Responsive neurostimulation device
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Responsive neurostimulation device or RNS system is the first and only brain-responsive neurostimulation system designed to prevent epileptic seizures at their source. Similar to a pacemaker that monitors and responds to heart rhythms, the RNS System monitors and responds to brain activity. The RNS System is made by NeuroPace, Inc.
The RNS neurostimulator is a small, implantable device connected to leads (tiny wires) that are placed in up to two seizure onset areas. The device continuously monitors brain activity, detects abnormal patterns, and in response delivers imperceptible electrical pulses to normalize the activity before an individual experiences seizures.
The RNS System was FDA approved in 2013 to treat adults with partial onset seizures that are not controlled by medications. The RNS System is currently available in most Level 4 Comprehensive Epilepsy Centers throughout the United States and is broadly covered by private and government insurance. As of March, 2017 over 1,000 patients have been implanted with the RNS System.
How the RNS System helps prevent seizures:
The RNS System continuously monitors brain activity at the seizure source. It works in the background, without the patient feeling anything.
The device is programmed by physicians to detect early, abnormal electrical patterns that can lead to seizures. These patterns are different for every individual, and the device can be personalized to recognize each brain's unique "fingerprint".
Within milliseconds of detecting abnormal brain activity, the RNS System sends tiny electrical pulses to disrupt the abnormal activity and normalize brainwaves. This real-time response is designed to prevent seizures from occurring.
The RNS System is the only treatment option that monitors and responds to brain activity directly at the seizure source. It delivers treatment when needed, on average less than 6 minutes of stimulation per day.
Once implanted, the RNS System is unnoticeable under and individual's hair, and device setting are personalized so that the stimulation is not felt.
A window to the brain: The RNS System is the only epilepsy therapy that also provides physicians clinically meaningful ongoing data about their patients’ seizure frequency and electrocorticographic activity. The patient uses a simple remote monitor at home to wirelessly collect and upload data from their neurostimulator. The data is made available to their doctor to review and analyze, so that they can improve patient care. The RNS System is surgically implanted in the skull by a trained neurosurgeon and typically involves an overnight stay in the hospital. The therapy is reversible; the procedure does not involve removing any brain tissue. For many medically refractory partial-onset epilepsy patients who are not candidates for epilepsy surgery, the RNS System provides a clinically proven therapy option to reduce seizure frequency and improve quality of life.
The RNS System Clinical Summary:
The RNS System was evaluated in a multi-center, prospective, randomized, controlled, double-blinded clinical study—one of the largest and most rigorously conducted pivotal trials for any neuromodulation technology. The study included adults who have medically refractory, partial onset seizures with up to two localized seizure foci, and who had failed at least two medications. In total, 191 patients were randomized 1:1 to either treatment with the RNS System or sham stimulation. After the four month blinded period, stimulation was turned on for all patients. Treatment with the RNS System resulted in statistically significant seizure reductions compared to the sham group. By the end of the blinded period, patients in the Treatment group had a 41.5% reduction in disabling seizures compared to 9.4% in the Sham group (p=0.008). The safety profile of the RNS System compared favorably to deep brain stimulation as well as implantation of intracranial electrodes and epilepsy surgery (Morrell, 2011).
Patients treated with the RNS System experience substantial seizure reductions in the first year that continue to improve over time. At seven years, patients achieved a 72% median reduction in seizures (Bergey, 2015). Quality of life (QOL) and mood are often negatively affected by epilepsy, particularly in patients with poorly controlled seizures. Patients treated with the RNS System reported statistically significant improvements in mood and overall quality of life, including physical health, mental health, cognitive effects, and seizure worry (Meador, 2015).
Patients treated with the RNS System show no evidence of cognitive decline. In fact, they have demonstrated statistically significant improvements in naming and verbal memory. This is meaningful because individuals with epilepsy are at risk for cognitive disability and decline which has also been associated with other epilepsy treatments. For example, many antiepileptic drugs have adverse cognitive effects, patients treated with deep brain stimulation have reported cognitive decline, and epilepsy surgery carries risks for decline in cognitive areas specifically related to those regions of the brain that are resected (Loring, 2015). Another notable feature of the RNS system is the subtle, virtually imperceptible, nature of the therapy. Device settings are personalized so that patients do not feel or notice the stimulation. This is in contrast to other therapies, such as vagus nerve stimulation, which can have chronic stimulation-related side effects such as voice alterations, coughing, throat discomfort, and shortness of breath.
- Electroencephalography (EEG)
- Electrocorticography (ECoG)
- Single-unit recording a method of measuring the electro-physiological responses of single neurons using a microelectrode system
- Responsive cortical stimulation for the treatment of medically intractable partial epilepsy. Morrell MJ; RNS System in Epilepsy Study Group. Neurology. 2011 Sep 27;77(13):1295-304
- FDA Advisory Panel Recommends Approval of the NeuroPace RNS® System for Medically Refractory Epilepsy
- (Wayback machine for http://www.seizurestudy.com/InvestigationalTreatment.html) The RNS System Information from a patient who started in the pivotal trial and is now in the long term trials.
- Morrell MJ, et al. Neurology. 2011 Sep 27;77(13):1295-304
- Bergey GK, et al. Neurology. 2015 Feb 24;84(8):810-7
- Meador KJ, et al. Epilepsy
- Behav. 2015 Apr;45:242-7, Loring, DW, et al. Epilepsia. 2015 Sep 19
Media Contacts: Hillary Marder MSL Group for NeuroPace email@example.com