We want you to present the case and tell us how you would deal with it and what questions you have. And then case by case, we'll ask people from the panel if they had any comments, and if not, we'd love to get comments from the audience, because many of you here have mapping experience. So please feel free to raise your hand and tell us how you would deal with it. First of all, I will show you three cases, and the first is a 39-year-old woman, professor of linguistics. It's very important. It's not hazardous. I do not believe in hazardous. With no previous medical history, her first partial seizure with speech arrest, and no more clinical examination. And you will see the MRI at very good quality, because many years ago. But you can see nonetheless, imagine very typical for a diffuse Le Gray Lama involving the canonical Broca's area. And the question is, what are you doing? The patient is well, and she had just one seizure. So maybe in order to help people who would like to do nothing, wait and see. So who would just watch this patient who is intact? Yeah. Except for one seizure. Who would watch? Okay. They don't dare. No. Nobody. Okay. Who would like to do a biopsy? Just a biopsy? In order to discuss from chemotherapy, radiotherapy? Okay, no biopsies. Strange is not really what happens in the real life. Well, but you have a selection bias. The people who are here, I think, are going to be more aggressive with these cases, which is good. Now the question is, how would you do it? Surgery under general anesthesia? Would anybody do that? No. Surgery under local anesthesia? Okay, awake? Yes, question while we're waiting. Okay. So I have a question for both of you. When you talk to this patient, do you offer them all three options of waiting, possibly biopsying it, or is it, you know, I really think you should have awake surgery, and if you don't believe me, here's somebody else that will tell you the same thing. Okay, well, I can tell you in my world, I don't try to talk anybody into anything, and I give them every option. I say, here's your option. You can do nothing, and we can watch it grow together, because in 100% cases, it's going to grow. You could, if you don't want surgery, you could have a biopsy, and then we could decide what to do based on the molecular markers. Or we could do a procedure, but if I'm going to do it, it has to be awake in this case. And then they always ask the inevitable question, what would you do if this were your loved one? Well, I say, I don't treat you any different than my family, so of course I would do it awake. So, do you give them the options, or do you just say, this is the way we're going to do it? I spent approximately two hours to the patient to explain everything. What we know, what we don't know about the natural history of the disease. What we can do, what we can propose in another department, and what I would propose. And at the end, the patient will select by himself, the patient with the family. Strangely, after my talk, in 99% of cases, the patient said, I would like to be operated on. I think the problem we have is that a lot of patients, you know, will see, many of us will see, they've been told this is not operable, they've been told they can't take it out. I'm about ready to submit a paper to the General Neurosurgery with every case I've ever gotten, from patients that I've operated on, who have been told it's, they came to me and said, this is not operable. So we start with that conversation, to show what you can do with the mapping technique. What about in China? Do you give people an option, or do you just say, we're going to do it this way? In China, I think the surgeon will offer the craniotomy to this incidental lung reclaimer. So I think my patient will obey my suggestion. Okay, well, this is, no, wait, wait a minute. This is not incidental. This is not incidental. It's a seizure. So we can talk about incidental. I hope we have an incidental case, Rich. But, okay. So you go, carry on. What is interesting is to see that the patient has been operated on in another institution, under general anesthesia. This is the reason why I like to show this case, because unfortunately, I have the habit to see this kind of case very frequently, too frequently. And of course, what happened, you can see by yourself. And the guy is a very good neurosurgeon, very honest, but he removed 20% of the tumor. So with no impact on the natural history of the disease. So tumor board, it was a low-grade glioma, oligodendroglioma, and they proposed to do chemotherapy on the residue, and oral radiotherapy, because it was 10 years ago. And the patient refused. She said, I don't understand, because they did not really explain the natural history of the disease. They say that it was possible to remove the tumor. And now, why propose chemotherapy? And the patient was not able to work, and she had, again, seizures. Then finally, I met the patient in these conditions. What are you doing now? You have the patient in front of you, and she was operated on three months before. She has seizures, she's not able to work anymore, and she doesn't understand. What do you do? So intractable seizures now? Yeah. Yeah. Two anti-epileptic drugs. Where's Guy? Okay. And you and Johannes. So now we've got a problem. We've got intractable epilepsy plus a low-grade glioma. I think when I talk to patients like this, I tell them that they have two separate problems, and whether or not their tumor's progressed, that their best chance of stopping their seizures is going to be to be able to remove the tumor. And so if it's not a medial temporal tumor, this one, you know, gross total tumor resection here, if you can get it, is likely to stop the epilepsy. Anything else you do is likely to not stop the epilepsy, and the seizures are what's going to keep the patient from quality of life. And also, as you know, there's some speculative evidence that seizures possibly might promote glioma growth, and if that actually turns out to be true, there's an even stronger impetus to stop the seizures. Well, you see, this patient was disappointed with her first surgeon, and I think it is not unfair to tell to the patient that there are various kinds of surgeons. Some are more hesitant, others are more courageous, and there are different levels of experience. So I would slightly pinpoint that she's now talking to somebody who has special experience with mapping and so on and so on, and maybe she can follow that, and, you know, this is a slight indication to maybe take the courage and go for a second type of surgery. Because the seizure thing is a big argument, because if you have untreatable seizures, you are at a higher risk of having severe accidents, your life expectancy is shortened just because people don't talk about it a lot because it's unpopular and it's bad news, especially if you do not manage to get rid of the seizures. The patient has all the bad news, but it can't be helped. But it's an argument. It's an argument for surgery. And by the way, we all know we can take out more than they did. We do know that. Let me just ask a question. Would we all agree that if you have a patient who has one seizure or two seizures, but basically is under control, that even you two would not do a corticography-based seizure operation? You would just agree to take the tumor out and that should fix the seizure issue. Is that correct? Yeah. Okay. Now, for glioma. Now, what happens if the patient's intractable? So let's say they come and the neurologist says, I can't do anything more. They're on three medications. They got a low-grade glioma and they're intractable. How many of the panelists would do a corticography-guided resection? So anybody in the audience? How many people would do a corticography-based resection in a patient with a low-grade who has intractable seizures? I see George's hand is up, but only a few people. How many would just take the tumor out and assume that's going to fix the seizures? So what's the right answer? You want to comment on that, Hugh? First of all, I would like to know if you ask for another examination. Of course, the discussion is if we should perform second surgery, in fact, the first surgery by trying to remove more. But before that, do you ask for another examination? You mean a scan? Another scan? What you want. Sure. What kind of examination you ask for? Do you mean an examination, an MRI scan or anything? Or do you want something else before surgery in order to help you to make a decision and to answer the patient who does not understand what happens? Okay. Yeah. I