Authors :
Presenting Author: Gaia Giannicola, PhD – Sorin Group Italia S.r.l.
Gaia Giannicola, PhD – Sorin Group Italia S.r.l; Ana Suller-Marti, MD PhD – Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry – Western University; Ryan Verner, PhD – LivaNova USA Inc.; Mark Keezer, MD PhD – Department of Neurosciences and School of Public Health – Université de Montréal; Andrea Andrade, MD – Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry – Western University; Martin Veilleux, MD – Department of Neurology and Neurosurgery – Montreal Neurological Institute and Hospital; Kenneth Myers, MD PhD – Research Institute of the McGill University Medical Center; Jorge Burneo, MD – Department of Clinical Neurological Sciences, Schulich School of Medicine and Dentistry – Western University
Rationale:
Generalized tonic-clonic seizures (GTCS) are highly debilitating seizures with significant health risk, including sudden unexpected death in epilepsy. For patients resistant to antiseizure medications (ASMs), and especially those for whom surgery is undesirable or not feasible, off-label use of device-based therapies like vagus nerve stimulation (VNS) can help. We aim to examine the real-world impact of VNS on non-seizure outcomes in patients with GTCS.
Methods:
Patients were enrolled into a prospective, multicenter observational registry called CORE-VNS (NCT03529045). We selected newly implanted patients with primary GTCS, and excluded patients who had focal seizures at baseline or GTCS in the context of Lennox-Gastaut Syndrome. These participants completed a three month retrospective baseline period, where patient-reported outcomes measures were collected prior to VNS implantation. After the implant, participants were followed for up to 36 months. At 3, 6, 12, and 24 months, patient-reported outcomes were collected. Participants completed questionnaires to evaluate the quality of life, quality of sleep (Pittsburg Sleep Quality Index [PSQI] and Children’s Sleep Habit Questionnaire [CSHQ]), and healthcare utilization.
Results:
We identified a total of 59 participants who fulfilled the criteria and who received an initial VNS implant for the study. Participants were implanted with VNS at a median age of 20.28 years (range 2.6 to 67.9), and 26 were children (< 18 years old) and 33 were adults. Participants had failed several previous ASMs (six median, range 2 to 20) and had been diagnosed with epilepsy for a median of 11 years (range 0 to 58). Most participants had some level of cognitive impairment: nine (15.3%) minimal, 19 (32.2%) moderate, and nine (15.3%) severe. Overall quality of life improved in 38.78% (n=19) of participants at 12 months and 33.33% (n=16) at 24 months. Sleep quality tended to improve after 12 months of VNS, but not significantly (PSQI: median -1, 95% CI: -3 to 0; CSHQ: median -1, 95% CI: -5 to 2). At 24 months, sleep quality continued its trend toward improvement but remained non-significant, with greater improvement in children (PSQI: median -1, 95% CI: -2 to 0; CSHQ: median -2.5, 95% CI: -6 to 2). Median seizure related emergency visit density compared to baseline and seizure related hospitalization density compared to baseline were unchanged (median 0% change), but < 5% of subjects experienced significant reductions in healthcare resource utilization. By 12 months, 35.6% (n=21) of participants experienced at least one adverse event and the most frequent side effects associated with VNS stimulation were dysphonia (11.9%,n=7), dyspnea (5.1%, n=3), cough (3.4%, n=2), and implant site pain (3.4%,n=2).
Conclusions:
In this prospective study, VNS was well tolerated and improved the quality of life of many patients living with GTCS. Some patients treated with VNS also saw reduced need for emergent care related to epilepsy. Quality of sleep trended toward improvement but was not meaningfully impacted.
Funding:
This work was funded by LivaNova USA Inc.