Abstracts

RATIONALE: Vagal nerve stimulation (VNS) is acknowledged as add-on therapy in pharmacoresistant epilepsy patients. Even patients without objective reduction of seizure frequency report a better overall well-being. The following investigation was performed to clarify the relation between objective and subjective effects of VNS. METHODS: We investigated 55 adults and 15 children with VNS. Follow-ups covered a period of one to twenty-six months after implantation. Each patient was seen several times. Seizure frequency was documented by seizure records. The patients' overall situation was measured using a semi-standardized interview. As subjective data served self-reports of the patients and assessments given by their relatives with respect to seizure frequency, severity and duration as well as postictal phase duration. RESULTS:_Objective effects: 48% of the adult patients had >50% reduction, 23% a reduction <50% and 26% no effect on seizure control. Children showed in 25% a >50 % seizure reduction, 17% lower profit (<50% reduction) and 58% no response. Subjective effects: In the adult group, seizure duration and severity were reported to be reduced in 48% and 55% independent from frequency. 67% of the children profited in their overall situation. 55% of the adults felt more vividness and drive in daily activities. Subjective effects appeared earlier and were stable whereas objective seizure improvement appeared later and showed an increase over time. CONCLUSIONS:_The results suggest that VNS has positive effects outside objective seizure control in epilepsy patients.