Lewy body dementia is a common cause of cognitive impairment in older adults but is often subject to significant delays in diagnosis and treatment, increasing the burden on patients and family caregivers. Understanding key features of the disease and use of biomarkers will improve recognition.

In this episode, Allison Weathers, MD, FAAN, speaks with James E. Galvin, MD, MPH, author of the article “Lewy Body Dementia,” in the Continuum December 2024 Dementia issue.

Dr. Weathers is a Continuum® Audio interviewer associate chief medical information officer at the Cleveland Clinic in Cleveland, Ohio.

Dr. Galvin is a professor of neurology at the University of Miami Miller School of Medicine in Miami, Florida.

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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 Weathers: This is Dr Allison Weathers. Today I'm interviewing Dr James Galvin, author of Lewy body dementias from the December 2024 Continuum issue on dementia. Welcome to the podcast, Dr Galvin. Please introduce yourself to our audience. 

Dr Galvin: Thank you, Allison. My name is Jim Galvin. I'm a neurologist, a professor of neurology at the University of Miami Miller School of Medicine.

Dr Weathers: We're so happy to have you with me today. Thanks, Jim, for your time. And as you highlight right from the start in your really outstanding and comprehensive overview of this really complex topic, even though Lewy body dementia is the second most common cause of neurodegenerative dementia, it often goes unrecognized in clinical practice, resulting in really potentially lengthy diagnostic delays. So, this is a really important article for a neurologist and an important topic for our listeners. So, I'm thrilled we're having this conversation today. While I traditionally start by asking the authors what they feel is the most important clinical message of their article, I would love to actually start a step earlier in this conversation with you. Can you start us off by explaining what's actually meant when we say Lewy body dementia?

Dr Galvin: Great. So, you know, I think this is a, this is an interesting concept. So, we're really talking about two diseases that have a shared common pathology. So, Parkinson's sees dementia and dementia with Lewy bodies. So, their shared pathology is a Lewy body and that's why they're often grouped together as the Lewy body dementias. And then there's arguments back and forth as to whether these are distinct diseases or sort of two ends of the same candle burning in different directions. So, Parkinson's dementia is a lot like what it sounds like. So, if someone has Parkinson's disease, then at some point later they develop a dementia. And so back in the 1800’s when Parkinson's disease was like first described as an entity, we basically felt that cognition wasn't affected. But we now know that's not true. And so most patients with Parkinson's do have some cognitive symptoms and a large proportion of them will eventually develop dementia. Perhaps up to 80% of Parkinson's patients will develop a dementia. The flip side is the dementia with Lewy body picture. And these are people who present primarily with a cognitive behavioral syndrome that may or may not have parkinsonism. So, they will sometimes have bradykinesia. They rarely have a rest tremor. And so, these are the people that are very much in the delayed diagnosis group. The Parkinson's dementia is more whether the clinician is checking their cognition as part of their annual visit. The flip side is that the people with DLB are often misdiagnosed early on, but together, this is Lewy body dementia, which is the most common disease that many people have never heard of.

Dr Weathers: That's a great tagline, I think, for the whole article and for this concept. So now that that we're all on the same page about what's meant when we use that the term, what would you want our listeners to walk away with as their one key takeaway from our conversation today?

Dr Galvin: Well, I think the article makes several key points, but I think if I put those all together into a single key point, it would really be that the Lewy body dementias are underrecognized, they're underdiagnosed, yet it is very possible to make the diagnosis using the standardized clinical criteria. They're very, very, very specific. They lack a little bit in sensitivity. So, because other diseases sometimes can look like this, but they're really quite specific. So, if you're confident clinically that the person has Lewy body dementia, you're probably going to be right. And in today's world, we have tests available to help confirm our diagnosis. The world is changing. We can make these diagnosed with much more confidence and we have confirmatory diagnosis laboratory tests that can help us.

Dr Weathers: I want to talk more about the diagnosis in one minute, but first, how common actually are dementia with Lewy bodies and Parkinson's disease dementia?

