Selected Podcast
Penn’s New Chair of Neurosurgery Discusses Neurotechnology
Daniel Yoshor, MD, is Penn Medicine’s New Chair of Neurosurgery. Join us as he discusses his research and the COVID-19 pandemic. In this podcast, he shares the development of a neurotechnology called the bionic eye and whether he thinks the discovery of other sequelae among Covid survivors would evolve over time and possibly have other implications for COVID patients including epilepsy or pituitary adenoma.
Featuring:
Daniel Yoshor, MD
Dr. Daniel Yoshor, MD is the Chair, Department of Neurosurgery and Vice President, Clinical Integration and Innovation at Penn Medicine. He attended medical school at the University of Chicago, and completed residencies at Baylor College of Medicine/Texas Children's Hospital. He was board certified in neurological surgery in 2003. Transcription:
Melanie Cole: Welcome to the podcast series from the Specialists at Penn Medicine, I'm Melanie Cole. And today we're meeting Penn Medicine's New Chair of Neurosurgery and Vice President of Clinical Integration and Innovation, Dr. Daniel Yoshor, he's here to discuss his research. Dr. Yoshor, it's such a pleasure to have you join us today. You've recently taken part in the development of a neurotechnology that's being called the bionic eye, explain a little bit about what this technology is, where we are in its development? And you've said you hope to see the restoration of functional eyesight to the blind in your lifetime.
Dr. Yoshor: Yes. This has been a tantalizing prospect to neuroscientists and engineers for quite a long time. And the idea is very simple. Think of a roadblock going around a roadblock in patients with acquired blindness, almost always. It's the eyes, the optic nerves, the early part of the visual processing system that's irreversibly damaged. So visual information can't get from the eyes to the brain because usually the eyes themselves are damaged or broken. What a visual cortical prosthetic aims to do is take visual information from the outside world and bypass the irreversibly damaged eyes or optic nerves, and put that information directly into the visual part of the brain. So the idea is that technology will take images from the outside world, digitize them with a camera and convert that image captured from the outside world into a series of electrical pulses that are used to activate the circuits in the brain that normally allow us to see by getting information directly from the retina and optic nerve. Instead we bypass the broken retina and optic nerve and deliver the information directly to the brain. That is the concept.
Host: Is amazing. Now, is there any reason these implants can't be used in children with inherited blindness or is there something to prevent this? Where do you see it going?
Dr. Yoshor: That's an excellent question. The way we envision the technology right now, in order for it to work, the visual part of the brain has to be developed. And that development of the visual part of the brain known as the visual cortex, which is mostly located in the back part of the head, those circuits are not developed without the experience of visual inputs that occur during infancy and childhood. So if someone is born with congenital blindness, that part of the brain is not developed and there's no target for us to deliver the visual information. So the technology we're working on will only help patients with acquired blindness. They have to have had some visual function during their lives. It can be early in their lives. They can be blind for many, many years, but they have to have the latent ability in their visual brain to process visual information. So that would apply to patients who are blind as a result of trauma, for example, or retinal disorders like retinitis pigmentosa, anything that damages the eyes permanently in patients who at one point in their life, were able to see relatively normally, those conditions would be appropriate for visual restoration, with a visual cortical prosthetic.
Host: So, will this research be continuing at Penn Medicine?
Dr. Yoshor: Working in this area in my laboratory previously in Houston, where I'm coming from for over a decade. And what we have largely done in the past is work with patients who are undergoing monitoring for medically intractable epilepsy. These are patients who have epilepsy that can't be controlled with drugs, and as part of their clinical workup, they undergo brain surgery for implantation of temporary electrodes in the brain. They're then brought into an epilepsy unit where their seizures are recorded. And that helps us as clinical neurosurgeons determine where the seizures are coming from so that we can fix them by resecting, surgically removing the part of the brain that's causing seizures. So these patients are sitting there in the epilepsy unit in a hospital, and there are dozens of these specialized units located in leading hospitals across the United States.
So we've been very generously supported by these patients and allowed to study their brains, to see how visual information is encoded in their brains. And what we've been able to do is transmit visual information directly into their brains on a very rudimentary level. More recently, we've been able to test these techniques on blind patients. And what we found is you have to deliver the information in a very specific way. It's not effective to deliver the information all at once. Forming little dots that coalesced together into an image like pixels on a video screen in order to deliver the information, what we found and we recently published on this in the Journal Cell, just a couple of months ago in May, we found that you have to stimulate the brain dynamically. You have to trace patterns across the brain in order to effectively get that information into the brain.
