A computer flash drive that can reprogram a person's brain to avoid epileptic seizures? Not exactly, but there are many interesting parallels with a new device that doctors at UAB are using to significantly reduce the occurrence of seizures among patients with epilepsy.
The advance is called responsive neurostimulation, or RNS, and UAB is the only medical center in the Southeast performing the procedure since it was approved by the FDA in November.
"The device is designed to record patients' specific brain activity and recognize patterns that are associated with seizures," says Kristen Riley, MD, associate professor in the Department of Neurosurgery. "The RNS system then delivers stimulation in order to help modulate and control the seizures."
Because each patient's brain is different, the doctors' first task is to determine the precise locations where the seizures are triggered. The electrodes are then placed to stimulate those areas.
The RNS device is slightly larger than a flash drive and is designed to match the curvature of a patient's skull, according to Jerzy Szaflarski, MD, professor in the Department of Neurology and director of the UAB Epilepsy Center, "As the seizures are recorded by the device," Szaflarski says, "we can adjust the programming so that it's more in tune with the specific patient's seizures."
"We drill a small trough for the device so that it's flush with the skull's surface," Riley says. "There's no raised area, because it's basically hidden within the skull."
The Center's initial implant--in June, for a 24-year-old woman from central Alabama--was the first in the Southeast. Another surgery has since been performed, with more scheduled, and other patients are now being screened for the potential procedure. The device is produced by a Mountain View, California company named NeuroPace.
The RNS system can communicate with a computer, meaning that it can be customized so that it learns which patterns within the brain immediately precede seizures for individual patients. Several years of research studies indicate many patients respond to such stimulation, says Szaflarski, and thus have significant reduction in the frequency of their seizures.
"This is not a treatment that will cure epilepsy," Szaflarski says, "but it will help control seizures in a very specific group of patients who are not otherwise candidates for surgery. I don't expect too many patients to become seizure-free, but if we can decrease their seizures by even half, we can make huge improvements in their lives."
RNS is geared toward patients who have severe seizures and do not respond to medications, or are not candidates for surgery because their seizure-onset location is in an especially sensitive part of the brain. "We see multiple patients like that every year," says Szaflarski, "and the RNS system could make a real difference in their lives. We're continuing to accept patients who are interested in a consultation, evaluation, or intervention.
"We don't yet know why the system doesn't stop all seizures, but the process is ongoing."
One added benefit, according to Szaflarski, is that the RNS unit seems to work in conjunction with the brain to fine-tune its results over a period of time: "There's some plasticity in the brain that occurs in response to the stimulation. As a result, a patient who has only a partial response in the beginning tends to see that response improve over the course of several months.
"We're very excited to be the first facility in the Southeast to offer this therapy to our patients who are not candidates for more traditional epilepsy therapies."
