Evaluate the real-world impact of VNS on GTCS.

GTCS are highly debilitating with significant health risks. Patients resistant to ASMs, especially those for whom surgery is undesirable or not feasible, the use of VNS is common.

Patients with only primary GTCS enrolled in the prospective, multicenter observational registry (CORE-VNS NCT03529045) completed a 3-month retrospective baseline period, where seizure information and other patient-reported outcomes measures were collected prior to VNS implantation and up to 36 months. For purposes of analysis, a subpopulation of patients implanted within 5 years of original epilepsy diagnosis were compared to those implanted greater than 5 years from diagnosis.  At 3, 6, 12, and 24 months, seizure diary information and adverse events were collected.  

A total of 59 participants met criteria and received an initial VNS implant for the study.  Twelve (12) subjects were implanted within less than 5 years and 47 were implanted later than 5 years of epilepsy diagnosis.  Patients implanted were younger (9.7 years old, median). Participants had failed several previous ASMs (6 median) across both groups.  For the entire cohort, the responder rate (≥50% reduction from baseline) for GTCS at 12 months was 59.6% and the median seizure frequency change was -66.3%.  At 24 months, the responder rate for GTCS was 65.4% and the median seizure frequency change was -69.0%.  Earlier implantation participants were slightly less likely to be responders at 12 months (55.6% vs 60.5%) and had a lower median seizure frequency change (-50% vs -73.3%), both non-significant.  By 12 months, 35.6% of participants experienced at least one adverse event (most common were dysphonia, dyspnea, cough, and implant site pain.

VNS was well tolerated and effective in reducing the frequency of GTCS.