Like any kind of pixelated image that you see on a screen in your daily life, the brain won't interpret that information readily as an image, but if you sweep the information dynamically across the visual part of the brain, by delivering the electrical impulses in rapid succession, the brain is able to interpret that information and convert it into a perception of a visual form. And that's the key for this technology. It's not difficult for us to get patients with acquired blindness to see spots of light by stimulating their brains. That's quite easy to do. And quite reliable. What's a challenge is to turn those spots of light into viable coherent forms. People don't want to recover vision and just be able to see a few spots of light. They want to be able to see objects. They want to be able to navigate in a street. They want to be able to see and recognize people. And that's why object recognition is so important. And our recent big advances that we've shown that if you enter the information into the brain dynamically, you can get patients who have never seen anything for years and several cases to be able to rapidly recognize visual forms like letters in the alphabet. And that of course is very exciting and a big step forward in the field.
Host: Dr. Yoshor, I understand that your interest and clinical specialty within neurosurgery is pituitary tumors. How does that relate to your interest in technology and visual neuroscience?
Dr. Yoshor: Pituitary surgery is a remarkable area of neurosurgical practice because it's changed so much over the past decade because of technology. And you're right, I'm very interested in the merger of technology and neurosurgery to improve patient outcomes. And in my practice over the past 20 years, the way I do pituitary surgery has changed enormously. And now we do all those surgeries entirely through the nose using endoscopic cameras and special instruments designed for endoscopy. So we do what we call minimally invasive approaches to all these tumors, including some very large and challenging tumors. And the great thing about this technology is how much it helps patients. And in my experience, having done over a thousand of these tumors, 90% of patients can go home the very next day, even patients with large challenging tumors. And that's very gratifying. And you asked it is connected to my interest in visual neuroscience and restoring vision. Well, one of the most gratifying things that we can do and in all of medicine is to take someone who can't see and bring the gift of vision back to them.
Well often, that's what we're doing also with pituitary surgery, because the pituitary gland is located very close to the optic nerves. And when these tumors grow and get large enough, they will compress the optic nerves and they cause visual loss and even blindness. And one of the most gratifying things in my practice. And I just did a case yesterday, just like this, where the patient came in with a severe loss of vision, and we did the surgery and the very next day her vision was back to normal. And of course that's enormously gratifying. So I would say my interest in vision informs what I do in the laboratory. And it also informs what I enjoy most about my clinical practice, giving the gift of vision back to patients who are in danger of losing it forever. Really one of the most gratifying things you can do as a Doctor.
Host: Dr. Yoshor, as we wrap up as the new chair of neurosurgery and vice president of clinical integration and innovation, what's your vision for the department? What would you like other providers to take away from this episode and what you're planning to do there at Penn Medicine?
Dr. Yoshor: Well, I'm very excited to be here at Penn Medicine. I think this is an extraordinary place. And I think the combination of a truly outstanding medical school, which we have here in the Perlman School of Medicine at the University of Pennsylvania, alongside, a really wonderful health system, a collection of really terrific hospitals across Pennsylvania and parts of New Jersey. It really gives us the opportunity to build something great. And my vision is to have our department be highly sub-specialized with a series of Doctors in neurosurgery that are experts in very specific areas in neurosurgery and focused on those very specific areas. And that those doctors are not only superb experts in technical neurosurgery within their subspecialty, but they're also harnessing the great science and engineering that we have at Penn to advance the field. So we don't want to just practice medicine at the highest level.
We want to innovate and improve medicine and specifically neurosurgery at the very highest level. And that's, what's going to make the difference here is we're going to be highly focused within specific areas within neurosurgery, whether it's brain tumors or pituitary tumors or brain aneurysms or spinal disorders or epilepsy. And then we're going to take the great science and engineering that is part of our DNA here at Penn, and use that to make care better and make patient outcomes better. And of course, we're going to do it with compassion because ultimately the science is not important if it's not helping people, it has to do both. So that's what we're very excited about here, and that's my vision. And I think there's no place better equipped to enjoy the future benefits of technology and medicine and position to do great things in healthcare than our system here and our medical school here at Penn Medicine.
