Responsive Neurostimulation

Some children cannot have resective surgery because seizures start in a part of the brain that cannot be removed. These children may benefit from one of the newer technologies to treat seizures with a device that uses responsive neurostimulation. “Responsive” means that the device is smart. It senses and responds to seizures in real time.

What is a responsive neurostimulation device?

There is only one responsive stimulation device approved by the FDA for treatment of epilepsy. This is the RNS System. It has three main parts:

• neurostimulator
• cortical strip lead
• depth lead.

The neurostimulator (also called a pulse generator) is a small, battery-powered device that generates electrical impulses. It is encased in metal. Electrodes from the device are placed on either the surface of the brain, deep within the brain, or both.

What is involved in surgery to implant the device?

• The surgeon makes an incision in the scalp
• A small opening in the skull is made. This is called a craniectomy.
• 2 – 4 electrodes are placed in the brain in areas where seizures start. The leads are placed using advanced technologies such as a special frame, robot, or stereotactic navigation.

Surgery to implant the device requires general anesthesia and takes 2 – 4 hours to complete. Most children can go home 2 – 4 days after surgery.

Intracranial EEG recording

One benefit of the RNS System is that it acts as a live EEG recording. This means that it will record seizures for months while your child goes about their daily activities. This helps the neurologist and neurosurgeon learn more about your child’s seizures.

For example, this data helps your child’s team understand whether seizures start in the left or right side of the brain. It can also help them understand which side of the brain has more seizure or how fast they spread. This information can help plan future treatments, including curative surgeries like resection o ablation.

Does responsive neurostimulation work in children?

The RNS System has only been used in children “off label” for a few years. Researchers are still trying to understand how well it works for children with different types of seizures. Early data shows that the RNS System is well tolerated by children and effective.

In one study, researchers looked at 17 children who were less than 18 years old when they had the RNS System implanted. One child was three years old and four children also had a resection at the same time.

The researchers found that:

• More than half of children experienced 50% or more reduction in disabling seizures
• 5 children experienced no improvement in their seizures
• None of the children had surgical complications

Research Studies

Researchers are still trying to understand if the RNS System is safe and effective for long-term use. There are currently two RNS System studies in the U.S. for children. Both studies are “single-blind” studies. This means some children will have the device activated and some will not. The children who do not get the device activated, and their parents, will not know this. It will include a two-month review of the child’s seizures before they get the treatment, and one month after they get the treatment. The device will be turned on after one month.

• NAUTILUS study:

  The study investigates whether the RNS system is effective for treatment of generalized seizures by stimulating a part of the brain called the thalamus. The study will last for two years and will include up to 100 people, including children ages 12 and up, in the United States. At least 80 of these people will get the RNS System.

• RESPONSE study:

This study investigates whether the RNS system is effective for treatment of focal seizures by stimulating the cortex of the brain. The study will last for two                  years and will include up to 200 people, including children ages 12 and up, in the United States. At least 150 of these people will get the RNS System.

LEARN MORE

Neuropace RNS System patient website

The RNS® System – A patient’s guide: this comprehensive guide from Neuropace provides extensive information about their RNS System.

Nagahama Y, Zervos TM, Murata KK, Holman L, Karsonovich T, Parker JJ, Chen JS, Phillips HW, Fajardo M, Nariai H, Hussain SA, Porter BE, Grant GA, Ragheb J, Wang S, O’Neill BR, Alexander AL, Bollo RJ, Fallah A. Real-World Preliminary Experience With Responsive Neurostimulation in Pediatric Epilepsy: A Multicenter Retrospective Observational Study. Neurosurgery. 2021 Nov 18;89(6):997-1004. doi: 10.1093/neuros/nyab343. PMID: 34528103; PMCID: PMC8637802.

CONNECT WITH OTHERS

The following online communities are provided for your information only. We do not endorse or guarantee the accuracy of statements posted by others.

• RNS, VNS, DBS for Epilepsy Support Group (Facebook)
• Pediatric Epilepsy Surgery Support (Facebook)