Prospective cohort study on the long-term effectiveness and safety of PINS vagus nerve stimulators for children and adolescent with refractory epilepsy.

Epileptic encephalopathy is very common in children and adolescent with epilepsy, but there is no data in clinical studies.The aim of this study is to evaluate the efficacy of the long-term vagus nerve stimulation for children and adolescent with epilepsy

Inclusion Criteria:

1. age 4-18
2. Diagnostic criteria for epilepsia brain disorders
3. Having tried appropriate anti-epileptic drugs (AEDs) more than 1 year and zt least 6 seizures per month
4. patients or his(her) families could understand this method and sign the informed consent
5. Patients with good compliance and could complete postoperative follow-up

Exclusion Criteria:

1. the vagus nerve lesion and damage
2. patients with progressive neurological diseases, cardiopulmonary anomaly, respiratory system diseases,digestive system diseases
3. patients'mental state is not stable，
4. patients with or anesthesia contraindications,such as long-term use of anticoagulation antiplatelet drugs etc.
5. patients have or need other implantable devices, such as pacemakers,defibrillators, cochlear and spinal nerve root stimulator.
6. patients due to their own reasons for the need for nuclear magnetic resonance imaging in the future clinical trials
7. patients have participated in other clinical trials.

patients at age 4-18; diagnostic criteria for epilepsia brain disorders; having tried appropriate anti-epileptic drugs (AEDs) more than 1 year and at least 6 seizures per month; patients or his(her) familys could understand this method and sign the informed consent; Patients with good compliance and could complete postoperative follow-up；without the vagus nerve lesion and damagement, progressive neurological diseases, cardiopulmonary anomaly, respiratory system diseases, digestive system diseases