Huntington’s disease is an inherited disorder that causes the progressive breakdown of nerve cells in your brain. It can cause rapid jerky body movements, personality changes, behavior problems, memory loss, and profound physical decline. The symptoms can appear at any time in life. They usually occur in those aged 40 to 60.
There’s no cure for Huntington’s disease, but there are medications and treatments that can help people manage the condition. Listen to an interview with James Boyd, MD. Dr. Boyd is a neurologist at the University of Vermont Medical Center, and an associate professor at the Robert Larner College of Medicine at UVM. He also is the director of the Frederick Binter Center for Parkinson’s Disease and Movement Disorders, which has been designated as a center of excellence by the Huntington’s Disease Society of America. A transcript of the interview is available below.
UVM Medical Center: There are, unfortunately, quite a few diseases that result in a gradual decline in your ability to move normally, like Lou Gehrig’s disease or multiple sclerosis. Our discussion today is about one of these that’s generally lesser known. It’s called Huntington’s disease. It’s an inherited disorder that causes the progressive breakdown of nerve cells in your brain, and it can cause rapid jerky body movements, personality changes, behavior problems, memory loss, and profound physical decline. The symptoms can appear at any time in life. They usually occur in those aged 40 to 60.
There’s no cure for Huntington’s disease, but there are medications and treatments that can help people manage the condition. Dr. James Boyd is with us today to tell us more about all this. He’s a neurologist at the University of Vermont Medical Center, and an associate professor at the Robert Larner College of Medicine at UVM. He also is the director of the Frederick Binter Center for Parkinson’s Disease and Movement Disorders, which has been designated as a center of excellence by the Huntington’s Disease Society of America. Thanks very much for being here.
Dr. James Boyd: Yeah, thanks for having me.
UVM Medical Center: Add to that overview I just gave.
Dr. James Boyd: Sure, so, Huntington’s disease is a unique condition in that it is a hereditary condition in all situations. It doesn’t occur as a sporadic condition except in very rare cases, so it is a family condition, as we describe them. It’s associated with a single type of gene change which can be inherited. If one is to carry just one of those genes on one of the two chromosomes, then you would express the gene during your life.
It is associated with what’s called a trinucleotide repeat gene abnormality, and what that means is that the size of that gene, which is present in everyone, as long as that’s small, it’s not associated with any type of a condition. As that gene becomes larger, it will create a risk of developing Huntington’s disease, and ultimately, if it gets large enough, someone will be guaranteed to get that during a normal lifespan.
UVM Medical Center: You can have the gene, but it doesn’t necessarily mean you’re going to develop it?
Dr. James Boyd: Well, there are different degrees of enlargement of the gene, and if it is slightly enlarged, then you may be at risk of developing Huntington’s, but may not get it. If it is even less enlarged, then you may not, on your own, have a risk of getting it, but you may have a risk of someone in your future generations of your lineage having the condition.
In most cases, when we’re testing people, they are at risk because we know of a history in their family, and they have a gene which is large enough to be expressed and produce the condition. Now, the gene testing only became available in the 1980s, and it has just in the last decade and a half become commonplace for people to get tested, because they know they’re at risk.
UVM Medical Center: There’s also familial cancer genetic counseling kinds of programs that can help with that, too, right?
Dr. James Boyd: Absolutely. We have a multidisciplinary genetic testing clinic, in which someone who is at risk because of a known family history will come in any time after the age of 18 – even if they are not having symptoms. We call it a presymptomatic clinic. They’ll come in, and they know that someone in the family has it, so it puts them at risk of developing the gene. It’s a 50/50 shot, because it is what we called a dominantly inherited gene, so if one of their parents has it, there is a one in two chance that they will have it as well, and we can tell them with a really high level of certainty whether or not they carry the gene and whether they’re at risk of having the condition in the future.
UVM Medical Center: Talk about the progression a little bit, if it’s say a normal onset, I think we said between 40 and 60, but how does this unfold for most people?
