Placing the Responsive Neurostimulation (RNS®) System

Placing an RNS® device happens only after a work-up for epilepsy surgery is done. This testing would include long-term EEG (electroencephalogram) monitoring at an epilepsy center to find out where seizures begin. Testing to see if this area can be removed or if RNS® is possible is done too.

When the decision to use responsive neurostimulation is made, each person should meet with their epilepsy team to learn about the procedure and the practical part of using the RNS® System at home.

  • Surgery under general anesthesia is needed to place the neorostimulator device.
  • The surgery does not involve taking out (resecting) a part of the brain.
  • The neurostimulator and leads are placed by a neurosurgeon trained in the procedure.
  • The neurostimulator device is secured into the skull or bone covering the brain. It is fixed to the skull so it can not move and it lies flat.
  • The neurostimulator does not touch the brain.
  • Thin wires or leads are placed on the surface or slightly below the area of brain where the seizures begin. Up to two wires can be placed if seizures come from more than one area.
  • The wires are then connected to the neurostimulator.
  • The device is tested in the operating room but is not turned on until later.
  • The incision in the scalp (skin covering the brain) is closed. Since the neurostimulator is not thicker than your skull, it will lie flat and is not visible to you or anyone else.
  • Generally, a person will stay in the hospital one or two days to recover, and then can return home.

Programming Phase

The RNS® System is personalized to you and your seizure pattern.

  • Before you leave the hospital, your health care team will review what you are expected to do at home.
  • You will need to have access to the internet.
  • You will be given equipment that includes a small wand and computer.
  • By placing the wand on top of your head, it can send the information in the neurostimulator to a secure database.
  • For a number of weeks after the RNS® device is first placed, the system will just record your brain wave patterns and activity that may look like seizures.
  • Your epilepsy doctor will look at this recorded data. She can then program (or set up) the RNS® to send tiny pulses of stimulation to the brain when specific patterns in the brain waves are seen.
  • During future visits to your epilepsy doctor, he or she will look at new data collected to see how you are doing and adjust the settings if needed.
  • Appointments for RNS® programing usually take longer than routine appointments. You may need to come frequently in the first few months. Then visits can be spaced out to about every three to four months, depending on how you are doing.

What are the risks of RNS® Therapy?

  • Everyone considering a change in treatment should weigh the risks as well as benefits of each therapy.
  • People considering epilepsy surgery, devices like RNS or VNS (vagus nerve stimulation), dietary therapy, or any new treatment should see an epilepsy specialist first to learn about their options.
  • The risks of surgery to place the RNS® device are low and include those that may be seen with any surgical procedure.
    • Some people may have trouble or side effects from anesthesia.
    • The most common short-term side effects (during the first year after surgery) included pain at the implant site, headache, and unpleasant or abnormal sensations. These side effects can be seen with other procedures of the brain or skull.
    • Other problems related to the surgery:
      • Infections of the skin (scalp) where the stimulator was placed occurred in 3.7% of people in the early studies.
      • Bleeding in the brain happened in 2.7% of people having the procedure. No long-term problems were seen after this.
      • Leaking of CSF (cerebrospinal fluid that surrounds the brain) or fluid could collect around the site of surgery.
  • Risks during programming may include:
    • Problems with the neurostimulator or leads not working as expected. However, since you are using the wand to collect and send data to your epilepsy doctor, he or she will see if any problems occur with the device.
    • Although rare, damage to brain tissue could happen.
  • The RNS® System is an incredible innovation for people with epilepsy, but there are still unanswered questions. For example, we do not know its effects in pregnant women, and the long-term effects have not been studied in close detail.
  • It could be that the RNS® System may interact with an implanted cardiac device and deliver inappropriate stimulation, but this needs to be looked at more.

What safety precautions are needed with RNS® Therapy?

  • The RNS® System should not be used in people who
    • Are at a high risk of complications from surgery
    • Already have a device that delivers electrical stimulation in the brain (e.g., Deep Brain Stimulator or DBS)
    • Are unable (or do not have help) to operate the system at home
  • People who have the RNS® system in place should not have procedures that use:
    • Magnetic resonance imaging (MRI)
    • Any procedure that uses high-frequency electromagnetic radiation or electric current to produce heat in the body. (These are called “diathermy procedures.”)
Talk to your doctor and epilepsy team for more details on precautions and safety with responsive neurostimulation.
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Authored By: 
Sloka Iyengar PhD and Patricia O. Shafer RN, MN
Authored Date: 
11/2017
Reviewed By: 
Mohamad Koubeissi MD and Joseph I. Sirven MD
on: 
Tuesday, November 28, 2017