Many patients with epilepsy can manage their seizures with medications and lifestyle changes. But for nearly one-third of patients with severe epilepsy, other treatment plans, including surgery, may be necessary.
In this podcast, Stephen Schuele, MD, MPH, chief of Epilepsy and Neurophysiology and professor of Physical Medicine and Rehabilitation at Northwestern Medicine, discusses the latest advancements in epilepsy diagnosis and surgical treatment. He talks about indications for epilepsy surgery and pre-surgical evaluation, including the 5-SENSE score, which can predict the outcome of more invasive explorations with stereotactic depth electrodes (SEEG), according to a study published in JAMA Neurology that he co-authored. Dr. Schuele also discusses exciting clinical trials currently underway and innovative treatment options offered at the Northwestern Medicine Comprehensive Epilepsy Center, including neuromodulation and laser ablation.
Advancing Surgical Management of Epilepsy
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Learn more about Stephan U Schuele, MD, MPH
Stephan Schuele, MD, MPH
Stephan U Schuele, MD, MPH is Chief of Epilepsy and Clinical Neurophysiology in the Department of Neurology and Professor of Neurology (Epilepsy/Clinical Neurophysiology) and Physical Medicine and Rehabilitation.Learn more about Stephan U Schuele, MD, MPH
Transcription:
Advancing Surgical Management of Epilepsy
Andrew Wilner, MD (Host): This is Better Edge, a Northwestern Medicine podcast for physicians. I'm your host, Dr. Andrew Wilner, Associate Professor of Neurology at the University of Tennessee Health Science Center and Division Director of Neurology at Regional One Health in Memphis, Tennessee.
Today, we are discussing epilepsy surgery with Dr. Stephan Schuele, Chief of Epilepsy and Neurophysiology in the Department of Neurology and Professor of Physical Medicine and Rehabilitation at Northwestern Medicine. Welcome, Dr. Schuele.
Dr. Stephan Schuele: Thanks for having me.
Andrew Wilner, MD (Host): Dr. Schuele, we're going to talk about your epilepsy work today and, well, of course, we're both epileptologists, but you are very involved with the surgical end. And I know most people respond to medication treatment, but when should we start thinking about doing epilepsy surgery?
Dr. Stephan Schuele: That's an excellent question. I choose my field because about two-thirds of patients actually are controlled with medication and that makes it very rewarding. But there's one-third of patients who really don't respond to medications. And I think those are the patients who at least should be referred to an epilepsy center and be diagnosed appropriately because, believe it or not, many patients actually may have the wrong medications for their type of epilepsy, or they may not have epilepsy to begin with. So that's, I think, the starting point.
The second point, what you're saying is that from the patients we realize have what we call focal epilepsy, so seizures coming from a focus in their brain, they're the ones who should consider surgery at some point. And I would say, if you fail two medications and you still have disabling seizures, meaning seizures where you lose awareness or even convulse and you're not able to drive or it really impacts your life and your safety and that has been going on for over a year, those are the patients I start the discussion about epilepsy
Andrew Wilner, MD (Host): Okay. So let's say I'm a neurologist in the community and I have a patient like you described. They're taking their medications. We've tried two or three. They just don't work. I send them to you. How do you decide which part of the brain to take out?
Dr. Stephan Schuele: That can be challenging, but we fortunately have probably one of the best tests. We can do an MRI, a very, very fine cut MRI to the brain. Often, there's special sequences for our patients with seizures. And in many patients with focal epilepsy, we can actually find a small lesion which makes sense that's what causes their seizures. The other part we do is we listen to our patients. We listen to their symptoms, to their seizures, and that really tells us a lot about where the seizures likely come from. And then the third thing we do is we do EEGs or we do brain wave testing looking for abnormal brainwave activity over the skull. And if those three things match, description of the patient's seizures and the lesion on the MRI and the abnormality on the brainwave testing, all kinds of point to the same spot, then that's already a good way into the pre-surgical evaluation.
Then, we obviously have to ask ourselves, is that an area we maybe can remove and don't harm the patient in any way? So we do what we call functional mapping or we explore the patient's function. And that is often done by sending the patient to a neuropsychologist to make sure that they get memory testing and other testing to see if the area we are trying to take out is highly eloquent, so we shouldn't touch it, or if it's an area that you can take out without doing any harm and actually stop the seizures.
