Stopping Seizures With Lasers
MIAMI, Fla. (Ivanhoe Newswire) - An estimated one in five children with epilepsy does not respond to medication. Now, patients and their parents are getting new treatment options with a medical breakthrough that uses lasers to stop the seizures.
When Jessie Fernandez was little, she woke up every morning scared.
"I was getting up every day thinking what if I have a seizure today?" Jessie told Ivanhoe.
She had her first epileptic seizure when she was ten, after that she would have one, two, up to five seizures a day.
"In our class they don't have desks or chairs, they have stools. So, I was just doing my work and I fell back and hit my head and they called the ambulance," Jessie said.
The seizures were caused by a small brain tumor. When medication didn't help, her only option was an invasive, brain surgery.
"Traditionally, the way we perform those surgeries is actually to remove part of the brain that's causing the seizures," Dr. John Ragheb, Chief of Pediatric Neurosurgery at Miami Children's Hospital, told Ivanhoe.
Jessie had a different type of surgery called Visualase Laser Ablation. An MRI focuses on the target area. A laser fiber is inserted into the skull. Heat from the laser then destroys the tissue causing the seizures and the tumor.
"We can accurately target just the tissue we want to destroy and protect the surrounding normal areas," Dr. Ragheb said.
Today, Jessie doesn't worry about seizures. She's focused on her future and hopes to become a neurologist one day.
Jessie is still seizure free. Recovery from the procedure is quick. Most patients go home the next day, compared to a week in the hospital with traditional brain surgery. So far, the technique has been used on about 300 patients in the U.S. with many types of epilepsy. The doctor said the results seem comparable to traditional surgery, but it will take time to know for sure.
BACKGROUND: Epilepsy is a medical condition that produces seizures affecting a variety of mental and physical functions. It is also referred to as a seizure disorder. When a person has two or more seizures, they are considered to have epilepsy. A seizure happens when a brief, strong jolt of electrical activity affects the brain. One in ten adults will have a seizure at some point during their lifetime. Seizures can last a few seconds or up to a few minutes. Symptoms can include loss of consciousness, convulsions, lip smacking, jerking movements of arms and legs, and blank staring. (Source: www.epilepsyfoundation.org
RISKS: Approximately 200,000 new cases of seizures and epilepsy occur every year. The underlying risk of developing epilepsy is about one percent. However, people in certain populations are at an increased risk. For example, it is estimated that epilepsy can be expected in:
• 25.8 percent of children with mental retardation
• 13 percent of children with cerebral palsy
• 50 percent of children with both disabilities
• 10 percent of Alzheimer's patients
• 22 percent of stroke patients
• 33 percent of people who have had a single, unprovoked seizure (Source:www.epilepsyfoundation.org)
EPILEPSY & THE BRAIN: The brain is the source of epilepsy. Symptoms can affect any part of the body, but the electrical events that produce the symptoms occur in the brain. The location of that event, how long the event lasts, and the extent of its reach within the tissue of the brain all have profound effects. These factors determine the character of the seizure, the social consequences, and its impact on the patient. (Source: www.epilepsyfoundation.org)
NEW TECHNOLOGY: Treating brain lesions are risky. The blood-brain barrier, which normally protects the brain from harmful chemicals, also keeps out many types of drugs. The new technology called Visualase offers people with epilepsy another option. It is a laser technology that utilizes light energy to destroy soft tissue, including damaged tissue and tumor. The energy from the laser is delivered to the lesion using a laser probe. When light is delivered through the laser probe, temperatures in the target area rise and destroy the unwanted tissue. The procedure is guided by MRI images, so it can provide precise targeting. The patient is wide awake throughout the procedure. It doesn't require radiation or a skull flap (the large skull opening in traditional craniotomies). It is minimally invasive and causes minimal or no pain during or after the procedure. It also does not limit use of additional or other treatment options. (Source: http://www.visualaseinc.com/)
John Ragheb, MD, Chief of Pediatric Neurosurgery at Miami Children's Hospital, talks about a new treatment option that uses lasers to stop seizures in patients with epilepsy.
How long have you been seeing kids with epilepsy?
Dr. Ragheb: I've been practicing pediatric neurosurgery for over twenty years and have been working here at Miami Children's Hospital since 1996.
Is epilepsy a disorder that people don't realize how common it is?
Dr. Ragheb: Yes, epilepsy is very common in the United States and worldwide. About two percent of the U.S. population suffers from epilepsy. Most epilepsy patients can control their seizures with medicine, but a small percent of those patients continue to have seizures even with the medication. Surgery is an option once medicine does not work.
Is epilepsy always caused by a tumor?
Dr. Ragheb: No, epilepsy can be caused by many things. Some of them are structural abnormalities in the brain and for some the cause is unknown. In children, those structural abnormalities are related to areas where the brain just didn't form properly during development. These malformations of cortical development are very common causes of epilepsy in children that require surgery. However, there may not always be a structural cause or explanation for epilepsy in the general population.
For treating those that don't respond to medication, is surgery and removing something in the brain usually the only option?
Dr. Ragheb: Historically, we've treated children who do not respond to medication with surgery. Traditional epilepsy surgery involves removing the part of the brain that is causing the seizures, assuming that it can be done safely. This involves opening the skin and the bone, and it's a pretty traumatic experience for both the child and their family. It is effective though and, when medicines don't work, it's the only option that could potentially cure a child of epilepsy.
When you're opening up the brain that's always a risky surgery, right?
Dr. Ragheb: All surgeries have risks involved. Neurosurgery can be very complex. We only operate in situations where medicines don't work and surgical intervention is the only option.
