Gerald Grant, MD, Chief of Pediatric Neurosurgery, with Stanford Children’s Health, talks about how the use of a robotic surgical tool has been a game changer in the treatment of epilepsy.
Explain what is a robotic surgical assistant?
Dr. Grant: ROSA™ is a robotic tool that allows us to precisely and more efficiently target deep areas of the brain. We can place several stereotactic electrodes in a very short period, maybe three to four minutes per electrode, which is a big difference from the old days when we used to take maybe 30, 40 minutes per electrode. We can target deep areas to uncover networks of the brain that are not just on the surface. It’s a very exciting approach. It’s a disruptive technology that allows us to be able to do this now for young children in a very efficient fashion.
How is this procedure minimally invasive? Do you have to shave the patients head?
Dr. Grant: We used to do large surgeries with large incisions and more hair was shaven, which kids don’t like. Now we rarely shave any hair at all, and we place one-millimeter little holes in the scalp that allow us to target these deep areas. The kids love it because they’re not in as much pain and they’re more comfortable after the surgeries. We can monitor them and keep them hooked up to stereo EEG – these kids are happy with these electrodes. We try to keep them busy and distracted while they are hooked up to the EEG since it can get pretty boring. They’re able to carry on with their normal activities and play – use their iPad or watch movies and not be distracted by the pain or have to give them medication because they need to treat discomfort.
Not having to shave their head is a huge advantage because much of the young teenagers are so frightful and stressed out about undergoing a neurosurgical procedure. This method has really been wonderful for these kids since it is so minimally invasive. We’ve studied how different an experience it is for a child to go through stereo EEG, which is placing these deep electrodes in a 3D network, than the old days of large incisions, big large craniotomies to put these grids on the surface of the brain. So, we’ve come a long way which is very exciting.
What type of conditions does this robotic technology treat?
Dr. Grant: This robotic tool helps us target these deep areas. We use this tool for biopsies or tumor patients, but we apply this tool because of its ability to hit multiple targets and put in maybe 16 to 30 electrodes in the brain to uncover the place in the brain where the epilepsy is starting from. There might be one area, there might be multiple areas along the 3D electrical network. So, we can look at where the epilepsy begins and how the current and the electricity travels from one point to the next point at the beginning of the seizure. That’s the excitement of uncovering the electrical roadmap in three dimensions. You can look at some of the depth of these electrodes and how the technology will allow you to uncover that network and solve that mystery. The robotic tool doesn’t itself treat the seizures. Instead, the robot guides the electrodes to target so we can figure out what we need to do to try and cure the seizures.
When you said 30 electrodes is that just one at one time?
Dr. Grant: We might place up to 30 electrodes in the brain for one child at one sitting and keep those in and record from multiple different areas of the brain. We pull them out before the patient goes home which takes about 20 minutes to do that and yes we shampoo the hair before they go home. It’s important to discuss the electrode plan with the epilepsy team to figure out exactly where these seizures are starting and how they’re spreading. Then we can try to figure out the next step, which is how to treat it. That might involve many different techniques that we could do in neurosurgery to try to treat seizures, such as open resection, laser ablation, responsive neurostimulation, or deep brain stimulation..
Tell me about Molly and her condition tuberous sclerosis.
Dr. Grant: Molly is born with a condition called tuberous sclerosis complex or TSC. It’s a genetic condition and there’s different forms of tuberous sclerosis. Unfortunately, it can cause tubers in the brain, not ‘tumors’ but ‘tubers’ which are like potatoes in the brain – they’re very firm areas which can disrupt normal networks in the brain.
Molly’s mom first noticed these events when she was 1-3 months of age, which at the time were not recognized as seizures. As the seizures progressed, she got worse, and was diagnosed with tuberous sclerosis. Unfortunately, some kids with that condition develop seizures from multiple areas of onset. It becomes challenging to figure out which tuber is the “hot” one that’s causing the seizures. That’s where the stereo EEG and ROSA™ has been so helpful because we can target many of the suspects and try to uncover that network. The stereo EEG approach allows us to study the 3D network of the brain and develop a strategy which could lead to a surgery to resect a tuber and surrounding brain causing the seizures or use a laser in a more minimally invasive approach.
