The Benefits of Deep Brain Stimulation for Patients With Parkinson’s DiseaseMay 13, 2014
Parkinson’s disease isn’t easy to continually treat, but deep brain stimulation can help with tremors and slowness of movement. Dr. Tom Miller speaks with Dr. Lauren Schrock about the procedure and the benefits of deep brain stimulation for patients with Parkinson’s disease.
Dr. Miller: Advanced Parkinson's disease and movement disorders. We're going to talk about what to do next on The Scope radio. This is Tom Miller.
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Dr. Miller: Hi, I'm here today with Dr. Lauren Schrock. She's an assistant professor in neurology and in charge of the movement disorders program. Lauren, we're going to talk about sort of advanced Parkinson's. I think it's pretty well known that after a period of time, a lot of folks who responded to medications and treatment of their Parkinson's start not doing as well on the medications. I think the thing that we would like to talk with you about today is that there are new therapies and those involve deep brain stimulation. When should a patient maybe start thinking about this option of treatment and whom they should be working with if they're thinking about this option for treatment?
Dr. Schrock: When medications start causing complications is often the term we use in Parkinson's specialists. Basically, over time, medicines don't last as long and they wear off in between doses and people can develop dyskinesias.
Dr. Miller: Yeah, what is a dyskinesia for our listeners?
Dr. Schrock: Dyskinesia is an extra involuntary movement. It almost looks like a wiggling and a squirming. The most known person who most people have seen have this issue publicly would be Michael J. Fox. That wiggling back and forth. That is something that can be caused by a combination of both having the Parkinson's disease and also having taken Parkinson's disease medication.
Dr. Miller: Did Mohammed Ali have a deep brain stimulation device implanted? Do you know?
Dr. Schrock: No. Mohammed Ali did not, as far as I know. His Parkinson's is likely thought to be a secondary Parkinson's disease related to the multiple hits to the head. In that type of Parkinson's disease, that's caused by something else, it's not expected to respond to deep brain stimulation.
Dr. Miller: Okay. Good to know.
Dr. Schrock: Very important point about when a person is considering, "Should I have deep brain stimulation?" because there are many things that go into predicting whether someone will respond well to deep brain stimulation and how they will do afterwards.
Dr. Miller: So tell us about how someone makes the decision about inquiring on this new type of treatment.
Dr. Schrock: I'm going to actually start with one and explain what it is a little bit more. If you imagine almost like a brain pacemaker, in the same way that people have pacemakers to help their heart keep beating, in Parkinson's disease there is something called deep brain stimulation where a wire is placed deep down within the brain. When it's in place it's often not very visible. Some neurosurgeons are going to pay a lot of attention to the aesthetics of it and others put it in the way it was designed, so to speak.
With deep brain stimulation, the first thing you want to do when you're considering asking the question of whether it would be appropriate is you'd want to see a specialist in Parkinson's disease. That would be a type of neurologist who specifically has done specialized training in things like Parkinson's disease and tremors.
Dr. Miller: Both medications and in the deep brain stimulation.
Dr. Schrock: Absolutely. Yes, in medications. Because many of my colleagues, who are involved heavily in D.B.S., like myself, really will say the most important visit is the visit with the Parkinson's specialist or we call movement disorder specialist. It's not uncommon for me to be able to work with a patient and actually say, "Oh, why don't you try this medication change," and then they call and say, "Oh, cancel that neurosurgery idea," which is deep brain stimulation.
Dr. Miller: So that must mean you also have close ties to the surgeons who implant the deep brain stimulation devices. Is that correct?
Dr. Schrock: Absolutely.
Dr. Miller: So you're working with them pretty much hand in glove to design a therapy and treatment for the patient.
Dr. Schrock: Absolutely, because our goal is to have good outcomes in all patients we select. So we have special selection procedures to be able to ensure that, voiding any complications with the surgery as can happen with any type of surgery, that patients are going to do well and have improvement in the symptoms that they want to have improvement in.
Dr. Miller: Now what percentage of patients that you see will benefit from a deep brain stimulation device?
Dr. Schrock: Usually, when we think about a patient who's going to be ready for deep brain stimulation, is someone who despite optimizing their medicines is having lots of ups and downs where their medicines are wearing off and they've developed dyskinesias. They also have not developed significant problems with memory and thinking. Early on in D.B.S. most centers would say maybe 10% of their patients who were referred for deep brain stimulation would actually be candidates.