Dr Galvin: That's a great question. I think one of the challenges, of course, we really don't know how many people have any disease because it's going to largely rely on how well people code the diseases in the medical record. So, if you look at the most common cause of dementia in the United States, it's really dementia not otherwise specified, right? But we believe it to be the second most common cause of dementia. The Lewy Body Dementia Association, about a decade ago, started to try to develop some estimates. So, we have an estimate about how many people roughly have Parkinson's disease and that about 80% of those individuals would go on to develop dementia. And we know from the dementia population that about 40% of those individuals coming to autopsy have Lewy bodies. So, when you start to put that all together, you can get a reasonable estimate of how many people likely have the disease. And then that can be expanded on an annual basis, just like the Alzheimer's Association uses, by extrapolating those estimates onto the census data. So, we estimate right now there are about 1.4 to 1.6 million Americans who are living with Lewy body dementia. That's less than the 6.8 million people who have Alzheimer's disease, but more than a lot of other common diseases. So, if you think about, again, I said before, it's the most common disease no one's ever heard of. You know, there are about a million people who have multiple sclerosis. There are about eight hundred thousand people who have a stroke. There are about seven hundred thousand people who have a brain tumor. There are two hundred and fifty thousand people who have muscular dystrophy. There are twelve thousand people who have ALS. But I think if you stopped clinicians or people in the street and say have you ever heard of ALS or muscular dystrophy, they would say yes. If you ask them if they've heard of Lewy body dementia, they would say no. 

Dr Weathers: That's an excellent point. And I know over the years I think there's been some increased awareness. I think sadly with some of the celebrities that have been impacted, I think that did a lot to raise awareness. But I think you're right that it's still so less commonly recognized by the lay public, by non-neurologists, than so many other diseases that you mentioned. And I think that leads back well into my next question into something that we've already mentioned just a few times already in our short conversation, this unfortunate and very common delay in the diagnosis. Why? And you mentioned earlier that there are these, you know, clinical criteria, these now ancillary tests. So, what makes the diagnosis so challenging? What aspects in particular do you think that neurologists find to be the most challenging in diagnosing patients? What trips us up? 

Dr Galvin: So, there's an old analogy, right, that, you know, if you'll be three blind men to an elephant and each of them are touching a different part of the elephant, they'll each think it's something different. So because Lewy body dementia has so many different diverse kind of symptoms, it would really depend on who's seeing the patient first. So, if a person presents predominantly with a memory cognitive disorder and they go see someone who specializes in memory disorders, they're highly likely to be called Alzheimer's disease. If they present predominantly with the movement problem, they're going to see a movement disorder person and be called Parkinson's disease. If they present with a behavioral disorder, they're going to go see a psychiatrist. Then they'll get diagnoses like, you know, geriatric schizophrenia or bipolar disease or major depressive disorder. If they present with the constitutional symptoms, which are very common and drive patients absolutely batty. So chronic constipation, REM sleep disorder, runny nose, you know, heat intolerance, urinary frequency, obstipation, and you know, they're going to be called all sorts of things. So, if you start thinking about this, who do you show up with first is going to guide how fast you can get a diagnosis. So, we interviewed at point over a thousand caregivers and what we found was there was about an eighteen month delay after seeing five to six doctors for the majority of patients, of which Lewy body dementia was misdiagnosed about 75% of the time for the initial diagnosis. 

Dr Weathers: Wow, what a sobering statistic. And you spoke about the criteria and some of the ancillary tests. What can really help, do you think, kind of mitigate or prevent this misdiagnosis? What is your approach in your own patients? 

Dr Galvin: Well, I think like every good clinician, not starting off with a preconceived notion of what the person has and trying to collect all the valuable information. So, one of the things I highlighted in the article was, while there are diagnostic criteria and people can follow diagnostic criteria, the truth is at your fingertips. You don't always sit and think about whether someone meets diagnostic criteria. So, in the first table in the article, we tried to really then put all the different common symptoms into buckets, right? Because people present like that. They say, well, I have this and I have this and I have this and I have this. Well, then you can start to think about, well, they have a cognitive symptom that's predominantly executive attention or visual perceptual in nature. And gee, they have constipation and heat intolerance and they say they can't smell quite as well as they once did, right, and they're having some disturbance in their sleep with excessive daytime sleepiness. Now you can start to say, well, even though that didn't fit the core and suggestive criteria, the fact is that spectrum of symptoms makes it much easier to begin to make a diagnosis. And so, it's investigative work. A lot of neurology is still investigative work. The old days, they used to say, we knew everything but could do nothing, but now we know everything and can do something about it. And so, I think it's really important that we try to apply this information in clinically useful ways. That was part of the gist of putting this Continuum article together was to try to present it not just as listing the diagnostic criteria, because you can get that anywhere, but how do you actually apply it in clinical practice?

