Abstracts

Rationale: To evaluate long term seizure reduction and on-demand magnet use in patients < 18 years with pharmacoresistant epilepsy treated with adjunctive vagus nerve stimulation (VNS) Therapy. Methods: N=57 (32 M, 25 F; 59.6% <=12 years). Mean age 11.4 ± 3.85 years; mean duration of epilepsy 9.3 ± 4.14 years; 64.9% were mentally retarded; 38.6% had neurological deficits; prior epilepsy surgery: 12.3%. Simple partial seizures: 38.6%; complex partial: 96.5%; secondarily generalized: 56.1%; myoclonic: 8.8%. Seizure reduction was evaluated after 6, 12, 24, 36 and 48 months of VNS Therapy in 56, 56, 54, 35 and 18 patients, respectively. Magnet effect (cessation of seizures, partial effect or no effect) was evaluated within the first week after implantation (‘early magnet effect’ - EME) and after 6, 12, 24, 36 and 48 months (‘stable magnet effect’ - SME). Results: Mean seizure reduction: 48.2%, 52.4%, 57.1%, 53.4% and 53.1%; seizure reductions >=50%: 46.4%, 50.0%, 55.6%, 51.4% and 50.0% of the patients after 6, 12, 24, 36 and 48 months, respectively. Seizure-freedom: 1.8%, 8.9%, 9.3%, 11.4% and 16.7% after 6, 12, 24, 36 and 48 months, respectively. EME: cessation of seizures, 16.1%; partial effect, 73.2%; no effect: 10.7%. SME: cessation of seizures, 8.9%, 8.9%, 9.3%, 8.6% and 5.6%; partial effect, 69.6%, 69.6%, 68.5%, 57.1% and 55.6%; no effect, 21.4%, 21.4%, 22.2%, 34.3% and 38.9% after 6, 12, 24, 36 and 48 months, respectively. Conclusions: Adjunctive VNS Therapy is effective for children and adolescents of all ages with pharmacoresistant epilepsy.