I understand that she had a surgical procedure before undergoing a minimally invasive procedure via the ROSA™ tool. How different was it and was it more invasive?
Dr. Grant: Molly has a severe form of tuberous sclerosis with many different types of seizures. So, we dealt with the one seizure type first that was the most active and the most debilitating to her development and quality of life. Once we identified the tuber responsible for these seizures, we performed surgery to place electrodes on the surface of the brain to confirm and then resect the tuber and area of brain around the tuber. Molly did very well from that first procedure and was seizure free from that area for quite some time. Then later another area on the opposite side of the brain started firing up. We then performed stereo EEG to identify the sources of these seizures and surgery to become seizure free again. Molly remains seizure free.
Molly’s parents were so amazing and patient through all of the work up and surgery to continue to have hope for Molly to be the best she can be. Molly’s development took off after the first surgery and she did some amazing things that she’s never been able to do before. Between the first surgery and the second surgery is when the technology in the field really transformed to perform stereo EEG to uncover the 3D network. In the second surgery, we did use the ROSA™ approach with the stereo EEG instead of the large surgery. That was important for her to avoid two big surgeries on both sides of the brain.
What was the recovery time from the first surgery to the second, minimally invasive surgery?
Dr. Grant: The ROSA™ technology platform has been transformative for these children to help us unravel the mystery around where the seizures are coming from in the brain. The recovery is much shorter and surgery better tolerated so the kid can be a kid again. It is also a bonus that we no longer need to shave any hair.
Epilepsy and tuberous sclerosis are conditions that Molly will have to live with and potentially will require more surgery in the future. What challenges can repeated surgery have on a patient’s mental and physical wellbeing?
Dr. Grant: Any repeated surgery, and in kids especially, is such a major factor to consider for the family and for the child. It can get even harder psychologically as Molly gets older. With other demands and living her life this is a distraction for her to have seizures, especially if she’s been seizure free and suddenly is not again. It’s a life changing moment for sure, but equally as life changing is becoming seizure free again and the chance to really become the best she can be. Molly’s true personality gets released once her seizures are controlled which is a blessing. So, it’s usually worth it for these kids and their families to strive for seizure freedom.
We’re always thinking about how to make surgery more minimally invasive. Once we confirm seizure onset with stereo EEG, we now use a laser fiber to target deep areas of the brain live in the MRI scanner. This is another game changer since the child has a small 1-2 mm incision and short hospital stay. This approach has been particularly exciting for tuberous sclerosis patients. However, we are cautious not to overdo it since we always must balance risk and benefit to each child. These kids have a lifelong risk and they may need to go back for more surgery so we do not want to take out or laser more than needed. This approach has really allowed us to be strategic and identify more precisely where the seizure is starting so we can plan a surgical strike to cure the seizures. It is a very exciting thing for a family and a child to know that we don’t have to open their head every time and take them back to surgery with a recurrence of seizures.
These kids also still need anti-epileptic medication to control the seizures. Our surgical approach is to remove the areas that are not responsive to medicine. We usually need to keep the children with tuberous sclerosis on medication after surgery since there are often multiple generators for the seizures. The overall goal is to preserve quality of life of each child so he or she can be the best they can be and seizure free.
Tell me how these procedures improved Molly’s development?
Dr. Grant: Early on Molly did have some delays in development. She had multiple seizures per day that were not recognized as seizures, until she had EEGs that confirmed the diagnosis. The amount of spiking her brain in between seizures unfortunately really slowed down her development and required more and more medicine to try to stop the seizures.
Unfortunately, medicines can also have significant side effects especially in combination. The seizures affect the development as well and along with the multiple medications can have a negative impact on cognitive and physical development. I do believe that Molly’s parents were most excited after the first surgery to have hope to get their Molly back. Her true personality returned and her seizure were well controlled which was amazing to see. Her parents were so ecstatic. Unfortunately this nirvana was only transient.
When Molly’s seizures returned, she had so many seizures that they changed her whole personality demeanor and of course caused significant developmental regression. To understand that Molly was now having seizures from another part of the brain and affect her language became so upsetting to Molly’s family. We went right back to the drawing board to develop a strategy to keep going. Together, with the epilepsy team, we outlined a plan for more interventions to prove the location or seizure onset. But would it all be worth it?
