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The use of the RNS System is a relatively severe intervention in the brain and thus involves several health risks. So most Most of the risks are rather connected with a health issues than with a ethical issues.

First of all there are some risks associate with surgery to implant the RNS Neurostimulator and Leads: post-implant infection (7%) and bleeding in the brain or under the skull because of the implant (4.7%). After about 2 or 3 years of using, the Neurostimulator have has to be replaced with the new one, so the patient must get through another surgery. However the second one is not so dangerous, because the doctor will not have to do any surgery on the bone.<ref name="NeuropaceSystemPatientManual"/>

The implanted devices also might negatively interact with another medical procedures, such as Computed Tomography or MR (magnetic resonance).<ref name="NeuropaceSystemPatientManual"/> It might also cause allergic reaction, skin erosion (around the Neurostimulator), lead migration (move from their desired implant location) etc. There always remain remains a risk of failure the RNS devices.<ref name="NeuropaceSystemPatientManual"/>

Serious risk might also come out from unknown effect of long-term brain stimulation.<ref name="NeuropaceSystemPatientManual"/> This conclusion support supports as well the study conducted by Loring, Kapur, Meador and Morrell.<ref name="Differential neuropsychological outcomes following targeted responsive neurostimulation for partial-onset epilepsy">LORING, D.W., KAPUR, R., MEADOR, K.J., MORRELL, M.J. Differential neuropsychological outcomes following targeted responsive neurostimulation for partial-onset epilepsy. Epilepsia [online], 2015, Vol. 56, No. 11, pp. 1836–1844. Available online at: http://onlinelibrary.wiley.com/doi/10.1111/epi.13191/epdf (Retrieved 6.11.2016)</ref> It is probably too soon to determine exact effect of the brain stimulation. The study for long time effect of the brain stimulation is still under way and the estimated completion date is May 2023. <ref name="RNS® System Epilepsy PAS">RNS® System Epilepsy PAS. ClinicalTrials.gov [online]. 2016, Sep. Available online at: https://clinicaltrials.gov/ct2/show/results/NCT02403843 (Retrieved 6.11.2016)</ref>

On the other hand , there are clear benefits of the RNS System. It was demonstrated that the RNS System significantly reduce reduces epileptic seizures. According to clinical studies (Pivotal study – 191 subjects and Feasible study – 65 subjects), treatment patients come to the monthly reduction in seizure frequency averaging 37.9% compared to a 17.3% reduction in the Sham group (control group).<ref name="NeuropaceSystemPatientManual"/>

So it is clear that the RNS System is risky, but at the same time it helps people with epilepsy to reduce seizures. It still does not help every patient with epilepsy, because the RNS System is designed only to certain type of the epileptic condition. However according to Thomas and Jobst the RNS System might not be as so effective in seizure reduction as epilepsy surgery.<ref name="NCBI"/> On the other hand, epilepsy surgery is not always appropriate for certain type of epileptic illness. The RNS System thus remains suitable alternative to treat epilepsy. Similar conclusion also supports The University of Southern California (USC) Neurorestoration Center and the Keck Hospital of USC, that are the world's first institutions to implant the RNS System post FDA approval. They confirm that:

Some danger might arise also from hacker´s attack. The device interacts with the programmer, which is possible to replicates replicate and then operates operate the Neurostimulator. But according to Frank Fisher, the CEO of the NeuroPace, it is very unlikely due to the fact, that it is significantly difficult and there is neither a reason for someone to do that, because the hacker has in theory only two options. One option is that he might do something with the device, so it was not function any more. Or he might delivered delivere several inappropriate stimulation and caused cause a seizure.<ref name="NeuroPace: Controlling Epilepsy With a Brain Implant">NeuroPace: Controlling Epilepsy With a Brain Implant. Interwiev with Frank Fischer, the CEO of NeuroPace, Inc. IEEE Spectrum [online]. 2013, Nov 5. Available online at: http://spectrum.ieee.org/podcast/biomedical/bionics/neuropace-controlling-epilepsy-with-a-brain-implant (Retrieved 6.11.2016)</ref> These risks should not have been taken lightly, even if they are very unlikely.

In case of the RNS System is required to consider, if benefits outweigh considerable risks. According to FDA, they did. But it depend depends on each patient individually after all. Some people might have a problem with the implementation of a devicein the brain, because every intervention to the brain is very risky. For some people it might be completely unacceptable that they would have a the device in their bodies, for example, based on their beliefs.

