Search for tag: "movement disorders"
Searching for the Causes and Cures of Spinocerebellar AtaxiasWhen he discovered the gene, Dr. Stefan Pulst… +5 More
April 26, 2021
Dr. Clardy: Hi, I'm Stacey Clardy, Associate Professor of Neurology at the University of Utah. I'm excited today to talk with Stefan Pulst for our series on where cures for brain diseases begin.
Stefan is the Chair of Neurology here at the University of Utah and has accomplished a tremendous amount in that role. But today I want to focus our discussion on his role as a very successful researcher in neurodegenerative diseases. Spinocerebellar Ataxias
Specifically, Stefan, you are quite well known internationally for your work on a group of conditions called spinocerebellar ataxias. How did you find yourself focusing on this group of diseases? They are rare diseases. Did you seek out that area based on a lecture you heard early in your career or a patient you had seen? Was there some sort of existing project? How did you settle on the spinocerebellar ataxias for your particular research questions?
Dr. Pulst: Well, it was a typical L.A. story. I was Chair of Neurology at Cedars-Sinai at that time, and I got a phone call, a phone call from a colleague at UCLA, who recalled that, as a resident at Columbia University, he had seen a family that had a very unique distribution of age of onset of a particular neurodegenerative disease. It appeared to happen earlier and earlier in each subsequent generation. Genetic Disease Research
And it's hard to believe today, but in the late '80s, I was one of the few neurology geneticists in Los Angeles. So that's why he called me. And I said to him, "I've never seen a genetic disease that I don't like," and we decided to fly out to New York State and examine that family, obtain DNA samples. And then my search began to find the actual mutated gene that caused this disease that we now call SCA2 or spinocerebellar ataxia type 2.
Dr. Clardy: And this is sort of unique and really, I think, drives home the point of the value of a clinician scientist, right, because you're both a scientist but also were able to come see the patients. You're a physician. You're able to examine them and get a sense of what was different about this, highlighting, I think, what's unique about academic medicine is that you serve in both those roles. And, of course, that was pre-Zoom era, so you had to fly out there.
Dr. Pulst: We had to fly out there. And we learned a lot from the patients. Part of cerebellar disease is that you are uncoordinated in your gait. And so one of our measures was to ask people to basically walk a line, like a police officer would do when they pull you over. And we had one young woman who we asked to come back and do the test again. And she was very concerned that she might actually have inherited the disease. And we later found out that she did. She was just a bit clumsier than some of her other family members. So when one learns a lot, and I think that, you know, I've been in this business now for 40 years, what I enjoy about it, going back and forth between lab and the patient and then back from the patient back to the lab, asking the questions.
Dr. Clardy: And you just hinted at what I was going to ask you next, which is how long have you been studying this condition? I think we somehow read a news release about an exciting research finding and we think that it happened in the last six months. So tell us when you started. How long has it really been? Identifying the Gene
Dr. Pulst: So we flew out to Syracuse, New York, in the late '80s and collected DNA samples. And then, for the next six years, we tried to identify this gene. And although this can be much faster today, this was a time where the genome was not mapped. We made different kinds of maps, maps based on distance and on location. And finally, in March 1996, we identified the disease gene that is now called ATXN2. All the ataxia-causing genes have numbers now. And we found out that it was a very unusual mutation, actually a mutation that was dynamic. It did not remain stable, and in the end that explained this phenomenon of having earlier and earlier disease onset in subsequent generations.
Dr. Clardy: And so what I heard you say was it took a long time to find the mutation. So what have you been doing on that mutation in that ensuing 25 years? Right? You get to discover what the problem is, and then what's next?
Dr. Pulst: Yes, and quite right. We thought climbing the Everest was finding the gene. That there was a lot of glory to be had to find the gene, and then somehow the therapy would just fall into our lab. And now we just know that we were in the hills leading up to Everest. Everest was really finding therapies. And for really a decade, maybe even two decades we and others spent our time trying to understand what this disease gene actually normally does, assuming that, when it's mutated, it has something like a deranged normal function.
