Abstracts

Rationale:
Refractory epilepsy can significantly reduce patient quality of life (QOL) metrics and cause substantially high mortality rates. Vagus Nerve Stimulators (VNS) and Responsive Neurostimulators (RNS) can provide complementary techniques to anti-seizure drugs (ASDs) and surgical resections to treat refractory epilepsy. Treatment success using these techniques is typically evaluated by magnitude of seizure decline, less commonly through measured QOL metrics. The purpose of this study was to analyze functional QOL measures among this patient population at Mayo Clinic Arizona (MCA) that contribute to optimal patient-reported QOL scores, specifically: personal life changes, financial status, driving and employment capabilities, memory aptitude, improvements in comorbidities, and medication reduction. Further, this study analyzes the metrics that factored into optimal, self-reported QOL scores by 10 MCA VNS/RNS patients.
Method:
This study is a retrospective analysis of the total epilepsy VNS and RNS patient cases (N = 140) at MCA between 1999-2018, identifying those eligible for phone interview regarding their QOL with VNS or RNS devices. Phone surveys were conducted from January 26 - March 2 of 2020; a total of 32 (VNS = 24, RNS = 7, Both = 1) patients were successfully interviewed on the above QOL outcome metrics. Descriptive statistics were utilized to analyze results.
Results:
Patients eligible for interview included total VNS and RNS patients, death (none from implantation) = 19 (mean age = 50.4 years), explant n = 13, with a final responder N = 32. From the total group of interviewed patients, 31.3% of all patients are seizure-free and 84.4% of patients reported that they would repeat VNS and/or RNS treatment, based on their current, comprehensive knowledge of their QOL outcomes surveyed.  A subgroup (n = 10) scored their overall QOL as optimal (5/5). Of this subgroup: 40% are seizure-free, 50% had medication reduction, 30% experienced positive personal life changes, 60% reported the same financial status as prior to VNS/RNS surgery, 40% are driving, 20% are working, 70% reported the same memory. Of the four from this subgroup that reported having comorbidities, three reported improvements in comorbid illness such as better motor function, breathing capabilities, and improvement in prior mental disabilities.
Conclusion:
Notable findings include that most of the patients from the optimally scoring group regarding overall QOL had not attained seizure freedom after VNS or RNS implantations and there was approximately one death per year among this total cohort of MCA refractory epilepsy patients who underwent neuromodulation. These suggest that there are other determinants of perceived QOL that may have greater implications than seizure freedom for refractory epilepsy patients, that patients believe the benefits of these procedures outweigh the consequences, and refractory epilepsy patients face significantly higher risks of mortality than the average person in the United States. Reference: Products - Data Briefs - Number 355 - January 2020. Published January 29, 2020. Accessed March 30, 2020. https://www.cdc.gov/nchs/products/databriefs/db355.htm
Funding:
:N/A