Dr. Miller: So one out of 10.
Dr. Schrock: Yeah.
Dr. Miller: One out of 10. Okay.
Dr. Schrock: However, I would say that our regional neurologists are very well educated around here and I would say that 70% of the patients who are referred to me specifically for the question of deep brain stimulation end up going on into deep brain stimulation within two years of that referral. So I really feel fortunate here. We have great neurologists in the area who really know what the indications are for the therapy.
Dr. Miller: Once this is put in you're able, just like with a pacemaker for the heart, to make adjustments in the way that you'd provide the treatment.
Dr. Schrock: Yeah, absolutely. So this is not a straight forward, like a medication sometimes can be. What you have is, with deep brain stimulation, you place this wire but it's going into a target in the brain that's about 3 by 6 by 6 millimeters. That target in the brain has several different sub areas that we have to get into. So we have to get into the little motor sub territory so any error more than 2 millimeters in our targeting is the difference between a success and a failure of surgery. So I'm dependent so much on the skills, excellent skills, of the surgeon for my ability to have great outcomes.
Dr. Miller: You say great outcomes. Tell me about that because you've got this person now that's sort of resistant to the medications. They've got the dyskinesias as you've mentioned. What do they see happening if it works?
Dr. Schrock: This only helps with what they call the motor symptoms of Parkinson's disease. So deep brain stimulation helps with tremor, slowness of movement, stiffness in the muscles as well as dyskinesias. So if you imagine a person with Parkinson's disease who's been taking medications for several years, when the medications now are only lasting every two to three hours, some people only one hour before they wear off, they can't count on any certain time. They can't go to a play and expect to be able to . . . they don't know if they're going to be able to get up and go home.
So what deep brain stimulation can do is by helping control these symptoms it can really give the person confidence in their day. That they're not going to go somewhere and get stuck. They're not going to go somewhere and start to have these wild dyskinesias that are going to be embarrassing for them. So really it's more of a smoothing out of the symptoms during the day.
Dr. Miller: How long can one expect to see that benefit from the deep brain stimulator?
Dr. Schrock: There's been growing research looking at the length of time and what symptoms are helped as time goes on. The early studies were one to three years out and showed there was very good persistence of benefits. Then we have now five-year and some 10-year studies. What they show for the symptoms that we expect it to benefit such as tremor, the dyskinesias, those continue to be well controlled even at 10 years.
Immediately after deep brain stimulation we often reduce medications anywhere from 30 to 80% but we have to gradually increase those medicines over time. What does gradually get worse is the slowness of movement. We aren't able to keep up with that as much as we are with tremor. The symptoms that D.B.S. doesn't help in the first place and those include balance, speech, freezing of gait where they get stuck and they can't keep moving, and memory and thinking issues. So all these things that D.B.S. didn't help in the beginning, at 10 years out those are the major issues.
Dr. Miller: But still, this is a great therapy to help people live a better life.
Dr. Schrock: Absolutely. As far as quality of life, all the studies that have looked at comparing optimization of medications or best medication management versus deep brain stimulation in patients with Parkinson's disease have shown much better quality of life in those with D.B.S. as compared to medicines alone. Many patients will explain to me they feel like their disease has been taken back five or 10 years.
Dr. Miller: It sounds like if you're a patient with Parkinson's or a physician's taking care of a patient with Parkinson's and they're staring to develop dyskinesias and they've been on the medications and they've been increasing the doses of the medications and things just aren't getting better, it probably is time to consider referring them to a movement disorder specialist in neurology.
Dr. Schrock: Earlier referrals are always better because we're never going to recommend surgery before it's needed and we can always provide education so you know when the time might be right.
Dr. Miller: Tell me about the other members on your team that you work with when you evaluate these types of patients.
Dr. Schrock: We have a big team that works together and we meet once or twice a month to discuss all the patients who are being evaluated. Myself, Dr. House, our neurosurgeon; and then we have a neuropsychologist who evaluates all our patients to look at memory and thinking. We also have a physical therapist who's a specialist in Parkinson's and movement disorders who does what we call our on and off medication testing because the best predictor of a patient with Parkinson's disease doing well with D.B.S. is how much they improve on their exam between when they are not taking their medicines and after they take their medicines. So we do formalized testing of that in all of our Parkinson's disease patients.
Dr. Miller: So this sounds like a very great team approach. A lot of great minds. Thank you very much, Dr. Schrock.
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