And really, for me, the change came with moving to Utah in 2007. We decided to completely refocus and target the mutated gene itself. After all, that's the first cause, the primary reason why patients develop this particular disease, a DNA change happens. And we thought, if we can somehow quiet this disease gene down, then we would have a path forward. And that's what we have been doing since 2007. And you're quite right, that is still 13 or 14 years ago, and it has taken us that long to develop a gene-directed therapy. What is Ataxia?
Dr. Clardy: Wow, that's incredible. And I want to back up a little bit before we get to talking about the therapy that you're working on. The mutation you found, tell us more about this class of conditions, the spinocerebellar ataxias. What do all the patients look like? Are they similar? Are they different? How many different types are there?
Dr. Pulst: Yes. So the patients with ataxia share a certain presentation. Most of them present with gait instability that then progresses to affecting their speech, their reaching movements, their stance, their eye movements, and sometimes also their thinking. So these are really neurodegenerative diseases. They share some features with other diseases, such as Huntington's disease, but also with diseases like Lou Gehrig's disease or motor neurone disease. So they really fall into the larger group of neurodegenerative diseases.
We have about 50 SCAs, spinocerebellar ataxia, so at least 50 genes or gene locations that cause dominantly-inherited ataxias. These diseases are called polyglutamine diseases because a repeat that normally codes for the amino acid glutamine, it now expands and causes very large stretches of glutamine that misshape the protein, misform it. It tends to aggregate and cause disease.
Dr. Clardy: So unlike some other neurologic diseases that are caused by, say, missing a piece of a chromosome or a deletion, in these spinocerebellar ataxias, most of them, it's really all the DNA is there, but there's extra and it's repeated. Is that right?
Dr. Pulst: That is correct. It's repeated and it's repeated in a part of the gene that directly codes for a protein, so it has a direct effect on the way this protein is formed, the way it behaves. And as we now know, these repeat expansions cause the proteins to aggregate and really cause havoc in the cell. Gene Mutations
Dr. Clardy: And I think what you're not saying is that a lot of this was not known. And certainly 50 different types were not known when you started this area of research. And you're saying that family had SCA number what?
Dr. Pulst: Number 2.
Dr. Clardy: Wow, so early on.
Dr. Pulst: Yeah, actually, in Utah, we are working on finding the mutation for a disease that is very common in Utah. It's called SCA4. So it was mapped to a chromosome a long time ago, but it has been very difficult to find the actual mutation causing that disease. SCA4 in Utah
Dr. Clardy: So SCA4, the fourth spinocerebellar ataxia to be discovered is actually common in Utah. I didn't know that. Can you tell me more?
Dr. Pulst: Yes. So this disease was originally described and mapped to chromosome 16 by a former faculty member here at the University of Utah, Dr. Kevin Flanigan. And when we came, we took this off and we realized it is a family, a gigantic family, with more than 1,000 members actually. And we traced them back. The individuals were early pioneers. Actually we know that they were born in the 19th century, came from Scandinavia to Utah. And it's a disease with late onset, so people have a normal number of children. And we have now mapped the disease more precisely to chromosome 16.
What we have also found out, that other families, that we became aware of, there's a smaller family in the U.S. state of Georgia, and we were able to map them genetically but also by family records back to southern Sweden. And we actually found out that the family in Georgia and the family here in Utah come from two villages in southern Sweden that are about 10 miles apart. And there appears to be even a link between them, a man who was an oiler, he oiled machines and he may have had relationships in these two villages.
Again, it's a neurodegenerative disease that affects mainly the cerebellum, so patients have uncoordinated gait. But, interestingly, it has other effects as well. They develop a very significant sensory neuropathy. So what that means is they cannot quite sense where their toes and ankle and their fingers are. So they really have to deal with double damage. Both the feedback from the joints is not correct, and then the part of the brain that should coordinate all this information, the cerebellum is also defective. We are now pretty certain that it's not a simple mutation. It is likely a complex rearrangement on chromosome 16 that has made it difficult to pinpoint down what the precise mutation is.