Host: Thank you so much, Dr. Yoshor, absolutely a fascinating segment. And thank you so much for joining us today. And that concludes this episode from the Specialists at Penn Medicine. To refer your patient to Penn Medicine, please visit our website at pennmedicine.org/refer, or you can call 877-937-Penn for more information, please remember to subscribe, rate, and review this podcast and all the other Penn Medicine podcasts. I'm Melanie Cole.
Melanie Cole: Welcome to the podcast series from the Specialists at Penn Medicine, I'm Melanie Cole. And today we're meeting Penn Medicine's New Chair of Neurosurgery and Vice President of Clinical Integration and Innovation, Dr. Daniel Yoshor, he's here to discuss his research. Dr. Yoshor, it's such a pleasure to have you join us today. You've recently taken part in the development of a neurotechnology that's being called the bionic eye, explain a little bit about what this technology is, where we are in its development? And you've said you hope to see the restoration of functional eyesight to the blind in your lifetime.
Dr. Yoshor: Yes. This has been a tantalizing prospect to neuroscientists and engineers for quite a long time. And the idea is very simple. Think of a roadblock going around a roadblock in patients with acquired blindness, almost always. It's the eyes, the optic nerves, the early part of the visual processing system that's irreversibly damaged. So visual information can't get from the eyes to the brain because usually the eyes themselves are damaged or broken. What a visual cortical prosthetic aims to do is take visual information from the outside world and bypass the irreversibly damaged eyes or optic nerves, and put that information directly into the visual part of the brain. So the idea is that technology will take images from the outside world, digitize them with a camera and convert that image captured from the outside world into a series of electrical pulses that are used to activate the circuits in the brain that normally allow us to see by getting information directly from the retina and optic nerve. Instead we bypass the broken retina and optic nerve and deliver the information directly to the brain. That is the concept.
Host: Is amazing. Now, is there any reason these implants can't be used in children with inherited blindness or is there something to prevent this? Where do you see it going?
Dr. Yoshor: That's an excellent question. The way we envision the technology right now, in order for it to work, the visual part of the brain has to be developed. And that development of the visual part of the brain known as the visual cortex, which is mostly located in the back part of the head, those circuits are not developed without the experience of visual inputs that occur during infancy and childhood. So if someone is born with congenital blindness, that part of the brain is not developed and there's no target for us to deliver the visual information. So the technology we're working on will only help patients with acquired blindness. They have to have had some visual function during their lives. It can be early in their lives. They can be blind for many, many years, but they have to have the latent ability in their visual brain to process visual information. So that would apply to patients who are blind as a result of trauma, for example, or retinal disorders like retinitis pigmentosa, anything that damages the eyes permanently in patients who at one point in their life, were able to see relatively normally, those conditions would be appropriate for visual restoration, with a visual cortical prosthetic.
Host: So, will this research be continuing at Penn Medicine?
Dr. Yoshor: Working in this area in my laboratory previously in Houston, where I'm coming from for over a decade. And what we have largely done in the past is work with patients who are undergoing monitoring for medically intractable epilepsy. These are patients who have epilepsy that can't be controlled with drugs, and as part of their clinical workup, they undergo brain surgery for implantation of temporary electrodes in the brain. They're then brought into an epilepsy unit where their seizures are recorded. And that helps us as clinical neurosurgeons determine where the seizures are coming from so that we can fix them by resecting, surgically removing the part of the brain that's causing seizures. So these patients are sitting there in the epilepsy unit in a hospital, and there are dozens of these specialized units located in leading hospitals across the United States.
So we've been very generously supported by these patients and allowed to study their brains, to see how visual information is encoded in their brains. And what we've been able to do is transmit visual information directly into their brains on a very rudimentary level. More recently, we've been able to test these techniques on blind patients. And what we found is you have to deliver the information in a very specific way. It's not effective to deliver the information all at once. Forming little dots that coalesced together into an image like pixels on a video screen in order to deliver the information, what we found and we recently published on this in the Journal Cell, just a couple of months ago in May, we found that you have to stimulate the brain dynamically. You have to trace patterns across the brain in order to effectively get that information into the brain.
