looking for a relative afferent pupillary defect. Extremely important for neurologists to feel comfortable with that. Remember, you cut an optic nerve, you're not going to have anisocoria. It's not going to cause a big pupil. The pupils are always equal because this is not an efferent problem, it's an afferent problem, an input problem. So basically, if the eye has been injured in the optic nerve and it can't get that information about light back into the brain, well, the endoresfol nuclei, both of them are going to reset at a bigger size. And then when you swing over and shine that light in the good optic nerve, the good eye, then the brain gets all this light and both endoresfol nuclei equally set those pupils back at a smaller size. So that's the test for the relative afferent pupillary defect. When you swing back and forth. Of course, when the light falls on the eye, that's not transmitting light as well to the brain, you're going to see the pupil dilate up. But it's not that that pupil is dilating alone. They both are getting bigger. It's an extremely powerful reflex for a unilateral or asymmetric bilateral optic neuropathy. But what you have to remember, extremely important, is, where does our optic nerve come from? Well, it comes from the retinal ganglion cells. It's the axons of the retinal ganglion cells, which is in the inner retina. And therefore inner retinal disorders such as central retinal artery occlusion, ophthalmic artery occlusion, branch retinal artery occlusion, they will also give a relative afferent pupillary defect because you're affecting the source. And this is extremely important. A retinal detachment will give a relative afferent pupillary defect. So, you can't just assume that it's optic nerve. Luckily for us, those things that also give a relative afferent pupillary defect from a retinal problem cause really bad-looking retinal disease. And you should be able to see it with your direct ophthalmoscope. And if you can't, you definitely will be able to see it with a picture, a photograph, or having an ophthalmologist or optometrist take a look for you. That's really the bedside. You mentioned confrontation visual fields. I still do them, but I am very, very aware that they are not very sensitive. And I have an extremely low threshold to- again, I have something in my office. But if I were a general neurologist, to partner with an eye care specialist who has an automated visual field perimeter in their office because it is much more likely to pick up a deficit. Confrontation fields. Just remember, one eye at a time. Never two eyes at the same time. They overlap with each other. You're going to miss something if you do two eyes open, so one eye at a time. You check their field against your field, so you better be sure your field in that eye is normal. You probably ought to have an automated perimetry test yourself at some point during your career if you're doing that. And remember that the central thirty degrees is subserved by 90% of our fibers neurologically, so really just testing in the four quadrants around fixation within the central 30% is sufficient. You can present fingers, you don't have to wiggle in the periphery unless you want to pick up a retinal detachment. Dr Berkowitz: You mentioned perimetry. You've also mentioned ocular coherence tomography, OCT, other tests. Sometimes we think about it in these cases, is MRI one of the orbits? When do you decide to pursue one or more of those tests based on your history and exam? Dr Newman: So again, it sort of depends on what's available to you, right? Most neurologists don't have a perimeter and don't have an OCT machine. I think if you're worried that you have an optic neuropathy, since we're just speaking about monocular vision loss at this point, again, these are tests that you should get at an office of an eye care specialist if you can. OCT is very helpful specifically in investigating for a macular cause of central vision loss as opposed to an optic nerve cause. It's very, very good at picking up macular problems that would be bad enough to cause a vision problem. In addition, it can give you a look at the thickness of the axons that are about to become the optic nerve. We call it the peripapillary retinal nerve fiber layer. And it actually can look at the thickness of the layer of the retinal ganglion cells without any axons on them in that central area because the axons, the nerve fiber layer, bends away from central vision. So, we can see the best we can see. And remember these are anatomical measurements. So, they will lag, for the ganglion cell layer, three to four weeks behind an injury, and for the retinal nerve fiber, layer usually about six weeks behind an entry. Whereas the functional measurements, such as visual acuity, color vision, visual fields, will be immediate on an injury. So, it's that combination of function and anatomy examination that makes you all-powerful. You're very much helped by the two together and understanding where one will be more helpful than the other. Dr Berkowitz: Let's say we've gotten to the optic nerve as our localization. Many people jump to the assumption it's the optic nerve, it's optic neuritis, because maybe that's the most common diagnosis we learn in medical school. And of course, we have to sometimes, when we're teaching our students or trainees,  say, well, actually, not all optic nerve disease, optic neuritis, we have to remember there's a broader bucket of optic neuropathy. And I remember, probably I didn't hear that term until residency and thought, oh, that's right. I learned optic neuritis. Didn't really learn any of the other causes of optic nerve pathology in medical school. And so, you sort of assume that's the only one. And so you realize, no, optic neuropathy has a differential diagnosis beyond optic neuritis. Neuritis is a common cause. So how do you think about the “what” once you've localized to the optic nerve, how do you think about that? Figure out what the cause of the optic neuropathy is? Dr Newman: Absolutely. And we've been trying to convince neuro-radiologists when they see evidence of optic nerve T2 hyperintensity, that just means damage to the optic nerve from any cause. It's just old damage, and they should not put in their read consistent with optic neuritis. But that's a pet peeve. Anyway, yes, the piece of tissue called the optic nerve can be affected by any category of pathophysiology of disease. And I always suggest that you run your categories in your head so you don't leave one out. Some are going to be more common to be bilateral involvement like toxic or metabolic causes. Others will be more likely unilateral. And so, you just run those guys. So, in my mind, my categories always are compressive-slash-infiltrative, which can be neoplastic or non-neoplastic. For example, an ophthalmic artery aneurysm pressing on an optic nerve, or a thyroid, an enlarged thyroid eye muscle pressing on the optic nerve. So, I have compressive infiltrative, which could be neoplastic or not neoplastic. I have inflammatory, which can be infectious. Some of the ones that can involve the optic nerve are syphilis, cat scratch disease. Or noninfectious, and