Dr. Peter Carlos Gerszten, University of Pittsburgh Medical Center neurological surgeon, talks about spinal cord stimulation helping stroke patients regain mobility.
Interview conducted by Ivanhoe Broadcast News in 2023.
You see a lot of people whose lives are changed by strokes. What do they struggle with the most after having one?
Gerszten: Well, a stroke is simply a term when part of the brain is injured. And any part of the body can be affected by having a stroke, for instance. And the most common visible symptom is that patients are unable to move their arm or their leg. But not only are they unable to move their arm and leg, being partially paralyzed, but sometimes they can’t speak and communicate. And also sometimes they are unable to feel their arms and their legs. And that can be equally as debilitating as being unable to move their arm or their leg.
What did you do to developing the epidural stimulation?
Gerszten: Well, as you can imagine, there are hundreds of thousands of patients every year in the United States alone who suffer a stroke. And the vast majority of these patients never recover from the stroke, meaning that for the rest of their lives, they have a disability that they are unable to move their arms or their legs. And we have known for many years that with certain types of electrical stimulation if placed in the right part of the spinal cord and with the right configuration of electrical stimulation that we have the ability to allow these patients to regain their function in movement. So it was a combination of knowing that there was a tremendous need for these patients because they really have no other way of- or there is no other way to treat these patients. There’s no other effective treatments. Once they develop a stroke and develop a paralysis, there’s no way to reverse that. And finally, we have the technology in 2021 or 2020 when we started to develop this of implanting these devices to allow these patients to recover from their strokes.
Can you explain what happens when you have a stroke?
Gerszten: Okay. So it’s at actually conceptually rather straightforward in that when a patient has a stroke, it means that part of their brain is not working. Think of it as the electrical wires between brain and the rest of the body are cut from the stroke and that- that causes a stroke can be from a vascular event where there’s no blood to the brain, but also from a trauma that cuts those, that connection the white matter. Or it can be from a tumor that grows. And when we as surgeons remove the tumor, we unfortunately have to cut those nerves. So anything that interrupts the gray matter of the brain from the rest of the body is a stroke to that area. So what we have done and developed is an electrical stimulation that is placed not inside the spinal cord, but on top of the spinal cord, in the neck or the cervical spine. And what it allows us to do is basically to send electrical impulses back up to the brain to circumvent the stroke so it allows the patient to communicate once again between the brain and the rest of the body. So another way of looking at it is laying down new telephone wires. If a big tree falls on your telephone wires between that- going from the street to your house and your telephone doesn’t work any longer. Well, what we have the ability to do is use new telephone wires that can circumvent the injured telephone wires. And that is what we are doing now with this electrical impulses.
Is it fair to characterize this as muscle stimulation?
Gerszten: Well, not really muscle stimulation. All muscles are stimulated by nerves because the muscle is the organ that is, when it’s stimulated, with a proper electrical impulses, the muscles work by having the right electrical impulses. So what we’re doing with these electrical stimulation, we’re not stimulating the nerves because that would be a stimulator inside the end muscle. We are stimulating the nerves and allowing the stimulation so that the brain can once again communicate with the muscles. So it allows a patient who is paralyzed and who was unable to move their arms because they could think about moving their arm, but they couldn’t move their arm or squeeze their hand. Now with a new electrical stimulation, they can think about squeezing their arms or hand, and then they can move their arms. So technically, it’s not a stimulation of the end muscle, but of the nerves.
So, the stimulation of the nerves end, is it something that once they’re stimulated, they’ll continue to perform from then on, or is it something that needs to be?
Gerszten: That’s a very important question because something to our great surprise and pleasure is what we found that these patients if then after we turn off the stimulator, they continue to be able to move their hands. Not as great as when we are actually stimulating but there is a clearly that the brain and the spinal cord have learned a new pathway and have generated a new pathway so that they have imagined or re-imagined a connection between the brain and the end organ, the muscle so that they have an improvement even when the stimulation is off. So what we’ve learned is that we are simply facilitating the connection, not actually just stimulating the muscle. And that’s far more exciting.
Tell us about your study.
Gerszten: Our study is rather straightforward, that we have identified patients and we have received a grant from the National Institutes of Health where we have selected certain patients in a variety- a wide variety of patients who have had strokes, meaning that the brain is working fine, but they cannot connect to move their arms and their legs. So our study was to take these patients, bring them to the operating room and do a rather minor procedure where we place an electrical stimulation, an electrode on top of their spinal cord, and the- connect it to a battery pack. And then they go home. They’re not in the hospital for this entire time, but by using the electrical stimulation from the battery pack, we have been able to allow them to once again move their arms. And when I say move their arms, not just the arm is made up of many different muscle groups. The hand, the squeezes, to move the different fingers to move the distal wrist, the proximal. And as I’ll show you in a moment, these electrodes span all of the nerves of the arm so that all of the muscles of the arm that had been injured, paralyzed by the stroke. All of them can be used once again. So it’s not just a single muscle group, but multiple muscle groups can all be improved with electrical stimulation.
