Of the 50 million people worldwide estimated to have epilepsy, almost a third do not respond to treatment. Those patients must rely on implantable anti-seizure devices that detect pre-seizure electrical activity and shoot small electrical impulses to the brain to interrupt the seizures.
Greg Stanley/Johns Hopkins University)
The downside is that the tech, still early in development, also produces false positives, causing devices to send currents to the brain when a seizure is not actually occurring. One new approach, developed by a biomedical and electrical engineer at Johns Hopkins University, appears to reduce those false alarms.
Tested on real-time recordings of brain activity in four patients who are resistant to drug therapy, Sridevi Sarma reports in the journal Epilepsy & Behavior that her software not only detected all actual seizures, but resulted in up to 80 percent fewer false positives when compared to other approaches. (The actual rate was 0.16 false positives per hour, or one every 6.25 hours.)
“If you introduce electric current to the brain too often, we don’t know what the health impacts might be,” Sarma said in a news release. “Also, too many false alarms can shorten the life of the battery that powers the device, which must be replaced surgically.”
Sarma and her team used a system made of electrodes connected to a neurostimulator and a sensing device located within the implant, and compared the electrical activity in the brains of the four patients before, during, and following seizures to better identify the precise moment when they begin.
Sarma says she hopes to eventually embed her software in a microchip that constantly monitors neuro-electrical activity and is triggered the moment a seizure begins to form. For now, she has secured a patent through the Johns Hopkins Technology Transfer office.