So, what do you do when children don't respond to medicine?
Dr. Ragheb: The children are evaluated by our Neurology, Neurophysiology, and Neuropsychology Teams to identify those children in whom surgery may be of benefit. Those children thought to be candidates for surgery are then discussed at the multidisciplinary surgical epilepsy conference to decide if surgery is indicated and what type. For children who have epilepsy that does not respond to medicine and surgery is an option, we have a new technique that allows us to treat some areas that are causing the seizures with an operation that avoids opening the head. It's much less traumatic to the child and to the family.
This one uses lasers, correct?
Dr. Ragheb: Correct. This procedure involves inserting a laser fiber into the area that has been identified as the source of the epilepsy. The area is chosen based on a lengthy and elaborate process prior to surgery. That carefully chosen area can then be targeted precisely using MRI imaging. The position of the laser fiber is also confirmed once in the brain using an MRI scan. Only the tissue causing the epilepsy is destroyed by heating that tissue, which is controlled very precisely by MRI thermography, or a thermometer system, in the MRI scanner. We can accurately target the tissue we want to eliminate and protect the surrounding normal areas.
How does the procedure work?
Dr. Ragheb: The procedure is performed with the child either with local or general anesthesia. Then, the laser fiber is inserted through this tiny fixation device through the skin and bone into the brain. It directly targets the area where the seizures arise. Only the tiny laser fiber enters the brain, which is about 2 millimeters in diameter. The only opening in the skull is about 3 millimeters, the size of the fixation device.
Is it safer? Is the recovery time reduced?
Dr. Ragheb: Because this is done through a tiny opening, the only thing that enters the brain is the laser fiber. It's fixed in the head so the incision in the scalp is just big enough to insert this bolt into the bone. The fiber goes through the bolt and then into the brain. Thus, the recovery time is significantly reduced compared to traditional surgery, which requires you to be in the hospital for a week. With this new minimally-invasive surgery, you can go home the next day.
Why not do every epilepsy surgery with this?
Dr. Ragheb: Ideally, in the future, every type of epilepsy would lend itself to this kind of less invasive treatment. The challenges now include our ability to precisely localize the area where the seizures arise and to be able to target that area safely. This system can only treat a small volume of tissue inside the brain by heating the tissue and destroying it. That tissue ultimately dies and this results in swelling. Sometimes the treated area can swell and cause pressure on healthy adjacent tissue. If we treat too large of an area inside the brain, it can make the adjacent healthy tissue sick and we can cause a new cascade of events with associated complications we would like to avoid. Thus, there is a limit to how large of an area we can treat with this surgery. There is also a limitation in the ability to precisely identify the area of epilepsy within the brain. As technology improves, so does the ability to target specific areas. Identifying the source of the epilepsy and narrowing the source of the seizures down to a very small volume will allow us to treat more children with this technique. Techniques like this will allow us to minimize the trauma to the child and treat more patients effectively with less invasive treatments.
Why can you target epilepsy better than with traditional brain surgery?
Dr. Ragheb: With traditional brain surgery, about half of the children require two operations. The first operation opens the skin and the bone and implants electrodes directly on the surface of the brain. Those recording electrodes then help us to precisely localize the part of the brain that's causing the seizures and map the brain function. The second operation actually involves removing the affected part of the brain. Sometimes, these are very large areas that have to be removed, such as an entire lobe of the brain, and sometimes they are very small areas. Ideally, we would be able to target just the source from which the seizures originate so that the treated area will be as small as possible. This will allow us to use this new noninvasive technique and avoid a large operation.
So, right now because you don't have that first surgery you're just using an MRI scanner to try to target the area of the brain that's causing epilepsy, correct?
Dr. Ragheb: Localizing the source of the epilepsy has its limitations, and we use many different modalities to identify what may be causing the seizures. MRI scans help us identify anatomic abnormalities in the brain. An EEG helps us identify electrical abnormalities in the brain. Tests that look at blood flow and metabolism, like SPECT scans or PET scans, allow us to see areas in the brain that have abnormal blood flow during a seizure or are metabolically abnormal. We also use a technique called 3-D source localization to identify individual electrical discharges within the brain and deep abnormal areas of electrical activity in the center of the brain. Combining physiologic data and anatomic data helps us identify where the seizures are coming from. Treating epilepsy is now dramatically better than it was twenty years ago. These techniques allow us to more precisely identify the source of the epilepsy and spare some children an extra operation to implant electrodes and identify the seizures.
Was Jessie a good candidate because she had a tumor that was small and you could see where the tumor was causing the problem?
Dr. Ragheb: Jessie had seizures that were not controlled with medicine and she had a very small area on the surface of the brain that looked suspicious for a tumor. It wasn't the kind of brain tumor that is going to grow rapidly or spread. Thus, our focus was to try to control Jessie's seizures in the most minimally disruptive way as possible. We tried a few medicines initially, but those were not successful in controlling the seizures. Because Jessie had a clearly defined abnormality on the surface of the brain, something we call a developmental tumor, her condition lent itself to this new technology. Jessie was the first patient we treated at MCH with the Visualase laser thermal ablation system; her tumor was a clear target in a safe area on the surface so she was the perfect candidate. Jessie's seizures have responded very nicely to this treatment.
Could this tumor come back with Jessie?
Dr. Ragheb: It has been almost two years since her procedure, and her seizures have not only gone away, but the tumor is gone as well.
FOR MORE INFORMATION, PLEASE CONTACT:
Miami Children's Hospital