Abstracts

Absence seizures may be seen in a variety of epileptic syndromes in childhood. Approximately 5-10% of the patients will have medically refractory seizures. Vagus nerve stimulation (VNS) Therapy may reduce the frequency of absence seizures in treatment-resistant patients and/or improve their quality of life., 16 patients (9 males, 7 females) were treated with adjunctive VNS Therapy for medically refractory absence seizures. All patients had the diagnosis of childhood absence epilepsy. Mean age at implantation was 8 years ([plusmn] 1.30; range, 6-12 years). Absence seizures were counted at baseline using 24-hour EEG recordings. The same evaluation was repeated every 6 months after implantation during the follow-up period of 18 months. Patients were treated with an average of 1.8 antiepileptic drugs (AEDs) per patient at baseline. No changes in AEDs were allowed., There was a total seizure reduction of 31% after 6 months (p-value = 0.0071; paired T test), 67% after 12 months (p-value [lt]0.0001; paired T test) and 76% after 18 months (p-value= 0.0156; Wilcoxon[apos]s paired signed rank test). Seizure reductions [ge] 50% were observed in 38% of the patients after 6 months, in 92% after 12 months and in 88% after 18 months of treatment. Three patients (18.7%) remained seizure free, and one patient (6.2%) showed no response to VNS Therapy at 18 months. Improvement in alertness ([ldquo]better[rdquo] or [ldquo]much better[rdquo]) was observed in 60% of the patients. Seizures became worse when stimulation stopped in one patient due to a lead break, and in two other patients due to end of battery life, with improvement after restauration of the stimulation., Adjunctive VNS Therapy was effective for the treatment of medically refractory absence seizures in this patient population, allowing a seizure reduction of 76% after 18 months. The percentage of patients showing seizure reductions increased over the 18 months of treatment. Alertness improved in 60% of the patients. These results are encouraging and worth further investigation.,