Deborah Howell (Host): Essential tremor is the most common movement disorder. It's estimated to affect about 10 million Americans. Today, we're here with Dr. Paul Koch, a VCU Health Neurosurgeon, who offers a new treatment option for patients with movement disorders like essential tremor called focused ultrasound.

This is Healthy with VCU Health. I'm Deborah Howell.

Thanks for being here today, Dr. Koch.

Paul Koch, MD: Absolutely. It's my pleasure. Thanks for having me.

Host: Well, let's start with the basics. What is essential tremor and what causes it?

Paul Koch, MD: So essential tremor is a neurological condition. And it is a process by which certain circuits in the brain began to evolve abnormally and you develop a shaking, a rhythmic shaking in your hands or in your head, or in your legs. And that while initially can be very mild, just a little tremble you might see from time to time, it progresses over time, even to the point of being unable to eat, unable to effectively write or type, or even walk in some cases.

Interestingly, it's often misdiagnosed as Parkinson's disease. Parkinson's disease is another type of movement disorder that includes tremoring, as well as other symptoms, but the Parkinson's tremor is a resting tremor, meaning when your arm is laying on your lap or on the table at rest, you see a shaking or a tremor, but when you go to use your arm, to pick up a cup, or type, or write, that tremor goes away.

Whereas essential tremor is a tremor of action, or of posture. So, you only see that tremor when your hand goes to use something. So, you can imagine that it can be potentially a much more disabling tremor than that associated with Parkinson's disease.

Host: It's fine until you try to pick up that cup of coffee.

Paul Koch, MD: Mmhmm. So, interestingly, we are not sure exactly what causes essential tremor. We can't really predict very well who's going to get it and who's not, although there is a genetic component. So, if you have a parent who has essential tremor, you've got about a 50 percent chance or so of having it yourself.

But many, many people who develop essential tremor don't have any known history in their family, and we're not very good at predicting who those people might be. And even though there is that genetic component by family history, that doesn't mean we know of any specific gene that could have gone awry to cause this.

Host: I see. And how is essential tremor diagnosed?

Paul Koch, MD: Well, it can be challenging, like I mentioned, it can be confused for Parkinson's disease. But there are a few telltale features. So primarily it's what type of tremor is it? So, is it that action tremor that rears its head when you go to do something? It also can respond to alcohol. Not that we recommend alcohol, but often when you ask somebody about their tremor, you might ask, you know, have you ever noticed that if you drink alcohol, it gets any better?

And if they tell you, oh, why yes, I sometimes I have to do that. You know, that's a good sign, that this might be essential tremor. But it can be a diagnosis of exclusion, meaning you want to be sure it's not any of these other movement disorders.

Host: All right and let us get into some of the treatment options. Can you speak to that?

Paul Koch, MD: So, the first line treatments for essential tremor are medications. There are several medications out there that can be very effective for patients, at least in the beginning. So, one of the things that we find is that, if certain medications are controlling a tremor for the first years that it's been diagnosed, they can fail over time as the tremor gets worse.

The other thing to understand about medications is that there isn't really any medication out there that is specifically designed to treat essential tremor. It's essentially borrowing different meds from other indications like blood pressure medications, for example, or anti-seizure medications.

So, people can have an intolerance to these meds either because it's doing something else in their body that they can't tolerate, or because it's completely ineffective. So, when those fail, when medications fail, we have basically two main surgical procedures that we can use to treat medication refractory tremor, and both of these involve disrupting the same circuit in the brain that we believe is responsible for the symptom of tremoring.

And probably the easiest way to understand this is to get a little bit into the history of these treatments. So, decades ago, the mainstay surgical treatment for essential tremor was something called radiofrequency ablation. And this is a procedure where we would place a probe down into the brain to a very specific spot in the brain called the thalamus.

And we would deliver radiofrequency energy to the tip of that probe. And that would transfer heat and it would make a tiny lesion or a tiny hole in the brain. And that hole was right in that circuitry that we think is responsible for tremor and it would disrupt the signals and was a very, very effective treatment for essential tremor.

And that was done for many, many years. Partly because of the technology at the time, it carried however, a significant side effect risk or complication risk. So, patients could potentially experience numbness or tingling in their hand or their face or weakness or difficulty speaking. And because you're making a hole, which is a permanent change in the brain, these were often permanent changes.

And this is still true. Because surgical procedures now, although I believe they're safer and potentially more effective, they do carry risk. And so it's important to understand that we reserve these treatments when essential tremor really becomes so bad that it's interfering with your life. It's interfering with your quality of life, doing the things that you need to, or you want to do, and you're willing to consider surgery to treat it. But then, several decades ago, the technology for developing batteries and small chips and being able to hold them in robust enough hardware that they can be implanted in the body, was developed.

