This diagram shows how the implanted VNS pulse
generator, lower right, is linked by electrodes to the left
vagus nerve in the neck. The enlarged section of the
diagram (upper right) shows how the ends of the
flexible silicone leads are wound around the nerve.
Implanting the VNS battery in a patient and connecting it to the vagus nerve takes about an hour. It is usually done under general anesthesia, though local anesthesia is sometimes used. The operation can be done on an in-patient or out-patient basis.
The surgeon makes two small incisions -- one in the neck to gain access to the vagus nerve, and one below the collarbone in the chest wall or armpit.
The surgeon places the VNS pulse generator into a surgically-made "pocket" under the skin of the patient's chest and threads a plastic tube containing the electrodes from the neck to the generator in the chest. He or she then gently wraps the flexible ends of silicone-coated electrodes around the vagus nerve.
Programming the Device
Some doctors turn on the VNS device immediately after surgery. Others prefer to start the stimulation during the check up visit afterwards. Doctors program the device to deliver pulses of electrical stimulation automatically, 24 hours a day.
A typical "dose" is about 30 seconds on and five minutes off, but settings may vary. The device continues the cycle until the neurologist re-programs it or until the battery runs out -- usually in about six years.
At that time another surgical procedure (which only involves the chest) can be done to replace the battery, usually with a local anesthetic.
Cost of Treatment
Once the neurologist recommends vagus nerve stimulation therapy as a possible treatment, there's the question of how much it costs and how to pay for it.
VNS therapy currently costs approximately $20,000, which includes the implant and surgical procedure. The patient will also need regular appointments with his or her neurologist to check the device. However, costs of surgery and care vary in different parts of the country and may increase over time.
Many insurance companies, along with Medicare and most Medicaid carriers, cover the costs of VNS therapy.
People who qualify for VNS therapy but do not have insurance or other funds to pay for the device may qualify for special assistance from the manufacturer of the implant. Under a special program, the company is donating a limited supply of its VNS therapy systems to eligible people. For more information about the special program, contact your neurologist.
Response to Therapy
It's hard to know in advance how someone with epilepsy will respond to VNS therapy.
Successful VNS therapy reduces the number of seizures people have and, sometimes, how long they last. It's unlikely to stop seizures completely.
Studies show that about one-third of people treated with VNS experience a major improvement in seizure control. One-third experience some improvement, and one-third continue to have seizures as before.
Even when people respond well, improvement usually takes time. It isn't likely to happen immediately after the doctor implants the device. Several months may go by before there's any change, followed by a slow but steady improvement.
However, seizure control is not the whole story for this type of treatment. For reasons that are still not well understood, VNS therapy appears to have some other effects as well.
Studies find that many people who have had the implant say they feel better, even if their seizures continue. They say they feel better after a seizure, are in a better mood, feel more alert, have better memory and fewer emergency room visits.