Dr. Clardy: Wow. So just one of the other . . . I know we only touched on a couple areas of research in your lab, but this is obviously another one. And I love so much of what was in that story. One, the power of genetics, that we can trace back history now. But, two, I think you and I talk about this frequently, both being sort of transplants who came here to work at the University of Utah, but just the power of the recordkeeping and the ancestral records and the Utah population database, how the original settlers continue to give us information to push the science forward. It's such a fun part of working here in Utah.
Dr. Pulst: Yeah. And to give our listeners a bit of a visual image, usually, when you draw a family tree, a pedigree, you know, it fits on a sheet of paper quite easily. In this SCA4 family, we have like a papyrus scroll because it is so enormous. And actually, when we unroll it, it goes across my office. It's quite remarkable. And it was really thanks to one particular patient who contacted family members and made this pedigree. And it extends from Idaho and Wyoming all the way to Arizona through Utah and to California.
Dr. Clardy: That's fantastic. And we have so many of those patients here who are really driving their own science. It's wonderful, right?
Dr. Pulst: Yes, it's great. And the family is very involved, and we owe it to them to find the genes. So we are trying to work as hard as we can on using some of the most modern gene-sequencing technologies. And at this point, as of today, we have not found the mutation. So we still need to examine more patients and hopefully narrow also the location on chromosome 16 even further. mRNA
Dr. Clardy: Wow. So a lot of areas of research going on in your lab. I want to switch back a little bit though. You started to allude to this. Your lab has developed what's called an antisense oligonucleotide as a therapy, potentially, for one of these types of spinocerebellar ataxia. And, as I understand it, this has actually also led into a potential treatment for Lou Gehrig's disease or amyotrophic lateral sclerosis. But can you tell us what is an antisense oligonucleotide and how might it work in this disease?
Dr. Pulst: So this goes back to the refocus on targeting the actual cause of the disease, the primary cause. And that's the faulty gene that then leads to a faulty molecule that we call "messenger RNA." It's a molecule that takes the message of how to make proteins from the nucleus into the cell body, into the cytoplasm, and then specifies how a protein is made.
So, as I said, there's an expansion of a DNA repeat, which means the mRNA, the messenger RNA is expanded and the protein has an expanded polyglutamine domain. So we thought, "Why don't we try to attack the faulty messenger RNA and make a molecule that is complementary to this messenger RNA, it binds to it?" And then, what the cell does is actually, when it sees a new molecule made out of a messenger RNA and a piece of DNA, it actually targets this new artificial molecule and destroys it. And that's really the basis of these antisense oligonucleotides. They're called antisense because they are complementary antisense to the messenger RNA. And the oligonucleotide just means they have between 18 and 22 base pairs, so they're much shorter than a long messenger RNA.
And then, when this happens, an enzyme comes in, chops up the messenger RNA, so it's not present anymore. The antisense oligonucleotide is released and can undergo another round of binding to messenger RNA. So, with modifications, these new molecules are very stable and can be effective for therapy.
Dr. Clardy: And if I'm understanding what you're explaining correctly about this mRNA approach, this could really potentially be used in people who are known to have inherited the mutation but aren't yet having symptoms. Is that right?
Dr. Pulst: Yes. Yes, that's actually our hope for genetic disease to target diseases as early as we can. It just makes the point for our listeners that it's important to ask your neurologist to really get to the basis of a disease, to get to the correct name of the disease. And sometimes that means being referred to a specialist who really lives with these diseases and knows a lot about them. Neurodegenerative Disease Trials
Dr. Clardy: You make a really great point there, which is it's one thing to treat the symptoms, but perhaps the strength of the University of Utah or other academic medical centers too is that while we're treating the symptoms, while we're addressing where the patient's at, we also want to know what caused it in the first place. And your lab is, obviously, one of the extreme examples of that where you've actually found the mutation. So what phase of trial or study is this antisense oligonucleotide in right now?
