Trial to Evaluate the Safety and Effectiveness of Vagus Nerve Stimulation for Children With Refractory Epilepsy

Inclusion Criteria: 1. Age 3-6 2. At least 6 seizure per month 3. Refractory Epilepsy 4. In good health except epilepsy 5. Patients or his(her) familyscould understand this method and sign the informed consent 6. Patients with good compliance and could complete postoperative follow-up Exclusion Criteria: 1. Results of MRI remind epilepsy caused by intracranial space-occupying lesions 2. The vagus nerve lesion and damage 3. Tumor, cardiopulmonary anomaly, progressive neurological diseases, asthma，mental disease，pepticulcer，diabetes，bad health etc, and other surgical contraindication 4. Cann't write the epilepsy diary 5. Participating other clinical trial 6. Cann't complate the operation 7. Complete the postoperative follow-up 8. Cann't complete the promgramming