Doctors at the UPMC Department of Neurosurgery are pioneering novel, less-invasive epilepsy surgeries that have fewer complications yet are effective at stopping seizures. These surgeries offer hope for the more than 1 million people living with what is known as medically refractory epilepsy—the type that does not respond to medication.
What is Epilepsy?
Epilepsy is a condition of the brain that causes seizures. Seizures are sudden bursts of electricity that disrupt the communication between neurons in the brain. This activity can happen in one small part of the brain and last for just a few seconds, or it can spread across the brain and keep going for many minutes.
Some seizures cause the body to jerk or shake, while others cause people to lose awareness or have unusual sensations. They can occur when the person is awake or asleep—and can severely affect the person’s safety and quality of life when left uncontrolled.
Epilepsy by the Numbers
Epilepsy is the 4th most common neurological condition in the U.S. It affects more than 3.4 million Americans, including 470,000 children. Medication can stop the seizures for about 60% of people who are living with epilepsy. But for the 40% of people whose epilepsy does not respond to medication, there have been few options.
“Surgery can be the next step when a patient’s epilepsy fails to respond to two medications or when the medications cause debilitating side effects,” says Jorge Gonzalez-Martinez, MD, PhD, FAANS, a world-renowned neurosurgeon specializing in epilepsy and co-director of the UPMC Epilepsy Center. “But, in the past, brain surgeries for epilepsy have been very invasive, often requiring removal of large portions of the skull and large resections, which led to significant complications and high morbidity.”
Over the past 2 years, Dr. Gonzalez-Martinez has led the UPMC neurosurgery team in initiating new, less-invasive surgical interventions that enable surgeons to explore the brain. One such intervention is robotic-assisted stereo-electroencephalography (SEEG) to help surgeons with the depth and placement of thin electrodes guided into the brain to find the source of the seizures. Once implanted, the electrodes record the electrical activity of the brain in a monitoring unit over 3 to 7 days.
Placing the Electrodes
“The decision where to implant the electrodes in the brain is defined at our Patient Management Conference by a multidisciplinary group of physicians, including neurosurgeons, neurologists, psychologists, and radiologists. The team studies the patient’s history, prior EEGs, and other test results to generate a hypothesis of where the seizures are coming from,” explains Dr. Gonzalez-Martinez.
“Then we design the implant map based on that information and transfer it into our robot. The robot uses a type of GPS to help us find the best routes to the parts of the brain where the activity is occurring.”
The surgeon places three rows of electrodes inside the brain while the patient is under sedation. The first row passively records seizures as they happen. Doctors use the second row to pass a small amount of current into specific parts of the brain to stimulate it in an attempt to provoke a seizure, which gives the surgeons more information.
Doctors use a third row of electrodes when they think they’ve found the origination point to figure out what would happen if that part of the brain were removed. Would it affect vision? Speech? Movement? While the patient is awake, the surgeon can ask them questions to monitor their speech or have them squeeze their hand to monitor movement.
SEEG-guided electrode placement sounds a bit scary, but is actually a very safe procedure. Dr. Gonzalez-Martinez reports that his team has performed more than 550 implantations of more than 7,000 electrodes with a complication rate of less than 1%.
Finding the Source of the Seizures
Sometimes a brain lesion will show up on MRI, so the surgeon knows where to go—but other times, the location is not so clear. Surgeons use the SEEG-guided electrode placement to either confirm or reject the multidisciplinary team’s location hypotheses. What surgeons do next depends on what they find.
“If we find a large lesion, we will do an open resection and aspirate the tissue, but if we find a tiny lesion, we don’t need to open the skull at all,” he says. “We can just put a probe in and use thermal coagulation to ameliorate it, or use the endoscopic endonasal approach.”
The endoscopic endonasal approach (EEA) is a minimally invasive technique pioneered and refined at UPMC that gives neurosurgeons access to the base of the skull, central brain, and top of the spine by operating through the nasal passages.
“EEA uses the nose and sinuses as natural corridors to access lesions in critical areas of the brain, allowing us to treat many hard-to-reach lesions without disturbing the skull,” says Dr. Gonzalez-Martinez. EEA is often used to treat a variety of brain tumors.
UPMC neurosurgeons have more than 25 years of experience using the EEA technique. Over the years, the team has constantly refined their skills and expanded the possible uses for this innovative approach.
Giving Hope When Options are Few
Neurosurgeons at UPMC perform between 100 and 150 epilepsy surgeries each year on people of all ages and from across the country and around the world. Dr. Gonzalez-Martinez’s team has a success rate of between 60% to 70%—meaning that these patients will no longer have seizures.
“These are patients who had minimal chance of becoming seizure-free on medications,” Dr. Gonzalez-Martinez emphasizes. “After surgery, they go on to live healthy lives without seizures—permanently.”
But what about those patients who are not candidates for surgery at all?
“Some of these patients can benefit from the implantation of a neuromodulation device—similar to a pacemaker—in the brain,” says Dr. Gonzalez-Martinez. “Neuromodulation can reduce the number or severity of seizures in about half of the nonsurgical group.”
Unfortunately, for a small subset of patients, there still is no treatment.
“That is where we focus our research—so that we can eventually help them gain better functional and quality-of-life outcomes,” he says.
For more information about the UPMC Comprehensive Epilepsy Center or to schedule an appointment, call 833-398-0286 or visit us online.