think what we would first ask the question, what do we want to know? We want to know where is the language area, because it was on the left hemisphere. And second, where is the ectogenic zone, because she's drug-resistant now. There will be somewhere close to the tumor, but where exactly? I need an investigation. I would put a grid and find out, and I can find out both where is the language area and the ectogenic zone using a big grid. Okay. Somebody had a comment over here. Yeah. So what other investigations would you do, if any? Probably I will do a functional MRI in order to see if brain plasticity made any change produced by the previous surgery. Any other comments? No. Okay. Let's see. We are just beginning with that, but with two anti-epileptic drugs, we are talking about an intratable epilepsy in terms of epilepsy surgery. So maybe I can investigate a little bit more about the type of seizures that she has and be sure that they are coming from nearby the tumor, or that the semiology of the seizure just adapts to that type of lesion. Just to think ahead to do the operation, not only for the tumor, but also for the seizures. Okay. So what did you speak? Maybe. You will. We are all surgeons sitting here, so nobody is going to dare say to not operate on the patient. So I'll do it. What's the molecular status of the 1p19q? I think it was co-deleted. Well, it makes a huge difference, because in co-deleted 1p19q, there's never been any study or even evidence looking at those patients treated with chemotherapy compared to resection. So in this particular patient, where you have a tumor that's not well delineated, it's somewhat diffused, and is 1p19q co-deleted, treatment with chemotherapy, plus-minus radiotherapy is a very valid option that can be proposed to the patient. Just because we have the tools to do elaborate mapping and resection of the tumor does not mean that this is the right answer or the right solution for this particular patient. Okay, Hugh, what did you do? I tried to understand what happened to the patient, because before seizures, she was not able to work anymore. So I asked, not fMRI, into our SEG, electrocorticography, 1p19q, I asked for a neuropsychological examination. Just think about the patient herself and her brain, and what happened? Disorders of verbal working memory, deficit of attention, but no language deficit. You have the answer now. You know why she's not able to work anymore. And you know that the plasticity allowed a compensation of language function. Everything became clear. Neuropsychological examination in order to better understand the brain of the patient in front of you, quality of life. No one said that. Of course, after that, you can do functional MRI, and you can say just because it's beautiful that you have the left Broca's area in the right and left Wernicke still in the left. Okay, so it's beautiful just to write paper and to show that brain plasticity exists. But it was not problem. The problem was verbal working memory. She's professor of university in linguistics, I say that. Now everything is clear. We can propose surgery definitely to the patient because we know that we have all chances to not induce any permanent deficit regarding language, and maybe to improve her, thanks to a post-operative rehabilitation regarding verbal working memory, you can plan before the second surgery. And it's exactly what we did. And we removed the so-called Broca's area because it does not exist under local anesthesia according to the functional boundaries with nothing except just the cortical mapping. And you can see the ventral premodal cortex, the lateral part of the precentral gyrus. And of course now you have understood the inferior frontoccipital fascicle with the semantic paraphagia induced at this level and the anterior part of the SLF3. Everything is just an evidence. And this is the reason why this patient had verbal working memory deficit because here the frontoparietal loop was just partly involved, as you have seen on the preoperative MRI, of course. Normally you should see the SLF3. I will show you again now. Here. You don't need DTI in order to see the SLF. So everything is clear. Now you can operate the patient and she understands. So she tells you, of course, I will do because you explained to me what happened. Okay. I just want to make sure everybody hears this. You would or you would not recommend removing Broca's area asleep? No. Never. Okay. But I do not recommend to operate the brain to remove the brain asleep. Never. But the point is many of you are hearing for the first time that you can remove Broca's area. But please understand you have to do that under awake conditions. Yes. And especially to find the pathways in the depth. Because I have shown you on the preoperative MRI that you cannot completely remove the tumor. Normally you should leave a small part in the SLF3, you have seen. And of course you will see the postoperative MRI. There is a residue, T1 and T2, at this level as expected. Just at the level of the superior longitudinal fasciculum. Everything is clear. Okay. Next case. Yes. There's a question back here. Why don't you load your next case? It's not finished. It's not finished. Specific functional rehabilitation. Okay. All right. Go ahead. Hold on. We got a question. Thank you. I can't speak to the neurosurgical side of this. I'm not a neurosurgeon. But I do want to add just another little tidbit of information. In all the work we've done in all the years with the fascic patients after stroke, lesions to Broca's area alone do not result in a persisting aphasia or speech problem. So to Broca's area alone, so I'm not speaking about fiber pathways underneath, I'm not talking about the insula, I'm not talking about area 47, for example. But to Broca's area alone, we don't see persisting speech or language deficits. I think there is evidence, as you pointed out in this case, that there can be a shift of some of the speech functions to the other hemisphere. And I would say for this particular piece of cortex, we find that to be true as well. Not so much with other speech or language functions, but certainly for those that have been ascribed to Broca's area. I'm not telling you what to do, one way or the other. I'm just saying. But this comes from the person who did the MRI scan on Broca's original brain, Laborgne. I don't know how you pronounce it. You took the brain, you did an MRI scan, and you showed that the reason that that was a deficit was because there was subcortical injury. Right. Thank you very much for telling that in a meeting of neurosurgeons. Thanks a lot. Please come with us in all meetings of neurosurgeons by telling exactly the same thing. Deliver the same message. Go ahead, because we've got to go through cases. Yes, but I'm sure you would like to see the flap. This is the most important. We have now, in fact, 10 years of improvement of the neuropsychological assessment. This is the point. How do you want to improve the neuropsychological assessment if you have no baseline? And the baseline was not known in the previous institution. I cannot understand that we are not objective. And we will say my patients are one. No, you don't know. No seizure anymore because we removed the tumor according to functional boundaries, of course. Only one anti-epileptic drug. We can discuss about that, but when a patient had many seizures and is afraid about that, it's difficult more and more for me to say, please stop. I mean, they decide by themselves. And most of them are afraid to experience again seizures, especially when the resection is not complete. For me, it's not really a chess. If a patient decides to continue to take one anti-epileptic drug, but it's really an emotional process and the patient decides by herself. Full working. This is the most important. This patient should continue to give her talks in a university in both languages. And finally, neurobiotic chemotherapy because I'm not worried. I'm sure that one day this patient will benefit from this treatment. But I would like to postpone then because I was sure that surgery could improve the functional, the epileptological, and the oncological issues. And it's exactly what happened. Nonetheless, I will continue next week probably to see my consultation patient operated on for the first time under general anesthesia with partial resection. And by the way, we will do chemo or rhiotherapy. Why? This is my message. Why? So, you know, just so you understand this, your oncologists are going to come to you because there was a recent