Food and Drug Administration (FDA) approval for vagus nerve stimulator (VNS) implantation is limited to patients older than 4 years of age with medically refractory partial-onset seizures. In younger children with severe generalized epilepsy, however, VNS implantation remains off-label. In this study, the authors followed up on their previously reported cohort to review the longer-term safety and efficacy of VNS placement in children younger than 6 years with generalized medically refractory epilepsy (MRE), providing the largest cohort with > 2 years of follow-up to date in this age group.
This was a retrospective observational cohort study of patients younger than 6 years of age with generalized MRE who underwent VNS implantation at a single institution between 2010 and 2020. Inclusion criteria encompassed failure of more than two antiepileptic drugs alone or in combination, neurologist referral for vagus nerve stimulation, informed consent with knowledge of the off-label status in young children, and > 1 year of follow-up. Outcome measures included seizure reduction rate ≥ 50% and postoperative morbidity defined nominally. Statistical analysis was conducted with Stata/SE.
Forty-five patients were included: 11 patients younger than 4 years of age and 34 between 4 and 6 years of age. There were no intraoperative complications. Perioperative complications within 1 year occurred in 11% (n = 5) of the patients and included two wound infections, a mild cough, hyperactivity, hoarseness, and 1 patient with persistent surgical site pain. A seizure reduction ≥ 50% was observed in 36.4% (n = 4) of the patients younger than 4 years of age at the 6-month and 1-, 2-, and 5-year follow-ups. In the 4- to 6-year-old cohort, this was observed in 32.4% (n = 11) of the patients at 6 months, 41.2% (n = 14) at 1 year, 38.2% (n = 13) at 2 years, and 41.2% (n = 14) at 5 years.
VNS implantation for patients younger than 4 years of age with generalized onset MRE has not been approved by the FDA. This retrospective study establishes feasibility, illustrates an acceptable safety profile in children younger than 6 years, and demonstrates efficacy comparable to that reported in older patients.
VNS; epilepsy; neurosurgery; pediatrics; seizure freedom; vagus nerve stimulator.