Seizures are the most tell-tale and dangerous symptom of epilepsy. During a seizure, a sudden surge of electrical activity in the brain -- usually in the cortex -- will suddenly alter a person's behavior. Seizure victims may black out, convulse, drool and their eyes may roll up. Teeth grinding, tongue biting and shaking are other physical signs of seizure.
Not all seizures, however, will be as severe or tell-tale as others and the symptoms can vary. Seizures lasting more than 30 minutes can cause permanent neurological damage or death. Seizure patients can also die from vomit inhalation during or after a seizure. Generally, however, seizures are not fatal and the life expectancy of someone with epilepsy is the same as that of a normal, healthy individual.
The only way to cure epilepsy is with surgical removal of the seizure-causing areas of the brain. For more than 50 years, this has been an accepted practice when medicines fail to prevent seizures. However, surgery for epilepsy, as with any brain surgery, is an incredibly delicate procedure requiring exact incisions and movements. Modern technology has reduced the amount of brain tissue lost during surgery by 50 percent in the last several years. New tools are also making mapping the brain before surgery even easier.
Electroencephalography (EEG) and video EEG record electrical impulses from the nerves in the head. Detectors are placed on the scalp and see what the electrical impulses look like when the patient is awake, asleep, in a room with flashing lights or when they breathe deeply. It determines if a patient's level of alertness is normal, if abnormalities exist in a particular part of the brain or if patients have a tendency to have seizures.
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Epilepsy and seizures
Epilepsy is usually diagnosed after an individual has two seizures not caused by a known medical condition.
 
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Do medications help control most children's epilepsy symptoms?
Dr. Adelson: Yes, for most children, medication is really the primary treatment. We really reserve surgery for those that are medically intractable, so they don't respond to either to medicines or other types of therapy. Then there are therapies such as the ketogenic diet, steroids or other types of medications. It really depends on the seizure type. There are certain seizure types that are a little bit more amenable to medication than others. For the children or patients that have epilepsy who are not medically treatable, we have to make a decision whether they are potential surgical candidates.
Who makes a good surgical candidate?
Dr. Adelson: A good candidate is somebody who has a very small seizure focus in a non-eloquent area in the brain. Those are areas that don't have any particular function or are bilaterally represented so that by removing that area, we're not going to cause him any problems. If you look at the history of epilepsy and epilepsy surgery, the temporal lobe, temporal lobe epilepsy and temporal lobe surgery has really been the primary focus of where surgery has gone because those were areas where you had two temporal lobes. If you could take out the non-temporal, non-dominant temporal lobe, you would be able to cure their seizures without causing them any neurological issues. So that classically was the one that was able to be diagnosed with simple EEG, electroencephalography and some rudimentary imaging.
It used to be just some new encephalograms or x-rays and for the most part, they would put electrodes in the hippocampus or into the temporal lobe, diagnose that was where the seizures were coming from and remove that area. That was really dating back to the 1950s and 1960s. What has been really remarkable for us is the ability for us to now look at a whole population of patients who were previously medically intractable but had no surgical options and we're now defining areas that we couldn't define before. That's really been just because of the miracle of technologic advancement. So when you sort of look at the fact that we can now, through PET scans or spec scans and now magneto electroencephalography, better EEG, better MRIs, better CT scanners, we're much more able to identify children who, before, depending on what kind of seizure syndrome they had, where was it coming from, we weren't sure whether in the right spot or not. Now we're able to say these children have the potential for benefiting from surgical intervention.
Does the new technology take away the guess work?
Dr. Adelson: No, it really doesn't because we still run into a large group of children whom we sort of know approximately where it is, but not exactly where it is. What would have been just children who had a right temporal lobe abnormality or left temporal lobe, we can now say there is maybe frontal lobe involvement or occipital lobe involvement or frontal temporal. Those were group patients that would not have even been considered for surgery before, but now, we can say we know approximately where it is, we have an idea of where the seizures are coming from. Now, let's use some of our other tools to really finally tune this and really know exactly what's causing the problem, and then go and do that.