study done. It was discussed at ASCO in 2014. Now it's been published and I think it was in the New England Journal recently. But that study now shows for this patient, they would get radiation chemotherapy. I'm just warning you that that's what you're going to start hearing from your oncologist. There's a paradigm shift based upon this study that was done in the United States showing that if, regardless of age, if you have residual disease, or if you're over 40 and you have no residual disease, those are two high-risk categories that had a double survival time if they got radiation chemotherapy up front. I'm just warning you that you're going to start hearing this from your oncologist and you're going to now have to fight for your patient. If you've done a good resection, you could say if their markers are good, they're not IDH wild-type, you can sit tight. But it's going to be a fight for us from now on because things are going to shift back from the wait-and-see to treat. And this means that an oncologist understood nothing about brain plasticity because when you leave a residue, sometimes you cannot reoperate, especially when you have an invasion of the connectivity, sometimes you can reoperate. And you know that, but they will not make the difference because they are seeing the tumor, not the brain, not the patient. 20-year, 28-year-old, in fact, woman, sorry, actress. No previous medical history, incidental discovery, of course, normal clinical examination, and to be honest, normal psychological examination. What are you doing? Okay, George, in England where things tend to be very conservative, this is an incidentally discovered low-grade glioma. Well, we are quite conservative. When I say we, I mean a group of oncologists and surgeons for low-grade gliomas, but there is now recently a paradigm shift and people tend to be a bit more aggressive. So what I would do in this case, this is a unique window of opportunity to provide cure to this patient. You can excise the tumor completely and a good healthy margin around it and literally cure the patient. So I don't think conservative follow-up will be the answer because you do know that this glioma will eventually grow and eventually will transform. So this is our window of opportunity to cure the patient and I will just act now. Okay, Monday morning at this meeting we have a session on incidentally discovered lesions, if anybody's interested. Anybody else on the panel? Would anybody wait and see? Steve? I think there's no question that you need to give this patient a chance by doing a very radical resection. I just had an identical case who received a right frontal lobectomy, very wide, super marginal resection. It was an IDH-wide type, astrocytoma, and this patient came back a year later with local recurrence surrounding the resection cavity and re-operated on this patient and now several months later he has progressive disease. So the molecular nature of this tumor is critical for making the decisions on how to treat those patients and if you do radical resection, the tumor recurs with an IDH-wide type phenotype, you will need additional chemotherapy, radiotherapy. It's not the topic, but we will submit paper with all my patients are operated on with IDH-wide type and 25% are still alive more than seven years after the first surgery. So it means that once again, I'm sorry it's not the topic, but I do not believe on molecular biology at the individual level. Okay, we're not going to get into this because the WHO is about to release its new category and I'm going to tell you that IDH-wide type is now a separate category because all of my IDH-wide type patients do horribly. They all recur within a year. We will demonstrate that. And I don't think extended resection affects that. Any comments from the audience? Incidental lesions. So what, everybody going to take this out? I just have a question about using the term cure with the patients and their families. How many people here would tell their patient they're cured with a supratotal resection or a gross total resection? We cannot say we can cure, but I published recently a paper with more than 10 years of follow-up selection of patients with supratotal removal and the rate of death is zero and the rate of anaplastic transformation is zero. But I'm very happy to listen for the first time in my life, maybe people from UK proposing supratotal removal in incidental discovery. So it's really a dream today with Nina Trunkers too, telling that Broca's era can be removed. It's strange. I'm dreaming. So my question about this, this is a fairly easy decision making. It's a non-dominant fernal. What if this incidental lesion was dominant insular in a bilingual patient? Which is exactly what I have. Okay. Where's Toshi? What if this was on the left side in Japan? Does it matter? If you ask, isn't the low-grade glioma like this? Left side. Left side. Bilingual. Bilingual. I think this is expressed by the word never-ending struggle. So timing is very difficult to decide when we operate her or him. But I will operate if the timing is very difficult, but MRI disclose any change, I will operate. This is a different opinion though. This is saying wait till there's a change. I wouldn't wait till there's a change, but that's an opinion. I think just to play devil's advocate, this patient's a 28-year-old actor in New York who walks into your office and newly diagnosed incidental lesion, nobody knows how long it's going to take to change or not change. It's already molecularly what it is, IDH mutated or not. So what's going on in his life? Did he just get his first job where he actually has an acting gig for the first time in five years? And if he doesn't do that now, he's going to lose his job. I would say to this, I'd find out what's going on, I'd say, look, it's coming out. So you just got to decide, are you ready to have it out now or are you not? But at some point, this is coming out of your brain and when are you ready for that? I thought there's this Norwegian study that shows that people who get biopsy, it's prospective kind of population control, people who have just a biopsy for non-enhancing lesion do worse than people who have up-front resection. That would be as close as possible to good quality evidence. I don't think he's saying biopsy and watch, I think he's saying it's got to come out. But you're right, that's a different issue, that's about extent of resection and outcome. No question that the biopsy group did worse and had a higher rate of malignant transformation in that study. Is there a comment over here? Yeah. Okay, great. So just full disclosure, I'm a neuropsychologist, not a neurosurgeon, but one is we haven't demonstrated that this is the non-dominant hemisphere, but obviously I'm sure you guys would do that. But the other thing, being an actor, right frontal lesion like this could affect porosity of speech and stuff. So I mean, if he's going to be an actor, doing a larger section might affect that. So this was the good reflection. I mean, the patient told me after two hours, I would like to be operated on. But I am an actress and what I would like is to continue to speak, of course, but also to be empathic in order to improvise and to be able to recognize the emotion of people in front of me, because this is my job, this is my patient. So. Okay. What did you do? A wake surgery, of course. Okay. In order to perform supra-total removal and in order to preserve the emotional process and also the nonverbal semantics. And what we did, you will see, I will not insist in the next talk, is a semantic task regarding the verbal and nonverbal processing, but also the mentalizing and I will not insist because Guillaume Herbet will explain to us this afternoon. But what I can show you is that you have, once again, the ventral premodular cortex here, but here you have a site involved in the mentalizing process. And here, the inferior frontoccipital fascicle involved in the right non-dominant hemisphere in semantic processing, as we will demonstrate this afternoon by administrating specific tasks in order to give her the possibility to avoid, of course, to be hemiplegic, aphasic, but also to continue to be empathic, because this high fourth is crucial for the semantic process. And the patient, we remove, as you have seen, the tumor completely, we took a margin around, and now we have follow-up and, of course, no recurrence with no chemo, no radiotherapy, and she enjoy a normal life with a normal neuropsychological scores, and she's happy. So how many people in the audience, knowing