Vagus nerve stimulation for treatment of medically intractable seizures. Evaluation of long-term outcome

Vagus nerve stimulation (VNS) constitutes an adjunctive, modern management of medically intractable seizures, especially when surgery is inadvisable. OBJECTIVE: To evaluate the long-term results as regards efficacy, safety and tolerability of VNS in epileptic subjects, with focal and/or generalised seizures, refractory to old and new AEDs, without indication for resective surgery. PATIENTS: 51 epileptic subjects (30 males, 21 females), aged 7-49 years, have been implanted so far. RESULTS: The results refer to the 47 subjects with a follow-up longer than 6 months. 22 (46.8%) of them had a greater than 50% reduction in seizure frequency, with a more than 75% reduction in 6. No significant difference was found in relation to type of seizures. The efficacy maintained steadily over time during the follow-up (mean 26.4 months). Twelve out of the 47 subjects had an improvement in alertness, attention and psychomotor activity. Complications were observed in 5 cases, leading to removal of the stimulator in 2. A moderate vocal hoarseness (40.4%), paresthesia (6.3%), pharingodinia and cough (4.3%) were the registered adverse events. CONCLUSIONS: Our results confirm that VNS is effective, safe and well tolerated and constitutes an alternative treatment for pharmacoresistant epileptic seizures.