Andrew Wilner, MD (Host): Okay. Well, that's great. And that works most of the time, but there are some patients where that initial workup is just not reassuring or conclusive enough, but still that patient needs surgery. What do you do then?
Dr. Stephan Schuele: Yeah. That's the more challenging part. And I recently bought the textbook about that. It's called A Practical Approach to Stereo Encephalopathy and that describes how we then may use targeted depth electrode s exploring directly the brain to see if we can identify the focus. That is necessary in about a third of patients who end up actually being good surgical candidates that there is no lesion on MRI and maybe the EEG from recording through the skull is not that revealing, that we have to kind of go a step further and actually try to pinpoint where the seizures come from by doing these invasive recordings with depth electrodes. But that can be done very safely nowadays. And fortunately with modern technology, robotic surgery, we can avoid the blood vessels and target these electrodes directly where we want them to be and patients tolerate that really well. In the old days of when we did these invasive recordings, so we actually put electrodes by doing a burr hole in the brain, that was much less well tolerated. But nowadays, these patients do really well. They come to our monitoring unit within a day after the surgery, we record their seizures and that often really lets us pinpoint exactly where the seizures come from.
Andrew Wilner, MD (Host): You recently published a study in JAMA Neurology where are you came up with kind of a formula when you should use this stereo electroencephalography. Could you tell us about that?
Dr. Stephan Schuele: Yeah, that's a very nice collaboration actually with a friend of mine from Montreal neurological. Institute and other people in the United States. We kind of validated a score which really allows us to do individual counseling for each patient when they come, because, as you said, the patients wants to know, "If I do this, what's the chances that you're going to find what you're looking for?" And I say, "Well, we have a 5-SENSE score. We can plug in what we already know about you. And we can come up with a number telling you what in your case is the likelihood that we're going to find a really discrete, focal onset and be able to pinpoint where the seizures come from."
And 5-SENSE score is rather intuitive. It takes into account things like, do you have a lesion on MRI? Do you have to test the surface? EEG shows that the seizures are very focal. Are your symptoms very focal? Do you describe something which feels like very specific coming from one particular area of the brain? Does psychological testing show that you have one discreet dysfunctional area in the brain, which doesn't work properly? And if you put all these factors together, you can come up with a score, which tells you that if you do the stereo, you have an 80%, 90% chance that we're going to find a very discrete and focal area where your seizures start from.
Andrew Wilner, MD (Host): Right. Because you don't want to be putting electrodes in the patient's brain if when all is said and done, you say, "Well, we can't operate," and that does happen of course, disappointing for everyone. So it would be nice to tell patients ahead of time, "Well, we could do this, but low likelihood of success or high likelihood of success," just by looking at information you already have. Is that right?
Dr. Stephan Schuele: Absolutely right. You don't want to do brain surgery, just to tell the patient that you can't do surgery. That's the last you want to do. You want to make sure that you have a really fair shot in pinpointing where the seizures come from.
Andrew Wilner, MD (Host): Now, there are some patients where the surgery just isn't going to work for them. Maybe they have epileptic foci in two or three areas of the brain. And so you can't really be removing all of that or you just can't find the focus. What about neuromodulation therapies? Is that where they come in?
Dr. Stephan Schuele: Yeah. And that is really the kind of the buzzword right now, neuromodulation. There has been some recent advances in different ways to modulate the brain in a way to stop the seizures, to reduce the burden. There unfortunately and probably will never be a curative procedure, which really completely get rid of the seizures. But with modern technology and understanding seizure networks better, we are More. And more able to target areas of the brain where we can modulate the seizures in the degree that the frequency gets significantly reduced to like less than 20%, 30% than what they were before and that also the severity kind of goes down.
And we have two types of stimulations where the classical maybe least invasive type of simulation, is that we place the stimulator for the vagus nerve which is actually placed in the chest and stimulates the vagus nerve in the neck. And that can modulate the brain from outside periodic stimulation. And that has been shown in many studies that it can be quite successful in reducing seizure burden. But we are even more sophisticated by being able to, when we do these invasive evaluations with stereo EEG, electrodes or depth electrodes, as you said, we may end up exactly knowing where seizures come from, but they come from an area we cannot remove, or it's two or three areas, which we identified. And for those patients, we have now the ability to put in a smart computer and battery, and leave these electrodes or put electrodes right in the seizure onset targets, and then the computer detects when the seizure is about to happen and can de-synchronize or I sometimes say defibrillate, like with the heart, can defibrillate the seizures and make sure that they don't evolve and spread and cause symptoms. So that's the second way of doing this.