what they now know, would feel comfortable doing this asleep? I'm just saying that's, okay, so a fair number. And how many would prefer to do it awake just because of what you've said? So there are several. The question is not, are you comfortable? The question is, are you able to answer yes to the patient when she asks you, I want absolutely to preserve mentalizing, can you do that? This is not the same question. I answer to the question of the patient, the room answer to your question. It was not the same. Okay, well, that's why we're all here, is you can see what people would do. I would do it asleep. I wouldn't be, you know, I think here, and listen, I'm not arguing with you, I'm not contradicting him, but I have a little bit of a different philosophy, you know, and that is that, for me, the key thing is, I don't really care if the patient's an actor, because the first thing I say in clinic is I say, look, let's divide your life into two parts. One is living and life, and the other is, you know, what you do for a living, and I understand that's very important, but a lot of people can do pretty much everything, even with some very mild, subtle issues. So even when I do neuropsychological assessment, we just published a study in neurosurgery where I showed that there were some very mild cognitive issues with people, but they didn't impair their ability to function at work. But I can understand if the patient said, I don't want to take any risk. Do you think it was against the oncological consideration? You can see the postoperative flare. No, no, no, I understand. I understand what you're saying. But I could, I would feel comfortable doing a pretty aggressive resection and not having the patient awake. I'm just saying that's, okay. Last one or? You have one more? More technical. Last one. Rich, we have some. How do you measure? Guillaume Herbet will explain you this afternoon. He will explain you. There is a tool dedicated to that. Okay. So how many cases do we have from the audience, Rich? Okay. Can we come up? I think it'd be better here. Just let's, because I want people who submitted cases to do this, to please present the case and tell us why you submitted the case. What's the issue you're concerned about? I want to thank those from the audience who submitted some cases and we're going to ask you to participate in the presentation of your case and just discuss with us what particular concerns you had and what questions you have for the panel. Why don't we start with this one? Is Dr. Ghazony here? Where are you? Okay. Very good. Please tell us what the issue is and why you submitted this case and what your questions are. First of all, thank you for showing my case. Sorry about my English, but I'm from Brazil. And I submitted my case just, I think it's the most important one. I think it will be the Insular Gladiolus one. I think it's the... The Insular. Yeah. I would like to ask about this case because in this case we took out the... Okay. You want me to present? Okay. This is a 25-year-old male, right-handed, and he started with scissors, just scissors, and some kind of headache. He was complaining of headaches. And when we did the MRI, it showed this extensive tumor of the left frontal lobe tumor reaching the operculum, and we proposed to him an awake surgery. But he's a very simple guy. He's a, how to say, it's a working guy in construction like this. And we did the awake surgery, and what we found there is the speech arrest was in the motor area, in the motor operculum, not in the Broca's area. So, it was... I found this in four or five cases, all my cases, I found the Broca's area or the speech arrest area in the motor strip, not in the parisopercularis or paristriangularis. And in this case, we took it out, the parisopercularis and triangularis, and he stayed well. And while I was listening to the meetings, I would like to ask, what's most important? Is the speech arrest on the cortical area, or there's another pitfalls that I must look for during surgery? So, the issue is, what do you use to make the decision as to do the resection? So, if there's speech arrest in the motor cortex, are you able to remove that component if there's tumor there? Is that your question? Yeah. No, no, you would do all of the language mapping, any of the batteries you feel comfortable doing, including looking for speech or counting arrest. And so, if there's nothing overlying that area, then it's safe to remove it. Again, the critical issue, as Hugh showed you, is you have to be willing to map subcortically to make sure you're not going to get down into the SLF when you do that, right? So, would anybody have done this case asleep? No. But when I see speech arrest in this area that's in the face motor region, especially if it has any association with movements of the pharynx, I have no problem removing that. Just like I remove the non-dominant face motor cortex all the time, and they get a bad facial droop, and then it comes back. In this case, they can become mute, and then after several days, it gets better, and they start talking again. Any other comments? Yes. I'll repeat the question. So, how do you know you're at the SLF? Well, you certainly can't rely on DTI. You just simply can't, because you don't know if that's functional. DTI is not a functional imaging modality. So, you have to map the SLF. Yes, but definitely we know that it's not the motor area. It's the ventral premotor cortex, the lateral part of the precentral gyrus. We published in Brain Pasteur a probabilistic map based on 700 stimulation positive mapping we did, and once again, if you induce a speech arrest, it will not be within the inferior frontal gyrus, except in 5 to 10% of cases. So, we know that the ventral premotor cortex abutment area 6 and not 4 is connected to the supramarginal gyrus and the posterior part of T1, the so-called Wernicke's area, through the SLF3. I mean, we know that. It's just like this in 100% of cases. Okay, so what you did was right. You did the mapping. You went all the way back to speech arrest. If the speech arrest had been over the tumor, I would have taken it out. I wouldn't have had any problem with that at all. As you go lower, you can't see the SLF. This is not a Klinger's dissection. So, you have to stimulate with your paradigms and see if there's any interruption of speech. Okay, Rich? All right, we have the next case. Whose case is this? It's the same person. Okay, please. That's okay. So, just in a nutshell, what was the clinical issue? What's your question? Okay, this is a 35-year-old male, right-handed too, and he's an economist. So, he has a very good connective follow-up. And he had been previously operated nine years ago, and he had an atympathological oligoastrocytoma. He had a total resection in the first surgery, and he came to me with a recurrence of his seizures, and he did an MRI that showed that the tumor had come back. The first surgery, he stayed aphasic for one month, like a month, and then he took it well after this. Can you show the MRI? And there is a recurrence of the tumor, and I proposed an awake surgery for him because of the first surgery, he had some speech problems that resolved, but we did it awake, and the mapping was negative for any language issues. But after surgery, he did a neuropsychological examination, because he was complaining of difficulties to understand what he was reading. When he was watching movies, he was unable to understand the legends. He could read, but when he was watching movies, he was unable to understand the legends. The neuropsychological examination showed some nomination problems, and I really didn't find this on surgery. After this, it came oligodendroblioma with the coagulation, and the oncologist wants to do the radiotherapy and chemotherapy, but it's near from his left hippocampus, which was a good resection. I stopped the collateral circles near from the hippocampus, and just advised him not to do radiotherapy. So you didn't find any stimulation mapping, and post-operatively, what happened to the reading issue? Yeah, and how long did that last? So it's permanent? Okay, so it's permanent. So that would have been the IFOF? Here, it's not related to the eye form, it's related to the infralongitinal fascicum, the posterior part connecting the occipital cortex to the visual work form area. So it means that probably you perform the cortical mapping and you find nothing, but you cut the infralongitinal fascicum. And then this is the reason why the patient had alexia. I will show that in the next talk. So if you