And this led to deep brain stimulation, which is currently the gold standard for treatment of essential tremor. And instead of making a hole in the brain, we now place an electrode in that same spot. And then the tip of that electrode delivers high frequency electricity, and that electricity disrupts that same circuit. And the primary advantage of this well, there are several, but regarding the conversation we've been having, if you turn off the electricity, usually the side effects and the benefit also go away. So, if you turn it on and you get tingling in your hand, you can turn it off and that tingling goes away.

Or what's more likely to happen is we can change many different parameters of how that electricity is delivered, oftentimes to eliminate those side effects while keeping the benefit on the tremor. You can imagine those settings can be changed over time, so as the disease progresses and gets worse, you can kind of keep up with it over time.

So, DBS has really changed the game in terms of essential tremor, and not just essential tremor, but many other movement disorders. And that is still the gold standard. But probably within the last 5 to 10 years, this newer technology called focused ultrasound has come along. And the thing to understand about focused ultrasound is that it is a new, safer and more precise way of doing the old surgery, which is making a tiny lesion or a tiny hole in the brain, disrupting that same circuit. So, we're targeting the same place in the brain that we did with radiofrequency ablation. We're targeting the same place in the brain that we do with DBS, but we're making a very precise, small lesion using focused ultrasound. And in the focused ultrasound has a number of advantages that make it safer and that are potentially more desirable for the right patient compared to DBS.

Host: Well, I'd really love to talk about the actual procedure and what a patient should expect.

Paul Koch, MD: So focused ultrasound procedure is done as an outpatient, and this is one of its big advantages. The way we do it here at VCU, you come in around seven in the morning and by noon or lunchtime, you're finished and you're able to go home. So, let's just talk through how the operation works.

You come in, in the morning, we get you changed into a hospital gown, and we give you a little bit of medication. So, we give you some Tylenol to help with any headache that might occur during the procedure, and we give you medication to combat nausea, because sometimes people can become a little bit nauseated, although that is pretty rare.

And then we have to shave your hair. So, this is a critical step because the way the technology works is it transmits ultrasonic energy from multiple sources that travel through your skin and through your skull down to the target where we're creating a lesion. And if you have hair, that disrupts the smooth transition of that energy and makes it unpredictable enough so that we can't control where it goes.

Host: Sure. Quick question, do you have to shave all the hair or just the hair around that area?

Paul Koch, MD: You have to shave all the hair. And not just clipped, but it has to be smooth. So, this is important, we talk about this with our patients ahead of time in the clinic, is they need to understand that it's not a negotiable thing.

Once that's done, we have to place a frame on your head. And this is a piece of equipment that has four pins that hold the head still. You can imagine your head cannot move during this procedure because we're targeting a very precise location. So, we inject a lot of numbing medication under the skin at these four spots and then you feel a little pressure, but there's no pain associated with it because you've got some local anesthetic.

And then you go into the MRI scanner. So, this procedure is done in an MRI scanner. And at first, we get a series of pictures and that lets us look at your brain and find the precise location where we want to make that lesion. And then we proceed, in steps. So, we deliver the energy in small bouts of about 10 to 15 seconds. And we call those individual energy deliveries a sonication. That's just the technical term for delivering sonic energy. And we do it in steps, so the first set of them are at a very low energy, just enough so that it shows up on an MRI picture that we're getting at the same time and can show us where that energy is being delivered so we can look at it and say, are we going to the right spot or do we need to move it a little bit? And this is before it's causing any damage.

If that looks good, then we move on and we increase the energy a little bit of these steps and we get into this zone where you can disrupt a portion of the brain with this lesion, but you don't cause any permanent damage. So, you might see an effect that lasts minutes, maybe an hour at most, but then resolves over time. And that is critical because it gives us an opportunity to check with the patient because of course they're not under anesthesia. They're awake and so we can deliver a small sonication like that, and we can go check and we can, we can say hey, how's your tremor? Are you feeling any tingling? Say a word for me, say a sentence. Are you having any difficulty speaking? And if we see a little bit of indication of these things, we still have the opportunity to move the target of where we're burning to be in either a more effective place or a place that does not have these side effects.

And then you can imagine that we eventually ramp up that energy when we're comfortable with where we're making the lesion to deliver enough to create a permanent lesion.

Host: Yeah, X marks the spot.

Paul Koch, MD: Yep, and so it's that combination of the ability to check in with the patient in these small steps, may get temporary lesion and being able to get an MRI in real time showing us in the anatomy of the brain where we're delivering that energy that really is a major step over the old way of making a lesion.

Host: So, the treatment lasts about two to three hours?

Paul Koch, MD: That's right. Again, you're sort of done by lunchtime. After you finish the procedure, we get that frame off your head, and then you come back for a couple of quick pictures in the MRI afterwards.

Host: Tell me about the difference between the circle the patient tries to draw at the beginning of the procedure and then the circle at the end.