Dr. Pulst: Okay, let me step one step back because it's important to realize, when I said that these ataxia sometimes are really neurodegenerative diseases that affect other nerve cells as well, and we recognized, just by seeing patients, that some of them had characteristics of Lou Gehrig's disease or amyotrophic lateral sclerosis. So, clinically, we saw that there appeared to be a connection between SCA2 and ALS. A colleague and friend of mine at Stanford, Dr. Gitler, then discovered molecularly a link between SCA2 and ALS.
So when we drove the development of this antisense oligonucleotide to ATXN2 forward, we partnered with a pharmaceutical company called Ionis and developed this initially in mouse models of ataxia but also in mouse models of ALS. And this molecule, the best one we identified in mouse studies and in studies in non-human primates, has now gone into a Phase I trial in ALS patients. And the reason it's in ALS patients, this is a more dramatic disease, very often, unfortunately, leading to death in three to five years, in some patients even earlier. And there are more ALS patients than SCA2 patients. So the dose finding study, knowing how much of this ASO to inject, is done in ALS patients. And a few patients have been injected so far with this new compound.
Dr. Clardy: It is very exciting, and it is really . . . you know, the neurodegenerative diseases are sort of the last frontier in neurology, right? They have, historically, hit a wall when it came to trials. And it sounds like your work and obviously the work done in other conditions and using antisense oligonucleotides is really the most exciting thing to come around in our entire generation.
Dr. Pulst: I agree. I think it's remarkable that really this dream of finding the genetic causes of disease actually now is leading to therapy. And I think another point is that even if you work on rare diseases or very rare diseases, if you pursue it, you may obtain insights into more common neurodegenerative diseases, as this connection between ALS and spinocerebellar ataxia type 2 shows. Types of Neurodegenerative Diseases
Dr. Clardy: Well, I know certainly when I see patients in our shared clinics who have a neurodegenerative disease, I really love telling them that, just down the hall, you're doing work on this and you're making progress. But I want to know what advice do you have for patients who are diagnosed with neurodegenerative diseases?
Dr. Pulst: I think the first line of advice is try to really find out what your neurodegenerative disease is. Does it have a name? Does it have a genetic cause? And that often requires to go to specialists or sometimes, as I call them, sub-specialists or sub-sub-specialists who really know about the disease. It is still true that there are actually very few ataxia specialists in the nation. And patients fly to Utah as they do to other ataxia centers to find the right diagnosis.
Genetic testing these days is less expensive than getting an imaging study. And insurance companies are slowly learning that it's the right way to go and to support these tests.
The other general piece of advice is be part of clinical trials. I think we know that patients do better when they're in clinical trials, even if they just "get the placebo." So you get to see specialists. You get followed up. People take great care of you. So I think that's the other one.
Dr. Clardy: Well, thank you, Stefan. Again, I've been speaking with Stefan Pulst, our Chair of Neurology here at the University of Utah, on his groundbreaking work on spinocerebellar ataxia and the possible translation over to amyotrophic lateral sclerosis as well. To learn more about his research, to support the lab, or any of the many, many research projects and labs here at the University of Utah, you can just go ahead and google "University of Utah neurology" where you'll find links about all of the ongoing departmental activities and information on how you can become involved.
Causes, cures and the research behind spinocerebellar ataxias. |
|
Dementia with Lewy BodiesDementia with Lewy Bodies is the second most… +4 More
July 14, 2014
Brain and Spine
Host: It's the second most common form of progressive dementia next to Alzheimer's. What is it? You're going to find out next on The Scope.
Medical news and research from University of Utah physicians and specialists you can use for a happier and healthier life. You're listening to The Scope.
