The Who, What, Where, When, and Why of Deep Brain Stimulation for Parkinson's Disease

Are you considering having Deep Brain Stimulation (DBS) for your Parkinson’s symptoms?

Have you heard of DBS but still aren’t clear on exactly what it does, who it’s for, or when someone should consider it?

You’re in the right place.

Today I want to share with you an interview I did with a friend and physical therapy colleague, Dr. Eric Rhoden, PT, DPT.

He shares my passion for Parkinson’s, is incredibly well versed in Deep Brain Stimulation, and took some time to answer the most common questions I hear from our online community about DBS.

His questions are below, or you can watch the full interview here: 

 
 

When should someone with Parkinson’s consider having Deep Brain Stimulation?

Eric: "That is probably the #1 question we get in our clinic and the answer depends. The prior standard was that it used to be the last resort treatment; after you've utilized every medication cocktail imaginable, then let's throw in deep brain stimulation. That paradigm has almost flipped on its end and there's a much larger push for early intervention of DBS recently. The thought process being that you will prolong your ability to utilize medications because you're going to have less off times [with DBS] so you won't need as much medication.

deep brain stimulation.jpg

As far as how early someone should consider DBS, I've had people 3 months diagnosed that have had deep brain stimulation surgery, as well as people that have had Parkinson's for 30 years. Both can do well. Not everyone does great which will lead to later. But, as far as when you should get it, it's really that conversation you have with your neurologist and your physical therapist.

If you are having drastic off-cycling motor fluctuations where you're just not able to control your symptoms correctly, DBS, duodopa, and newer stuff coming on the horizon maybe the choice for you."

Medtronic’s Guide to Deep Brain Stimulation 


What Parkinson’s symptoms does Deep Brain Stimulation help and not-help with?

Eric: "With regards to Parkinson’s symptoms DBS is the most helpful with, it tends to be your triage of tremor, rigidity, bradykinesia.

It does not fix postural instability and typically doesn’t have a significant impact on balance. However, it depends on the source of your balance issue. If the source of your balance problem is because you're rigid, stiff, and you're unable to break out of that bradykinesia (slowness of movement) then, yes, that will likely improve to some degree. But, if you have an underlying postural problem (which your physical therapist can help you tease out with thorough testing), that may not get better. The only way those types of symptoms get better is with good physical therapy.

Freezing of gait (FOG) has mixed results. It's not one of the symptoms we campaign to be able to “fix” with DBS, but if rigidity or bradykinesia are contributing to your FOG, DBS may be able to help with it.

We had a recent patient where [freezing of gait due to rigidity] was his main complaint. We switched him on and he hasn't frozen since he got DBS. That was a great success for him. There are are other people where this isn’t the case.

The question becomes: Why did that guy see improvements versus the other one?

It comes back to where DBS is hitting on the brain. In particular, your executive function (high level thinking) is controlled by the frontal cortex. That spot is where spatial reasoning lives, which controls how we problem solve. If that area of the brain has a deficit, that can exacerbate these freezing of gait moments. In addition, anxiety and different stressors can also exacerbate FOG so learning relaxation techniques, breathing techniques, yoga, and other mindfullness and stress-management techniques may significantly improve your FOG as well."

VIDEO: Watch Minor's journey through Deep Brain Stimulation to significantly improve his Parkinson's tremor


When people are considering getting DBS, what is the process that you go through to determine if someone is a good candidate?

Eric: "It varies facility to facility depending on the Movement Disorder doctor. Generally you start with “on- and off-state testing” where you’re put through arsenal of questions and tests, motor and medication-based.

First, you go through these tests in an “on-state” (ie. when your medications are at their most optimal effectiveness).

Then you wash out all your Parkinson's medication, which everybody hates to do because you feel terrible, and retest all those same things in an “off-state” and you see how much different your symptoms are.

They're looking at your Total score as well as your Motor score in particular because those tend to be the areas where DBS is most effective. In general, if your symptoms vary by 20 to 30% or more between the “on” and “off-state” this indicates that you’re likely a good candidate for DBS.

deep brain stimulation testing

In addition to that, if you're showing any signs of cognitive impairment, your MDS may recommend formal neuropsychology testing. This is a 6-hour event where you sit down with a neuropsychologist and they put you through a series of questions and tests.  The rationale behind the testing is that some research shows that if you already have cognitive impairment, DBS may exacerbate that to some degree. So they want to make sure you don't have an underlying cognitive issue beforehand."