these are usually your autoimmune such as idiopathic optic neuritis associated with multiple sclerosis, or MOG, or NMO, or even sarcoidosis and inflammation. Next category for me would be vascular, and you can have arterial versus venous in the optic nerve, probably all arterial if we're talking about causes of optic neuropathy. Or you could have arteritic versus nonarteritic with the vascular, the arteritic usually being giant cell arteritis. And the way the optic nerve circulation is, you can have an anterior ischemic optic neuropathy or a posterior ischemic optic neuropathy defined by the presence of disc edema suggesting it’s anterior, the front of the optic nerve, or not, suggesting that it's retrobulbar or posterior optic nerve. So what category am I- we mentioned toxic, metabolic nutritional. And there are many causes in those categories of optic neuropathy, usually bilateral. You can have degenerative or inherited. And there are causes of inherited optic neuropathies such as Leber hereditary optic neuropathy and dominant optic atrophy. And then there's a group I call the mechanical optic neuropathies. The obvious one is traumatic, and that can happen in any piece of tissue. And then the other two relate to the particular anatomy of the eyeball and the optic nerve, and the fact that the optic nerve is a card-carrying member of the central nervous system. So, it's not really a nerve by the way, it's a tract. Think about it. Anyway, white matter tract. It is covered by the same fluid and meninges that the rest of the brain. So, what mechanically can happen? Well, you could have an elevated intraocular pressure where that nerve inserts. That's called glaucoma, and that would affect the front of the optic nerve. Or you can have elevated intracranial pressure. And if that's transmitted along the optic nerve, it can make the front of the optic nerve swell. And we call that specifically papilledema, optic disk edema due specifically to raised intracranial pressure. We actually even can have low intraocular pressure cause something called hypotony, and that can actually even give an optic neuropathy the swelling of the optic nerve. So, these are the mechanical. And if you were to just take that list and use it for any piece of tissue anywhere, like the heart or the kidney, you can come up with your own mechanical categories for those, like pericarditis or something like that. And then all those other categories would fit. But of course, the specific causes within that pathophysiology are going to be different based on the piece of tissue that you have. In this case, the optic nerve. Dr Berkowitz: In our final moments here, we've talked a lot about the approach to monocular visual loss. I think most neurologists, once we find a visual field defect, we breathe a sigh of relief that we know we're in our home territory here, somewhere in the visual task base that we've studied very well. I'm not trying to distinguish ocular causes amongst themselves or ocular from optic nerve, which can be very challenging at the bedside. But one topic you cover in your article, which I realized I don't really have a great approach to, is transient binocular visual loss. Briefly here, since we're running out of time, what's your approach to transient binocular visual loss?  Dr Newman: We assume with transient binocular vision loss that we are not dealing with a different experience in each eye, because if you have a different experience in each eye, then you're dealing with bilateral eyeball or optic nerve. But if you're having the same experience in the two eyes, it's equal in the two eyes, then you're located. You're located, usually, retro chiasmally, or even chiasm if you have pituitary apoplexy or something. So, all of these things require imaging, and I want to take one minute to talk about that. If you are sure that you have monocular vision loss, please don't get a brain MRI without contrast. It's really useless. Get a orbital MRI with contrast and fat suppression techniques if you really want to look at the optic nerve. Now, let's say you you're convinced that this is chiasmal or retrochiasmal. Well then, we all know we want to get a brain MRI---again, with and without contrast---to look specifically where we could see something. And so, if it's persistent and you have a homonymous hemianopia, it's easy, you know where to look. Be careful though, optic track can fool you. It's such a small little piece, you may miss it on the MRI, especially in someone with MS. So really look hard. There's very few things that are homonymous hemianopias MRI negative. It may just be that you didn't look carefully enough. And as far as the transient binocular vision loss, again, remember, even if it's persistent, it has to be equal vision in the two eyes. If there's inequality, then you have a superimposed anterior visual pathway problem, meaning in front of the chiasm on the side that's worse. The most common cause of transient binocular vision loss would be a form of migraine. The visual aura of migraine usually is a positive phenomenon, but sometimes you can have a homonymous hemianopic persistent defect that then ebbs and flows and goes away. Usually there's buildup, lasts maybe fifteen minutes and then it goes away, not always followed by a headache. Other things to think of would be transient ischemic attack in the vertebra Basler system, either a homonymous hemianopia or cerebral blindness, what we call cortical blindness. It can be any degree of vision loss, complete or any degree, as long as the two eyes are equal. That should last only minutes. It should be maximum at onset. There should be no buildup the way migraine has it. And it should be gone within less than ten minutes, typically. After fifteen, that's really pushing it. And then you could have seizures. Seizures can actually be the aura of a seizure, the actual ictal phenomenon of a seizure, or a postictal, almost like a todd's paralysis after a seizure. These events are typically bright colors and flashing, and they last usually seconds or just a couple of minutes at most. So, you can probably differentiate them. And then there are the more- less common but more interesting things like hyperglycemia, non-ketonic hyperglycemia can give you transient vision loss from cerebral origin, and other less common things like that. Dr Berkowitz: Fantastic. Although we've talked about many pearls of clinical wisdom here with you today, Dr Newman, this is only a fraction of what we can find in your article with Dr Biousse. We focused here on monocular visual loss and a little bit at the end here on binocular visual loss, transient binocular visual loss. But thank you very much for your article, and thank you very much for taking the time to speak with us today. Again, today I've been interviewing Dr Nancy Newman about her article with Dr Valerie Biousse on the approach to visual loss, which appears in the most recent issue of Continuum on neuro-ophthalmology. Be sure to check out Continuum audio episodes from this and other issues. Thank you so much 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 this 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.

