BACKGROUND

To evaluate the clinical efficacy and side effects of vagal nerve stimulation (VNS) in Norwegian children with difficult-to-treat epilepsy.

MATERIAL AND METHODS

We have performed an open retrospective study of 60 children with pharmaco-resistant epilepsy who had a VNS implantation between October 1996 and May 2003. The effects and side effects of VNS were evaluated on the basis of the medical records and a questionnaire filled in by the patients and/or their relatives.

RESULTS

Forty-six patients (77%), 25 females and 21 males, aged 4-16 years at the time of implantation, filled in the questionnaire. All patients had tried > or = 6 antiepileptic drugs prior to the implantation. Five of them had undergone resective epilepsy surgery. After a mean of 2.5 years of follow up, 33 patients (72 %) reported positive effects of VNS. Twenty-nine patients (63%) reported decreased seizure frequency and/or less severe seizures, 20 (43%) achieved > or = 50 % seizure reduction, but only two became seizure free. Sixteen (35%) experienced a shorter and milder postictal phase. In 10 patients (22%) the need of diazepam treatment to terminate seizures was considerably reduced. Twenty-eight of the children (61%) experienced a positive effect of magnet activation. Twenty-three patients (50%) reported minor and waning side effects. Because most of the patients (32) had their antiepileptic medication changed after the implantation, the results should be interpreted with caution.

CONCLUSIONS

A majority of the patients (72%) reported positive effects on seizure frequency and/or epilepsy-related symptoms. The side effects were modest. Our findings support previous reports about VNS being an effective additional treatment in children with refractory epilepsy.