And it's very exciting, we've been able to identify deeper targets in the brain, which when we stimulate them either again in a periodic fashion or in response to a seizure, can modulate the rest of the brain in a way that they interrupt the network and can reduce the seizure frequency and the seizure severity.
Andrew Wilner, MD (Host): Well, it's great to know that patients with uncontrolled seizures have so many options. Well to wrap up, are you involved in anything new? Anything we should look forward to, clinical trials or something new for people with epilepsy at Northwestern?
Dr. Stephan Schuele: So maybe two things to mention. One is that we are one of the centers who do laser ablation. That is a very attractive method to actually remove the seizure onset if it's small enough or shaped enough that we can do that. Combined with what I call a minimal invasive evaluation, like stereo EEG, where you do very fine little burr holes, is a very noninvasive way of actually removing the spot, which causes the seizures. So patients really literally, after laser ablation, they sit in my office a week or two later and you can't really tell that they had any brain surgery. There's no scar. There's been the single stitch to kind of close the whole. So these patients look great. And obviously, these kind of more minimally invasive procedures are much better tolerated and accepted by the patients. And so that's obviously for many patients now, one of the ultimate goals, "Am I a candidate for one of these modern laser ablation?" So that's, I think, we're involved and we do quite a number of them and exploring more and more different types of causes of epilepsy if we can help them with laser ablation.
We are obviously also involved in clinical trials. We have an adult genetic clinic, which identifies the genetic causes for some of the epilepsies. And that opens often the door that, instead of just randomly picking one medication, we are able to predict or precisely choose the medication which may work for this particular epilepsy because of this particular gene abnormality better than other medications. So that is super exciting. And then we are also involved in clinical trials, there's a rising interest in patients who have uncontrolled seizures to at least have rescue medications, which they can take instantaneously and maybe abort a bigger seizure, or make sure that they don't go into a cluster of seizures. So we are involved in those clinical trials as well.
Yeah, so there's a lot of excitement going on in the area of epilepsy and a lot of new methods of surgically and also medically treating patients better and preventing them from getting harmed.
Andrew Wilner, MD (Host): Dr. Schuele, I want to thank you for this very informative discussion and for joining me on Better Edge.
Dr. Stephan Schuele: Thank you for having me. It was a pleasure to talk to you, and I'm glad to have such a knowledgeable interview partner.
Andrew Wilner, MD (Host): Well, thank you. To refer your patient or for more information, head on over to our website at breakthroughsforphysicians.nm.org/neuro to get connected with one of our providers. And that wraps up this episode of Better Edge, a Northwestern Medicine podcast for physicians. I'm your host, Dr. Andrew Wilner. Thank you for listening.
Advancing Surgical Management of Epilepsy
Andrew Wilner, MD (Host): This is Better Edge, a Northwestern Medicine podcast for physicians. I'm your host, Dr. Andrew Wilner, Associate Professor of Neurology at the University of Tennessee Health Science Center and Division Director of Neurology at Regional One Health in Memphis, Tennessee.
Today, we are discussing epilepsy surgery with Dr. Stephan Schuele, Chief of Epilepsy and Neurophysiology in the Department of Neurology and Professor of Physical Medicine and Rehabilitation at Northwestern Medicine. Welcome, Dr. Schuele.
Dr. Stephan Schuele: Thanks for having me.
Andrew Wilner, MD (Host): Dr. Schuele, we're going to talk about your epilepsy work today and, well, of course, we're both epileptologists, but you are very involved with the surgical end. And I know most people respond to medication treatment, but when should we start thinking about doing epilepsy surgery?
Dr. Stephan Schuele: That's an excellent question. I choose my field because about two-thirds of patients actually are controlled with medication and that makes it very rewarding. But there's one-third of patients who really don't respond to medications. And I think those are the patients who at least should be referred to an epilepsy center and be diagnosed appropriately because, believe it or not, many patients actually may have the wrong medications for their type of epilepsy, or they may not have epilepsy to begin with. So that's, I think, the starting point.