What can you tell us about how it impacted Heather?
Gerszten: Well, it’s very simple. She sustained an injury to her brain approximately eight years ago. I might be off by a couple of months, but approximately eight years ago where she was left paralyzed with her arm, so she was unable to do anything with her arm whatsoever. And her dream was simply to cut a steak or to hold a coffee cup, but she couldn’t do all of that. So after the lead was placed in with the electrical battery that I’ll show you in a minute that’s underneath the skin, she’s able to do all of these things. Now, her hand is not 100% normal, but she’s able to now use her arm and hand, which he has been unable to use for nearly a decade.
That’s interesting you say that.
Gerszten: I was just saying, you can imagine a young woman in the prime of her life who was all of a sudden, one day she awoke and she could not move her arm. Completely devastated her life. But now I don’t want to say too much, or put too many words in her mouth. But basically we’ve given her her life back by able to now having two functioning arms.
Talk to me a little bit about what you just mentioned, and she mentioned it. As you know, she had a series of four or five strokes as young as 22 years old in college. Talk to us, maybe not in Heather’s case, but in general, is that something I don’t want to say an unheard of because it’s not, but tell us about that, strokes in young victims.
Gerszten: It’s very common. So most of us think of strokes as being something in elderly patients in their ’80s or ’90s when they have a vascular problem where a piece of a clot from the carotid artery goes to the brain and causes a stroke. And that’s true that many people or many patients who sustain a stroke are elderly patients but there are many tens of thousands of patients every year in the United States who are young in their 20s and 30s who have a different vascular problem, or a benign tumor or a malignant tumor, or from an injury to their- a trauma to their arteries that they sustain a stroke also so that this is not just a problem of the elderly, but a problem that robs people of their ability to work, to do the things they want to do, to live independently in their 20s and 30s. So this is for the first time ever a treatment for those patients because before our study, there was simply no treatment option for these patients other than rehabilitation and physical therapy that could only go so far. And assistive devices, different devices that they could use to help them. This is the first ever in medicine, a device that’s implanted into the body that will allow them to actually regain function.
Tell me a little bit about how that works.
Gerszten: Well, you can imagine a young woman or a man in their 20s who all of a sudden, in the prime of their life, all of a sudden can’t move their arm. It allows them- it unfortunately, it inhibits the ability for them to work, to type, to live independently, to dress themselves, to have a normal life. But now, in her 30s, now that we have implanted this device and have literally given her her life back, she can live a normal, healthy life. She can do the things that she wants to do. She is not dependent upon others to cut her steak or to help her cook. She can do anything that she wants to do and live a normal life using both of her hands.
What’s next for the study and for patients?
Gerszten: What’s next is really twofold. Just like everything in medicine is getting better and faster and smaller the next generation of what we’re doing. We know that this works. We have absolutely determined that this is very safe, very effective but the next generation is that we will be able to develop even better, what we call leads electrodes that we can implant into the spine using a more minimally invasive procedure while the patients are awake as an outpatient and with less comfort and more safety so that the electrodes will get smaller and better and faster. But also the second is that the generators that we implanted under the skin will be better, just like many patients who are walking around with pacemakers that they place under the clavicle that are getting smaller because they can be- the generators can be recharged externally so they don’t need an internal battery. That’s really where we’re headed right now, is to make the technology better and safer. And then newer iterations will be so that we will be able to program these from an external so the patients, can even hook up to their telephone and, or a device so that we will be able to be sitting here in Pittsburgh, Pennsylvania and the patient may be living in another state or another country on the other side of the world and we will be able to use an app on their telephone, just like we do with hearing aids, same concept, and we will say, oh, it appears that you’re not getting enough function in your hand, but maybe too much in your upper arm. And then we can pre-program from a distance the devices so that we can improve the devices. And then at some point with artificial intelligence, the devices themselves will say, well, to move this arm, I see that the patient is only moving using a little bit of this electrode, but more of that electrode. And the- with artificial intelligence, the battery genera- or generator itself can improve the function of the internally place late. So I would say that the sky is the limit. This is really just the very beginning of a whole exciting new way of treating these patients.
Heather described it as having something put in but then having something removed, it was temporary. So I didn’t completely understand it. Help me understand it.
Gerszten: That’s a little bit different and that’s- that’s definitely not going to be in the future when this is placed in patients. With her because she was the very first study patient as part of with the National Institutes of Health Study and investigation, we weren’t sure how well this would work so the initial study for her being the pioneer and initial patient, we implanted this with the idea of only a temporary implantation for 28 days. Then we had to remove it. And then I don’t want to say unfortunately, with the approval of the National Institutes of Health and an external review board, she had gained so much function that we were permitted to implant it once again. But that’s definitely not that was as part of the research protocol but in the future, in the coming years, this will all be done all at the same time.