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  29:00
• April 2025 Neuro-ophthalmology Issue With Dr. Valérie Biousse

  In this episode, Lyell K. Jones Jr, MD, FAAN, speaks with Valérie Biousse, MD, who served as the guest editor of the Continuum® April 2025 Epilepsy issue. They provide a preview of the issue, which publishes on April 3, 2025.   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. Biousse is a professor in the departments of neurology and ophthalmology, as well as the Reunette Harris Chair of Ophthalmic Research, at Emory University in Atlanta, Georgia.  Additional Resources Read the issue: Neuro-ophthalmology Subscribe to Continuum®: shop.lww.com/Continuum More about the American Academy of Neurology: aan.com  Social Media  facebook.com/continuumcme  @ContinuumAAN  Host: @LyellJ  Guest: @vbiouss  Full episode transcript available here 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 Valerie Biousse, who recently served as Continuum's guest editor for our latest issue on neuro-ophthalmology. Dr Biousse is a professor in the departments of neurology and ophthalmology at Emory University in Atlanta, Georgia where she's also the Renette Harris Chair of Ophthalmic Research. Dr Biousse, welcome and thank you for joining us today. Why don't you introduce yourself to our listeners? Dr Biousse: In addition to what you just mentioned, I would like to highlight that I have a French accent because I was born and raised and went to medical school in France in Saint Pete Pierre, where I trained as a neurologist. And I even practiced as a stroke neurologist and a headache specialist in the big university in Paris before I decided to move to the US to pursue my passion, which was really neuro-ophthalmology. And at the time, it was impossible to get a license in the US, so I had to repeat a residency and became an ophthalmologist. And this is what led me where I am today. Dr Jones: We're fortunate that you did that. I'm glad you did all that extra work because your contributions to the field have obviously been magnificent, especially this issue, which I think is an incredibly important topic for neurologists. This is why we include it in the rotation of Continuum topics. We all know the saying that the eyes are the windows to the soul, but for neurologists they are also the windows to the brain. The only part of the CNS that's visible to us is the optic disc. I think in spite of that, I think neurologists, our readers and our listeners would acknowledge the importance of the ophthalmic exam and respect the importance of that aspect of the neurologic exam. It's an area that feels challenging to us, and many of us, even with lots of years of experience, don't always feel very comfortable with this. So, it's a really important topic and I'm glad you have edited this. And let's start off with, you know, as you've reviewed all these articles from, really, the pinnacle experts in their specific topics in neuro-ophthalmology, as you were editing this issue, Dr Biousse, what would you say is the one biggest, most important practice-changing message about neuro-ophthalmology you would want to convey to our listeners? Dr Biousse: I think its technology, advances in technology. Without any doubt. The ophthalmology world cannot evaluate a patient anymore without access to fundus photography, optical coherence tomography (OCT) of the back of the eye, not just the optic nerve, but the retina. These advantages in technology have completely changed the way we practice ophthalmology. The same applies to neuro-ophthalmology. And these techniques can really help neurologists do a basic eye exam. Dr Jones: So, let's get right into that. And I'm glad you started with that because I still feel, even though I've done it thousands of times, I still feel a little fumbly and awkward when I'm trying to examine and fundus through an undilated pupil, right? And so, this is I think where technology has helped us quantitate with, as you mentioned, OCT, but I think from an accessibility perspective, I think nonmydriatic fundus photography is a very interesting tool for neurologists and non-neurologists.  Tell us how, how does that work and how could neurologists implement that in their practice? Dr Biousse: It's a very important tool that of course neurology should be able to use every day. You can take fundus photographs of the back of the eye without dilating the pupil. The quality of the photographs is usually very good. You only have access to what we call the posterior pole of the eye, so the optic nerves and the macula and the vascular arcade. You don't see the periphery of the retina, but in neuro-ophthalmology or neurology you don't need access to the periphery of the retina, so it doesn't matter. What is remarkable nowadays is that we have access to very highly performing fundus cameras which can take pictures through very, very small pupils or in patients of all ages. You can use it on a two-year-old in a pediatric clinic. You can use it on a much older person who may have a cataract or other eye problems. And what's really new and what this issue highlights is that it's not just that we can take pictures of the back of the eye, we can also perform OCT at the same time using the same camera. So, that's really a complete game changer for neurologists. Dr Jones: And that's extremely helpful. If I'm in a neurology clinic and I would like to use this technology, how would I access that? Do I need special equipment? Can I use my smartphone and an app? How would that work in terms of getting the image but also getting an interpretation of it? Dr Biousse: It all depends on what your ultimate goal is. The fundus cameras, they are like regular cameras or like any technology that would allow you to get brain imaging. The more sophisticated, the better the quality of the image, the more expensive they are. You know, that's the difference between a three-tesla MRI and a head CT. You buy a camera that's more expensive, you're going to have access to much easier cameras and to much higher resolution of images, and therefore you're going to be much happier with the results. So, I always tell people be very careful not to get a tool that is not going to give you the quality of images you need or you may make mistakes. You basically have two big sorts of cameras. You have what we call the tabletop cameras, which is a little more bulky camera, a little more expensive camera that's sitting on the table. The table can be on wheels, so you can move the table to the patient or you can move the patient to the table. That's very convenient in a neurology clinic where most patients are outpatient. It works in the emergency department. It's more difficult at bedside in the hospital. Or you can have a handheld camera, which can be sophisticated, a device that just uses a handheld camera or, as you mentioned, a small camera that you place on your smartphone, or even better, a camera that you can attach to some of the marketed direct ophthalmoscopes. In all situations, you need to be able to transfer those images to your electronic medical records so that you can use them. You can do that with all tabletop cameras, most handheld cameras; you cannot do it with your smartphone. So that gives you an idea of what you can use. So yes, you can have a direct