The second point, what you're saying is that from the patients we realize have what we call focal epilepsy, so seizures coming from a focus in their brain, they're the ones who should consider surgery at some point. And I would say, if you fail two medications and you still have disabling seizures, meaning seizures where you lose awareness or even convulse and you're not able to drive or it really impacts your life and your safety and that has been going on for over a year, those are the patients I start the discussion about epilepsy
Andrew Wilner, MD (Host): Okay. So let's say I'm a neurologist in the community and I have a patient like you described. They're taking their medications. We've tried two or three. They just don't work. I send them to you. How do you decide which part of the brain to take out?
Dr. Stephan Schuele: That can be challenging, but we fortunately have probably one of the best tests. We can do an MRI, a very, very fine cut MRI to the brain. Often, there's special sequences for our patients with seizures. And in many patients with focal epilepsy, we can actually find a small lesion which makes sense that's what causes their seizures. The other part we do is we listen to our patients. We listen to their symptoms, to their seizures, and that really tells us a lot about where the seizures likely come from. And then the third thing we do is we do EEGs or we do brain wave testing looking for abnormal brainwave activity over the skull. And if those three things match, description of the patient's seizures and the lesion on the MRI and the abnormality on the brainwave testing, all kinds of point to the same spot, then that's already a good way into the pre-surgical evaluation.
Then, we obviously have to ask ourselves, is that an area we maybe can remove and don't harm the patient in any way? So we do what we call functional mapping or we explore the patient's function. And that is often done by sending the patient to a neuropsychologist to make sure that they get memory testing and other testing to see if the area we are trying to take out is highly eloquent, so we shouldn't touch it, or if it's an area that you can take out without doing any harm and actually stop the seizures.
Andrew Wilner, MD (Host): Okay. Well, that's great. And that works most of the time, but there are some patients where that initial workup is just not reassuring or conclusive enough, but still that patient needs surgery. What do you do then?
Dr. Stephan Schuele: Yeah. That's the more challenging part. And I recently bought the textbook about that. It's called A Practical Approach to Stereo Encephalopathy and that describes how we then may use targeted depth electrode s exploring directly the brain to see if we can identify the focus. That is necessary in about a third of patients who end up actually being good surgical candidates that there is no lesion on MRI and maybe the EEG from recording through the skull is not that revealing, that we have to kind of go a step further and actually try to pinpoint where the seizures come from by doing these invasive recordings with depth electrodes. But that can be done very safely nowadays. And fortunately with modern technology, robotic surgery, we can avoid the blood vessels and target these electrodes directly where we want them to be and patients tolerate that really well. In the old days of when we did these invasive recordings, so we actually put electrodes by doing a burr hole in the brain, that was much less well tolerated. But nowadays, these patients do really well. They come to our monitoring unit within a day after the surgery, we record their seizures and that often really lets us pinpoint exactly where the seizures come from.
Andrew Wilner, MD (Host): You recently published a study in JAMA Neurology where are you came up with kind of a formula when you should use this stereo electroencephalography. Could you tell us about that?
Dr. Stephan Schuele: Yeah, that's a very nice collaboration actually with a friend of mine from Montreal neurological. Institute and other people in the United States. We kind of validated a score which really allows us to do individual counseling for each patient when they come, because, as you said, the patients wants to know, "If I do this, what's the chances that you're going to find what you're looking for?" And I say, "Well, we have a 5-SENSE score. We can plug in what we already know about you. And we can come up with a number telling you what in your case is the likelihood that we're going to find a really discrete, focal onset and be able to pinpoint where the seizures come from."
And 5-SENSE score is rather intuitive. It takes into account things like, do you have a lesion on MRI? Do you have to test the surface? EEG shows that the seizures are very focal. Are your symptoms very focal? Do you describe something which feels like very specific coming from one particular area of the brain? Does psychological testing show that you have one discreet dysfunctional area in the brain, which doesn't work properly? And if you put all these factors together, you can come up with a score, which tells you that if you do the stereo, you have an 80%, 90% chance that we're going to find a very discrete and focal area where your seizures start from.
Andrew Wilner, MD (Host): Right. Because you don't want to be putting electrodes in the patient's brain if when all is said and done, you say, "Well, we can't operate," and that does happen of course, disappointing for everyone. So it would be nice to tell patients ahead of time, "Well, we could do this, but low likelihood of success or high likelihood of success," just by looking at information you already have. Is that right?
Dr. Stephan Schuele: Absolutely right. You don't want to do brain surgery, just to tell the patient that you can't do surgery. That's the last you want to do. You want to make sure that you have a really fair shot in pinpointing where the seizures come from.