If you don't know a lot about dementia with Lewy bodies disease you're not alone. It's something even a lot of physicians don't know a lot about, but luckily we're here with an expert and we're going to find out more about this disease which is a lot more common than you might thing. We're with Dr. Rodolfo Savica. He's the Director of the Dementia with Lewy Bodies and Parkinson's Disease at the Dementia Clinic of University of Utah healthcare. Thanks for taking time. First question: what is this disease? Is it similar to Alzheimer's?
Dr. Rodolfo Savica: This disease is very close to Alzheimer's and is very close to Parkinson's disease. I would say something in-between the two. The interesting thing is that dementia with Lewy bodies share the same pathology with Parkinson's disease but behaves somehow differently. Try to imagine you have a brain that is affected by Parkinson's disease but you have a more diffused involvement of the brain so together with tremors, shakiness, rigidity, stiffness typical of Parkinson's disease but you also have memory loss but not the typical memory loss that you see in people with Alzheimer's. It something completely different, to some extent. Some people have more problem with planning rather than remembering events.
Host: Okay. So planning versus remembering?
Dr. Rodolfo Savica: For example.
Host: Okay.
Dr. Rodolfo Savica: Or people are having problems with another part of memory which is visual/spatial. So people have trouble with depth perception. People have hallucinations that can be pretty bothersome because sometimes they may interfere dramatically with the life of the individual. So it's something in-between the two but some things different than Parkinson's and Alzheimer's disease.
Host: All right. Can it kill you? The first time I've ever even heard about it was Casey Kasem. Now I heard he's dead. Is that what killed him?
Dr. Rodolfo Savica: That's right. Unfortunately, all the neurodegenerative disorders can kill you. One thing that we know is that, if you use the similarity with Parkinson's disease, we know nowadays that people with Parkinson's disease don't die because of Parkinson's disease.
Host: Okay.
Dr. Rodolfo Savica: They die of normal aging. We don't have the same data available for dementia with Lewy bodies, but the two diseases are very close. The vast majority of people with dementia with Lewy bodies don't die because of the disease. However, there are some forms of dementia Lewy bodies that are pretty fast, basically they kill you in 16 months, but those are the rapid progressive Lewy body disease that is something pretty different than what we normally see in the clinic.
Host: How common is this disease?
Dr. Rodolfo Savica: As you were saying in the beginning, it is the second most common form of dementia and it's the second most common form of Parkinsonism. So Parkinson's is first, second is dementia with Lewy bodies. There's Alzheimer's disease first, second is dementia with Lewy bodies. It's more common than we think because, as you were saying before, it's been poorly understood and for many years was under recognized. This disease was identified for the first time in the 80s by a Japanese physician, Dr. Kozaka, a very interesting man that I had a pleasure to meet. For many years it's been forgotten almost and now we know that people with Parkinson's disease, when they have a more diffused degeneration of the brain, for example, they all have these kinds of symptoms. So it's much more common than what we thought.
Host: And it's difficult to diagnose for a lot of physicians.
Dr. Rodolfo Savica: Yes, because, unfortunately, since it's something in-between Alzheimer's and Parkinson's you have to have dual expertise to understand this. You need to know about Alzheimer's and Parkinson's at the same time. Unfortunately, not a lot of people are trained in both of these two major diseases. So it's kind of difficult because some of the symptoms are very similar to Parkinson's and some are very similar to dementia. So it requires some specific skills and expertise to identify.
Host: Yeah, somebody who's got a lot of expertise with this particular disease.
Dr. Rodolfo Savica: Correct.
Host: So they're so close to these other diseases. What happens if it's misdiagnosed? Is that a bad thing?
