Abstracts

Rationale:
Seizures due to epilepsy can greatly limit a person’s capacity to perform daily activities, including driving. Vagus Nerve Stimulation (VNS) and Responsive Neurostimulation (RNS) provide adjuncts to work with anti-seizure Drugs and surgery to treat epilepsy and have been shown to reduce seizures and improve patient outcomes. This study aimed to focus on the patient-reported outcomes of refractory epilepsy patients with neuromodulation devices at Mayo Clinic Arizona (MCA), including their impact on seizure severity, frequency, and ability to drive.
Method:
We performed a retrospective review of the VNS and RNS surgeries (N=140) at MCA from 1999-2018, analyzing clinical data and supplementing it with patient responses from phone interviews. A phone questionnaire was conducted in 2020, where patients were asked to follow-up on their epilepsy status and outcomes. Results32 patients (VNS=24, RNS=7, Both=1) were able to self-report their seizure frequency and severity as well as if they are currently driving. We excluded 19 deceased patients and 13 patients with explanted devices. Descriptive statistics were utilized to analyze results. Of the RNS patients, 2 reported the same frequency (Engel Class IVB), 4 reported less frequency (Engel Class II), and 1 patient had more frequent seizures (Engel Class IVC). Of the VNS patients 4 reported the same frequency (Engel Class IVB), 19 reported less frequency (Engel Class II), and 1 patient had more frequent seizures (Engel Class IVC). The 1 RNS & VNS patient reported less frequent seizures (Engel Class II). 10 patients reported that they are seizure-free (Engel Class I). Of those, 4 are RNS patients and 6 are VNS patients. 9 out of the 32 patients (28.1%) interviewed are driving, 1 RNS patient and 8 VNS patients. Of those patients, only 2 patients are seizure-free. Of those 22 patients who still have seizures, patients ranked their seizure severity on a Likert scale from 1 (less) to 5 (more). In total, 3 patients ranked seizure severity as 1, 6 patients ranked seizure severity as 2, 7 patients ranked seizure severity as 3, 2 patients ranked seizure severity as 4, and 4 patients ranked seizure severity as 5. (RNS: 1 patient reported 3, 2 patients reported 5; RNS & VNS: 1 patient reported 1; VNS: 2 patients reported 1, 6 patients reported 2, 6 patients reported 3, 2 patients reported 4, 2 patients reported 5).
Conclusion:
75% of all patients reported a reduction in seizure frequency post-implant, 40.9% of patients ranked their seizure severity below a Likert 3, 31.3% of patients report being seizure-free, and most notably, 28.1% of patients are driving. Patient responses highlight their perception of treatment effectiveness, and that RNS and VNS devices provide a clinically meaningful impact on epilepsy patients as well as enable patients to gain autonomy, evident through their driving capabilities. Reporting driving as a functional clinical outcome may give patients a better sense of whether the therapy is acceptable to pursue.
Funding:
:N/A