On Oct. 24, 2022, Dr. David VanSickle, a neurosurgeon with Neurosurgery One and the medical director of the Denver DBS Center led a webinar for the public on recent advancements in deep brain stimulation. He was joined by neurologist Dr. Luisa Solis-Cohen, with Littleton-based Colorado Neurodiagnostics, and neurologist Dr. Ramy Zaza, with Lakewood-based CHPG Neurosciences.
Following the presentations, attendees were invited to share their questions. Below are the questions that were asked along with the physicians’ answers. Watch the webinar.
Are you able to get DBS for essential tremor if you have a pacemaker, defibrillator or ICAD?
Dr. VanSickle:
The simple answer is yes. Being able to do the asleep DBS technique depends very much on being able to get an MRI. Sometimes a pacemaker or defibrillator is not MRI compatible, but even often when they’re stated to be not MRI compatible, an MRI can still be performed under certain protocols, and we have those here at Littleton Hospital. So, in almost all cases, the answer is yes.
Has Dr. VanSickle trained other surgeons outside the Denver area to perform asleep DBS for patients who cannot be in Denver?
Dr. VanSickle:
Yes, we did a lot of training before Covid. In fact, we used to have somebody learning from us about asleep DBS literally every few weeks. That’s really slowed down after Covid, and almost gone away. There are asleep DBS surgeons that have similar techniques. Maybe it’s not robotic, but they’re actually very similar in character in several other areas, [asleep DBS] is much more common here in the west, say in Phoenix or in Oregon, or in Seattle, San Francisco area; it’s much less common on the East Coast. So, as you go east of here asleep DBS gets rarer.
With remote DBS programming, patients can come to Denver for their asleep DBS surgery, and then I can program their DBS system remotely, saving them additional travel. It’s really revolutionized the way we approach DBS and made the procedure an option for many people who live in rural areas. With remote DBS programming, once patients have their DBS system in place, which for asleep DBS typically requires two surgeries a few weeks apart, then they can have their remote programming done from their homes. Programming of the DBS system often requires monthly adjustments for the first 6 months. So rather than travel to Denver multiple times, you only have to travel for the surgeries.
Is asleep DBS covered by Medicaid/Medicare?
Dr. VanSickle:
Yes, asleep DBS is covered by Medicare and Medicaid as long as patients meet certain requirements, which are qualifications to be a candidate for surgery.
Do we know when Abbott will be coming out with rechargeable DBS batteries?
Dr. Vansickle:
Rechargeable batteries do exist now, just not from the manufacturer Abbott. I believe that Abbott makes the best technology for DBS, and that’s the system that I prefer to use. Boston Scientific makes a good quality rechargeable battery right now that is MRI-compatible just like the Abbott device. However, it does not have remote programming. And Medtronic makes a rechargeable battery, although I wouldn’t recommend that one at the present time. I do know that Abbott is working on a rechargeable battery. I’ve heard it is going to be available early next year. They have not released a date, so I can’t comment on when it’s going to be available, but I can say I’ve heard about it coming.
When you are out of state what would be your first step to determine if you are a candidate for asleep DBS?
Cindy Kuykendall:
You could conveniently set up a telehealth appt with Dr. VanSickle to discuss your specific condition. You could also have neuropsychological evaluation and Unified Parkinson’s Disease Rating Scale, or tremor rating scale done and sent to Dr. VanSickle for assessment of candidacy.
What is the failure rate of DBS? What % of failures result in fatalities?
Dr. VanSickle:
Complications can be divided into two groups: issues that can be fixed and issues that cannot be fixed. The big thing that I cannot fix, that we all worry about the most, is that during surgery for asleep DBS, a stroke can occur due to bleeding inside the brain. Fortunately, it is very, very rare, but when it happens, it can leave somebody with a permanent neurologic deficit. And so that’s something to know about before making the decision.