ophthalmoscope with a little camera mounted. This is very inexpensive. It is very useful at bedside for the neurologists who do- who see patients every day, or the resident on call. But if you really want to have a reliable tool in clinic, I always recommend that people buy a tabletop camera that's connected to the electronic medical record. Dr Jones: You know, the photos always make it so much more approachable and accessible than the keyhole view that I get with my direct ophthalmoscope in clinic. And obviously the technology and the tools are part of the story, but also, it's access to the expertise. Right? There are not many neuro-ophthalmologists in the world, and getting access to the experts is a challenge, I think, everywhere, everywhere in the world really. When you think about how technology can expand that---and here I'm getting at AI, which I hesitate to bring up because it feels like we talk about AI a lot---are there tools that you think are here now or will be coming soon that will help clinicians, including neurologists, interpret fundus photography or other neuro-ophthalmologic findings, maybe eye movements, to make that interpretation piece a little more accessible? Dr Biousse: Absolutely. It's going to happen. It's not there yet. OK? I always tell people, AI is very important and it's a big part of our future without any doubt. But to use AI you need pictures. To get pictures, you need a camera. And so I tell people, first you start with the camera, you implement the camera, you incorporate the camera in your electronic medical record. Because if you do that, then the pictures become accessible to everyone, including the ophthalmologist who’s maybe offsite and can review the pictures and provide an official interpretation of the pictures to help you. You can also transfer those pictures using secure mode of transfers and not your smartphone text application, which you really don't want to use to transfer medical information. And that's why I insist on the fact that those pictures should definitely appear in the patient's medical record. Otherwise you're going to break HIPAA laws, and that's an issue that comes up quite often. Once you have the pictures in the electronic medical record and once you have the pictures in the camera, you can do three things. You can look at them yourself. And many of my neurology colleagues are very competent at declaring that an optic nerve is normal or an optic nerve is swollen or an optic nerve is pale. And very often that's all we need. You can say, oh, I don't know about that one, and page the ophthalmologist on call, give the patient 's medical record number, have them look at the pictures, provide an interpretation, and that's where you have your answer. And this can be done in real time, live, when you're at bedside, no problem. Or you can use AI as what I call “Diagnostic A.” I always compare it as, imagine if you had a little robot neuro-ophthalmologist in your pocket that you could use at any time by just taking a picture, clicking submit on the AI app. The app will tell you never, it's normal or it's papilledema or it's pale. The app will tell you, the probability of this optic disk of being normal is 99% or the probability that this is papilledema. And when I say papilledema, I mean papilledema from rest intracranial pressure that's incredible as opposed to optic disc edema from an optic neuritis or from an ischemic optic neuropathy. And the app will tell you, the probability that this is papilledema is eighty six percent. The probability that it's normal is zero. The probability that it's another cause of disc edema is whatever. And so, depending on your probability and your brain and your own eyes, because you know how to interpret most fundus photographs, you really can make an immediate diagnosis. So that is not available for clinical use yet because the difficulty with the eye, as you know, is to have it have a deep learning algorithm cleared by the FDA. And that's a real challenge. But many research projects have shown that it can be done. It is very reliable, it works. And we know that such tools can either be either incorporated inside the camera that you use---in which case it's the camera that gives you the answer, which I don't think is the ideal situation because you have one algorithm per camera---or you have the algorithm on the Cloud and your camera immediately transfers in a secure fashion the images to the Cloud and you get your answer that way directly in your electronic medical record. We know it can be done because it happens every day for diabetic retinopathy. Dr Jones: Got it. And so, it'll expand, and obviously there has to be a period of developing trust in it, right? Once it's been validated and it becomes something that people use. And I get the sense that this isn't going to replace the expertise of the people that use these tools or people in neuro-ophthalmology clinics. It really will just augment. Is that a fair statement? Dr Biousse: Absolutely. Similar to what you get when you do an EKG. The EKG machine gives you a tentative interpretation, correct? And when the report is “it's normal,” you really can trust it, it's normal. But when it says it's not normal, this is when you look at it and you ask for a cardiology consultation. That's usually what happens. And so, I really envision such AI tools as, “it's normal,” in which case you don't need a consultation. You don't need to get an ophthalmology consultation to be sure that there is no papilledema in a patient with headache, in a patient with possible cerebrospinal fluid shunt malfunction. You don't need it because if the AI tool tells you it's normal, it's normal. When it's not normal, you still need the expertise of the ophthalmologist or the neuro-ophthalmology. The same applies to the diagnosis of eye movement. So that's a little more difficult to implement because, as you know, to have an AI algorithm, you need to have trained the algorithm with many examples. We have many examples of pathology of the back of the eyes, because that's what we do. We take pictures every day and there are databases of pictures, there are banks of pictures. But how many examples do we have of abnormal line movement in myasthenia, of videos or downbeat nystagmus? You know, even if we pulled all our collections together, we would come up with what, two hundred examples of downbeat nystagmus around the world? That's not enough to train an AI system, and that's why most of the research on eye movement right now is devoted to creating algorithm that mimic abnormal eye movements so that we can make them and then train algorithm which job will be to diagnose the abnormal eye movement. There's an extra difficult step, it's actually quite interesting. But it's going to happen. You would be able to have the patient look at the camera on the computer and get a report about “it’s normal” or “the saccades, whatever, are not normal. It's most likely an internucleosomal neuralgia” or “it is downbeat nystagmus.” And that's not, again, science fiction. There are very good groups right now working on this. Dr Jones: That's really fascinating, and that- you anticipated my next question, which is, I think neurologists understand the importance of the ocular motor exam from a localizing perspective, but it's also complex and challenging. And I think that's certainly an area of potential growth. And you make a good point that we need some data to train the models. And until we have these tools, Dr Biousse, that will sort of democratize and provide access through technology to diagnosis and, you know, ultimately management of neuro-ophthalmology disorders, we know that there are gaps in the care of these patients right now in the modern day. In your own practice, in your own work at Emory, what do you see as the biggest gap in practice in caring for these patients?  