Understanding Vagus Nerve Stimulator (VNS) Placement
A vagus nerve stimulator (VNS) is a device that can help prevent seizures. It can also treat depression, obesity, autism, and neurodegenerative disorders. A VNS has two parts: a pulse generator and leads. The pulse generator sits in your chest under your skin. The leads run from the generator to a vagus nerve in your neck. The VNS is put in your body during a surgery.
What are the vagus nerves?
The vagus nerves are long nerves that travel from your brain. You have one vagus nerve on the left and one on the right. They lead down through your neck and into your chest and abdomen. Each nerve has branches that go to your vocal cords, to some of the muscles of your throat, and to other organs in your body.
How a VNS works
The ends of the VNS leads wrap around your left vagus nerve. The VNS is similar to a pacemaker. The pulse generator creates low-energy electrical signals. The leads carry those signals to the vagus nerve. The pulse generator is programmed though the skin. The strength, length, and frequency of the pulses can be changed as needed. A VNS can also improve mood. It can be used to treat depression that has not responded to other treatments.
Why a VNS is used
Seizures caused by epilepsy are often treated with medicines. But sometime the medicines don’t work well, or have severe side effects. Seizures can also be treated with a diet high in fat and low in carbohydrates (ketogenic diet). Brain surgery is another treatment. But sometimes these are not options. A VNS may be used to treat seizures from epilepsy if:
Medicine doesn’t control your seizures
You can’t follow a ketogenic diet
You still have seizures while on a ketogenic diet
You don’t want to or are not able to have brain surgery
You had brain surgery, but you still have seizures
A VNS may be advised for you if you have severe depression that is hard to treat.
Risks of having a VNS
All procedures have some risks. The risks of surgery to place a VNS may include:
Temporary paralysis of one vocal cord (rare)
Possible side effects of VNS
After a VNS is in place, it may cause some problems such as:
Hoarse voice (most common)
Shortness of breath
Nausea and vomiting
Worsening sleep apnea in people who already have it
New sleep apnea in people at risk for it
Leads not in correct position
Malfunction of pulse generator
Most VNS side effects will get better or go away with adjustment of the VNS settings. If you have sleep apnea, using a continuous positive airway pressure (CPAP) machine while you sleep may help.
October 17, 2017
Karceski A, Schacter SC. Vagus nerve stimulation therapy for the treatment of epilepsy. UpToDate.
Fetterman, Anne, RN, BSN,Jasmin, Luc, MD