Melanie Cole, MS (Host): Welcome to AHN Med Talks, an informative resource for physicians across various specialties as we delve into the latest medical insights and best practices, ensuring you stay at the forefront of your field. I'm Melanie Cole. And today, we're highlighting Parkinson's disease, movement disorders, and the role of DBS.

Joining me is Dr. Dorian Kusyk. He's an Assistant Professor of Neurosurgery with the Allegheny Health Network. Dr. Kusyk, welcome. Thank you so much for being with us. As we get into this topic, what is usually the first-line treatment for tremors resulting from movement disorders such as Parkinson's and for patients that haven't seen positive effects from medication?

Dr. Dorian Kusyk: Thank you for having me, Melanie. Always a pleasure to have the chance to talk about Parkinson's disease and essential tremor, especially in how they can be treated with deep brain stimulation.

Now, deep brain stimulation can definitely sound scary. And so, it isn't the first line of treatment. The first line tends to be some sort of medication. So, for example, with Parkinson's disease, we often try things like carbidopa/levodopa which in some patients can give a measure of control. With essential tremor, we try other medications such as primidone and propranolol. However, in a large fraction of patients, these medications do not do enough to control tremors, and these patients have really a hard time living the quality of life that they want to live because of the tremor.

I hear this story a lot that they're afraid to go out to eat because they're afraid "to serve salad to the table behind them," or they feel self-conscious about their tremor. And in those cases and others, DBS might be an option

Melanie Cole, MS: Well then tell us a little bit about DBS. Give us a little evolution of it, and let's talk about clinical indications.

Dr. Dorian Kusyk: Definitely. So, DBS or deep brain stimulation has been around since the mid-1990s. There are five indications for it: Parkinson's disease, essential tremor, dystonia, epilepsy, and obsessive-compulsive disorder. We're going to focus on essential tremor and Parkinson's disease as those are the two main indications for DBS.

Like I mentioned, it's been around since the mid-90s, approved by the FDA since 1997. And since we've been doing it for so long, we've gotten pretty darn good at it. It involves a minimally invasive brain procedure where we take a electrode that's no thicker than 1.2 millimeters and under robotic guidance or stereotactic guidance, we implant that into a specific node in the patient's brain, and we match that node to the patient's pathology and disease state, where gentle electrical stimulation can then be used to help normalize some of the circuits at play in the brain and in these diseases and really improve people's quality of life.

And that can be as simple as in essential tremor when people have treatment-resistant tremor that is affecting their quality of life. With DBS, we can get their tremor 80%, 90% better and for an extended period of time as well. With Parkinson's disease, the complications are a little bit more varied, because DBS does so much more than just tremor.

Tremor is a big indication since so many patients have it and are dealing with it. However, in Parkinson's disease, DBS can also help reduce medication burden, can reduce the side effects of medications such as dyskinesias or dystonias. It can also reduce other symptoms of Parkinson's disease like the stiffness, the rigidity.

Melanie Cole, MS: Well, thank you for that. So as we think of patient selection, what's unique about the DBS workup at AHN for Parkinson's patient? You mentioned that we are mainly talking about essential tremor and Parkinson's. So, patient selection, what's important to note?

Dr. Dorian Kusyk: So, with Parkinson's disease, we're very proud of the multidisciplinary clinic we run. We'll take any patient that you may think is a candidate, and we can go over those indications just a little bit. And then, once they come see us, they see neurology, neurosurgery, our programmers for DBS, physical therapy, neuropsychology, and everyone sort of gets together to try to figure out and to answer two questions.

One, is DBS a good option for the patient? And two, is there anything we can change about in the process to make this procedure more fitted to the patient? I always say that with Parkinson's disease, you meet one patient with Parkinson's disease, you've met one person with Parkinson's disease. It's so varied among every individual who's living with this process. And so, it's kind of crazy to think that a one-size-fits-all approach would work. So, we're really proud of the fact that we make lots of tiny little modifications to the process based on our workup to try to fit the procedure to your disease and how it's manifesting in you.

