Vagus nerve stimulation has generally been used to treat epilepsy. The U.S. Food and Drug Administration (FDA) approved VNS in 2005 as an option for people with treatment-resistant depression. The procedure involves stimulating the vagus nerve via electrical shocks. This stimulation appears to change brain wave patterns and help reduce or eliminate symptoms of depression.
There are two vagus nerves, one on each side of the body. Both start at the base of the neck and run from the brain stem down to the chest. VNS involves the surgical implantation of a pacemaker-like device called a pulse generator in the chest. This device is slightly bigger than a silver dollar. It is connected to the left vagus nerve via a wire threaded underneath the skin. The pulse generator is programmed to deliver electric current in continuous cycles. It stimulates the nerve for a set period of time. It then pauses for several minutes before the next pulse is delivered.
Doctors aren’t entirely sure how stimulation of the vagus nerve alleviates symptoms of depression. It appears that VNS may help reset chemical imbalances in the mood centers of the brain. Many medical professionals have compared it to electroconvulsive therapy (ECT). ECT is a treatment that involves stimulating parts of the brain with electrical pulses.
Vagus nerve stimulation has been used to treat depression only in recent years. Research on how well it works is still ongoing. It’s generally considered to be a last resort option. Doctors usually recommend that you try different types and combinations of medication and psychotherapy before trying VNS.
The treatment is only recommended for adults 18 and older who have treatment-resistant depression. The FDA also recommends that you continue with other forms of therapy in conjunction with VNS. Other treatments include medication and cognitive behavioral therapy.
People who are pregnant or have any other neurological condition might not be eligible for VNS. Your doctor can help you determine whether vagus nerve stimulation is an option for you. Many health insurance plans do not cover VNS. The procedure can cost thousands of dollars.
Vagus nerve stimulation involves major surgery to implant the pulse generator. Complications may arise both during and after surgery. Common risks associated with the surgery include:
- breathing problems
- damage to the vagus nerve
Another risk with VNS surgery is the possibility of vocal cord paralysis. This can occur if the device moves after implantation. You may also need to stop taking certain medications several days before the procedure.
People who have had VNS surgery may experience a variety of side effects afterward. These can include:
- chest pain
- throat pain
- difficulty swallowing
- difficulty breathing
Depression may also worsen in some people. The pulse generator might break or need to be adjusted in some cases, requiring another surgery.