can predict that, it means that you will continue to do reading when you will continue to perform the resection into the contact of the fibers. Once again, the danger is not the cortex, the danger is the connectivity. So I had a case like this recently on a young woman who was a school teacher. And I did the mapping and I subcortically looked for that pathway, I couldn't find it. And post-operatively, she had problems reading. And she said, so this is going on like month, six weeks. And she sent me a note now saying, I'm back teaching, I read definitely slower than I ever did before, but I can still teach. So still working, but can teach, right. Okay, but definitely I caused a deficit, but it's not debilitating, so that's the key. Now, if you found stimulation-induced alexia, yes. Yes, I would stop. I didn't find it. So this brings up another issue. Let's get everybody's buy-in on this or understanding. You know, how often do you see lesions in the, let's say in the right-handed person, in the left hippocampus. And the patient comes in and says, well I was told if you remove this, I'm not gonna be able to remember anything. And I don't know if George is still here, but I remember I had a case where I sent him the picture and I said, what do you think about predicting memory deficits? Because I have to say, even with this neuropsych testing, if I see a focal lesion in the hippocampus and I resect that focal lesion, I have not seen permanent memory issues. So I don't think it's a contraindication to surgery. Do you want to comment on that, Sveen? I think, right, right, I mean if the patient presents with memory problems, then I think it's different. Yeah, if they don't present, I think it's quite safe. They probably have a lot of representation of memory. But if they have some symptoms, I would be very worried about it. So it's important to keep this in mind. If they come to you normally and they have a focal lesion, in my opinion, removing a focal lesion in the hippocampus on the left side and the right-handed person does not cause a memory deficit. Can we hear from Dr. Schramm on this, please? Yeah, okay. You've been in the hippocampus a few times. Yes, that's true. Well, actually, I have collected and published a series of 235 temporal mesobasal tumors. And half of them, approximately, were on the left side. And I've never seen a disastrous memory problem following the removal of a mesobasal tumor. If some of them come and have slight verbal recall problems, verbal memory problems, but not a major disaster just because of the surgery. The major problem was a few vascular problems going through the cervical fissure, the vascularity. And much more important in this group, in this tumor group, was visual field defects. But not the memory. So don't be worried about the dominant hippocampus if it's mostly a focal lesion. Did you do a WADA test on memory on that patient? I'm gonna walk back to George and Nina. What role does a WADA test have in defining whether you could operate on the hippocampus, whether there's an issue predicting memory? Quite some years ago, we actually did a study looking at the predictive value of the WADA test on predicting post-operative memory after a mesial temporal resection. Their WADA test memory measures are a little different from one institution to another. There are a couple of different ways of doing it. It turned out that neither one of them was sufficiently predictive to be usable in an individual patient. That the standard way that it's been reported to be done, you might as well just flip a coin. So I don't think the WADA test is very useful. There are a lot of reasons for that. One of which is that some of the time, you put the amytol into the carotid and it simply doesn't go to the places that you're interested in, which is the mesial temporal lobe. You can use EEG monitoring to show that, but it doesn't help you much because it isn't there anyway. But in any event, my experience at least has been that the WADA test is not useful and in the epilepsy business, I would never deny a patient, for example, a temporal resection based on that criteria. Now there's some other criteria that are highly predictive of whether you're gonna have a memory problem or not with a mesial temporal resection, which the most powerful is how good is their preoperative memory. Yeah, I think it's really more than just sight testing. I can't speak to the WADA issue, but I can say that in stroke cases that we've seen with left hemisphere hippocampal infarctions on testing, you can see very profound verbal memory deficits. However, that's in a clinical environment with some really stringent testing. I wouldn't say that the patients necessarily complain that that really interferes with their life. And if you're making the balance, making the decision, obviously that weighs in. And keep in mind, acute injuries are very different than chronic injuries. You've seen examples, I showed you examples, you will today, later, that there is a chance for plasticity with chronic lesions. So it's very different with an acute situation versus a chronic lesion in the dominant hippocampus. How many times have I seen patients come to me and said, I was told this is inoperable, what do you think? And I've never turned a patient down for fear of causing a memory deficit from a focal lesion in the hippocampus. Question about something you said, which is that you mapped the white matter tracts and left an indominant temporal lesion and you didn't get a response and the patient had that deficit. So that's, my question is about the rate of false negative in white matter mapping in the dominant hemisphere for memory. Yeah, I don't know how, I can't give you a number on that. I'm not sure why in that case I couldn't find the pathway. I can't tell you, I honestly don't have an answer. But I would say that the mapping with the bipolar that I use, I mean, this is a very unusual circumstance. I would say 95 plus percent of the time, if my mapping is negative, I feel very comfortable taking that area out. I think just one last thing about the hippocampus. It's very clear from our epilepsy numbers or looking at patients before surgery and after surgery. Those with a full functioning left hippocampus and normal memory scores have a lot to lose in verbal memory. If that hippocampus has been displaced by tumor, I mean, it's already lesioned. It's already disconnected largely. But the neuropsych testing, I think, is an important component. If you're deciding, am I gonna stop at the collateral sulcus here or am I gonna keep on going? In this case, where the hippocampus is not infiltrated and the person has epilepsy, it'd be nice to know what their neuropsych scores were ahead of time. But if it's infiltrated, I don't hesitate to take the hippocampus out if it's already tumor infiltrated. Okay, so that's another good lesson that we'll take away from this. The dominant hippocampus with a focal lesion is resectable. Okay, do you have another case? So this person had surgery and it looks like then had chemotherapy. Anything else you wanna add to this case? Any other comments? Your oncologist wants to treat this? Okay, so you sent the patient for radiation therapy because you were worried about the left hippocampus. But you now heard that that's not, you don't need to do that. Especially with conformal radiation. Okay, go ahead, do you have somebody else? Yeah, hold on a minute. Let's just see if we've got somebody. We've got a bunch of cases here. Dr. Marnette? Where is the case? Okay, where is Dr. Marnette? Okay, great. So tell us about the case and what your questions are. This case, this patient was referred to us on my last on-call duty. And was not, I mean from a clinical perspective, was not assessed by us. But by the referring doctors. So it's a 28-year-old man without any medical background. Who presented with two inaugural seizures with loss of consciousness. We don't know about if it was a complex partial or generalized seizures. Anyway, the MRI with a contrast. So I put T1 intense, T1 hyper-intense lesion and T2 hyper-intense lesion of the posterior part of the paracentral lobule. As well in the precuneus and the posterior part of them. And simulate a gyrus. And we were discussing about the diagnosis. About if it was a low-grade glioma or malformation of cortical development. We don't know about, for what would you propose to this patient? Anybody, this is a great case. There are lots of issues here. Anybody want to comment? So we have somebody who presents with seizures. There's no question