Vagus nerve stimulation

Placement of the neuro-cybernetic prosthesis-NCP system for intermittent vagus nerve stimulation has undoubtedly opened up a new, non-drug for patients with epilepsy who are ineffective in treatment with appropriate antiepileptic drugs and cannot accurately locate epileptic foci and surgical resection. A method of treating epilepsy. At present, there are more than 5,000 clinical treatments in countries around the world. Two VNS Symposiums were held in 1996 and August 1998. The surgical device was officially approved by the US FDA in June 1997. Some units in China have introduced applications. Animal experiments and clinical studies have confirmed that vagal stimulation can reduce the frequency of seizures, shorten the duration, and reduce the severity. However, the mechanism of vagus nerve stimulation of antiepileptic effects is still unclear. The vagus nerve is a mixed nerve that contains the body and visceral afferent and efferent nerve fibers. The vagus nerve contains approximately 80% of afferent fibers and 20% of efferent fibers. The afferent fibers reach the hypothalamus and amygdala hippocampal complexes and diffusely project to the cerebral cortex either directly or through the solitary tract nucleus and its ascending reticular system. The wide distribution formed may be the basis of treatment for VNS. It has been confirmed that vagus nerve stimulation can directly or indirectly cause the brain stem and cerebral cortex to release -aminobutyric acid and p-hydroxyphenylglycine extensively, inhibiting the nerve conduction medium and acting as an anti-epileptic effect. This is the anatomical and physiological biochemical basis of vagal stimulation in many areas of the brain to increase the inhibitory effect and prevent the occurrence and spread of epilepsy. In short, the mechanism remains to be studied. Treating diseases: epilepsy Indication Vagus nerve stimulation is suitable for patients with intractable epilepsy who are not suitable for resection, some patients with complex and/or secondary systemic seizures, but the current indications have an expanding trend. If used in children, treat Lennox-Gastant syndrome or primary generalized epilepsy. According to FDA approval, it is only suitable for drug-induced partial seizures. Adolescents and adults over 12 years old are only used as an adjuvant treatment to reduce the frequency of seizures. Contraindications In the past, the left neck has a history of vagus nerve cutting. There is a progressive nervous system or systemic disease. Arrhythmia, asthma or active lung disease, peptic ulcer, insulin-dependent diabetes-dependent diabetes, and pregnancy. Surgical procedure Generally, the left vagus nerve is used for stimulation treatment (several vagus nerve is used to cause severe bradycardia). Incision Make a transverse incision in the lower part of the neck of the left clavicle, and sneak up and down the skin. The retractor retracts the skin, vertically cuts the platysma, and separates the sternocleidomastoid and carotid sheath. 2. revealing the vagus nerve The vagus nerve is revealed between the internal jugular vein and the carotid artery. This nerve is generally located in the posterior part of the carotid sheath and reveals a 3 cm long vagus nerve. 3. Implant stimulator Make a transverse incision in the chest wall of the left subclavian region, 7 to 10 cm long. The subcutaneous tissue of the subclavian region is bluntly separated from the chest fascia to form a capsular bag for accommodating the stimulator, and then the shunt guide is used to guide the electrode lead through the subcutaneous tunnel from the chest incision into the neck incision. A spiral electrode is wrapped around the left vagus nerve. The short wires are connected underneath, the long wires are connected upwards, and the wires are connected to the stimulator. 4. The incision is sutured by layer. complication In general, VNS is safe and reliable, with fewer adverse reactions and less complications. The most common adverse reactions were hoarseness or sound changes (37% in the high frequency group and 13% in the low frequency group), sore throat (11.1% and 11.7%), cough (7.4% and 8.3%), and dyspnea (5.6%). And 1.7%), rare complications include vocal cord paralysis, myocardial infarction, subcutaneous accumulation of fluid around the stimulator, and infection of the implanted device site.