There are many successful stories of patients with implanted RNS System. One of the first patient, who received the RNS System outside the study group was Tracey Drake in November 2014 at New York-Presbyterian/Weill Cornell Medical Center. She has reported very positive experience with the RNS System.<ref name="Epilepsy Team Implants First NeuroPace RNS Neurostimulator ">Epilepsy Team Implants First NeuroPace RNS Neurostimulator. Weill Cornell Brain and Spine Center [online]. 2014, Nov 7. Available online at: http://weillcornellbrainandspine.org/in-the-news/epilepsy-team-implants-first-neuropace-rns-neurostimulator (Retrieved 6.11.2016)</ref> There are several similar stories that show positive effect effects of the RNS System.

Now is also especially necessary to establish exactly which role the RNS System will play in treatment of epilepsy. In fact, the RNS System is still at the beginning and it is perceived more like alternative to AED (antiepileptic drug) or surgery. <ref name="AES_ResponsiveNeurostimulation_and_Cognition"/> There remains a question how will look like the RNS System in the future. Frank Fischer note that:

The RNS System was approved (Premarket Approval, PMA) by Food and Drug Administration (FDA) in 2013 based on clinical studies. Those contain a Feasibility study, a Pivotal study, and a Long-term Treatment study. There were also several studies in laboratory, where were tested every single device of the RNS System. Before human studies, there were also studies on animals, particularly on sheep. The Feasibility study contained 65 subjects and was aimed on at preliminary safety and effectiveness. The results of the Feasibility study was used in the Pivotal study, which was performed ''"to establish a reasonable assurance of safety and effectiveness of the RNS System"''. It was contained containing 191 subjects in total. The Long-term Treatment study is still ongoing. It contains 230 subjects. <ref name="SSFD">Summary of Safety and Effectiveness Data (SSED). U.S. Food & Drug Administration [online]. 2013. Available online at: http://www.accessdata.fda.gov/cdrh_docs/pdf10/P100026B.pdf (Retrieved 4.11.2016)</ref>

DBS treatment is stimulation of the different areas of central nervous system. Most extensively has been studied the stimulation of the anterior nucleus of the thalamus. The DBS stimulation has been approved first by European Union (Conformité Européenne, CE) for company Medtronic in 2013 <ref name="Medtronic Receives European CE Mark Approval">Medtronic. Medtronic Receives European CE Mark Approval for Deep Brain Stimulation Therapy for Refractory Epilepsy. Medtronic, Inc. [online]. 2010. Available online at: http://newsroom.medtronic.com/phoenix.zhtml?c=251324&p=irol-newsArticle&ID=1773303 (Retrieved 5.12.2016)</ref> , and than by FDA in 2013 for treatment of epilepsy (under the FDAs Humanitarian Device Exception)<ref name="Deep Brain Stimulation: Expanding Applications">TEKRIWAL, A., BALTUCH, G. Deep Brain Stimulation: Expanding Applications. Neurol Med Chir, Tokyo, 2015, Vol. 55, No. 12, pp. 861–877.</ref>. The other areas of the stimulation are, for example the cerebellum or the hippocampus. Effectiveness of the stimulation in the anterior nucleus is estimated on 4050% reduction seizures.<ref name="Neurostimulation for the Treatment of Epilepsy"/>

There are also some similar devices, that treat the different kind of diseases. One of them is, for example the Activa Deep Brain Stimulation Therapy System (Medtronic), which is targget to treat tremor associated with Parkinson´s disease and essential tremor. It was approved by FDA in 1997.<ref name=" FDA Okays Brio">JEFFREY, S. FDA Okays Brio Neurostimulation System for PD, ET. Medscape [online]. 2015, Jun 12. Available online at: http://www.medscape.com/viewarticle/846456 (Retrieved 3.12.2016)</ref> Similar device for reducing the symptoms of Parkinson's disease is the Brio Neurostimulation System, which has been was approved by FDA in 2015.<ref name="FDA approves brain implant to help reduce Parkinson’s disease">FDA Administration. FDA approves brain implant to help reduce Parkinson’s disease and essential tremor symptoms. FDA Administration: FDA News Release [online]. 2015, Jun 12. Available online at: http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm451152.htm (Retrieved 3.12.2016)</ref>