this is a glioma. No question in my mind that it's a glioma. It's got mass effect, it's expansile. It involves the mesial parietal lobe and then crawls up underneath the motor cortex involving the cingulate. Okay, so from my point of view, if I was doing this case, my concern would be the descending motor pathways. The mesial parietal lobe from my point of view in this location is, again, fairly safe in terms of resecting it. I think it's very safe in terms of resecting it. The problem that I would be concerned about is right up in here, where the motor pathways descend. So in this case, I would do this case awake. And I like to do this very differently. I like to put the patient supine with the head flexed forward. And I like to operate behind the patient so that I can stimulate the descending motor pathways. So I would operate on the patient. I would do it awake. I would come in and I would clean all this out. And then I would put a strip electrode first over here. And I'd find the motor cortex and the stimulation parameters. And then as I started to core this out, I would stimulate looking for the descending motor pathway. So that's how I would do it, okay? So, Jinsong, you want to comment? And maybe Ren. To my opinion, I think we need much more image information. For example, MR spectroscopy and RCBF image and also the MET PET scan before we make a decision, operation on the operation. And in case this is, for example, the MR spectroscopy, the quality of the index is higher than two, I think maybe the glioma. I agree with your opinion. We can do the awake anatomy to take out partially the tumor lesion. But gross total resection may be impossible for us. Thank you. But you agree it's a glioma. What do you think, Lorenzo? Because this gets near the motor system. I think it is a glioma. The issue are the following. You have, okay, you have actually, the first issue is here, you have the motor condition pathway coming from the supermarginal gyrus go to the supplementary motor area here. And so I will do this awake to find out where these pathways are here. Then you have the issue of keeping the sensory motor integration for the leg, which is quite difficult. So for the leg and for the hand here. Then when this will be found, and so I will have the lateral border of the resection and all this part will go away, I will put the patient back under general anesthesia to map with the past technique this area and go under this and keeping the receiver part of the leg here and all what is possible go toward the supplementary motor area. Okay, I would just say in full disclosure, I routinely resect the sensory cortex. I have no problem with it. I tell the patient what's gonna happen. And I find that within about three or four months, a significant amount of their proprioceptive and sensory functions come back due to the thalamus taking over. But I tell them they're gonna have a permanent deficit, but it's not gonna be debilitating to the point that they can't walk. But I have no problem inducing a deficit here to get a better extent of resection. That's me. Well, I do the same. But for this case, I think there's a very good chance of having corticospinal tract involved in the tumor. I would get DTI, which is not very accurate, but at least it would show you if there is some compression of the tracts anteriorly, which would give it a chance. And otherwise, I think it may be an inoperable tumor with no oncological impact if you leave a lot of infiltrated tumor in areas that involve the corticospinal tract. So I don't think it's mandatory in every case to do resection, even a partial resection of this tumor. You would resect tumor or no? So the DTI would tell me that most probably you've got fibers going into the hyper-intense FLIR images. That's gonna be different if I see the corticospinal tract compressed anteriorly, which means that there is some displacement of the corticospinal tract. If there's no displacement, I think it's a noble meaning of doing the resection. Okay, remember, be careful. DTI is not a functional imaging study. It's anatomical. I understand that awake is safe, but under general anesthesia and asleep is safer. And some patients, it's a long surgery, and some patients complain after a while that they are tired, they have some pain, et cetera. So my question is, what is the advantage of doing awake instead of asleep? In a case of this, I mean, motor situations, not for language. There's no question you get a much, much more detailed map of either the cortical and or the subcortical pathway. No question about it. That's the advantage. Can I get a hand with the computer up here, please? For some reason, it's not showing. May I just ask you and answer you the fact that the goal is not to remove the tumor under local anesthesia demonstrated this morning. It's to turn around, and then you will go very quickly in order to avoid to induce a disconnection syndrome. But it's not a motor problem in this case. As said by Lorenzo, I totally agree. In fact, you have seen the SLF2 laterally, and Paolo Bartolomeu will speak about that this afternoon. If you get it, you will induce visual cognition deficit, and the patient will have many problems regarding a neglect, especially if you have somatosensory disorders in addition to. And sometimes I disagree with the fact that the patient will completely recover if they have an invasion also of the SLF2 and the pyramidal pathways. And then it means that it's not just a motor problem in this case. You should see the network around and let run it. Yeah, I have a paper that's been accepted to JNS. It's all on parietal lobe resection of tumors, and in the four permanent deficits that I had, each one of those were high-grade gliomas that infiltrated into the tracts. No DWI positive lesion, no transection on the post-operative DTI. But if tumor's invading those tracts, they don't recover as well. So what did you do? What have you done? Have you done anything yet? No, the patient was sent to us on my last, on Goal Duty, that was last week, so he's not operate yet. So what would you do based on what you've heard? American to me, it's not, I'm not consultant in the hospital, so I would, I would advise my consultant to do an American to me, and use operative tools as DTA or fMRI. Thank you. Our next case here is Jeff Ogerman. Where's Dr. Ogerman? There he is. Are you related to George? Yeah. How come you don't have as much hair as he does when you're younger? I just wanted to, so this, yeah, we can't all be as handsome as you, Mitch, it's true. I have two cases where the mapping seemed to interfere with what I wanted to do. So this first one is a 14 year old. Everything localized well in the left frontal cortex, but there were, the exact localization was unclear. On the next slide. I think, I think you're gonna need the lid up here. Yeah. So we went ahead and did a phase two study. Here we go. And there were, it was multifocal in the dominant left frontal lobe, and one focus based on depth electrodes was an abasive sulcus immediately under where multiple modalities found language disruption. So she had this left posterior frontal hypometabolism with thought abasive sulcus lesion there, but also wound up having orbital frontal foci that were separate. And actually, yeah. Yeah, where that big arrow is. in the circle, and then the hypometabolism here. So we were worried about these areas, but in additional, this wound up also being a base of sulcus abnormality, and we resected this one based on the seizure types and the expected morbidity. The next slide shows the invasive monitoring. Next. A cortical dysplasia. And next, and that's what we, was our montage. We had one set of seizures that were here in these depth electrodes that were in the base of sulcus. Next. And then a separate set of onset that was primarily orbital frontal and anterior frontal. And on the next, this was her neuropsychology testing and the importance, so I did an anterior frontal resection, she actually had some fairly significant deficits from it. It didn't, her school performance was actually improved, so it was very mixed. You see some pretty notable verbal memory increase as part of the partial seizure control. Next. But this was the area that I left behind. So this, it was right in this depth of sulcus. This was the functional MRI. We had a grid that overlaid that and the very profound speech arrest with stimulation of that area. And her seizures came back. Not as bad as before, but we're still impairing her. So what do I do? Okay, it's a good question because