Who is a good candidate for deep brain stimulation for Parkinson's Disease? Read UCSF's Guidelines for referring neurologists


Once someone has been cleared to have Deep Brain Stimulation surgery, what is that process?

Eric: "After your surgical consult, as long as you don't have any other comorbidities or complications based on your scans of the brain, then you're scheduled for surgery.

You'll go in the day before you have your DBS placement and get what are called fiducial markers, which are probably the most painful of the entire surgery component. These essentially assist the neurosurgeon during your DBS surgery.

On the day of your DBS placement, they drill nickel to quarter-sized holes on either side of your head. The exact location depends on the structure they’re aiming to stimulate. If you're essential tremor, you're looking at VIM. If you're Parkinson's, you're looking at STN or GPi. Again, as far as which one is which that's a whole other topic of discussion.

During the surgery you’ll be in a semi-sedated state, feeling very relaxed. They place your stimulator and then do a reading on you intraoperatively. You're able to follow directions so your surgeon can have you move your hand and do other simple movements to determine if the leads are hitting the right spot. As soon as they know the leads are placed correctly and that you’re dialed in, they sew you back up.

Post-operative care varies drastically from facility to facility. At our clinic, we go right away. Within the week of your brain surgery, you get your IPG (which is your battery and computer) which can be placed in numerous sites. Your battery pack will be placed either at the chest or the abdomen, and often the abdomen is more comfortable.

Some facilities, will wait 4 to 6 weeks after your surgery before they’ll even touch you. At our facility, we jump into it week 1. We chase your swelling and try to get you dialed in with your stimulation settings as quickly as possible."

VIDEO: Parkinson’s Disease Patient Explains DBS Treatment (MJFF)


What’s coming down the pipeline with regards to Parkinson’s and Deep Brain Stimulation?

St. Jude / Abbott Infinity DBS System

St. Jude / Abbott Infinity DBS System

Eric: "Up until the last few months, Medtronic was the only company producing deep brain stimulators. Now there are a lot of other companies internationally that may be coming to the United States soon. Recently, there's a new directional DBS that has come out by Abbott called the Infinity stimulator. The benefit that they're promoting with the Infinity is the additional of a directional component.

Medtronic also offers a stimulator that’s similar to a certain extent. They offer something termed “interleaving” which is different than directional stimulation. Basically they put two programs on one side, and it's going back and forth, and that reduces the activation of those particular tissues.

Down the line I think everyone with DBS is going to have a directional lead. As far as which brand (Medtronic v. Abbott v. someone else) is going to be better, that's up for debate. But, the good part is that there’s competition, and competition is good. It brings down the cost of everything and we're excited for it. New tech is good."

St Jude Medical Infinity DBS System approved for Parkinson’s and Essential Tremor


For those people who have had Deep Brain Stimulation, how do they know that they are at an optimal setting to control their Parkinson’s symptoms?

Eric: "Normally the goal of DBS is to improve management of your symptoms, reduce your off-cycling time and, ideally, reduce medications. So for one, if you're having less off-cycling, your DBS is working.

If you're still having that same amount of off-cycling once you've had DBS, there may be an issue with:

  1. Not enough stimulation, or
  2. Poor medication management.

You may not be set at a high enough frequency or not have a high enough dose of your medication to even out your on- and off-times.

If you’re under-stimulated, you’ll likely feel your typical symptoms: rigidity, your tremor returns, maybe even cognitive slowing. The latter tends to be a little bit more lack of dopamine pharmaceutically so using levodopa may be better in that case. The cognitive component with dopamine is a separate conversation, but that is something you want to look out for because you need to have that perfect mix of the two (medication + DBS).

On the other hand, your DBS may be working maybe a little too much. We frequently hear, "I feel overstimulated." You're wired like you just had a shot of espresso. That might be a feeling of overstimulation. In that case, you may just need to turn your frequency down a little bit and you'd be good.

Another big component is dyskinesia. Dyskinesia is that uncontrolled movement that makes you look like you're dancing. It can be in your neck, leg, arm, even whole trunk. Dyskinesia tends to be the most common side effect of overstimulation and over-medication because in a way DBS is like an electronic medication. As you’re increasing your DBS stimulation, ideally you should also be able to decrease your medication. That's what you’ll be playing with (with the help of your neurologist and physical therapist). It's a perfect cocktail of the two (medication + DBS), especially in the early phase after DBS when these fluctuations are most common."


Do you have any other words of advice for people who have had Deep Brain Stimulation who don't feel like it’s been as effective for their Parkinson’s symptoms as they want it to be?

