Vagus Nerve Stimulation
We use vagus nerve stimulation (VNS) to treat epileptic seizures that are not well controlled by medications or other interventions (called medically refractory epilepsy). We also use it for patients who cannot tolerate the side effects of anti-seizure medications. The treatment has been around since the 1990s.
The vagus nerve is the longest of your 12 cranial nerves, running from the base of the brain all the way to the abdominal cavity. The vagus nerve has both motor and sensory functions.
Less invasive than DBS, vagus nerve stimulation involves surgically implanting a small device under the skin in the chest, just as we do with a heart pacemaker. We attach the device, called a pulse generator, to an insulated wire that sends mild electrical signals to the left vagus nerve in the neck. This procedure does not involve your brain. The electrical signals travel along your vagus nerve into the brain stem and then to various neural circuits in the brain. You will not feel these electrical signals, you are not aware of the normal electrical signals that tell your feet how to move when you walk.
We perform VNS under general anesthesia. You usually spend a night in the hospital, though we can also do it as a same-day procedure. After the surgery, our neurologist programs the settings of your pulse generator—the frequency, amplitude, and width of the electrical impulses—to match your individual needs and provide maximum relief of symptoms.
Many patients who undergo VNS for treatment of epilepsy find they can reduce the amount of medications they need to take to control their seizures, which decreases the side effects. We may give you a magnet to place close to the pulse generator in your neck when you feel a seizure happening or about to start, to thwart the seizure or make it less severe.
We also use vagus nerve stimulation to treat major depression that is not well controlled by medication or psychotherapy or electroconvulsive therapy. “Studies suggest that at the three-year mark approximately 40 to 50 percent of patients who undergo this procedure for depression report a significant reduction of symptoms,” saysDr. Brian Kopell, Director of the Center for Neuromodulation.