Dr Biousse: I think there is a lack of confidence amongst many neurologists regarding their ability to perform a basic eye exam and provide a reliable report of their finding. And the same applies to most ophthalmologists. And that's very interesting because we have, often, a large cohort of patients who are in between the two specialties and are getting a little bit lost. The ophthalmologist doesn't know what to do. The neurologist usually knows what to do, but he's not completely sure that it's the right thing to do. And that's where the neuro-ophthalmologist comes in. And when you have a neuro-ophthalmologist right there, it's fantastic, okay? We bridge the two specialties, and we often just translate what the ophthalmologist said to the neurologist or what the neurologist said to the ophthalmologist and suddenly everything becomes clear. But unfortunately, there are not enough neuro-ophthalmologists. There is a definite patient access issue even when there is a neuro-ophthalmologist because not only is there a coverage heterogeneity in the country and in the world, but then everybody is too busy to be able to see a patient right away. And so, this gap impairs the quality of patient care. And this is why despite all this technology, despite the future, despite AI, we teach ophthalmologists and neurologists how to do a neuro-op examination, how to use it for localization, how to use it to increase the value and the power of a good neurologic examination so that nothing is missed. And I'm taking a very simple example. Neurologists see patients with headaches all the time. The vast majority of those headaches are benign headaches. 90% of headache patients are either migraine or tension headache or analgesic abuse headaches, but they are not secondary headache that are life threatening or neurologically threatening. If the patient has papilledema, it's a huge retina that really should prompt immediate workup, immediate prevention of vision loss with the help of the ophthalmologist. And unfortunately, that's often delayed because the patients with headaches do not see eye doctors. They see their primary care providers who does not examine the back of the eye, and then they reach neurology sometimes too late. And when the neurologist is comfortable with the ophthalmoscope, then the papilledema is identified. But when the neurologist is not comfortable with the ophthalmoscope, then the patient is either misdiagnosed or sent to an eye care provider who makes the diagnosis. But there is always a delay in care. You know, most patients end up with a correct diagnosis because people know what to do. But the problem is the delay in appropriate care in those patients. And that's where technology is a complete life-changing experience. And, you know, I want to highlight that I am not blaming neurologists for not looking at the back of the eye with a direct ophthalmoscope without pharmacologic dilation of the pupil. It is not possible to do that reliably. The first thing I learned when I transitioned from a neurologist to an ophthalmologist is that no eye care provider ever attempts to look at the back of the eyes without dilating the pupils because it's too hard. Why do we ask neurologists to do it? It's really unfair, correct? And then the ophthalmoscope is such an archaic tool that gives only a very small portion of the back of the eye and is extraordinarily difficult to use. It's really not fair. And so, until we give the appropriate tools to neurologists, I don't think we should complain about neurologists not being reliable when they look at the back of the eye. It's a major issue.  Dr Jones: I appreciate you giving us some absolution there. I don't think we would ask neurologists to check reflexes but then not give them a reflex hammer, right? So maybe that's the analogy to not dilating the pupil. So, for you and your practice, in our closing minutes here, Dr Biousse, what's the most rewarding thing for you in neuro-ophthalmology? What do you find most rewarding in the care of these patients?  Dr Biousse: Well, I think the most rewarding is the specialty itself. I'm a neurologist at heart. This is where my heart belongs. What's great about those neuro-ophthalmology patients is that it is completely unpredictable. They are unpredictable. They can have anything. I am super specialized because I'm a neuro-ophthalmologist, but I am a general neurologist and I see everything in neurology. So my clinic days are fascinating. I never know what's going to happen. So that's, I think, the most rewarding part of my job as an neuro-ophthalmologist. I'm having fun every day because it's never the same, I never know what's going to happen. But at the same time, we are so useful to those patients. When you use the neuro-ophthalmologic examination, you really can provide exquisite localization of the disease. You're better than the best of the MRIs. And when you know the localization, your differential diagnosis is always right, always correct, and you can really help patients. And then I want to highlight one point that we made sure was covered in this issue of Continuum, which is the symptomatic treatment of patients who have visual disturbances from neurologic disorders. You know, a patient with chronic diplopia is really disabled. A patient with decreased vision cannot function. And being able to treat the diplopia and provide the low vision resources to those patients who do not see well is extremely important for the quality of life of our patients with neurologic disorders. When you don't walk well, if you don't see well, you fall. When you're cognitively impaired, if you don't see well, you are very cognitively impaired. It makes everything worse. When you see double, you cannot function. When you have a homonymous anopia, you should not drive. And so, there is a lot of work in the field of rehabilitation that can greatly enhance the quality of life of those patients. And that really covers the entire field of neurology and is very, very important. Dr Jones: Clearly important work, and very exciting. And your enthusiasm is contagious, Dr Biousse. I can see how much you enjoy this work. And it comes through, I think, in this interview, but I think it also comes through in the articles and the experts that you have. And I'd like to thank you again for joining us today for a great discussion of neuro-ophthalmology. I learned a lot, and hopefully our listeners did too.  Dr Biousse: Thank you very much. I really hope you enjoyed this issue. Dr Jones: Again, we've been speaking with Dr Valerie Biousse, guest editor of Continuum's most recent issue on neuro-ophthalmology. 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 this 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.