Dr. Rodolfo Savica: It can potentially be a bad thing because the symptoms are quite different, however similar, and the response to medication is pretty different as well. For example, one of the classic drugs that is highly used in Alzheimer's disease is a class called anti cholinesterase inhibitors, Donepezil, a drug that has been used for more than ten years in the U.S. and the rest of the world. This drug works better in people with dementia Lewy bodies than in people with Alzheimer's disease, so you want to do a good diagnosis and a correct diagnosis because then you have to manage the symptoms appropriately. If you have a wrong diagnosis it's not going to be the case.
Host: You're using the wrong drugs.
Dr. Rodolfo Savica: For example.
Host: Could that cause death if you were given the wrong drugs for the disease?
Dr. Rodolfo Savica: It can cause problems.
Host: Like what type of problems?
Dr. Rodolfo Savica: It can cause problems. For example, if you use another class of drugs that are called neuroleptics people with dementia Lewy bodies, for example, if you use haloperidol, a drug that's used a lot in our geriatric population, you may have a bad reaction. You have something that can lead potentially to death to some extent or definitely can lead to confusion, worsening of memory loss, worsening of Parkinsonism. So it's definitely something that is impacting highly the wellbeing of the individual affected and also the caregivers.
Host: So if you have a physician and he's like, "Oh, boy, I don't know," then that might be a time as a family member for that loved one to seek out a specialist?
Dr. Rodolfo Savica: Oh, yeah. Absolutely. I would say that every time there's a doubt from a physician or from family members it should be better to seek out a specialist. Unfortunately, there aren't very many in the U.S.
Host: Yeah, you're one of the few and this is one of the few clinics in the whole United States that actually is dedicated to this disease, if I understand correctly.
Dr. Rodolfo Savica: That's right. The current number is four.
Host: That's not very many, is it?
Dr. Rodolfo Savica: Not very many at all.
Host: I would imagine that number is going to increase at some point.
Dr. Rodolfo Savica: I hope so, actually. There's actually five in these world.
Host: So how do you determine? Are there any tests for it or is all just cognitive stuff?
Dr. Rodolfo Savica: Well, there are some tests. Usually whenever I evaluate a patient with a possible dementia with Lewy bodies diagnosis I run several tests. This includes neuropsychological assessments and formal four hours evaluation for memory, plus imaging, MRIs, and other imaging like functional imaging, something called FTG CAT scan or DaTscan, dopamine transporter scan, that can be very helpful to identify this disease and better clarify the diagnosis and also the baseline status of the patient, where the patient is and what can happen in the future.
Host: So there are some tools available to you?
Dr. Rodolfo Savica: Absolutely, yes.
Host: None of them give you a definitive answer. You have to take all of these things together.
Dr. Rodolfo Savica: That's right. With clinical criteria and neural imaging we can be very close to the top six level. There are also some people that we're going to misdiagnose but there are not very many.
Host: Is there a cure for it?
Dr. Rodolfo Savica: There isn't anything that can delay the progression or block the progression of the disease. It is something that is present in any disorder that involves neurodegeneration, Lou Gehrig's, Parkinson's, and dementia in general. But there is a cure in a sense that we can do a lot to improve the quality of life, the wellbeing, and also the survival of people with this particular disorder.
Host: So if somebodies looking for more information on this do you have a resource you'd recommend?
Dr. Rodolfo Savica: Sure. First of all, I would like to say that for any questions, please feel for the contact us directly through the phone that you can find online at this particular website. It is UtahMovementDisorder.com.
Host: Are there any final thoughts you have on this topic, anything you'd want the listeners to know or take away?
Dr. Rodolfo Savica: I would like the listener to know that they're not alone. We are a team of people who are invested in this particular disorder. We are also launching, other than the clinic, a support group specifically devoted to people with this particular disorder. We are trying to do our best in terms of clinical care and research to help these people with this disease. In addition, I also say that we are more than happy to see all the possible patients that are interested to be seen with this disorder, but it's always better to talk with their physician first.
Announcer: We're your daily dose of science, conversation, medicine. This is The Scope. University of Utah Health Sciences Radio. |