PURPOSE

A retrospective study, based on a prospectively built database, presents the results of long-term follow-up care of pediatric vagus nerve stimulation (VNS) patients in terms of seizure outcome, surgical aspects, the potential impact of maturation, and medication changes.

METHODS

From a prospectively built database, 16 VNS patients (median age 12.0 years, range 6.0 to 16.0 years; median seizure duration 6.5 years, range 2.0 to 15.5 years) followed for at least 10 years were graded as non-responder - NR (seizure frequency reduction < 50%), responder - R (reduction ≥ 50% and < 80%), and 80% responder - 80R (reduction ≥ 80%). Data about surgical aspects (battery replacement, system complications), seizure dynamics, and medication changes were taken from the database.

RESULTS

The early percentages of good results (80R + R) were 43.8% (year 1), 50.0% (year 2), and 43.8% (year 3). These percentages remained stable between years 10 and 12 (50% year 10; 46.7% year 11; 50% year 12) and increased in years 16 (60%) and 17 (75%). Depleted batteries were replaced in ten patients, six of whom were either R or 80R. In the four NR, the indication for replacement was improved quality of life. Three patients had VNS explanted or switched off-one had repeated asystolia and two were NR. The effect of hormonal changes in menarche on seizure was not proven. During the study, antiseizure medication was changed in all patients.

CONCLUSIONS

The study proved the efficacy and safety of VNS in pediatric patients over an exceptionally long follow-up period. The demand for battery replacements indicates a positive treatment effect.