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  24:17
• Diversity and Underserved Patient Populations in Epilepsy With Dr. Dave Clarke

  Despite advances in epilepsy management, disparities and lack of inclusion of many people with epilepsy are associated with increased morbidity and mortality. Improving awareness and promoting diversity in research participation can advance treatment for underserved populations and improve trust. In this episode, Teshamae Monteith, MD, PhD, FAAN speaks Dave F. Clarke, MBBS, FAES, author of the article “Diversity and Underserved Patient Populations in Epilepsy,” in the Continuum® February 2025 Epilepsy issue. Dr. Monteith is a Continuum® Audio interviewer and an 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. Clarke is the Kozmetsky Family Foundation Endowed Chair of Pediatric Epilepsy and Chief or Comprehensive Pediatric Epilepsy Center, Dell Medical School at the University of Texas at Austin in Austin, Texas. Additional Resources Read the article: Diversity and Underserved Patient Populations in Epilepsy 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: @HeadacheMD Full episode transcript available here Dr Jones: This is Dr Lyell Jones, Editor-in-Chief of Continuum, the premier topic-based neurology clinical review and CME journal from the American Academy of Neurology. Thank you for joining us on Continuum Audio, which features conversations with Continuum's guest editors and authors who are the leading experts in their fields. Subscribers to the Continuum Journal can read the full article or listen to verbatim recordings of the article and have access to exclusive interviews not featured on the podcast. Please visit the link in the episode notes for more information on the article, subscribing to the journal, and how to get CME. Dr Monteith: This is Dr Teshamae Monteith. Today I'm interviewing Dr Dave Clarke about his article on diversity and underserved patient populations in epilepsy, which appears in the February 2025 Continuum issue on epilepsy. So why don't you introduce yourself to our audience? Dr Clarke: Sure. My name is Dr Dave Clarke, as alluded to. I'm presently at the University of Texas in Austin, originating from much farther south. I'm from Antigua, but have been here for quite a while working within the field in epilepsy surgery, but more and more getting involved in outreach, access to care, and equity of healthcare in epilepsy. Dr Monteith: And how did you get involved in this kind of work? Dr Clarke: That's an amazing question. You know, I did it in a bit of a inside out fashion. I initially started working in the field and trying to get access to persons in the Caribbean that didn't have any neurological care or investigative studies, but very quickly realized that persons around the corner here in Texas and wherever I’ve worked have had the exact same problems, getting access via fiscal or otherwise epilepsy care, or geographically getting access, with so few having neurologists close at hand. Therefore, I started working both on a regional, national, and it transcended to a global scale. Dr Monteith: Wow, so you're just everywhere. Dr Clarke: Well, building bridges. I've found building bridges and helping with knowledge and garnering knowledge, you can expand your reach without actually moving, which is quite helpful. Dr Monteith: Yeah. So why don't you tell us why you think this work is so important in issues of diversity, underserved populations, and of course, access to epilepsy care? Dr Clarke: Sure, not a problem. And I think every vested person in this can give you a different spiel as to why they think it's important. So, I'll add in a few facts pertaining to access, but also tell you about why I think personally that it's not only important, but it will improve care for all and improve what you believe you could do for a patient. Because the sad thing is to have a good outcome in the United States presently, we have over three hundred epilepsy centers, but they have about eight or nine states that don't have any epilepsy centers at all. And even within states themselves, people have to travel up to eight hours, i.e., in Texas, to get adequate epilepsy care. So that's one layer. Even if you have a epilepsy center around the corner, independent of just long wait times, if you have a particular race or ethnicity, we've found out that wait may be even longer or you may be referred to a general practitioner moreso than being referred to an epilepsy center. Then you add in layers of insurance or lack thereof, which is a big concern regardless of who you are; poverty, which is a big concern; and the layers just keep adding more. Culture, etcetera, etcetera. If you could just break down some of those barriers, it has been shown quite a few years ago that once you get to an epilepsy center, you can negate some of those factors. You can actually reduce time to access and you can improve care. So, that's why I'm so passionate about this, because something could potentially be done about it. Dr Monteith: That's cool. So, it sounds like you have some strategies, some strategies for us. Dr Clarke: Indeed. And you know, this is a growth and this is a learning curve for me and will be for others. But I think on a very local, one-to-one scale, the initial strategy I would suggest is you have to be a good listener. Because we don't know how, when, where or why people are coming to us for their concerns. And in order to judge someone, if they may not have had a follow-up visit or they may not have gotten to us after five medications, the onus may not have been on that person. In other words, as we learned when we were in medical school, history is extremely important, but social history, cultural history, that's also just as important when we're trying to create bridges. The second major thing that we have to learn is we can't do this alone. So, without others collaborating with us outside of even our fields, the social worker who will engage, the community worker who will discuss the translator for language; unless you treat those persons with respect and engage with those persons to help you to mitigate problems, you'll not get very far. And then we'll talk about more, but the last thing I'll say now is they have so many organizations out there, the Institute of Medicine or the International League Against Epilepsy or members of the American Epilepsy Society, that have ways, ideas, papers, and articles that can help guide you as to how better mitigate many of these problems. Dr Monteith: Great. So, you already mentioned a lot of things. What are some things that you feel absolutely the reader should take away in reading your article? You mentioned already listening skills, the importance of interdisciplinary work, including social work, and that there are strategies that we can use to help reduce some of this access issues. But give me some of the essential points and then we'll dive in. Dr Clarke: OK. I think first and foremost we have to lay the foundation in my mind and realize what exactly is happening. If you are Native American, of African descent, Hispanic, Latinx, geographically not in a region where care can be delivered, choosing one time to epilepsy surgery may be delayed twice, three, four times that of someone of white descent. If you are within certain regions in the US where they may have eight, nine, ten, fourteen epilepsy centers, you may get to that center within two to three years. But if you're in an area where they have no centers at all, or you live in the Dakotas, it may be very difficult to get to an individual that could provide that care for you. That's very, very basic. But a few things have happened a few years ago and even more recently that can