Then there’s everything else which can be fixed, like infection. If you look at the statistics, there is less than a 1% chance you could get an infection. If it happens though, we have to take the whole system out, give you antibiotics, and then put the whole DBS system back in. The infection rate years ago used to be as high as 10%, and then it dropped to about three and a half percent, and in our practice is under one. Another fixable complication of DBS is that a lead can be misplaced, no matter how good the surgical technique is. There’s always a chance a lead is not placed exactly where we want it to be or where it’s going to do the most good. About once every other year, I will move a lead to a different location or make a slight adjustment to it. Other complication is that a lead can break–I’ve seen that happen before, especially with the extension lead, and that’s the connection lead that goes behind the ear down to the chest. I seem to replace one connection lead about every year. So, if you’re doing, you know, 70, 80 of asleep DBS surgeries a year, you can do the math and say it’s a little over 1% maybe that has that issue. And if you add all the complication rates up, we’re running in and around 2%. So there’s about a 2% chance that something will happen during the asleep DBS procedure where we have to do a surgical adjustment of some kind and about 0.1%, or one in a thousand chance that it could be really problematic and lead to a stroke or something wouldn’t be able to fix it.
Explain please when/if DBS has, as a side effect, changes to a person’s personality, mood, behavior, or cognition.
Dr. Zaza:
This is an active area of research. So, in 2020 there was a study done on STN DBS patients, a large series of patients showed that they did not have an increased risk of dementia. Now there were some changes associated with verbal fluency with STN DBS, like word hesitancy. And then other DBS procedures, like thalamotomy procedures, can cause other issues with speech.
But as far as mood, that’s a little bit harder to answer. I’m not sure of any direct studies showing a direct effect on mood when we’re doing DBS for essential tremor and for Parkinson’s. But there have been applications of DBS in psychiatry. So that would be something that we would have to assess every time when we see a patient in our office. Then if there were some concerns for mood or behavior changes, we might want to verify the placement of the leads. I should say that, in STN DBS, if a certain part of the STN is stimulated, it can cause changes in mood in some patients, which we can actually avoid with directional stimulation that Dr. VanSickle was talking about.
Dr. Solis-Cohen:
Yeah, I agree with you Dr. Zaza, I’ve seen a couple cases where it’s important to know what a person’s mental state is like before surgery, and knowing folks well helps optimize outcomes with stimulation. Occasionally, if you’re stimulating in an area of the brain that’s sort of a little off our desired target, we may see some fluctuations in mood, but it’s rare, just like you mentioned.
I have had good success with the Medtronic leads from awake surgery in 2012. Should I consider getting the new directional leads as I get older?
Dr. Solis Cohen:
I would say straightaway, if you’re having great success, the answer is no. That means your leads are generally well placed by your surgeon and you should stick with them. The risk of another surgical intervention is probably not worth it.
How long do the DBS batteries typically last? Are there potential contraindications for patients with Parkinson’s? What is the length of recovery time? What is the % of time implants are malfunctioning?
Dr. VanSickle:
So, with the Abbott system in two small generators, you should get seven plus years, on average, of battery life. That doesn’t mean that you’ll get that. Some people will get less and some will will get more depending on their settings.
For the recovery time, it’s not a very painful surgery. So, from a physical perspective, the recovery should be very short. Literally, just a few days. However, many people will have a slight cognitive deficit that is transient. As Dr. Zaza mentioned, long-term cognitive deficits really are not apparent in most individuals, but a two- or three-week period of time where maybe you’re not quite yourself, that would be fairly typical and you should expect that and prepare for that in and around surgery.
Dr. Zaza:
As far as potential contraindications for patients with Parkinson’s, number one is if you have had a diagnosis of Parkinson’s, not necessarily the symptoms, but the diagnosis for under four years. Number two would be dementia, or uncontrolled mood issues. So we’d want something like a uncontrolled depression, under control before a proceeding. If the Parkinson’s is basically idiopathic Parkinson’s disease, so if we could say that it’s MSA, PSP, et cetera, or due to strokes or medications, that would not be a good reason to get DBS.