So, in the future it’s going to be implanted and stays?
Gerszten: Exactly.
This isn’t just for stroke victims, who else may benefit from this?
Gerszten: So what we are finding that very, very exciting is that this absolutely will not be just limited to stroke, this stroke patients. There is a whole new horizon that we are seeing to use spinal cord stimulation for a variety of patients with some sort of neurological deficit. The most exciting is with patients with spinal cord injury. And this is work that’s already been done in humans around the globe at certain centers where it’s in. So it’s the same elec- electricode stimulators that I’m going to show you. It’s the same- the same devices, the same generators, but placed in a different part of the body. So that can be placed lower over the thoracic cord to allow patients to walk again. And that’s already been done in humans into a very great success. And are going- with all of patients like Heather, we’re learning the best way to program these generators and electrodes, the electrical stimulation in order to allow them to walk again. So spinal cord injury is definitely here and already being implanted. The other is- there’s another devastating disease called spinal muscular atrophy or SMA. That is a devastating disease for usually occurs in patients when they are young in their teens where they lose the ability to walk. And we have already begun a clinical trial here.
Heather was the first trendsetter, for lack of a better description. And I know it’s not necessarily better, but where are you at now?
Gerszten: So, we have implanted four patients. So far, the fifth patient has already been scheduled in the coming months. And then afterwards we’re already working with the National Institutes of Health to pull this data so that we will hopefully in the next year be able to transition to a permanently implanted device, and we’re already working on the next generation of that device that can be implanted, that will just be better. As I stated before, the electrodes will be better, they will be more coverage, they will be smarter for lack of a better word, the generator will be smarter, smaller, and that’s where we’re working so that every year we’re going to be improving. I don’t want you to leave with the impression that we just did this and this is as good as it gets. We have a lot of different technology on the horizon that we’re developing.
Is there anything important you want to make sure we get that we didn’t touch on?
Gerszten: Well, I want to touch on what’s very important to me as a surgeon is that the procedure that we’re talking about is not a type of procedure that you have to come to one institution in the entire world and we will be the only place that has the ability to perform this procedure. This is a procedure that a variation of a procedure that’s performed hundreds of thousands of times every year throughout the world, where we implant spinal cord stimulators for a variety of problems, neurological problems, usually for pain. So this is simply a different type of implant, but it’s the procedure itself is done by a variety of different types of physicians in an outpatient setting. What I want to leave the audience with, it’s so important to me. Is it this is one day, hopefully in the near future, where in your local hospital across the United States, on every country in the world, we will have a relatively inexpensive way to implant these devices that can benefit patients all over the world in a very safe and easy and effective manner. It won’t be so high tech that you have to come to a major academic medical center. That’s what I think is so exciting for me. And with Heather and our patients to explain the whole process. So what we did was we brought her to the operating room and we implanted the device as I showed you. Mean, the wires were placed over her spinal cord and with wires that were brought out through her skin for four weeks. Then she went to our laboratories where we tested her. We tested different stimulation patterns in order to see which would be the best patterns for her to allow her movement. So we weren’t stimulating her muscles. We were stimulating the connections that allowed her thinking to allow when she wanted to move her arm, that she was allowed to move her arm and her hand and her muscles again. And what we found to our very great pleasant surprise is that she could move her hand again, that she had been unable to move for six years prior to the implantation of the electrodes greater than we had ever expected because we were very concerned, number one, that her muscles wouldn’t understand what to do with an electrical impulse. But we found that the learning curve with just a few days, which her brain could figure out how to move her hands again after a six-year period of interruption, could move the muscles again very, very quickly. So she had to basically learn again how to move her hands. And not only could she move them very quickly and move them very finally, but also she continued to improve day-by-day, week-by-week, that the muscles became stronger and stronger. And even at night when she went home and the device was turned off, she continued to improve with those muscles as if the brain had learned the new way of getting the impulses around the stroke to the muscles. Part of her trial was that and the understanding of the protocol was at four weeks, we had to remove the implant because the design of the trial was just to have the implants inside of her for four weeks. So after we did remove them and fortunately, she continued to improve afterwards as well. And then you had the other question was, about and not stimulating.
Voluntary movement?
Gerszten: Yeah. Voluntary movement, yes. So it’s a little bit difficult to explain, but it is very important that what we’re doing with these electrodes is we’re not stimulating the muscles and we’re not even stimulating the nerves to move the muscles because if that were the case, we would have to tell and program the electrode, which would be the muscles that need to be stimulated in order to move and the patient wouldn’t be able to have any control over that. What we’re doing is we’re allowing the patient’s own brain to move the muscles in the arm that has been paralyzed by a stroke, by reconnecting the synapses. So the patient themselves are saying, I want to move my hand and we’re facilitating electrically the ability to move the hand. But we, I say we, the electrodes are not moving the fingers, they are providing the connections between the patient’s own brain and own arm to allow the movement.
END OF INTERVIEW
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