Dr. James Boyd: The symptoms are widely varied in terms of first symptoms that people will have, so the first symptoms could be changes in personality, irritability, changes in mood, depression, anxiety, and what we call behavioral or psychiatric symptoms. Or they could be changes in movement or mobility, so mild balance problems, extra movements of jerking or moving which are involuntary, which we call caria. And then less commonly people will present, initially, with having changes in cognition, thinking and memory differences, and that’s usually a later stage symptom.
UVM Medical Center: Now, what about the pace of it? Does that vary a lot patient to patient?
Dr. James Boyd: It does. That gene which I made mention of earlier does not have an impact on the rate of progression. We don’t have a very good idea of why some people progress more quickly than others. The sources of disability are widely varied, so again, if there’s this mix of cognition problems, coordination and involuntary movement problems, as well as psychiatric problems, for each person, what gives them the most difficulty in a day can be widely varied. We know that the life expectancy of someone who has Huntington’s, from the time that they first develop motor symptoms or physical symptoms, typically the life expectancy is an average of 17 years.
UVM Medical Center: Has that lifespan increased with medications?
Dr. James Boyd: We don’t have any medications which impact the rate of progression. We do have the ability to reduce symptoms, but we have not had a significant dramatic impact on the rate of diagnosis to time of death.
UVM Medical Center: Let’s talk a little bit more about the medication situation. What do you have, and what help does it provide?
Dr. James Boyd: When you have a condition which progressively gets worse over time, and you have symptoms which go along with it, we have two priorities. One is how you make people feel better today and improve their quality of life. But the Holy Grail, so to speak, when it comes to progressive conditions, is what can we do to impact the progression over time, reduce the disability over time, and/or the most impactful thing would be to cure the condition. I’ll speak first about symptomatic treatment.
In general, these are very directed toward the thing that I had mentioned earlier, so if someone has depression or anxiety, hallucinations or other psychosis that impacts the quality of their day, there are many options for trying to improve the symptoms that can go along with those types of complaints. From a movement standpoint, we use a combination of different medications to control those involuntary movements, and we can do quite a good job of reducing them with off-label use of medications which were originally designed as anti-psychotics.
They block the effects of a chemical called dopamine in the brain, and in reducing that chemical’s function, it can reduce the amount of involuntary movements. What we don’t have a good treatment for are the balance and coordination problems that go along with the condition. We don’t have a proven treatment for improving clarity of cognition and/or memory, and those are big challenges, because as people have had a condition a longer period of time, there is a lot of disability that goes along with balance problems, swallowing difficulty, falling, and progressive dementia, which goes with the condition.
UVM Medical Center: A lot of this is supportive care. I mean, you do so much with medication, but talk about other members of your team, and the center, and what’s involved with the bigger picture of what’s available for folks as they struggle with this.
Dr. James Boyd: Importantly, there are a number of things which I alluded to which don’t have easy medication control or treatment, so it is important to have a more comprehensive approach to how to maintain function for people, and how to reduce the burden on themselves and on their families. To do so, that’s a lot of where we have tried to create a coordinated and comprehensive approach to not only Huntington’s disease, which we’re talking about today, but also for other movement disorders like Parkinson’s.
To do so, you really need to provide support from a psycho-social standpoint as well as from a therapy standpoint, and provide a team approach. In our team, we have a counselor and social worker. She provides assistance in terms of caregiver support, patient support, in terms of emotional support and therapy. She also assists us with identifying resources within the community that can assist patients to maintain their status at home, if possible. If not, to help them with the transition to a skilled facility or other place which would provide a greater level of care that they might need.
We work closely with our therapists over at Fanny Allen, and we have a multidisciplinary movement disorders clinic which includes our social worker who I mentioned, physical therapy, occupational therapy, and speech and language pathology for speech and swallowing problems. I think that’s really the most important, is to approach this from every angle and, although we don’t have a good treatment from a medicine standpoint for something like balance or for swallowing problems, we can reduce the risks associated with that, if we’re minding them properly and approaching them with therapies.