In terms of patients that seem to be really good candidates for DBS, in Parkinson's disease, it tends to be really good for patients mid disease. So, people who've had Parkinson's disease for three, four, five years, who have tremor despite optimal medication management, who are starting to really oscillate and fluctuate with their symptoms despite good medication management. So, that might mean taking carbidopa/levodopa four or five times a day. That might mean trialing a second line agent and failing it. That might mean situations where patients take medication, they feel like they don't get an effect. We call that pseudoresistance. And that might also mean that the sort of patients who have the bad side effects of carbidopa/levodopa, such as dyskinesias, which are these uncontrollable movements that you might remember from Michael J. Fox or things like hallucinations.

Finally, DBS in Parkinson's disease is also very good for patients who just simply cannot tolerate the medications. They do get a good benefit from them. But because of other side effects such as GI upset or something like that, they can't get a high enough dose to keep their symptoms in check. So, those three categories of patients do really well with DBS for Parkinson's. Once again, that was people with tremor that doesn't respond to medication, people who are already on a lot of medications and are fluctuating between having the side effects or "off" state in Parkinson's disease, and then patients who just simply cannot tolerate high enough doses of Parkinson's medication.

In essential tremor, it's a little easier. Basically, if you failed the first or second line treatment for your tremor in terms of medication and you're still having quality of life inhibiting tremor that you'd be interested in discussing deep brain stimulation as an option, then we can definitely have that conversation to see if you'd be a candidate.

Melanie Cole, MS: Dr. Kusyk, so you've told us a little bit about how it's evolved over the years and when we think of the first step to ensure success in DBS for these patients, how has that criteria changed to include more patients over the years and how has the technology changed so that you can widen the base of inclusion?

Dr. Dorian Kusyk: I think there's two core topics there that I'm going to try to tease apart. First, how have the indications really expanded? I think as the technology has gotten safer, as the surgery has gotten safer. We are doing it for more and more patients. So, recent studies have mentioned that DBS is about as risky as getting your gallbladder out. So, risks of 1.7% or less according to nationwide data. So, it's very safe surgery. It's the safest brain surgery I do. And because of that, our age range is expanding. We're doing it on increasingly elderly patients or who may be a little bit more frail, but they will still benefit from the procedure.

And then, simultaneously, we're also learning so much more about the brain from doing these procedures and seeing how people react. And so because of that, we're also doing it for a wider range of symptoms within Parkinson's disease and essential tremor, obviously. And then, as we learn more about the circuitry, other indications have come about, right?

So now, we implant DBS for epilepsy, for example, which requires us to understand the epilepsy network before we implant patients. We also do this for dystonia, which is uncontrollable, discoordinated muscle movements, and we're learning more about the specific subtypes of dystonia that do well with it. And finally, we do have an indication for OCD, and we're learning more about which subtypes of OCD respond better for DBS versus other interventions.

So, to tackle the first part of your question, we're learning so much, we're doing it so safely that we're really expanding the populations we're about to reach. From the question of technology, you know, I've already mentioned how the technology has gotten smaller. We've had amazing success with things like rechargeable batteries, which means that patients have to come in fewer times for surgery to get their battery replaced.

We saw the rise of directional leads, which helps us adjust the field of stimulation to help drive the stimulation towards the regions of the brain that give benefit while limiting side effects. And we're also seeing the rise of other adjuncts to programming. So, there's really fantastic image-based programming from some companies that really streamline the process for patients after implantation.

We're also seeing a new indication for what we call adaptive stimulation from some of the companies, where they can use the electrodes within the brain to sense brain activity and actually change the stimulation that is delivered based on the internal brain state to better fit that stimulation profile to that patient's disease.

So, really exciting technology coming down the line, coupled with just the incremental progress in terms of the surgical process, that the combination of that means that we're reaching more and more people and improving more and more lives with this technique.

Melanie Cole, MS: Well, I'm glad you mentioned adaptive DBS that's targeting these different regions, because that is such a fascinating aspect and really such an exciting time. So, Dr. Kusyk, why should Parkinson's patients be referred to a movement disorder specialist earlier in the course of the condition?

