Responsive Neurostimulation

What is responsive neurostimulation?

Responsive neurostimulation is a surgical treatment for seizures, in which an implanted device monitors brain activity and delivers electronic stimulation when a seizure is detected. The mild electrical pulses act to prevent or shorten the seizure.

A small battery-powered device is implanted in the skull, under the scalp, with one or two wires leading to points on or within the brain where seizure activity is originating. The wire ends sense abnormal brain activity and emit the electrical stimulation.

Who is a candidate for responsive neurostimulation?

Responsive neurostimulation is considered as a treatment for patients who have focal seizures originating at one or two points in the brain, that are not controlled by medications, after at least two medications have been tried.

In some cases, seizures may originate deep in the brain or close to brain tissue that controls critical functions. In these cases, responsive neurostimulation can be an alternative to traditional surgical procedures that remove the brain tissue, reducing the risk of neurologic deficits.

How is responsive neurostimulation performed?

Responsive neurostimulation is performed while your child is under general anesthesia.

An incision is made in the scalp and an opening cut in the skull just large enough to implant the neurostimulator device. The wires are positioned with the leads at the points in the brain where the seizures originate. The device is attached to the skull to align with its outer surface, and the skin of the scalp closed over it.

What to expect during responsive neurostimulation

Before responsive neurostimulation surgery

Before starting responsive neurostimulation, tests are done to identify the point or points in your child’s brain where the seizures originate. This usually includes stereo-EEG. Imaging is performed before surgery to assist the robotic placement of the wires in the precise location of the onset of your child’s seizures.  The neurostimulator device is placed where it will be least noticeable under your child’s hair.

On the day of the surgery and immediately after

On the day of the surgery, your child will undergo general anesthesia. At Children’s Hospital of Philadelphia (CHOP), you can trust our specially trained pediatric anesthesiologists to keep your child comfortable and safe before, during and after their procedure. Read more about our dedicated pediatric anesthesiology team.

The surgery itself takes three to four hours.

Your child will stay in the hospital overnight for recovery and may be released the next day or two or three days later. No extended bed rest is required.

Going home after responsive neurostimulation

Your child will be able to return to normal activities within a few days.  

Once each day you will use a remote monitor to collect data from the neurostimulator, a process that takes a few minutes. Once a week you will upload those data to a secure web database where your child’s medical team can review it.

When you or your child notice a seizure, they will swipe a special magnet over the device, which will prompt the device to store data about brain activity immediately before and after the seizure. That information will then be transmitted to your care team in the weekly upload. The medical team will use the data to fine-tune the sensing actions of the neurotransmitter over time, to detect and further reduce seizure activity.

Your child will return for follow-up appointments every four to six weeks to discuss seizure activity. Keeping a journal of seizure activity can help compare the data from the neurostimulator device with your child’s experiences, and to refine the programming of the device for greater effectiveness.

Responsive neurostimulation doesn’t end all seizure activity, but it reduces the number and severity of seizures experienced. By reviewing the data and fine-tuning the device’s seizure detection settings, seizure frequency can be reduced further over time.

Why choose CHOP for responsive neurostimulation

At Children’s Hospital of Philadelphia, your child will have access to pediatric experts from the Division of Neurosurgery, the Pediatric Epilepsy Program and others who specialize in the care of children with epilepsy and seizures.

Our team of experts work closely together to ensure that candidates are screened appropriately for responsive neurostimulation, and to provide the full range of supportive therapy before and after epilepsy surgery to optimize outcomes.