Some of the literature I’ve read suggests that a pallidotomy is as effective as DBS but less invasive, less expensive, and less maintenance heavy. Do you agree?
Dr. VanSickle:
No. Well, maybe in part, but it is generally not as effective as DBS and the literature would heavily suggest that it is more invasive. You’re destroying part of the brain with pallidotomy, whereas DBS really does not cause nearly such an injury. Pallidotomy burns bridges where you cannot go back and make corrections. Unlike with DBS, which can be removed if you don’t like it, pallidotomy is going be permanent, you’re going to have it forever. Pallidotomy also has more side effects. So, any side effect that occurs from DBS, you can potentially program around or, you know, in the worst-case scenario, move an electrode. If you do a pallidotomy and destroy an area of the brain, you’re stuck with it. So, if they destroy possibly an area that’s adjacent, and you have some speech effects or some balance effects, you’re stuck with them lifelong. So, I think pallidotomy should be relegated to sort of the history of neurosurgery and not pursued from this point on. And that’s true with most programs around the country. It may be less expensive, that may be true, but most of us would not recommend moving forward with it at all.
From the presentation it appears you don’t need to wait the 4 years post diagnosis to be a candidate for DBS with essential tremors, is this correct?
Dr. Solis-Cohen:
If you have medication refractory essential tremor, which means you have tremors that are not responding to medications and are interfering with quality of life, you don’t have to wait a four year marker for that.
If the DBS procedure has been done and future improvements become available, can we take advantage of the improvements?
Dr. Solis-Cohen:
That’s an individualistic question with an individualistic answer. It depends on if the technology you have has an upgradable feature or not. You would need to discuss it with your doctor, because we may have a different answer depending on the technology that you have. I would also mention it’s important to consider the technological differences of the three systems before committing and may want to sort of educate yourself about that.
Any newer batteries for DBS?… smaller… longer lasting…. when?
Dr. VanSickle:
It’s hard to comment on DBS technology, which has not yet been announced by the companies. Sometimes we hear about things, and it could be they could never come out with it, it could be next year, it could be in five years. And it’s so hard to know for us.
As levodopa decreases in effectiveness, will DBS at some point not be as effective over time?
Dr. Zaza:
The short answer is no. The effectiveness of the levodopa, or the ineffectiveness of the levodopa, does not necessarily correlate with the DBS becoming less effective over time. Now there was some early thought that there is a phenomenon called habituation in DBS in which it’s possible that the brain becomes accustomed to the electrical stimulation and because of that, the symptoms are not as well controlled. More recently, the data for that has shown that maybe that is not the case. But as far as I’m aware, the data has not been conclusive that no, there is no such thing as habituation or that it does occur, but it doesn’t necessarily have to do with how you respond over time to levodopa itself.
VanSickle mentioned that there were “unacceptably poor outcomes” with the previous “standard” awake procedures. Have there been any “unacceptably poor outcomes” with the asleep procedures?
Dr. VanSickle:
There is no procedure that is perfect a hundred percent of the time. So, the complications of asleep DBS we talked about previously, such as, stroke with bleeding inside the brain or with electrodes that break or need to be moved, I would consider those unacceptably poor. Also, there are some individuals that respond differently, and it may be that we were wrong about their disease initially, that they didn’t have typical Parkinson’s like other people have, and that may account for some individuals that don’t respond the way we expect them to respond. However, the number of such individuals is vastly smaller than it used to be. And that has to do with the fact that we can put DBS leads in a much more accurate location or precise location than we were able to in the past.
Can a person with an Insulin pump & glucose sensor transmitter also use DBS?
Dr. VanSickle:
Yes, it should not be a problem at all. We would want to make sure your glucose was well controlled and your hemoglobin A1C was normalized, which could reduce your risk for infection with surgery. But we should be able to work around that with no problem.
