Sameer Sheth, MD, Associate Professor of Neurosurgery at Baylor College of Medicine, talks about Deep Brain Stimulation, an alternative to medication for treating disorders such as Parkinson’s and essential tremors.
Dr. Sheth, we’re here to talk about deep brain stimulation. Tell me, how does it work?
So deep brain stimulation, or DBS, is a therapy that we have for various neurological conditions, especially Parkinson’s disease and essential tremor. It’s a system that you can think of, basically, like a pacemaker, but rather than being a pacemaker for the heart, it’s a pacemaker for the brain. So, the idea is that the brain has many circuits, essentially, that govern a lot of the things that we do, including how we move, even how we think, how we process emotions, how we make decisions. So, if the movement circuit is not working properly, we may have a movement disorder like Parkinson’s, for example, where there is a slowness of movements and stiffness, or essential tremor, where there’s a tremor of the hand or the voice. So, if we can identify the circuit within the brain that is not working properly, we can use this device, which, again, is like a pacemaker, to reset the rhythms in the brain and restore the balance within that circuit so that our movements can be smoother or better controlled or without a tremor. It basically consists of one or two wires that go into a specific spot within the brain. They’re connected under the skin to a battery that sits under the chest skin, just like a pacemaker battery would, and that system delivers electrical stimulation via those wires to that specific spot in the brain to restore that balance within the circuitry and to treat the symptoms of that disorder.
So why does it work? To the average person that’s watching this that’s never heard of it, why is this effective versus other treatments that are out there?
It’s been around for a long time; it is not new or investigational for things like Parkinson’s and tremor. It has been around, really, 30 years or more. Approved by the FDA, covered by insurance, etc. So, it’s a therapy that works very well. There’s been a lot of studies over the years, very good, randomized trials that are presented in the top medical journals that show that for the appropriately chosen patient, DBS is more effective than the best medical therapy. For the patient that has tried medicines and they have not been effective enough. So, in that appropriately chosen patient, DBS can be very successful at improving tremor for essential tremor and tremor stiffness, rigidity and those other motor symptoms for Parkinson’s disease.
Back to how the device actually works. Can you explain to me in layman’s terms, just from the moment that the device is implanted until the patient goes home and is able to control and manage it himself or herself? Can you explain to me that process?
It starts even before surgery. So, there’s a fairly intense evaluation process that we go through to find patients that we think are going to be good candidates for this therapy. Again, these are patients who have perhaps one of these disorders, has tried the medicines for it, those medicines may have not been successful, or the medicines may have caused their own side effects. We evaluate those patients in a multidisciplinary committee that consists of neurologists who are specializing in movement disorders, neuropsychologists, physical therapists, and neurosurgeons like myself. We meet and decide that a patient has the appropriate types of symptoms that would benefit from DBS. Once we decide that, then we do the surgical evaluation. Then the surgical procedure is actually performed– it’s typically done in two stages. The stage one procedure consists of placing the electrodes in the brain and the second part is connecting those to the battery. Once it’s all done, there’s nothing sticking out of the skin, there’s nothing visible, it’s all implanted under the skin and not visible. So, once the surgery is done, then the patient goes back and meets with the neurologist. The neurologist typically does the programming, the system is a programmable system. It’s adjustable, modifiable, and there’s a wireless kind of remote control that communicates with that battery that’s been implanted and then the settings can be changed, the specific parameters can be adjusted to fine-tune what they should be for each individual patient. So, it’s a very individualized therapy and by doing that programming in a very specific way for the individual patient, we can make sure that we treat that patient’s symptoms whether it’s tremor, stiffness, slowness, unwanted twisting movements, whatever it is, the parameters can be adjusted specifically, to treat the symptoms for that patient.
And then once the patient goes home, do they take the remote with them, and do they turn it on and off? How does that work?
The systems have a programmer that the clinician uses in the office to make the adjustments and fine-tune those parameters of programming, but the patient also gets their own patient programmer. So, they can check how much battery is left, they can turn it on or off, they can even adjust some of the settings based on what the clinician has given them the ability to do. There are some patients who are very savvy with these things and they can even make some adjustments depending upon what they’re doing that day. So, if they happen to be doing something where they need even better tremor control, they can make some adjustments themselves. So, they learn how to do that, but they do have control over the system. They can check battery life and they can make these simple adjustments so that over the course of the day they can really manage their own symptoms themselves.
The alternative, in terms of procedures and treatment, it’s just medication, correct?
That’s right. For all of the typical disorders treated with DBS, Parkinson’s disease, tremor, a few others, there are medications for all of these things, and medications are always tried first. Unfortunately, we can only get so far with medications. Oftentimes, many patients try them, and they may work for a little while– a few months, maybe a few years, maybe several years. But at some point, oftentimes, unfortunately, the medications stop working as much because the disorder tends to progress over the years. It could get worse and the medicines may not be able to keep up. Many of the medicines, themselves, have their own side effects. So, you get to a point where, yes, perhaps the medicines are helping to a degree, but they’re causing their own side effects and exactly when we get to that point is when we introduce the idea of a surgical therapy like DBS, of course, again, it’s very individualized. But we have a very good idea of the types of symptoms that respond well to DBS. It’s a very individualized discussion with that patient, but it’s good to have that at the right time because patients need to know that there are these alternatives. They need to know that they’re not necessarily stuck with these symptoms, that there may be a different way to get better control. That discussion is, of course, individual specific, but the availability of these types of surgical treatments is important for patients to know about.
Is there anything else that you would like to add that you haven’t addressed?
Well, I think it’s important to know that this is a very standard kind of treatment. These are procedures that we do week in and week out. I mean, any given week, we’ll do one, two, three of these. It’s a very standard type of therapy, it’s not investigational or experimental. Everything we do in life has risks, and so, these are not zero risk, but the risks are very, very tiny. In the appropriately chosen patient, there’s also a risk of doing nothing, doing nothing more. The symptoms get worse, you’re unable to continue to function in life as you’d like to, so there’s a real risk of inaction. So, that discussion, again, is very individualized. But around the world, 150,000 patients or more have had DBS for Parkinson’s or tremor and the success rates are 90, 95 plus percent. So, the thing is, with how much experience that we have, we know what gets better and what doesn’t. We can really tailor that discussion for the patient and help them make the right decision.
How long does this procedure take once a patient is wheeled into the doctor’s?
The surgery itself takes two or three hours for the first part, which is the placement of the brain electrodes. That can be done with the patient completely asleep under general anesthesia– which a lot of patients like because they just go sleep and wake up and it’s done. Or it can be done where they’re awake for the middle portion of the surgery where we test the electrode once it’s in place. Again, it’s a discussion that is very tailored to the patient. We can discuss the pros and cons of each of these. That procedure takes about two and a half to three hours. Then, the second part, which is the placement of the battery and the connection of the wires to the battery, takes about an hour. So, altogether, it’s two and a half, three hours for the first part, an hour for the second part. Most of the time patients will stay one night, overnight after the first surgery, and then the second surgery is usually outpatient, so they go home the same day.
Interview conducted by Ivanhoe Broadcast News.
END OF INTERVIEW
This information is intended for additional research purposes only. It is not to be used as a prescription or advice from Ivanhoe Broadcast News, Inc. or any medical professional interviewed. Ivanhoe Broadcast News, Inc. assumes no responsibility for the depth or accuracy of physician statements. Procedures or medicines apply to different people and medical factors; always consult your physician on medical matters.
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