Dr Weathers: That's a great point. And that table that you referenced was really fantastic. And I know I say this a lot, but they're true. So, you know, many of the tables, the reference to Continuum, one I will certainly kind of come back to again, again, as an excellent point of care tool. So, I know in, in preparing for today and reading more about, about you and your areas of research that one of your particular areas of focus and expertise is in healthcare disparities, especially in the early detection of neurodegenerative dementias. What is the greatest inequity or disparity that you see in the diagnosis and treatment of patients with Lewy body dementia? 

Dr Galvin: So, there's a couple things that are that are really interesting. So first, unlike Alzheimer's disease, which tends to be a little bit more female predominant, the Lewy body dementias are male predominant. It's about 1.6 men for everyone woman. So, it's going to be a different presentation. It's going to be largely men and their caregivers are largely going to be their spouses. So, you're going to see sort of a different person looking, you know, staring on the other side of the table to you. It's going to be largely a male. And the other thing that's really interesting is that almost all of the series, case series, case reports, clinical papers are in predominantly white populations. So, this lends to some interesting things. So, you know, is the disease less common in African Americans and other minority populations or are we just really bad at ascertaining the disease? You know, many of the case reports in Alzheimer's disease include African Americans. In fact, we know that African Americans may be at a twofold increased risk of developing Alzheimer's disease compared to nonHispanic whites, probably due to vascular risk factors. But in case series of Lewy body dementia, almost all the patients are non-Hispanic white. There also seems to be a higher risk in Asian populations, and in fact, some of the very earliest case reports were from Japan. Is this a case ascertainment problem or is this really a disparity in how the disease presents? And I think those are really important questions that still need to be asked. I know as researchers, we struggle to try to develop cohorts that could help us understand that. I would say in my twenty five years of seeing these patients, I would say the large percentage of them, and I've seen a lot of them, have been no-Hispanic white. 

Dr Weathers: So, so definitely more research needed in this very important area. So, moving on to somewhat of a personal question, I always, this is such an honor. I always talk about that I get to have this time to sit down with the authors of these outstanding articles and learn not only more about their subjects, but about them as people. I had shared during my last interview that my paternal grandmother had Alzheimer's disease, and unfortunately also my maternal grandmother actually did as well. In preparing for this, I had listened to one of your previous interviews and learned that you also have a personal connection that led you to this subspecialty with several family members impacted. How has this connection inspired your research and your interactions with your patients? 

Dr Galvin: Yeah, I mean, so my personal connection was that my maternal grandfather had Lewy body dementia. So, I grew up in a two family home in New Jersey. My grandparents lived on the second floor. We lived on the first floor. I wass very close to my grandparents. I'm still close to my grandmother, who's a hundred and three years old. But when I was a high junior in high school, my grandfather was driving me home from a swimming practice. I was thinner, fitter and more athletic at that point in my life, and he made the world 's slowest left hand turn and we were broadsided. So luckily no one was hurt. But I remember because I was sixteen at the time and just learning how to drive us, Grandpa, what happened? And he's like, oh, the car didn't react. Or, you know, he was blaming the car. And I didn't think much of it because, you know, I was sixteen years old. Sometime after that he was at work, and he was a greaser. So, he would climb through the machines at Colgate Palmolive and keep them all moving.