Does the procedure for essential tremors help with unsteadiness as well as the essential tremors?
Dr. Zaza:
No, unfortunately not. With DBS, especially in essential tremor, the benefit is strictly in the tremor. It does not help the ataxia that you can see with essential tremor.
How do you differentiate essential tremor from Parkinson’s?
Dr. Zaza:
If you look in the book the distinction is rather stark. Parkinson’s, you have resting tremor, essentially tremor, you have an action tremor. In reality most people don’t read the book and there can be a little bit of an overlap between the two, which can make it challenging to make the diagnosis, but that still holds true for the most part. You know, if you’re having predominantly a resting tremor with a little bit of an action tremor, that’s going to be more likely Parkinson’s or vice versa, more likely essential tremor. Now, if you’re also having features that you would only see in Parkinson’s, such as rigidity or bradykinesia, or we could do other or use other symptoms as hints such as like small handwriting, things of that sort. That would also be a way to differentiate the two. But, in some patients, it can be a little bit of a challenge and we have to see how things change over time.
Do you know, given Moore’s law of innovation, if there are there any non or less invasive electro-ceuticals in development?
Dr. Zaza:
As far as Moore’s law, the main way that that is manifested in DBS is the miniaturization of the pulse generator. And so, every time that one of the companies, be it Abbott, Medtronic, or Boston come out with a new battery, they tend to be smaller, but more efficient. It’s more of a cosmetic advantage because it doesn’t stick out as much under your skin, but it’s still significant. There are other procedures, surgical procedures for Parkinson’s and essential tremors such as focused ultrasound, which kind of is a riff on the old, ablative procedures. And maybe I’ll let Dr. VanSickle kind of take it from there if he has an opinion on the focused ultrasound or other things.
Dr. VanSickle:
Yeah, I’ve looked at the data for focused ultrasound in depth and there may be individuals where that is the best option. We’ve chosen not to offer it in our program overall. The reason why is that it is actually only for essential tremor. It’s not FDA approved as I know right now for Parkinson’s and is only for one side of the body. So, you can’t treat tremor in both hands, you can only treat tremor in one. The reason for that, it is a destructive lesion surgery. So, it is non-invasive, but you are destroying tissue in the brain. DBS does not do that. And if you destroy areas that are adjacent to where you intended, causing damage to say speech areas et cetera, you can’t go back. So, there’s no way to fix those things. Plus, the tremor control about one year later after the ultrasound procedure is only about 50%. So with all those limitations, it just doesn’t stack up well with DBS. That doesn’t mean that somebody might not find it better. But in general, it doesn’t stack up well from a data perspective versus DBS.
I’ve had DBS for tremors. There were major complications and in acute rehab for an extended period of time. A lead was bent during insertion or as a result of brain swelling. I’m a bit hesitant to go back in and get it replaced. Should I get it replaced? I also got aphasia as a result of surgery. Will this last forever?
Dr. VanSickle:
I would need to see you in person and conduct imaging of your lead to assess whether or not it might need to be replaced. Our team does several revision surgeries for patients who have had their leads placed elsewhere.
Would DBS affect PD gut problems related to the Vagus nerve?
Dr. VanSickle:
DBS would not benefit GI issues related to Parkinson’s disease.
What is a resting tremor?
A resting tumor occurs when the muscle is not engaged. Also referred to as a rest tumor, a resting tumor can cause legs, arms, or hands to shake uncontrollably when they were otherwise at rest. These types of tremors are often associated with Parkinson’s disease.
How long does a battery last?
Battery life of your generator(s) depends on battery type and manufacturer used. There are rechargeable and non-rechargeable options, both with their pros and cons. The average non-rechargeable battery life for Abbott is 5-7 years depending on your specific configuration and settings. We always strive to help our patients understand the benefits of one type over the other on an individual case by case basis.