we've been talking about speech arrest and quote, Broca's area. So now you've got this abnormality and you mapped it and there was speech arrest. So how would this be handled? Let's see, Professor Schramm. I know what I would do. Well, obviously, nobody wants to be the patient of FASIC, so we have to refrain from being too aggressive. I think it's as simple as that. I have no solution, I must admit. I come from a functional neurosurgery background, so how about RNS? Neurosection, response to neurostimulation. Single focus, cannot be resected. Might be a good option. Yeah, our center, this would go for RNS. Maybe the next step. She's 14. Yeah, the trial was 18 and above, so you're right, that'd be a problem for a 14-year-old. Thank you. Any other comments? She has compressive seizures. She has, I don't know, a mechanical arrest. So we need to do a seizure. How often are the seizures? I'll retract. Huh? Daily. Okay, well, I would look at this differently. I would take her back intraoperatively, do her awake, if she's cognitively capable of doing that, and I would try to push the resection. And if I got an area that caused decrease in speech production, I would keep going and remove what was epileptically active, realizing that I think there's a very high likelihood that the speech production's gonna come back. That's what I would do, because I wouldn't let her continue to seize like this. One of the advantage to RNS is if you put the electrodes in and you put the electrode monitor system in the skull, you can leave it in for literally for years and get longitudinal data to decide, is it really coming from that area? Is it coming from above that area? And then try to decide what you really need to take out. Okay, another comment, guy. Sometimes you can get fooled on exact grid location of the surface. I think I'd put stereo EEG electrodes in both banks of the dysplasia, record it, make sure the seizures are coming from both banks and then stimulate them individually and see whether or not stimulating at that cortex gives you a deficit. With the idea of seeing whether or not it acts as a resection candidate with the depth of dysplasia being non-functional. Because that's exceedingly low risk and if there's no deficit on stimulating that, then you're probably gonna be okay. If there's a significant deficit, I don't think I would remove it. What if you stimulated a depth of like that and that was an interesting outcome? If you stimulated that, do you think it would work? You mean gotten the rest of the surface but not the base? I mean, you'd have to convince yourself. It looks like the whole gyrus is dysplastic on MR. And I don't think taking out the base and leaving the surface and let, I'd have to look at the MRI more carefully. So if it was truly just depth of sulcus, I mean, Eddie Chang had a paper looking at the UCSF where when you get just the depth out, at least in that series, the glottisia freedom's really good. I mean, this is a different, seems like this is different than a lot of focal cortical dysplasia because it's really hyperfocal. So if you thought that abnormality was really only the depth, then yeah, I think that'd be a reason to think about it. Eddie, you wanna comment on it? If it's active on the surface but not in the depth? Sure, I think that we do see these cases occasionally. And so I think that one of the first things we might try is actually another thing we haven't talked about, which is subpial transsection, which is what do you do in the case of epilepsy, especially in the case of dysplasia, where you map it out, it's determined to be eloquent. And one option is what we call subpial transsection. And it's a little bit controversial, but in a small minority of patients, actually, it can be quite effective. I think it's tough when you have a young patient with RNS, because there isn't really a proof for that. I also have an interesting case where it was a very devastating sort of refractory situation where we discussed with the family just what the potential consequences were. And given the data that Nina's been talking about with the stroke literature and patients that have had broken areas with stroke, we talked about removing, and we did that, and the patient actually did pretty well with the typical kind of transient post-op aphasia. That's why I would go for it. Okay, so did you say, Rich, there's another? Yes, yes. Oh yeah, sorry. Okay. Oh, I'm sorry, Jeff. Here, here. First resection, it was type 2A, this is corticospalasia. I actually did a laser ablation of the base of it and came in from a coronal approach, and there were two sulci that were concerning, and ablated just the sulcus. She's seizure-free, only three months out, but she had absolutely no complaints afterwards. Okay, so it proves you could have done it and resected it and not had a problem. Because you ablated it, so what's the difference? Another possibility would be to do the same thing with ultrasound directed. There is an improvement that can allow. Yes, you can, yes, you will ablate the lesion without having to do some path destruction. It's a technology not available in everywhere, but perhaps in this case we could have done the same thing without the path damage. So an ablative strategy with laser, high-intensity ultrasound. So we have, let's see, Sean, are you here? I don't know if Sean's here. Sean? Sean Jumper? No, I don't think he's here. Do you have other cases? Yeah, I've got 20 other cases, but this is the one we have loaded up, so I guess we'll go with it. Okay. 32-year-old left-handed male, six-month history of spells, left arm, hand, and neck. Workup fMRI DTI tractography, left-sided language. So that's left-sided language, right-sided lesion. Is that it, Rich? Okay. So, Lorenzo, you wanna have a stab at that? Actually, the issue there is you have laterally the ventral premotor part that is mostly within the tumor, so you have to dissect the ventral premotor fibers from the face N1 fibers. Then you are going back more medially, and you have the hand area, and the hand-originating fibers, you can push the resection within N1. Then you have the supplementary motor area there. I will go to the supplementary motor area as the last part, because first, all this part will be done awake. I will also wake the anterior part to disconnect the anterior part of the tumor till down to the hyphal, and then when everything has been disconnected, I will go under general anesthesia for the supplementary motor area. And to, of course, with NEP monitoring, to be sure that the leg and the hand are kept. I will anticipate to this patient that we have the supplementary motor area syndrome in the post-operative period. Okay, would anybody do this asleep? Yeah, I agree. I mean, if you are going to take something like this on, you want to do this awake with cortical and subcortical mapping. So that's what was done, awake motor mapping craniotomy. It was at grade three, all ago. And there was a post-op SNA syndrome, which recovered within four days, left-handed weakness improving. So Sean's not here, but we don't know whether that posterior rim stimulated as to why he didn't go back further, but I assume there was some functional component to it. Yeah. Right. So now, Hugh, based on what we know on plasticity, the chance exists to come back at some later point, right? Would you treat to grade three? I'm not completely convinced because there is an invasion of the fibers themselves. So it means that the potential of plasticity is very low. Second, it's a high grade glioma, so it means that we have the time to wait, like in low grade glioma, you can wait many years. So I would recommend to give adjuvant treatment. The question is, maybe just PCV, because it's a 1p9eq codelated, and I'm afraid about radiotherapy too early. So we can discuss about that, but it's not the topic today. Okay, so the point here is that Hugh made a point, I don't know if everybody picked up on it, but it seems like the plasticity issue is much more effective with cortically-based lesions, and less effective as a phenomenon if it's purely subcortical, right? Okay. So in this case, you can't wait for plasticity, it's a grade three, you have to treat it, and you can't expect plasticity like you would a cortically-based lesion. So that's the difference in that whole concept. Okay, any other comments, questions from anybody in the audience? Yes. Yes, in a case like this, when it's obvious it's not gonna be a gross total resection, what about up front, the new adjuvant treatment, after the biopsy, and then try to resect