Authors :
Presenting Author: Stephen Jaffee, MD – Allegheny General Hospital
Trenton Kite, BS – Allegheny General Hospital
Shaifali Arora, MD – Allegheny General Hospital
Christopher Sanfillipo, MD – Allegheny General Hospital
Praveer Vyas, MPH, BS – Allegheny General Hospital
James Valeriano, MD – Allegheny General Hospital
Timothy Quezada, DO, MPH – Allegheny General Hospital
Dorian Kusyk, MD, MS – Allegheny General Hospital
Alexander Whiting, MD – Allegheny General Hospital
Rationale:
Responsive neurostimulation (RNS) is a promising treatment for medically refractory epilepsy that utilizes a “closed loop” system implanted in the skull with connection to 1 or 2 depth or paddle electrodes implanted in key nodes within the seizure network. RNS has been shown to be a safe and effective means of achieving seizure reduction. There are few large single center cohorts within the literature regarding RNS outcomes. Further characterization and subgroup analysis of patients within a single center may provide valuable clinical insights.
Methods:
A retrospective chart review was completed utilizing the electronic medical record of all patients treated with the RNS device at our institution from 2017 until 2024. All patients had at least six months of clinical follow-up and 2 RNS programming sessions post-operatively. Data gathered included: patient demographics, epilepsy history, epilepsy characteristics, medications, imaging, and operative reports. Post-operative seizure frequency was measured using subjective data collected from patient interviews. Descriptive statistics were completed, a one-way ANOVA test was used to measure the mean frequency of post-operative seizure frequency across all lead placement groups and a Chi-square was completed to assess the percent of patient who achieved an ENGEL Classification 2B or better post-operatively. All statistics were performed using GraphPad Prism (V.10). Results:
30 patients underwent RNS implantation over the study period. 73% of patients were male (n=22) and the mean age at RNS implantation was 34.6 years. 8 patients had previous vagal nerve stimulator (VNS) placement, 4 patients had previous lobectomies, and one patient had prior laser interstitial thermal therapy. Notably, 13 patients had bilateral mesial temporal, 3 patients had bilateral thalamic, 4 patients had cortical non-mesial temporal and 18 patients had left mesial temporal implantations. Overall mean seizure frequency reduction was found to be 69% ± 21 and overall median seizure frequency was found to be 75% (53-92). In terms of post-operative ENGEL classification, 4 patients achieved ENGEL 1A/1B, 17 patients achieved ENGEL 2B and 9 patients achieved ENGEL 3A. Use of XCopri had a statistically significant relationship with achieving a post-operative ENGEL 2B or lower classification (p< 0.035) as well as prior VNS placement (p< .0003); however, lobectomy was not significantly associated with post-operative ENGEL 2B or lower classification. There was no statistically significant difference in post-operative seizure reduction based solely on lead location. Regarding complications, there was no permanent morbidity or mortality, with no infections, hardware complications or wound breakdowns.