UVM Medical Center: It is one of those diseases that’s just such a big burden on the caregivers and the families, because at some point, it becomes a constant need for help.
Dr. James Boyd: Yeah, correct. We often compare many of our conditions to things that people are familiar with, like Parkinson’s disease. In general, Parkinson’s comes on in someone’s lifetime when they are typically reaching retirement age, they potentially have the support of their children who are adults, or other family members. For folks with Huntington’s disease, they often don’t have one of their parents, because, by design, one parent probably had Huntington’s disease. They often are younger, so they have non-adult children, so it’s a real challenge in terms of them not having the family support that other conditions do.
UVM Medical Center: A couple minutes left. Let’s talk about what’s coming down the pike, in terms of research. Is there anything that’s hopeful?
Dr. James Boyd: Yeah. There are a number of different things that are really interesting. We have some newer medications that are being developed for control of symptoms. One in particular is being reviewed by the FDA currently, and we participated in the research bringing that to the FDA for review. It’s a modification of the previous medication which was already FDA approved, which had some difficulties in terms of its tolerance. Although it could help with reducing involuntary movements, it often was at the consequence, or with a limitation of, producing some side effects along the way.
It’s a medicine which is being produced by a company called Teva, and they have created a slow metabolized version by changing the formulation of the medication into a new compound. It appears to be more effective than the current one, with respect to reducing involuntary movements, and it also seems to be better tolerated. From a quality of ability to reduce involuntary movements, that’s a positive which is very close on the horizon. Other things that are coming which I think are really very exciting are ways to try to modify the disease course. I think that’s probably the priority in all of our minds.
I mentioned earlier that this condition is associated with a single gene, so we can predict who is going to get it. We can estimate when they are going to get it based on the size of the gene and their age, so it’s a unique condition, because we don’t know when people are going to get other conditions, but with this, we can predict that, if you carry the gene, and we can intervene early, we may be able to prevent the condition from happening at all. It is a single gene and with advances in gene therapy and being able to turn off genes or turn down genes, you could envision that we may be able to just shut the gene off so that it doesn’t produce the condition over the course of a normal lifespan.
UVM Medical Center: It’s coming?
Dr. James Boyd: It is, it is. We’re also participating in some disease modifying studies. The gene that is associated with Huntington’s disease and its development causes an excessive accumulation of a particular protein. This gene, when it’s too large, produces too much of a protein called Huntingtin, sounds like Huntington, which is the name of the condition, and that protein accumulates and essentially clumps up in the brain, and we think that’s the reason that it causes a loss of cells and that causes the progressive brain condition. We’re participating in a study which looks at using an antibody which reduces the ability to send immunity to the nervous system.
That clumping of protein in the brain produces an inflammatory response, and the inflammation is presumed to be the cause of loss of brain cells. This is an intravenous infusion that’s done on a monthly basis, and we are following people over time with the decision of whether or not it’s impacting the condition based on some imaging techniques. We’re looking with MRI and with PET scanning to see whether or not we’re slowing the progress over the course of a year to two years. I am excited about where we are, in terms of our advancements in genomics and gene control.
This condition, in particular, I feel like is something which is very tangible as a curable condition within my career. We’re getting close enough where we know how to control genes, and now it’s just finding out whether we can control them and not cause other problems.
UVM Medical Center: Good. On that hopeful note, I’m afraid to say we’re out of time, but I want to thank my guest today, Dr. James Boyd. He’s a neurologist at the UVM Medical Center and associate professor at the Robert Larner College of Medicine. He’s also director of the Frederick Binter Center for Parkinson’s Disease and Movement Disorders, which has been designated as a Center of Excellence by the Huntington’s Disease Society of America. Thanks for being with us today.
Dr. James Boyd: Thank you for having me.