Molly’s parents saw the difference in the first surgery and the second surgery just based on how the epilepsy field has evolved over the last five years. We are excited to be able to offer so much more to patients and their families. The emergence of stereo EEG, robotic technology, laser ablation, responsive neurostimulation, and deep brain stimulation have all been transformative for children with severe medically refractory epilepsy. Therefore, our toolkit is now much bigger. We are now better able to localize the seizure onset zone and treat the seizures more precisely and safer and also maximize seizure freedom and quality of life for the child.
How is Molly today?
Dr. Grant: Molly is doing amazing well. She is an incredibly warm young lady. She’s still gets a little anxious when she sees us, but I don’t blame her for what she has endured at a young age. She’s warming up to us which is exciting. It’s so wonderful to see her true colorful personality and see developments continue to improve. In the classroom she’s able to learn and that’s just so exciting and gratifying for us to see how far she has come from when we started. That’s why we love what we do to help kids like Molly. One of the most gratifying achievements we can do as neurosurgeons with the greatest impact is to allow a child to be seizure free. To see the development blossom after I treat their seizures is truly special.
How many other hospitals are using this technique?
Dr. Grant: More and more hospitals are adopting some type of robotic technique to treat seizures. I hope the idea of doing stereo EEG and having pediatric epilepsy doctors now think in 3-D about seizures is here to stay. Robotic platforms have led to less time under anesthesia, greater precision, and at the same time less invasive. All these things do matter especially when trying to convince a child or young teenager that it’s worth doing going the next step on a path to cure their seizures. Their number one question is about their hair, not so much about the seizures or procedures. They would say, ‘I don’t want to shave my hair,’ and just to tell them that we’re not going to shave any hair at least for the localization that is really exciting for them to hear.
In the past we often performed more invasive surgery to place large grid electrodes on the surface of the brain along with a few depth electrodes. Now we have converted almost exclusively to stereo EEG which allows for much more coverage in 3D deep in the brain to uncover the network. In the old days it was a very difficult conversation with a family to go through all the open surgery to then tell a child that, “sorry, we cannot help you.” Now we can identify if a child is a surgical candidate for laser or open surgery in a much more minimally invasive fashion. Our group has published extensively on the precision, efficiency, and lower pain scores for the child with this technique.
Molly’s language soared after the second surgery but we were still cautious about our resection plan for her to limit the area of resection to maximize benefit but minimize a deficit to her language. Every kid is wired differently and how his or her brain is mapped is unique, especially with tubers. We have used sophisticated white matter tracking of the highways of the brain called diffusion tensor imaging (DTI) to navigate around the mine field. The Synaptive platform has also enabled us to map the tracts, tubers, and areas of seizure onset and function all on the same 3D map. We are also using virtual reality now with Surgical Theater and 3D printing the brain with the electrodes in place so the child can “fly through” their own brain. This innovation has been so engaging for the child to feel more part of our discussion as they hold the joystick and take control.
How do you and your team prepare for somebody like Molly or other patients when using a robotic surgical tool?
Dr. Grant: These surgeries take hours of planning. We have a multidisciplinary epilepsy team of 25 people that meet weekly. We talk about Molly from all aspects. We look at her imaging, seizures, onset propagation, video of how the seizures look, development, and how the seizures spread. We look at the MRI scan in terms of where these tubers are and how close they are to language, motor, or vision.
This takes a village to achieve the best possible outcome for every child. The epilepsy team is so comprehensive because you’re relying on so much different areas of expertise to find the best possible solution for a child like Molly to keep her safe and make the biggest impact possible on her seizures and development. Even during the surgery, we make judgment decisions that have real risks and clear benefits. We might map areas of seizure onset in the operating room and find an adjacent area that is still spiking. Do we chase it? Do we keep going to try to suppress these spikes? Will that intervention help Molly or will it hurt her quality of life?
It’s these minute to minute decisions we make that I don’t make in a vacuum but instead is made at every step with a team of people in the operating room to try to help with these complex decision making. The teamwork is so valuable for these patients with severe epilepsy. We pull all stops and rely on all the possible technologies available with the most innovative approach and expertise around the table to help each child like Molly reach seizure freedom.
Interview conducted by Ivanhoe Broadcast News in March 2020.
END OF INTERVIEW
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