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Purpose Vagus nerve stimulation (VNS) is an effective adjunctive therapy for drug-resistant epilepsy. Nevertheless, information is lacking regarding optimization of stimulation parameters to improve efficacy. Our study examines the safety and efficacy of rapid duty cycle VNS (OFF time ≤1.1 minute keeping duty cycle less than 50%) in pediatric cohort with intractable epilepsy. Methods Retrospective chart review of 50 patients (one to 17 years) with drug-resistant epilepsy treated with VNS between 2010 and 2015 at a single pediatric epilepsy center. Safety and tolerability data were aggregated across all patient visits to determine frequency of adverse events between differing duty cycles. We also compared seizure reduction rates for each patient at (1) last regular duty cycle visit, (2) first rapid duty cycle visit, and (3) last recorded rapid duty cycle visit. Results Rapid duty cycle was well tolerated, with no adverse events reported in 96.6% patient encounters. At the last visit before switching to rapid duty cycle 45.5% patients were showing response to VNS (seizure reduction rates ≥50%). This rate increased to 77.3% after switching to rapid duty cycle and remained at 77.4% at the last rapid duty cycle visit. Fifteen patients (34.1%) became responders to VNS after switching to rapid cycling; another 19 (43.2%) maintained their response with mostly improved seizure reduction rates. In only a few instances, responders became nonresponders after switching to rapid duty cycle. Conclusions Rapid duty cycle VNS is probably safe and well tolerated; it may also be more efficacious than regular cycling VNS in some patients. This study highlights the necessity of prospective, long-term, double-blinded studies for understanding the advantages of this VNS modality.

Childhood neurologic disorders, as a group, include relatively common conditions such as migraine (prevalence between 3% and 10.6% in children 3–15 years of age1,2), transient tic disorders (TDs) (3%),3 and specifically Tourette syndrome (TS) (0.8%),3 and rarer disorders such as infantile spasms that may occur in only about 1,200 infants each year in the United States. These disorders account for a disproportionately higher number of emergency department visits, intensive care admissions, deaths, and higher costs when compared to other childhood illness.4 Generally, delivery of quality care should improve outcomes and result in decreased unnecessary utilization of health services.4