Your vagus nerve is one of your body’s most important nerves. It starts in your brainstem and extends throughout your body, sending signals back and forth between most of your organs and your brain and plays a role in modulating the activity of your heart, lungs and digestive tract . It helps control involuntary functions like swallowing and digestion, as well as the immune system and sensory information like taste and hearing. “It is called the vagus nerve because it wanders all over, and the Latin word for wander is vagare, like in vagabond,” said Robert Bina, MD, a neurosurgeon with Banner Brain & Spine.
Scientists have been able to study the vagus nerve in animals for a long time — it is easy to find in most birds and mammals. In the human brain and body, researchers have found that stimulating the vagus nerve can help:
- Epilepsy that’s hard to control with medication
- Depression that isn’t responding well to other medication and therapy
- Stroke rehabilitation
“When treating depression and epilepsy, we think that the vagus nerve is acting on the brain to change the way the brain is wired and how it functions. For stroke recovery, we think vagus nerve stimulation helps the brain re-wire disrupted signals,” Dr. Bina said.
How does vagus nerve stimulation work?
While we know vagus nerve stimulation works, we don’t know exactly how. An implanted device, called a vagus nerve stimulator, sends electrical signals to the vagus nerve, which causes the nerve to carry electrical impulses into the brain. There, a neurotransmitter called norepinephrine is released. “Increasing norepinephrine causes parts of the brain to slow down and focus,” Dr. Bina said.
How is a vagus nerve stimulator implanted?
If your doctor recommends a vagus nerve stimulator, you can often have it implanted in a same-day procedure that takes 45 to 90 minutes. It’s possible to have local anesthesia, but it’s more common for doctors to use general anesthesia.
Your surgeon will make two incisions, one in your neck and the other in your chest, about an inch and a half below your collarbone. The vagus nerve is exposed in your neck, and three coils are wrapped around it. Two of these are electrodes and the other coil anchors the lead in place. It then runs under the skin to the chest, where it is attached to the device. Once everything is in place, the surgeon tests the system to ensure it's stimulating your vagus nerve properly, then secures all the wires and the device and closes the incisions.
You can return to your everyday activities in about 48 hours, and after you heal for two to four weeks, you’ll return to your doctor’s office to have the device turned on or to increase the stimulation. It’s programmed using computer software, and you’ll usually start with low levels of stimulation to see how it works for you.
What are the risks?
“The risks are pretty minor, and most people don’t have any trouble at all,” Dr. Bina said. Some people have a hoarse voice or cough when the stimulator turns on. Usually, these symptoms improve with time. Some people notice skin numbness or chest tightness while they are getting used to the stimulator. Infection and pain are also possible side effects.
Batteries last for several years, depending on your device and how much stimulation you need. Replacing the battery is a simple procedure.
Looking to the future
While vagus nerve stimulation is approved by the Food and Drug Administration (FDA) for treating certain people with epilepsy or depression or stroke survivors, it’s being investigated for various conditions, including irritable bowel syndrome (IBS), rheumatoid arthritis (RA), diabetes, migraine and other conditions. “There will likely be more research showing that this type of stimulation works for a variety of other diseases in the future,” Dr. Bina said.
The bottom line
Vagus nerve stimulation, which uses an implanted device to send electrical signals to the brain and spinal cord via the vagus nerve, is a treatment that can help with long term management of epilepsy, depression and stroke. And researchers are studying ways it might treat a lot of other health conditions.
Looking to learn more about vagus nerve stimulation?
Schedule an appointment with a Banner Brain & Spine specialist.
