A Single-Center Evaluation of Responsive Neurostimulation as Treatment for Drug-resistant Epilepsy
Sean Beattie1, Gloria Ortiz Guerrero2, Utku Uysal3
1Neurology, University of Kansas Medical Center, 2University of Kansas Medical Center, 3University of Kansas Medical Center Department of Neurology
Objective:
To determine the efficacy and safety of RNS in the treatment of drug-resistant epilepsy and to determine the potential complications.
Background:
Epilepsy Surgery is an effective treatment for patients with drug-resistant epilepsy (DRE). Although resection/ablation of the epileptogenic zone is the preferred method to achieve seizure freedom, many patients are not appropriate for resection/ablation due to potential neurologic risks or limited benefits. Responsive Neurostimulation System (RNS) was approved by the US Food and Drug Administration FDA as an adjunctive treatment of drug-resistant focal epilepsy.
Design/Methods:
A database search was performed for patients who underwent RNS placement between 01/01/2014-04/01/2022 at our institution. Patients with >12 months follow-up duration were included in the final data analysis. The primary outcome is seizure freedom as defined by Engel/ILAE seizure outcome classification systems. Variables were reported as mean or median for numerical variables and percentage for categorical variables. The Chi-square and Fisher’s exact tests were applied to compare independent groups for categorical variables.
Results:
A total of 50 patients fit the inclusion criteria during this time period. 19 were excluded as they had less than one-year follow-up. Overall, 22.6% reached a state of freedom from disabling seizures (Engel 1 or ILAE I/II). With 28 total patients getting RNS alone or as a final procedure, 21.4% achieved freedom from debilitating seizures (Engel 1 or ILAE I/II), and 60.7% had a >50% reduction in seizure frequency (ILAE III/IV). There was no difference regarding seizure freedom in patients based on electrode placement (p = 0.645).
Four patients (8%) had complications (1 encephalopathy, 2 scalp infections, and 1 scalp infection with meningitis). The other 92% had no major complications.
Conclusions:
Overall, RNS provides worthwhile seizure reduction in most of the population seen at the University of Kansas Medical Center. The outcome from our center is comparable to the outcomes reported in literature.