18. Vagus Nerve Stimulation

Vagus nerve stimulation (VNS) therapy is used for halting those seizures of medically refractory epilepsy patients in which therapy by antiepileptic drugs (AEDs) has failed to provide any reasonable comfort. Another disease which can be treated by VNS is chronic or recurrent depression in adult patients that is unmanageable by antidepressant drugs. In VNS, the stimulator device is implanted in the upper region of the patient’s chest. The electrodes are fastened to the vagus nerve in the neck. Although not yet confirmatively known, it is believed that constant and recurrent electrical stimulation of the vagus nerve causes the release of brain neurotransmitters that decrease seizure activity, as required for epilepsy control, or regulate the patient’s mood, as needed for the treatment of depression. Actually, the therapy for clinical depression was started on the basis of improvements in cognition and mood that were observed in patients who were treated for epilepsy. Encouraging results have also been reported by VNS for the management of rheumatoid arthritis.