Vagus nerve stimulation in Lennox-Gastaut syndrome: Twenty-four-month data and experience from the CORE-VNS study

The drug-resistant epilepsy associated with Lennox-Gastaut syndrome (LGS) has a long-term effect on patients and is difficult to treat with conventional pharmacological and nonpharmacological therapies. Our objective is to demonstrate that adjunctive vagus nerve stimulation (VNS) can help manage the seizures associated with LGS.

CORE-VNS (NCT03529045) is a prospective, multicenter, multinational observational study to collect data on seizure and nonseizure outcomes following treatment with VNS. Participants were identified as having a documented LGS diagnosis and received initial VNS implants. Baseline seizure frequency data and patient-reported outcome measures were collected at 3, 6, 12, 24, and 36 months. This interim analysis compared baseline data to VNS therapy outcomes at 24 months, and the results are presented here.

Sixty participants in the CORE-VNS study had a diagnosis of LGS and received an initial implant of VNS. The population was geographically diverse: 31.7% European, 26.7% from the Americas, and 26.7% from the Western Pacific. The median age at implant was 11.8 years (range = 2.2-47.6), and only 26.7% of those diagnosed with LGS were >18 years of age. Most (70%) of the participants had severe cognitive impairment. The LGS participants failed a median of 6 antiseizure medications, and 83.3% had not undergone epilepsy surgery. The LGS responder rate (≥50% reduction in seizure frequency) at 24 months for focal and generalized seizures was 66.7% and 47.4%, respectively. Some participants (20%, 12/60) experienced a ≥80% reduction in total seizure frequency. VNS was well tolerated, with only 15% (9/60) reporting at least one treatment-emergent adverse event, primarily cough, dysphonia, and oropharyngeal pain.

LGS participants who received adjunctive VNS therapy to manage seizures were predominantly severely cognitively impaired children. Reductions in seizure frequency, including those with drops, and the sustained nature of the response support VNS as a promising therapy in LGS.