And so, he was at work and he fell off a ladder and then broke his ribs. And in the emergency room, when my grandmother went to pick him up, the ER doctor turned to her and said, how long has your husband had Parkinson’s disease? And she's like, what are you talking about? And then that was the first time that all of us had noticed his rest tremor. And the reason he turned the wheel so slow is because he was Bradykinetic. And so then over the next few years, he progressed in his motor symptoms. And then as I got into college, he developed the cognitive symptoms. And so, by the time I had finished medical school that was doing my residency, he was no longer oriented to time. So that even though I had finished medical school, I was in my neurology residency, I was married and with children, I was still in college at that time for him. So, he would always ask me, you know, have I heard anything from getting to medical school and the like. So, I got to watch this person who I grew up with go through all of the different stages of disease. And then eventually he developed lots of hallucinations. And although he was relatively immobile, he experienced a hallucination and jumped out of his chair, fell down, and broke his hip. And so, he underwent a hip replacement, being rather severely demented, and then passed away in the rehab hospital. As I was living this with my grandparents, the one thing that my grandfather, while he could still communicate, and that my grandmother continued to say to me, you know, up until fairly recently was, you know, what are you going to do about this? You know, we're counting on you to make a difference. And so, a lot of my research is really focused on how I can make a difference for people. One, to make sure they get diagnosed properly. Two that we would have something to offer the patient and the family. And three, we can provide hope that we are actually going to come away with effective treatments to make a difference in their lives.

Dr Weathers: Well, that is really inspiring. And I think you have really done that in your work. I always like to end these conversations on a hopeful note. So, what are the developments that are on the horizon in terms of diagnosis and treatment of Lewy body dementia that you are most excited about? 

Dr Galvin: Well, I think there are three things that are of great interest right now. I mean, there's lots of things, but I think three things of great interest are, one, on the diagnostic side is that we now have assays that allow us to assess synuclein in body fluids and body tissues. So, we can measure synuclein seeding assays in the spinal fluid and we can visualize Lewy bodies through skin biopsies. And that's a tremendous advance because we were really, really limited otherwise to using indirect evidence, and the only indirect evidence we had was abnormalities on DAT scanning. So, we're looking at dopamine deficiencies. But as I mentioned earlier, that's very abnormal in Parkinson's disease. But in dementia with Lewy bodies, it's a little more subtle. So, the extent of dopamine degeneration in- particularly in early DLB is limited. So, you have to look very carefully. If we're not doing quantitative DAT scan imaging, then you may miss those subtle changes. So, I think that being able to directly visualize either synuclein seeding or synuclein aggregation has really changed the game. Plasma assays, blood-based biomarkers are probably a little farther away because they're- the red blood cells have a lot of synuclein and so it interferes with the ability to get a good sensitive assay. But I do think in the next couple of years we will see PET ligands that also bind  synnuclein. So, I think diagnostically we're going to be able to provide better, earlier, and more precise diagnoses. From a treatment perspective, traditionally we've just borrowed medicines from other fields to treat symptoms, but there are a number of disease-modifying trials that are ongoing. I was fortunate to be the academic PI on two very large NIH grants where we test tested disease modifying medicines. Both of those studies are fully recruited and we should get a readout toward the end of 2024 or the beginning of 2025. So very, very excited about that. I also am fortunate to be MPI an NIH grant where we're just going to be testing the first inhuman synuclein vaccine. So very, very excited about the potential to offer disease-modifying medicines and to fulfill the promise that I made to my grandma and grandpa twenty years ago. And I think the third thing is that right now there's a little bit of like an emerging controversy about developing some integrated staging paradigms between the movement disorder world and the cognitive world. And so, while those paradigms are currently published, you know, not everybody agrees with them. But I think whether I like that staging paradigm now or not, the fact that we're coming together and trying to develop some unified staging paradigms, I think, is going to make a big difference in increasing the ability for clinicians to make early diagnoses that are more precise so that we can either get people into clinical trials or into clinical treatment protocols at the earliest possible time. And that's going to make all the difference in the world for the patients and their families. 

Dr Weathers: I think that was a fantastic answer. Really, all really exciting things that I think are all, I normally, I say on the horizon. I'm thinking, you know, pretty far ahead. And I think the really wonderful thing is that all of these are either here now or very, very close to being here. So, definitely a very positive way to end this discussion. Well, Jim, thank you so much for taking the time to speak with me today.

Dr Galvin: Thank you. This was wonderful. I hope the listeners found this enjoyable and interesting and read the Continuum issue. I think it's going to be the latest and greatest on what we know about the dementias. 

Dr Weathers: Again, thank you again, Dr Galvin, for joining me on Continuum Audio. Again, today I've been reviewing Dr James Galvin, his article on the Lewy body dementias, dementia with Lewy bodies, and Parkinson's disease dementia appears in the December 2024 Continuum issue on dementia. 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.