The second advancement has really been in surgical techniques and anesthetic techniques. It allowed us to do the surgery much safer. Lets go back to temporal lobe epilepsy for a second. A recent randomized clinical trial done out of Canada was very impressive because it showed that the mortality from continued medically intractable seizures was worse than the mortality from doing the surgery and actually the morbidity, so the long-term effects of continued epilepsy and continued seizures was worse than having the surgery. So even though seizures had the potential for causing problems, it was at much lower percentage than those who were treated with medicines.
Is surgery the only cure for epilepsy?
Dr. Adelson: Yes. Because the seizures are believed to be coming from an abnormal electrical area of the brain, unless you're able to remove that part, you're not going to actually cure it. People that have seizures and have chronic seizures and get on medicine, it's not frequent that they would come off the medicine at any given time. This is really sort of a lifelong therapy. Surgery gives them potential for coming off the medicine at some point.
How has patient treatment improved over the last few years?
Dr. Adelson: I think over the last few years and the last couple of decades, with the advancements in our technologic capability, our ability to really fine tune the process of identifying children who would potentially benefit from surgery and the education of neurologists who are involved with these children and primary care physicians referring appropriately these children, they are being evaluated earlier. We are also understanding which ones are not going to become treatable with medicine. What we saw, 10 to 20 years ago is was an explosion of new medicines that really were treating patients who hadn't been well treated before. That delayed those patients actually coming to surgery until they have tried that. Now, we're starting to understand where those medicines really fit in, the types of seizure syndromes that they are most likely going to benefit. Then we can make a decision that a patient is not going to be medically treatable and then try to potentially look at their tendency for surgery.
Why is it beneficial for patients to have surgery at an earlier age?
Dr. Adelson: Well, using the analogy that children are developing, learning language and mathematics, writing and reading and all of those kinds of things, children who have medically intractable seizures are getting hit from a number of different ways. The number of medicines that they are on is often toxic to the point that they're so sleepy and non-reactive in order to try to gain some control of the seizures. The second is the seizure is kind of an interruption in their thinking and in their ability to absorb information. So it's kind of like opening your Microsoft Word file and then getting an energy surge or something like that. It doesn't save. If you get the program not responding, you've lost all that data. That's exactly what happens in the brain. You're dealing with a child who is trying to develop, trying to absorb all the stimuli around them in a drunken haze with these hiccups and power surges that doesn't allow them to imprint that information. You basically have a drunk child whose computer is on the fritz.
These children are really getting hit from all ends in their ability to develop more normally. If you can arrest the seizures and thus reduce the medicine that they're on so they don't have that electrical surge and that hiccup in their ability to absorb information, and you've been able to reduce their medicine so that they can function without the drunken feeling of all the toxic levels of medicine, they are more likely to develop more normally. In fact, the studies have shown that cognitive function, language function, motor function, all of those developmental milestones that we want to see in a developing child are achieved when they are not having seizures and they're able to reduce their medicines.
How does doctor collaboration contribute to these advancements?
Dr. Adelson: Epilepsy surgery has always been a wonderful collaboration between neurology and neurosurgery. It's one of those really truly collaborative areas of medicine that has dated back for 50 plus years. What's really been important, though, is that it has really been the ability of younger and other epileptologists who are at the art level understanding the imaging, the neurophysiology and all of those interactions in a very positive way, and they are aggressively approaching those patients. I think that we are wonderful here and we've always had a good reputation for identifying children who have seizure problems and those that can come to surgery and the like.
I think Dr. Holder has been much more aggressive in being able to define those children that are not likely to gain an improvement with continued medical therapy and really make a decision on whether somebody is truly going to have potential for surgery or not. Having said that, we've also benefited remarkably with an administrative understanding of what epilepsy surgery brings. So despite the fact that we've had a program around here for a number of decades, we truly didn't have the hospital administration that was understanding of what was going on. We have a hospital administration that, luckily, has been very positive in looking at what it is that we're doing, what are we bringing and then really being able to understand and support us with staff. It's very labor intensive because you need a nurse for almost every patient or two. So it's almost like ICU level care. You also need an EEG technician, so you need someone there all the time that they're in. All of these factors have been very important in our ability to grow the program. It's been a wonderful partnership with Dr. Holder and myself and the rest of the epileptologists, but it's also been a wonderful collaboration with neuroradiology, with hospital administration, with the departments of neurology and pediatrics. All of that has really, I think now in the last for us three or four years, really come together. I think that's why we have been able to really push it forward.