Like any kind of pixelated image that you see on a screen in your daily life, the brain won't interpret that information readily as an image, but if you sweep the information dynamically across the visual part of the brain, by delivering the electrical impulses in rapid succession, the brain is able to interpret that information and convert it into a perception of a visual form. And that's the key for this technology. It's not difficult for us to get patients with acquired blindness to see spots of light by stimulating their brains. That's quite easy to do. And quite reliable. What's a challenge is to turn those spots of light into viable coherent forms. People don't want to recover vision and just be able to see a few spots of light. They want to be able to see objects. They want to be able to navigate in a street. They want to be able to see and recognize people. And that's why object recognition is so important. And our recent big advances that we've shown that if you enter the information into the brain dynamically, you can get patients who have never seen anything for years and several cases to be able to rapidly recognize visual forms like letters in the alphabet. And that of course is very exciting and a big step forward in the field.
Host: Dr. Yoshor, I understand that your interest and clinical specialty within neurosurgery is pituitary tumors. How does that relate to your interest in technology and visual neuroscience?
Dr. Yoshor: Pituitary surgery is a remarkable area of neurosurgical practice because it's changed so much over the past decade because of technology. And you're right, I'm very interested in the merger of technology and neurosurgery to improve patient outcomes. And in my practice over the past 20 years, the way I do pituitary surgery has changed enormously. And now we do all those surgeries entirely through the nose using endoscopic cameras and special instruments designed for endoscopy. So we do what we call minimally invasive approaches to all these tumors, including some very large and challenging tumors. And the great thing about this technology is how much it helps patients. And in my experience, having done over a thousand of these tumors, 90% of patients can go home the very next day, even patients with large challenging tumors. And that's very gratifying. And you asked it is connected to my interest in visual neuroscience and restoring vision. Well, one of the most gratifying things that we can do and in all of medicine is to take someone who can't see and bring the gift of vision back to them.
Well often, that's what we're doing also with pituitary surgery, because the pituitary gland is located very close to the optic nerves. And when these tumors grow and get large enough, they will compress the optic nerves and they cause visual loss and even blindness. And one of the most gratifying things in my practice. And I just did a case yesterday, just like this, where the patient came in with a severe loss of vision, and we did the surgery and the very next day her vision was back to normal. And of course that's enormously gratifying. So I would say my interest in vision informs what I do in the laboratory. And it also informs what I enjoy most about my clinical practice, giving the gift of vision back to patients who are in danger of losing it forever. Really one of the most gratifying things you can do as a Doctor.
Host: Dr. Yoshor, as we wrap up as the new chair of neurosurgery and vice president of clinical integration and innovation, what's your vision for the department? What would you like other providers to take away from this episode and what you're planning to do there at Penn Medicine?
Dr. Yoshor: Well, I'm very excited to be here at Penn Medicine. I think this is an extraordinary place. And I think the combination of a truly outstanding medical school, which we have here in the Perlman School of Medicine at the University of Pennsylvania, alongside, a really wonderful health system, a collection of really terrific hospitals across Pennsylvania and parts of New Jersey. It really gives us the opportunity to build something great. And my vision is to have our department be highly sub-specialized with a series of Doctors in neurosurgery that are experts in very specific areas in neurosurgery and focused on those very specific areas. And that those doctors are not only superb experts in technical neurosurgery within their subspecialty, but they're also harnessing the great science and engineering that we have at Penn to advance the field. So we don't want to just practice medicine at the highest level.
We want to innovate and improve medicine and specifically neurosurgery at the very highest level. And that's, what's going to make the difference here is we're going to be highly focused within specific areas within neurosurgery, whether it's brain tumors or pituitary tumors or brain aneurysms or spinal disorders or epilepsy. And then we're going to take the great science and engineering that is part of our DNA here at Penn, and use that to make care better and make patient outcomes better. And of course, we're going to do it with compassion because ultimately the science is not important if it's not helping people, it has to do both. So that's what we're very excited about here, and that's my vision. And I think there's no place better equipped to enjoy the future benefits of technology and medicine and position to do great things in healthcare than our system here and our medical school here at Penn Medicine.
Host: Thank you so much, Dr. Yoshor, absolutely a fascinating segment. And thank you so much for joining us today. And that concludes this episode from the Specialists at Penn Medicine. To refer your patient to Penn Medicine, please visit our website at pennmedicine.org/refer, or you can call 877-937-Penn for more information, please remember to subscribe, rate, and review this podcast and all the other Penn Medicine podcasts. I'm Melanie Cole.