Andrew Wilner, MD (Host): Now, there are some patients where the surgery just isn't going to work for them. Maybe they have epileptic foci in two or three areas of the brain. And so you can't really be removing all of that or you just can't find the focus. What about neuromodulation therapies? Is that where they come in?
Dr. Stephan Schuele: Yeah. And that is really the kind of the buzzword right now, neuromodulation. There has been some recent advances in different ways to modulate the brain in a way to stop the seizures, to reduce the burden. There unfortunately and probably will never be a curative procedure, which really completely get rid of the seizures. But with modern technology and understanding seizure networks better, we are More. And more able to target areas of the brain where we can modulate the seizures in the degree that the frequency gets significantly reduced to like less than 20%, 30% than what they were before and that also the severity kind of goes down.
And we have two types of stimulations where the classical maybe least invasive type of simulation, is that we place the stimulator for the vagus nerve which is actually placed in the chest and stimulates the vagus nerve in the neck. And that can modulate the brain from outside periodic stimulation. And that has been shown in many studies that it can be quite successful in reducing seizure burden. But we are even more sophisticated by being able to, when we do these invasive evaluations with stereo EEG, electrodes or depth electrodes, as you said, we may end up exactly knowing where seizures come from, but they come from an area we cannot remove, or it's two or three areas, which we identified. And for those patients, we have now the ability to put in a smart computer and battery, and leave these electrodes or put electrodes right in the seizure onset targets, and then the computer detects when the seizure is about to happen and can de-synchronize or I sometimes say defibrillate, like with the heart, can defibrillate the seizures and make sure that they don't evolve and spread and cause symptoms. So that's the second way of doing this.
And it's very exciting, we've been able to identify deeper targets in the brain, which when we stimulate them either again in a periodic fashion or in response to a seizure, can modulate the rest of the brain in a way that they interrupt the network and can reduce the seizure frequency and the seizure severity.
Andrew Wilner, MD (Host): Well, it's great to know that patients with uncontrolled seizures have so many options. Well to wrap up, are you involved in anything new? Anything we should look forward to, clinical trials or something new for people with epilepsy at Northwestern?
Dr. Stephan Schuele: So maybe two things to mention. One is that we are one of the centers who do laser ablation. That is a very attractive method to actually remove the seizure onset if it's small enough or shaped enough that we can do that. Combined with what I call a minimal invasive evaluation, like stereo EEG, where you do very fine little burr holes, is a very noninvasive way of actually removing the spot, which causes the seizures. So patients really literally, after laser ablation, they sit in my office a week or two later and you can't really tell that they had any brain surgery. There's no scar. There's been the single stitch to kind of close the whole. So these patients look great. And obviously, these kind of more minimally invasive procedures are much better tolerated and accepted by the patients. And so that's obviously for many patients now, one of the ultimate goals, "Am I a candidate for one of these modern laser ablation?" So that's, I think, we're involved and we do quite a number of them and exploring more and more different types of causes of epilepsy if we can help them with laser ablation.
We are obviously also involved in clinical trials. We have an adult genetic clinic, which identifies the genetic causes for some of the epilepsies. And that opens often the door that, instead of just randomly picking one medication, we are able to predict or precisely choose the medication which may work for this particular epilepsy because of this particular gene abnormality better than other medications. So that is super exciting. And then we are also involved in clinical trials, there's a rising interest in patients who have uncontrolled seizures to at least have rescue medications, which they can take instantaneously and maybe abort a bigger seizure, or make sure that they don't go into a cluster of seizures. So we are involved in those clinical trials as well.
Yeah, so there's a lot of excitement going on in the area of epilepsy and a lot of new methods of surgically and also medically treating patients better and preventing them from getting harmed.
Andrew Wilner, MD (Host): Dr. Schuele, I want to thank you for this very informative discussion and for joining me on Better Edge.
Dr. Stephan Schuele: Thank you for having me. It was a pleasure to talk to you, and I'm glad to have such a knowledgeable interview partner.
Andrew Wilner, MD (Host): Well, thank you. To refer your patient or for more information, head on over to our website at breakthroughsforphysicians.nm.org/neuro to get connected with one of our providers. And that wraps up this episode of Better Edge, a Northwestern Medicine podcast for physicians. I'm your host, Dr. Andrew Wilner. Thank you for listening.