help. COVID created this groundswell of ambulatory engagement and ambulatory care. I think that can help to mitigate time to get into that person and improving access. In saying that, there are many obstacles to that, but that's what we have to work towards: that virtual engagement and virtual care. That would suggest in some instances to some persons that it will take away the one-to-one care that you may get with persons coming to you. But I guarantee that you will not lose patients because of this, because there's too big a vacuum. Only 22% of persons that should actually get to epilepsy centers actually get to epilepsy centers. So, I think we can start with that foundation, and you can go to the article and learn a lot more about what the problems are. Because if you don't know what the problems are, you can't come up with solutions. Dr Monteith: Just give us a few of the most persistent inequities and epilepsy care? Dr Clarke: Time to seeing a patient, very persistent. And that's both a disparity, a deficiency, and an inequity. And if you allow me, I'll just explain the slight but subtle difference. So, we know that time to surgery in epilepsy in persons that need epilepsy surgery can be as long as seventeen years. That's for everyone, so that's a deficiency in care. I just mentioned that some sociodemographic populations may not get the same care as someone else, and that's a disparity between one versus the other. Health equity, whether it be from NIH or any other definition, suggests that you should get equitable care between one person and the other. And that brings in not only medical, medicolegal or potential bias, that we may have one person versus the other. So, there's a breakdown as to those different layers that may occur. And in that I'm telling you what some of the potential differences are. Dr Monteith: And so, you mentioned, it comes up, race and ethnicity being a major issue as well as some of the geographic factors. How does that impact diagnosis and really trying to care for our patients? Dr Clarke: So again, I'm going to this article or going to, even. prior articles. It has been shown by many, and most recently in New Jersey, that if you're black, Hispanic, Latin- Latinx, it takes you greater than two times the time to surgery. Reduced time to surgery significantly increases morbidity. It potentially increases mortality, as has been shown by a colleague of mine presently in Calgary. And independent of that, we don't look at the other things, the other socially related things. Driving, inability to work, inability to be adequately educated, the stigma related to that in various cultures, various countries. So, that deficit not only increased the probability of having seizures, but we have to look at the umbrella as to what it does. It significantly impacts quality of life of that individual and, actually, the individuals around them. Dr Monteith: So, what are some of these drivers, and how can we address them, or at least identify them, in our clinic? Dr Clarke: That's a question that's rather difficult to answer. And not because there aren't ideas about it, but there’s actually mitigating those ideas or changing those ideas we're just presently trying to do. Although outlines have been given. So, in about 2013, the federal government suggested outlines to improve access and to reduce these inequities. And I'll just give you a few of them. One of those suggestions was related to language and having more improved and readily available translators. Something simple, and that could actually foster discussions and time to better management. Another suggestion was try to train more persons from underserved populations, persons of color. Reason being, it has been shown in the social sciences and it is known in the medical sciences that, if you speak to a person of similar culture, you tend to have a better rapport, you tend to be more compliant, and that track would move forward, and it reduces bias. Now we don't have that presently, and I'm not sure if we'll have that in the near future, although we're trying. So then, within your centers, if you have trainings on cultural sensitivity, or if you have engagements and lectures about how you can engage persons from different populations, those are just some very simple pearls that can improve care. This has been updated several times with the then-Institute of Medicine in 2012, 2013, they came out with, in my mind, a pretty amazing article---but I'm very biased---in which they outline a number of strategic initiatives that could be taken to improve research, improve clinical care, improve health equity through health services research, to move the field forward, and to improve overall care. They updated this in 2020, and it's a part of the 2030 federal initiative not only for epilepsy, but to improve overarching care. All of this is written in bits and pieces and referenced in the article. To add icing on top, the World Health Organization, through advocacy of neurological groups as well as the International League Against Epilepsy and the AES, came out with the Intersectoral Action Plan on Epilepsy and Other Neurological Diseases, which advocates for parallel improvement in overall global care. And the United States have signed on to it, and that have lit a fire to our member organizations like the American Epilepsy Society, American Academy of Neurology, and others, trying to create initiatives to address this here. I started off by saying this was difficult because, you know, we have debated epilepsy care through 1909 when the International League against Epilepsy was founded, and we have continually come up with ways to try and advance care. But this have been the most difficult and critical because there's social dynamics and social history and societal concerns that have negated us moving forward in this direction. But fortunately, I think we're moving in that direction presently. That's my hope. And the main thing we have to do is try to sustain that. Dr Monteith: So, you talked about the importance of these global initiatives, which is huge, and other sectors outside of neurology. Like for example, technology, you spoke about telemedicine. I think you were referring to telemedicine with COVID. What other technologies that are more specific to the field of epilepsy, some of these monitorings that maybe can be done? Dr Clarke: I was just going to just going to jump on that. Thank you so much for asking. Dr Monteith: I have no disclosures in this field. I think it's important and exciting to think how can we increase access and even access to monitoring some of these technologies. That might be expensive, which is another issue, but…. Dr Clarke: So, the main things in epilepsy diagnosis and management: you want to hear from the patient history, you want to see what the seizures look like, and then you want to find ways in which to monitor those seizures. Hearing from the patient, they have these questionnaires that have been out there, and this is local, regional, global, many of them standardized in English and Spanish. Our colleagues in Boston actually created quite a neat one in English and Spanish that some people are using. Ecuador has one. We have created someone- something analogous. And those questionnaires can be sent out virtually and you can retrieve them. But sometimes seeing is believing. So, video uploads of seizures, especially the cell phone, I think has been management-changing for the field of epilepsy. The thing you have to do however, is do that in a HIPAA-compliant way. And several studies are ongoing. In my mind, one of the better studies here was done on the East Coast, but another similar study, to be unnamed, but again, written out in the articles. When you go