Paul Koch, MD: One of the metrics or tests we use to gauge one, how bad somebody's tremor is, and number two, how effective a treatment has been, is to draw a spiral on a piece of paper. So, we usually have sort of template and these lines that you have to start from the center and draw circles like in a spiral going further and further out in diameter and somebody with this severe tremor, many of our patients who undergo this procedure, it's not even recognizable as a spiral. It's just bunch of scribbles is what it looks like.

And the remarkable thing about the procedure is we have them draw the spiral after each of these sonications. And we can see visually how that tremor is improving. So, you might have just scribbles before the procedure. After we do maybe a temporary lesion, maybe their spiral starts to look a little bit like a true spiral. You can recognize it as such. And by the end, sometimes we get a near perfect spiral. And so, comparing that nearly perfect spiral to an unrecognizable one before surgery; it's just a very dramatic visual demonstration of the effectiveness of what we've done.

Host: Remarkable. I can imagine there are emotional responses from the patients as they see their progress.

Paul Koch, MD: Yes, that is true. Partly because it is instantaneous and it's not just the patients either. So, one of the really cool things about doing this procedure is that we have a fantastic team at VCU, including the MRI technicians, our nursing staff, and even our trainees, our residents and fellows who are there with me.

The whole team becomes emotionally involved and after our first patient, we had several people crying from being happy. So, everyone gets very involved and is very committed to these patients and it certainly is a nice experience.

Host: That team atmosphere is such a benefit. What are some of the other benefits of focused ultrasound?

Paul Koch, MD: A couple. As I mentioned, it's done as an outpatient procedure. So, you don't need to be in the hospital for several days, which is what you would need for deep brain stimulation. You come in in the morning and you're done by lunch. So, that provides a significant advantage, particularly to people who may have a lot of comorbidities that being in the hospital poses an elevated risk to them.

You also do not need general anesthesia, or a breathing tube placed, which is typical for classic operations. The reason for this is kind of interesting. So, number one, you don't have to make any incisions in your scalp and you don't have to drill any holes in the skull, which is what you would need to do for deep brain stimulation and many other just traditional neurosurgical procedures. You don't have to worry about the pain of an incision, the pain of making a hole in the skull. And the other thing that makes it possible, is that the brain itself, ironically, does not have any pain receptors. Even though it is your brain that is interpreting pain that is sensed in nerves in your finger or wherever.

The brain itself, doesn't have nerve endings. So, delivering high energy, even to the point of making a lesion, is not painful from that lesion itself in the brain. So, we don't really need any general anesthesia to do this procedure. And that is a major advantage for people who have other comorbidities that make an anesthetic high risk to them.

Host: So that would make your recovery very speedy.

Paul Koch, MD: It does. Usually, people are back to their normal activities within a few days, at home. And then the other advantage is, many people are on medications that thin their blood or make their blood less likely to clot. So, patients who've had strokes, for example, or heart attacks are often on medications that slow the blood's ability to clot because that's part of the problem in those conditions.

Of course, that makes surgical procedures more dangerous. And so usually for neurosurgical procedures, we have to have people stop those medications for a long period of time, both during and after the procedure. Focused ultrasound, although there is a theoretical risk of bleeding, that risk is very, very low. And so, we typically only stop those medications for a couple of days. So that also poses an advantage.

Host: Dr. Koch, I know how busy you are, but I have a final question for you. What does the future of focused ultrasound look like?

Paul Koch, MD: Focused ultrasound for essential tremor is really the tip of the iceberg. As you can imagine, this is a technology that lets us safely and precisely disrupt a circuit in the brain. The ability to change the risk profile for something like that, where it doesn't involve major hospitalization, it doesn't involve having hardware implanted in your body, right, so deep brain stimulation has hardware that's implanted in the body that because it's an artificial device, it has a rate of failure. When the battery runs low, it either needs to be charged or replaced, etc. So, because we have that, it really opens the door to disrupting other types of circuits. And so, we already are pursuing, are there targets in the brain that we can treat refractory epilepsy? Or patients that have seizures that are not controlled by medications.

And we disrupt circuits in potentially psychiatric illnesses. So, all of these things are being thought about and pursued. And then there's a related technology where rather than this, so what we were talking about is high frequency focused ultrasound. There's also low frequency focused ultrasound, and this is delivering lower energy, and this has even arguably more remarkable properties. So, it is able to modulate the tissue, in ways that are temporary and not temporary in terms of minutes, but temporary in terms of weeks to months. And that opens other possibilities for modulating circuits again in the realm of epilepsy, for example.

Host: Truly, truly exciting.

Paul Koch, MD: Yes.

Host: Well, thank you, Dr. Koch, for taking the time to be with us today and share about this exciting new treatment and all the possibilities ahead. We really do appreciate it.

Paul Koch, MD: Well, I appreciate the opportunity. Thanks so much.

Host: And you can learn more by visiting vcuhealth.org/focusedultrasound. To listen to other podcasts from VCU Health, visit vcuhealth.org/podcast. This is Healthy with VCU Health. I'm Deborah Howell. Have yourself a great day.