Approximately 20 percent of people with epilepsy cannot adequately control their seizures with antiepileptic drugs (AEDs). For people with frequent, disabling partial onset seizures imperfectly controlled by medication, a responsive neurostimulation (RNS) device may be considered. To be eligible, there must be one or two seizure targets identified by a neurologist.
The RNS system is an implanted device that monitors brain activity and provides pulses of stimulation to disrupt any abnormal brain activity before a seizure can start. RNS is used in conjunction with AEDs.
What does it involve?
RNS implantation involves a surgical procedure. You will be placed under general anesthesia. The neurosurgeon will place the small, electronic RNS device inside the skull and connect one or two leads from the device to the seizure targets. After the scalp has healed, there will be no visible sign of the RNS.
You can expect to stay in the hospital for one or two days after receiving a RNS device.
Over the next few days, the device will be programmed to detect and record brain activity patterns and respond with electrical stimulation when abnormal patterns are detected. The device is calibrated to the individual so that stimulation cannot be felt. You will continue taking AEDs after receiving an RNS device. When you go home, you will receive a brain activity monitor that will record data and send it to the neurologist.
In conjunction with AEDs, RNS can help reduce the frequency of seizures. Some people experience improvements in memory and language after receiving RNS.
Studies have shown that RNS decreases seizures by a median of 44 percent at one year, 53 percent at two years, and 60 to 66 percent from three years to six years after receiving the system.
Any surgery carries risks including blood clots, blood loss, infection, breathing problems, reactions to medication, and heart attack or stroke during the surgery.
RNS may not be successful in reducing your seizures.
Responsive Neurostimulation – Epilepsy Foundation