into these apps, you can actually type in a history and upload a video, but the feed is not only going to you, it may be going to the primary care physician. So, it not only helps in one way in you educating the patient, but you educate that primary care physician and they become extenders and providers. I must add here my colleagues, because we can't do without them. Arguably in some instances, some of the most important persons to refer patients, that's the APPs, the PAs and the nurse practitioners out there, that help to refer patients and share patients with us. So, that's the video uploads they're seeing. But then the other really cool part that we're doing now is the ambulatory world of EEGs. Ceribell, Zeto, to name of few, in which you could potentially put the EEG leads on persons with or without the EEG technologist wirelessly and utilize the clouds to review the EEGs. It's not perfect just yet, but that person that has to travel eight hours away from me, if I could do that and negate that travel when they don't have money to pay for travel or they have some potential legal issues or insurance-related issues and I could read the EEG, discuss with them via telemedicine their care, it actually improves access significantly. I'm going to throw in one small twist that, again, it’s not perfect. We're now trying to monitor via autonomic features, heart rate movement and others, for seizures and alert family members, parents, because although about 100,000 people may be affected with epilepsy, we're talking about 500,000 people who are also affected that are caregivers, affiliates, husbands, wives, etcetera. Just picture it: you have a child, let's say three, four years old and every time they have a seizure- or not every time, but 80% of times when they have a seizure, it alerts you via your watch or it alerts you in your room. It actually gives that child a sense of a bit more freedom. It empowers you to do something about it because you can understand here. It potentially negates significant morbidity. I won't stretch it to say SUDEP, but hopefully the time will come when actually it can prevent not only morbidity, but may prevent death. And I think that's the direction we are going in, to use technology to our benefit, but in a HIPAA-compliant way and in a judicious way in order to make sure that we not only don't overtreat, but at the end of the day, we have the patient as number one, meaning everything is vested towards that patient and do no harm. Dr Monteith: Great. One thing you had mentioned earlier was that there are even some simple approaches, efficiency approaches that we can use to try and optimize care for all in our clinics. Give me what I need to know, or do. Give me what I need to do. Dr Clarke: Yeah, I'll get personal as to what we're trying to do here, if you don't mind. The initial thing we did, we actually audited care and time to care delivery. And then we tried to figure out what we could do to improve that access and time to care, triaging, etcetera. A very, very simple thing that can be done, but you have to look at costs, is to have somebody that actually coordinates getting persons in and out of your center. If you are a neurologist that works in private practice, that could potentially be a nurse being associated directly one-and-one with one of the major centers, a third- or fourth-level center. That coordination is key. Educate your nurses about epilepsy care and what the urgent situations are because it will take away a lot of your headache and your midnight calls because they'll be able to know what to do during the day. Video uploads, as I suggested, regardless of the EMR that you have, figure out a way that a family could potentially send a video to you, because that has significantly helped in reducing investigative studies. Triaging appropriately for us to know what patients we can and cannot see. Extenders has helped me significantly, and that's where I’ll end. So, as stated, they had many neurologists and epileptologists, and utilizing appropriately trained nurse practitioners or residents, engaging with them equally, and/or social workers and coordinators, are very helpful. So hopefully that's just some low-hanging fruit that can be done to improve that care. Dr Monteith: So why don't you give us some of your major takeaways to how we can improve epilepsy care for all people? Dr Clarke: I've alluded to some already, but I like counts of threes and fives. So, I think one major thing, which in my mind is a major takeaway, is cultural sensitivity. I don't think that can go too far in improving care of persons with epilepsy. The second thing is, if you see a patient that have tried to adequately use medications and they're still having seizures, please triage them. Please send them to a third- or fourth-level epilepsy center and demand that that third- or fourth-level epilepsy center communicate with you, because that patient will eventually come back and see you. The third thing---I said three---: listen to your patients. Because those patients will actually help and tell you what is needed. And I'm not only talking about listening to them medication-wise. I know we have time constraints, but if you can somehow address some of those social needs of the patients, that will also not only improve care, but negate the multiple calls that you may get from a patient. Dr Monteith: You mentioned a lot already. This is really wonderful. But what I really want to know is what you're most hopeful about. Dr Clarke: I have grandiose hopes, I'll tell you. I'll tell you that from the beginning. My hope is when we look at this in ten years and studies are done to look at equitable care, at least when it comes to race, ethnicity, insurance, we'll be able to minimize, if not end, inequitable care. Very similar to the intersectoral action plan in epilepsy by 2030. I'll tell you something that suggests, and I think it's global and definitely regional, the plan suggests that 90% of persons with epilepsy should know about their epilepsy, 80% of persons with epilepsy should be able to receive appropriate care, and 70% of persons with epilepsy should have adequately controlled epilepsy. 90, 80, 70. If we can get close to that, that would be a significant achievement in my mind. So, when I'm chilling out in my home country on a fishing boat, reading EEGs in ten years, if I can read that, that would have been an achievement that not necessarily I would have achieved, but at least hopefully I would have played a very small part in helping to achieve. That's what I think. Dr Monteith: Awesome. Dr Clarke: I appreciate you asking me that, because I've never said it like that before. In my own mind, it actually helped with clarity. Dr Monteith: I ask great questions. Dr Clarke: There you go. Dr Monteith: Thank you so much. I really- I really appreciate your passion for this area. And the work that you do it's really important, as you mentioned, on a regional, national, and certainly on a global level, important to our patients and even some very simple concepts that we may not always think about on a day-to-day basis. Dr Clarke: Oh, I appreciate it. And you know, I'm always open to ideas. So, if others, including listeners, have ideas, please don't hesitate in reaching out. Dr Monteith: I'm sure you're going to get some messages now. Dr Clarke: Awesome. Thank you so much. Dr Monteith: Thank you. I've been interviewing Dr Dave Clarke about his article on diversity and underserved patient populations in epilepsy, which appears in the most recent issue of Continuum on epilepsy. 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 this 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.

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