Is surgery less dangerous than the seizures themselves?
Dr. Adelson: Yes. It used to be that you were really more worried about the risks of surgery. Now, the data has become clear over the last few years that you're really weighing whether continued medically intractable seizures is a lead to a better outcome. It used to be a concern that with surgery, there was the risk of dying, the risk of being neurologically impaired, for not being able to move your arm and leg, to be paraplegic. The reality is that you're more likely to have most of those impairments -- if not worse -- with continued seizures than you are with surgery. So now, the risk of surgery all told -- neurologic, bleeding, infection -- mortality is under five percent and we know that the risk for continued seizures, particularly with cognitive decline is much higher.
What are the long-term outcomes for these children?
Dr. Adelson: With our imaging capabilities and our ability, in a place like this, to provide the whole gamut of services for these children, I think nowadays the surgery is a much safer endeavor with a much happier long-term outcome. With our basic straightforward surgeries, using temporal lobe as an example, we've had a greater than 90 percent seizure-free rate in these children. I like to say it's because I'm a wonderful surgeon, but I think I would probably like to say that we have just been able to better understand those children that are going to benefit from it. When we make the decision about surgery, we're making it for the right reasons and having really a wonderful outcome. So, we can say what a great surgeon I am, but in reality, I think it's a wonderful team effort, a collaborated effort.
What do you call the surgical methods you're using?
Dr. Adelson: We can do three different types of surgery. We can do surgery upwards of removing half the brain -- that is called a hemisectomy. We can also remove what is considered the ultimate focal resection. We do resective surgery, which is removal of a part of the brain, so the temporal lobe, frontal temporal lobe, part of the frontal lobe. The second part is what we call disconnective surgery. That's where we actually interfere with the seizure spread. That has a much lower percentage of cure than resective surgery for removing a piece of the brain. Then the newer areas are what is called neuromodulatory, where the Vegas nerve stimulator -- or deep brain stimulation -- comes in. Vegas neural stimulation has been around for a while, but deep brain stimulation is probably one of the areas of the future. I especially think that that may have some potential bearing for children who we can't find a resective area of brain to take out. The other aspect of it really is the diagnostic portion, the phase 2 evaluation, where we open up the head and place the electrodes on the surface of the brain or in the brain itself, close everything up and then monitor them in the monitoring unit to see their seizures.
How long are those patients monitored?
Dr. Adelson: One or two weeks. We have gotten much better at that. It was not unusual that we would keep patients three, three and a half weeks. Now, it's unusual if we go beyond a week because now we know how to get them to have seizures. We understand them much better so that we get them in and we have them having seizures and then we take out the grids or the electrodes the following week with the epileptic focus, because the grid gives us a map of where we need to go.
What benefit do you get from that grid system?
Dr. Adelson: Well, it gives me a lot more confidence because not only do we record off the grid -- the electrical abnormalities -- but we can also stimulate back along the grid to see if there is a functional area there. So if I know that seizure is coming from points one through four and we know that the language area is in section 16 through 19, then I know I can take one through four without a problem and not worry about language, motor or whatever. So I really enjoy having the grids because I have a lot more confidence that it's something that is not going to cause them a problem. Sometimes their seizure syndrome is so clear-cut and the imaging is adequate and the abnormality is, lets say a tumor or vascular malformation. Then it's less often that we need the grids in those cases and we might go straight to the resective portion of the surgery.
How do you explain the grid system to the patients?
Dr. Adelson: Most of the patients have undergone multiple EEGs before, so they've had the electrodes on the scalp surface. By putting the grid right on the surface of the brain, we know where that seizure focus directly is coming from and which way it's spreading, which is what we don't pick up on the surface. That is usually a pretty good analogy.
It's also like a very detailed map because the surface electrodes at most, they may have 64 electrodes around the whole head -- most times it's just 16. What we're doing is putting 64 electrodes within an 8 x 8 centimeter square. It's much more concentrated and there is only a centimeter spread between the electrodes. Right now, it gives us really the best road map to point out exactly where we go. We know what the numbers are on the electrodes. Not only are they numbered on the electrodes, but they're numbered by wire. We're able to say, 'Numbers one, two, five, eight, six, seven, nine, 10 need to removed.' That's exactly how we do it. It doesn't take brain surgery.
