Abstracts

OBJECTIVE: At the end of this activity, participants should be able to discuss the outcome of pediatric patients receiving vagus nerve stimulation (VNS) Therapy for refractory seizures.
RATIONALE: Physicians treating patients with VNS Therapy voluntarily submit information to the manufacturer-maintained patient outcome registry, which records baseline demographic data and tracks changes in seizure frequency and quality of life. This analysis compares pediatric registry patients aged 0 through 11 years with those aged 12 through 17.
METHODS: The registry was queried for a constant cohort of pediatric patients with data available at baseline and after 3 and 12 months of VNS Therapy. Demographics and changes in seizure frequency and quality of life of patients aged 0 though 11 years (younger) were compared with those of patients aged 12 though 17 (older).
RESULTS: The younger group had 297 patients (56.6% males) and the older group had 263 (53.2% males). Epilepsy syndromes were distributed as follows: localized, 39.7% younger, 50.6% older; generalized, 27.6% younger, 22.4% older; Lennox-Gastaut, 28.3% younger, 24.0% older; other, 4.4% younger, 3.0% older. Median duration of epilepsy before VNS was 6.3 years in the younger group and 12 years in the older group. Median age at onset was 1year in the younger group and 2 years in the older group. Reductions in seizure frequency were similar between groups. Median seizure frequency reduction after 3 months was 47% younger, 50% older; after 12 months, 60% younger, 62% older. Proportional seizure reductions were [gte]50% after 3 months, 48% younger, 51% older; after 12 months, 61% for both groups; [gte]75% after 3 months, 30% for both groups, after 12 months, 40% younger, 36% older. After 12 months 8% of the younger and 5% of the older group reported no seizures. After 12 months physicians reported improvements in quality of life for 48% of both groups for seizure clustering and achievements at school. Improved alertness was reported for 75% younger, 71% older; postictal period for 51% younger, 57% older; verbal communication skills for 49% younger, 38% older; mood for 46% younger, 42% older; memory for 38% younger, 35% older.
CONCLUSIONS: The younger and older groups were fairly well matched for demographics and outcome, and only slight differences were apparent. This larger study confirms previous findings that patients younger than 12 years seem to respond similarly to those aged 12 to 18 years (Helmers SL, Wheless JW, Frost M, et al. Vagus nerve stimulation therapy in pediatric patients with refractory epilepsy: retrospective study. J Child Neurology 2001;16:843-848).
(Disclosure: Grant - Cyberonics Inc., Honoraria - Cyberonics Inc.)