after? Okay, so Hugh, you have the most experience with treating up front with neoadjuvant chemotherapy to shrink? I do that only if I cannot perform at least a subtotal removal, namely with 10 to 15 cc of residue according to what you published 20 years ago, and we reproduce exactly the same results in French consumption. So it means that I have a tool, nonetheless, in order to calculate the volume of the tumor, and the volume of the tumor, I think I will leave according to the probabilistic map of brain plasticity I will speak about this afternoon. If I am beyond 15 to 20, then I prefer just a biopsy and to give a neoadjuvant chemotherapy, except if you have mass effect or intractable seizures. If you can, like here, probably leave approximately five to seven cc, I think that you can make a difference, except the fact that, of course, it's a OO grade three, but I continue to have some problems with the OO classification. This is another history. Okay, so the message is, if you think you can do a pretty significant resection with mapping, go for it. Don't try to do, it's only when you're dealing with very, very diffuse lesions that you would try that. In my experience, I maybe do it 1% of the time, 2% of the time, you know, a couple times a year, but that's about it. You do 10%. Yeah, that's about it. Any other comments from the audience about any practical issues that we've encountered so far? Yes, please. I'm a very young neurosurgeon with limited experience. Around three years, around 18 mapping experience. I very appreciate with this course heating. It give me a lot of experience and lesson. But I have a question. Our team do a lot of pre-surgical functional imaging, and I do believe that this functional image will help us do a planning. In the course in the lunchtime, we show a lot of MR, and we decide how to operate. But every time I'm yelling that, give me the functional image. And I think it's really helpful to help you to make a mapping design or making plan. And every time, because I do the image by myself, every time I can find a fiber before the surgery, I can identify the fiber and the relationship with the tumor, and I can identify it during the surgery with my stimulation. And I still think it's very powerful. Okay, I'm gonna go back to Alex on this one. You're gonna have to, you know, the issue is, so would you tell a patient in the clinic that they have an inoperable tumor based upon preoperative imaging? Yes, you would. I totally disagree. With all due respect, seriously. So tell us what you think. They rely, he relies on, yes, he said he would tell a patient that he thinks it's not a surgical, it's inoperable, I'll use that word, based upon, you know, preoperative, functional, or whatever imaging you wanna use. So I actually, thank you for letting me clarify this. Because yesterday I did say that one of the questions is whether a case is operable or not. And I, what I mean by that mostly is that people come to us being told that their tumors are inoperable, and that with the use of non-invasive functional mapping, you can show to them a strategy which might make their tumor operable. The other point I would make is, at least in our center, even if we know up front that we're going to have a subtotal resection, the oncologist and the pathologist really prefer that to a biopsy, in any event, because they really want large tissue samples, they wanna be able to send it for array, and they also want it for inclusion into clinical trials. So, at least for us, it's very limited, the patients who are only getting biopsies, that would be like a salamic leon, those types of patients. So, I think as time, I mean, I can predict, maybe you can tell me in 10 years, but I bet you in time, you'll take a chance at some of these cases, and you might be pleasantly surprised. And then, you know, maybe you'll change your view, maybe you won't, I don't know. I'm not trying to change it for you, but I'm just saying that, keep an open mind. You never know until you try. But I think if you shut the door on patients, then basically you shut any hope that they have of trying to be aggressively treated. So, it's something to keep in mind. Yes, Hugh. I can tell you that my consultation is full of patients not selected for surgery in another institutions based on functional imaging, every week. And finally, we've removed the tumor. This is just a fact. That's why I put this paper together. That's being worked on. Yes, Hugh, come. Question about the role of biopsy, and I'm talking about, you know, patients coming to you or Dr. DePoe. They're pre-selected. I mean, they have seen that, I am that one neurosurgeon they see first. You know what I mean? And you tell a 28-year-old, you have abnormal lesion on the temporal lobe, which is an incidental finding. You know, they didn't have a seizure or anything. I mean, you know, I hear there's not a role for biopsy and the downside of it. Sometimes, I mean, you know, we know they need a resection and a awake craniotomy. It's very hard to sell it to a 28-year-old with a three-month-old. I mean, is there a role for biopsy? I mean, you know, for us, that makes it more a manageable problem rather than saying, oh, you know what? We're gonna do this massive awake craniotomy, and she's more conscious about how much hair I remove and so on and so forth. Well, I would say in this day and age with imaging, whether it's anatomical or physiologic imaging, you should be pretty much 99% sure that it's a tumor, and if it's a tumor, why would I ever want a biopsy? It's something that I'm gonna try to take out. It's just, it's not a logical step, I don't think. Well, I think it's more a proof of the biopsy than that. But you proved it with the imaging. You don't gain anything. That's my opinion. I just wanted to make two comments. Number one, about the biopsy. I tell patients that a biopsy is like taking a hair from your head. I mean, if you got all black hair, it will become black, it will be right, but if you got black and white, you may get the wrong thing, meaning that in low-grade gliomas, I mean, it's not uncommon that if you remove the whole tissue and you make the pathologist to study whole tissue, they got different steps of degree of malignization. So a single biopsy is not 100% indicative of how the whole tumor is. Only in pituitary tumors, they are chronic. All the cells are the same, while in gliomas, it's a different thing. The second thing is that I don't like people to say that low-grade gliomas are benign lesions. They are not benign lesions. They will come back as malignant at a given time. And this is a message important to transfer to patients and to the neurologist and all these people because if we keep waiting for the bomb to explode, it may explode in a moment, which means we lost the opportunity to remove it, to help the patient. So low-grade gliomas, I think all of us will agree, they are not benign lesions. They will become malignant over the time. A biopsy is not certainly enough. You may be misled by the results. Did you have one more comment? Okay, one more comment. Who's moderating the next session, Richard? Guy. Guy, come on up. Let's get the first speaker loaded. It's a technical question, please. So it's a technical question. Some of these patients have some kind of deficit. They may have a motor deficit or they may have a disfeasance. So what would it change during the mapping? It's more difficult to do a mapping if the patient has a motor deficit. Do we have to increase the stimulus? And if the patient is disphasic, how do you do this? Well, again, just while people are moving around, if they have a deficit motor-wise and they can't get anti-gravity, then the mapping's not gonna help you. So what I try to do is give them high-dose decadron diuretics and see if I can elevate their status. If they're missing two out of three words, if they can't get more than 30% right, 40% right, then nothing's gonna help. You're not gonna be able to map them because as you saw from Z, things deteriorate even before they get into the operating room. So give them a chance, three to five days, steroids, diuretics, and they have to be pretty good, 60, 70, 80% positive. And otherwise I wouldn't do it. Because I've tried conversational mapping where I go into the operating room and just see if I can preserve what they have and it's not gratifying.

brain tumors

neurosurgeons

surgical techniques

complications

stimulation-induced alexia

memory loss

left hippocampus

WADA test

motor system

awake surgery

cortical mapping

neurostimulation