Keck Medicine of USC has become the world’s first medical center to implant a responsive brain device newly approved by the Food and Drug Administration (FDA) to treat epilepsy. It has the potential to help millions of people worldwide.
The treatment involves surgical implantation of a device that detects and then directly responds to abnormal brain activity to prevent seizures before they occur. In a three-hour surgery Dec. 18, USC faculty physicians implanted the device in a 28-year-old Lakewood, Calif., woman who was diagnosed with epilepsy in 2004.
“I’m just so lucky to be here at USC,” said Kathleen Rivas, an aspiring journalist who sought care from the university’s student health center in 2009 while earning her master’s degree. “Without faith and trust in my neurologist and neurosurgeon, I don’t know where I’d be. My life is in their hands.”
Rivas elected to have the implant because medication had not fully controlled her seizures. Over the next few months, her doctors will program the device to detect brain activity that indicates a seizure’s onset.
The device is the world’s only responsive neurostimulation (RNS) system approved for clinical use. USC physicians have been studying the technology since 2006 and are among the first authorized to prescribe its use since FDA approval on Nov. 14.
A ‘game changer’
“This has the potential to be a game changer in the care of patients with epilepsy,” said neurologist Christianne Heck, associate professor of neurology at the Keck School of Medicine of USC, medical director of the USC Comprehensive Epilepsy Program and principal investigator of the device’s clinical study at USC. “Every individual’s epilepsy is different. Unlike other neurostimulators on the market, this system looks for just the right circumstances to stop a person’s seizure from happening.”
Epilepsy is a debilitating neurological condition that causes recurrent seizures, affecting about 65 million people worldwide, including nearly 3 million in the United States. Those who can tolerate medication and whose seizures are completely controlled usually lead a normal life, but the disease can be devastating for the up to 40 percent who experience uncontrolled seizures.
Most people with epilepsy gain complete control of their seizures or are able to significantly reduce the number of seizures they experience by taking medicine or having surgery to remove the area of the brain where the seizures originate. Having developed new methods to identify and cut out the seizure-onset zone, the surgical epilepsy program at USC has had an 80 percent cure rate among patients who do not respond to anti-seizure medications. RNS may help the remaining 20 percent.
“We have become very good at finding and surgically removing the areas of the brain where these seizures start, but we have limited options when a person’s seizures begin in critical zones, such as those that affect speech or movement,” said neurosurgeon Charles Liu, professor of neurosurgery and neurology at the Keck School, surgical director of the USC Comprehensive Epilepsy Program and director of the new USC Center for Neurorestoration. “Devices like this provide an option for the population with epilepsy who live with uncontrollable seizures because no available treatment works for them. Implanting it is probably safer than traditional epilepsy surgery because we’re not taking anything out.”
Heck, who is also co-director of the USC Center for Neurorestoration, sought to join the clinical trial of the RNS device in December 2005 and testified before the FDA in 2012. USC implanted its first RNS patient in December 2006 and ultimately enrolled and treated 10 patients.
FDA approval of the RNS device came after a randomized clinical trial of 191 patients with drug-resistant epilepsy across 32 clinical sites. The study showed that, by three months after the device was turned on, patients experienced a nearly 38 percent reduction in monthly seizures, compared to a roughly 17 percent reduction in monthly seizures among patients who had the implant turned off. Two years post implant, 55 percent of patients experienced a 50 percent or greater reduction in seizures.
Patients with the RNS device cannot undergo magnetic resonance imaging procedures, diathermy procedures, electroconvulsive therapy or transcranial magnetic stimulation. The energy created from these procedures can be sent through the device and cause permanent brain damage. The most frequent adverse events reported were implant site infection and premature battery depletion.