Vagus nerve stimulation

Vagus nerve stimulation

Vagus nerve stimulation device

MeSH	D000000

Vagus Nerve Stimulation (VNS) is a medical treatment that involves delivering electrical impulses to the vagus nerve. It is primarily used to treat epilepsy and treatment-resistant depression.

Overview

The vagus nerve is the tenth cranial nerve and is responsible for various functions, including heart rate, gastrointestinal peristalsis, sweating, and muscle movements in the mouth, including speech. VNS therapy involves the use of a device that is surgically implanted under the skin in the chest, with a wire that connects to the left vagus nerve in the neck. The device sends regular, mild pulses of electrical energy to the brain via the vagus nerve.

History

Vagus nerve stimulation was first approved by the Food and Drug Administration (FDA) in 1997 for the treatment of epilepsy. In 2005, it was also approved for the treatment of major depressive disorder in patients who have not responded to traditional therapies.

Mechanism of Action

The exact mechanism by which VNS exerts its effects is not fully understood. However, it is believed that the electrical stimulation of the vagus nerve affects neurotransmitter levels in the brain, including serotonin and norepinephrine, which play a role in mood regulation and seizure activity.

Clinical Applications

Epilepsy

VNS is used as an adjunctive therapy for patients with refractory epilepsy, meaning their seizures are not controlled by medication alone. Studies have shown that VNS can reduce the frequency and severity of seizures in some patients.

Depression

For patients with treatment-resistant depression, VNS can be an option when other treatments, such as medication and psychotherapy, have failed. Clinical trials have demonstrated that VNS can lead to improvements in mood and overall functioning in some patients.

Procedure

The implantation of a VNS device is a surgical procedure that typically takes about 1 to 2 hours. It is usually performed under general anesthesia. After implantation, the device is programmed to deliver electrical impulses at specific intervals. The settings can be adjusted by a healthcare provider using a special programming device.

Side Effects

Common side effects of VNS include hoarseness, throat pain, cough, and shortness of breath. These side effects are often related to the stimulation of the vagus nerve and may decrease over time.

Research and Future Directions

Ongoing research is exploring the use of VNS for other conditions, such as anxiety disorders, Alzheimer's disease, and chronic pain. The potential for VNS to modulate brain activity and improve symptoms in these conditions is an area of active investigation.

Also see

• Epilepsy
• Major depressive disorder
• Cranial nerves
• Neurostimulation