Dr. Dorian Kusyk: Ultimately, the earlier patients are seen by movement disorder specialists, the earlier we can start having these conversations about advanced therapies. We spend a lot of time talking about DBS, but there's also pumps that we can look into and other adjuncts. We can also have conversations about what supportive therapies these patients might benefit from.

So many patients have gait issues that might benefit from specialized Parkinsonian physical therapy. So many patients have swallow and speech issues where they might benefit from speech therapy. So many patients might benefit from occupational therapy. Through the AHN Multidisciplinary Center, we have a wonderful network of therapists that will help patients. And so, even if it sounds scary that we're sending someone in to talk about DBS, we're just talking about DBS, and we're really trying to evaluate the patient and see what in our range of advanced therapies would best benefit the patient at that point.

Melanie Cole, MS: When we think of Parkinson's patients, when should they think about seeing a movement disorder specialist or talking to someone about DBS? If they've been working with their primary care, they've been working with their neurologist, what would you like them to know about thinking about DBS and what they can expect?

Dr. Dorian Kusyk: At the core of it, this is quality of life surgery. So, if you as a patient ever realize that maybe the quality of your life isn't where you want it to be, maybe that's time to discuss these advanced therapies like DBS.

I often say to Parkinson's patients, in the beginning when you get diagnosed, you take carbidopa/levodopa once, twice, three times a day. It's a small dose. It's a consistent effect, and you can plan your life around it. But eventually, you get to the point where you're taking more and more medication. The effects become more and more unpredictable. And at some point, you are limiting what you want to do because you're afraid that maybe you'll be in your off-medication state when you want to do something. When you start having those sort of thoughts, that's when DBS might help, because it can help tremor. It can help the sort of side effects of medication and can help simplify your medication profile while being managed for your Parkinson's disease.

And the other thing I'll add is that this isn't the surgery of the '90s. We've made so many improvements to the procedure. And personally, I'm a big proponent of what I call stealth neuromodulation, where I don't want anyone to know you had this surgery unless you want them to know. So, I really have focused my training and practice on hair-sparing approaches, where I do a little work to try to make sure that there are no little bumps where the hardware might be seen from the outside. We try to make this as elegant, as pain-free as possible because this is quality-of-life surgery.

Melanie Cole, MS: Well, it certainly is, and I, really appreciate that you spoke about that, about it being elegant and quality of life. I think that's such an important point here. And as we wrap up, Dr. Kusyk, what would you like other providers to take away? The key messages about the recent advances that you're very excited about and a blueprint for what you see or hope to see in the future for DBS.

Dr. Dorian Kusyk: At the core of it, I think neuromodulation is one of the most exciting parts of neurosurgery, with new advances nearly every couple of months. And we really want to work on leveraging our experience with the technology, with our knowledge of these new advances to try to improve the lives of more and more patients.

So, to my fellow providers, I would really say that if you have a slightly challenging Parkinson's patient, someone who's been diagnosed for three, four, five years, even if you think they're too good for surgery at this point, send them our way. We'll have a conversation. If they're too early in their disease course, that's fine. I just love to get to know these patients myself. But throughout the process, I've never met anyone who wishes that they waited longer. I've only met patients who wish they've had the conversation sooner.

And ultimately, if this is something you're interested in as a fellow provider, we often have arrangements where we might help with the initial programming, but then you can take over, because I know there are many community neurologists who have an interest in DBS programming and would like to learn that, and we are more than willing to sort of work with you and partner with you because you do have that established therapeutic relationship with that patient, and we don't want to take them from you.

Melanie Cole, MS: Thank you so much, Dr. Kusyk, for joining us today and really sharing your incredible expertise for other providers. And to learn more or to refer your patient, please call 844-MD-REFER or visit findcare.ahn.org. Thank you so much for listening to this edition of AHN Med Talks with the Allegheny Health Network. I'm Melanie Cole.