Eric: "The easiest way to tell if it’s working or not is to turn it off. It’s not something I recommend to everyone, but you have your remote.

Turn it off. Wait. See how you feel.

If you're like, "Oh, my gosh. I feel terrible.” or “My tremor is going out of control," DBS is obviously doing something for you.

However, sometimes you can have a carryover effect in some people, meaning a person could shut off the DBS and that person may look perfect for some time afterwards. And then, all of a sudden, the true nature of the disease comes back.

They talk about this “lesioning effect” or this “honeymoon effect” that you get post-surgery where, all of a sudden, your symptoms are suddenly better even though the DBS isn't actually on. It's just that aspect of putting something in your brain and that area of your body reacts that way.

In a similar manner, it can be that way when you turn it off. Your body psychologically thinks, "Oh, well, it's still there," when in fact it isn’t turned on anymore. Then, all of a sudden, it realizes, "Oh, we don't have the juice that we need." Now, you start seeing your symptoms re-emerge.

In general you should be looking at your symptoms from a long-term perspective. Ask yourself: How was I before surgery?

If your answer is that you were popping Rytary or Sinemet 6 times a day, having off-cycling every 2 hours, didn't have good tremor control, and couldn't think clearly or lacked focus… versus now…  you’re still taking Rytary or Sinemet 6 times a day of but now you can go 4 hours without an off-cycling moment, then you may be benefitting, even if it's not perfect. You got to have a certain perspective of progress.

We use this all the time in physical therapy. People say, "Oh, I'm not getting better." It's like, "Well, what are you measuring?” You got to look at what you're measuring and there are probably gains that you may not even be aware of."


Is Deep Brain Stimulation effective for someone who has essential tremor (ET) and Parkinson's?

Eric: "The answer to this question gets a little tricky because there are different target structures in the brain with DBS depending on what symptoms you’re focused on.

A lot of the time we'll see patients where they may start with Parkinson's-like symptoms (“Parkinsonism”) or start with ET, and then it manifests into both Parkinson’s and ET. Unfortunately, they seem to be cousins to each other as far as what's going on in the brain.

So when you have tremor symptoms as well as bothersome Parkinson’s symptoms, finding the appropriate target site is challenging. You may have to choose which symptoms are more debilitating in nature.

There are a few people that have both VIM and STN surgeries, meaning they have double placement on both sides of the brain aiming to correct Essential Tremor (ET) issues as well as Parkinson's symptoms. That's a conversation to have with your neurologist and neurosurgeon to determine if they actually feel that kind of DBS placement is going to help you or not.

If you do have to choose between focusing on ET or Parkinson’s symptoms, however, I would suggest you go after your more debilitating issues.

Ask yourself:

What symptoms are most disruptive and frustrating in my daily life?

Is it the action tremor when you're grabbing for something?

Is it the fact that you cannot move because you're freezing?

Is it rigidity that’s more problematic for you?

I'd aim for whatever symptom is the most prevalent with relation to your quality of life more than anything else."


Could you give us some insight into Functional Ultrasound (FUS) - the non-invasive brain surgery option - and what you know?

Eric: "It’s appealing, right? It's noninvasive. You don't have to have anything drilled into your brain. They shoot in the ultrasound and magically you’re better...

Now, what is actually occurring is a focal ultrasound (FUS). Based on the trajectories of how this ultrasound enters in your brain, the argument is it causes minimal to no damage to any of the surrounding structures. It's essentially like a laser that pinpoints that particular area and structure in the brain. Then, ideally, your symptoms go away.

As far as the technical components of how they figure out exactly what spot in the STN, VIM or thalamus to target. It is essentially an ablation of that particular site, meaning they kill that tissue.

Again you can argue, "Okay. That's great. Noninvasive. Boom. It may fix my symptoms immediately." But, as we know - and as you all have experienced - Parkinson’s is not just a disease of the brain. It is a systematic problem and there's a lot more going on than just killing one spot of the brain.

I think it is a good alternative. As far as long-term benefit, it's too new to say. I think it's a great alternative for people that maybe can't have deep brain stimulation because of structural issues. Maybe focalized ultrasound is their best option at that time."   

Learn more about Functional Ultrasound and How it May Improve Parkinson's Symptoms (from the FUS Foundation)


Looking for more information on Deep Brain Stimulation? 

Watch Sarah's recap from the World Parkinson's Congress in Portland, Oregon here:

 
 

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