Abstracts

Vagus nerve stimulation (VNS) is an alternative treatment for patients with medically refractory epilepsy, who are unsuitable candidates for conventional epilepsy surgery, or who have had such surgery without optimal outcome.
The present experience with VNS at Gent and Dartmouth comprises 131 patients with minimal follow-up of 3 months.
We prospectively assessed seizure frequency, seizure type, prescribed anti-epileptic drugs and side effects. Mean monthly seizure frequency during the year before and the full follow-up period after implantation were compared.
131 patients included in this study had a mean age of 32 years (range:4-59 years) and a mean duration of refractory epilepsy of 22 years (range:3-49 years). 106 patients had complex partial seizures with/without secondary generalization; 4 had simple partial seizures only; 21 had generalized seizures. Mean post-implantation follow-up was 37 months (range:3-94 months). Mean number of antiepileptic drugs after implantation remained unchanged (3; range:1-5). Mean stimulation output was 1.25 mA (range:0.25-3.25 mA). 62 patients (47%) are to be considered responders with a reduction of seizure frequency of [gt] 50 %. Mean reduction of CPS, SPS and generalized seizures was 49% (range:0-100%), 57% (range:0-90%) and 49% (range:0-90%) respectively. Eight patients (6%) became free of complex partial seizures for at least one year. No peri-operative morbidity was reported. Shortness of breath, unpleasant sensation in the throat or hoarseness during the stimulation on-time were the most frequent side-effects.
VNS has been successful in reducing seizure frequency in the majority of patients in this series. It is a useful alternative treatment with few side-effects that remains efficacious with longer follow-up.
[Supported by: grants BOZF-011A099 and BOZF-01104495 from Ghent University and by grant 1.5.236.99 from the Fund for Scientific Research-Flanders]