Vagus Nerve Stimulation (VNS)
The vagus nerve (VN) is one of 12 nerves that connects the brain to the rest of the human body. The nerve extends from the medulla oblongata to the lower abdomen. It is the longest parasympathetic nerve in the human body, and is responsible for control of the heart, lungs, and digestive tract.
Vagus Nerve Stimulation (VNS) refers to the electrical stimulation of the vagus nerve. VNS uses electrical pulses to treat several conditions, ranging from epilepsy to mental illness. Most commonly, VNS is used to prevent epileptic episodes when other treatment methods have been unsuccessful.
VNS May be Used to Treat:
Research has supported the efficacy of VNS in the treatment of the following conditions:
How is the Device Implanted?
Implantation of a vagus nerve stimulator requires two parts. The surgeon begins by making a small incision in the chest and implanting a tiny device, not much larger than a coin, on the muscles of the chest under the skin.
A second incision is made at the neck level and wires are placed on the vagus nerve and connected pulse generator.
Typically, after short adjustment period, patients do not feel the implanted device or the electrical sensation created by the stimulator.
The entire procedure is performed an outpatient basis and usually takes between an hour and hour and a half. Depending on the patient’s general health and how they’re recovering from the procedure, rarely, a one night hospital stay is needed.
How Does Vagus Nerve Stimulation Work?
Soon after implantation, the vagus nerve stimulator is programmed to deliver very precise electrical impulses to the nerve trunk. These impulses suppress impending seizures with great efficacy. The exact timing and strength of these impulses is determined on a case-by-case basis. The device can be adjusted by a qualified physician or technician, if necessary, over time.
In cases where patients experience auras before a seizure, it may be appropriate to offer manual activation of the vagus nerve stimulator. This is achieved by placing a magnet over the device when a patient believes a seizure is imminent. The device will then trigger an electrical impulse to with the goal of suppressing the seizure before it happens.
The battery operated impulse generator typically lasts about 5 to 10 years. Replacement is a simple follow-up surgical procedure to swap out the device.
Risks Associated with Vagus Nerve Stimulation
Beyond the inherent risks of a surgical procedure such as pain, blood loss and infection, there are a few significant risks associated with vagus nerve stimulation. These risks will be discussed during consultation and may include:
- Ineffective function–not all patients will receive the relief that they expect from a vagus nerve stimulator. Despite excellent results, the effectiveness of the electrical stimulation may diminish overtime. This can be mitigated with regular adjustments.
- While the vagus nerve stimulator will offer a great deal of relief in most patients, it may not suppress all seizures.
- When the battery eventually runs out, the pulse generator needs to be replaced surgically.
- In time, the leads may shift creating a less efficient stimulation process. This requires additional surgery to replace or reattach the leads
The device itself may also cause certain side effects, typically when generating an impulse. These include:
- Difficulty swallowing
- Slowed heart rhythm
- Coughing and hoarseness
- Tingling sensations
Preparing for Surgery
- Pre-Admission Testing (PAT) – Patients will be contacted to make an appointment for Pre-Admission Testing (PAT). Patients should bring a copy of their insurance information, a list of medication being taken, any advance directives, and a copy of their pre-surgery packet. The PAT includes several tests. Patients must also receive appropriate medical clearance before the operation.
- Blood Donation – Discuss with your surgeon to see if blood donation is necessary prior to surgery. Donations may be used during or after surgery should complications arise. If blood donation is recommended, contact New York Blood Services 1-800-439-6876.
- Pharmacy – Please advise doctors and surgeons of any allergies that you may have. Antibiotics and Analgesics may be used to treat infection and reduce pain post-surgery.
- Brace Information– Some patients may require a brace post-surgery. Spinal braces provide stability, and limit dangerous movements during the postoperative period.
- Smoking– Smoking-related diseases increase both anesthetic risks, as well as risks of complications during surgery and recovery. If patients choose to seek surgical treatment, patients must cease smoking.
The Day Before:
Noon – 3:00 PM:
Patients should call the Same Day Admit Unit (516-663-2293) to confirm their arrival time. If surgery admission is scheduled for a Monday, the patient should be sure to confirm their time on Friday afternoon.
Pack a hospital bag
Patients should prepare a “hospital bag” that includes needed personal items. Personal items may include toiletries, glasses, hearing aids and denture cases. Patients should not bring valuables. Bringing additional clothing is not necessary. The hospital will provide gowns and non-slip socks.
Pack a rehab bag:
Some patients will need to prepare a bag for rehabilitation following the surgery. If you will not be returning home, be sure to pack comfortable (loose-fitting) clothing, undergarments, pajamas, shoes, socks and toiletries.
Prepare home for post-surgery arrival:
Patients should prepare their homes for post-surgery arrival. Keep in mind that individuals may feel weak, tired, or lightheaded after surgery. Remove objects/obstructions from staircases, floors and pathways. Remove loose throw rugs or other slippery surfaces. If necessary, place grab bars and slip-resistant strips in bathtubs, toilet areas, and other hazardous areas.
Patients should not eat or drink after midnight, as this may complicate the patient’s reaction to general anesthetics. Patients should remember to relax, and rest.
Recovery after VNS surgery is typically swift. Patients will remain in the recovery room for a few hours after the procedure and will be monitored by the nursing staff.
Patients should arrange for transportation back home as the general anesthesia and pain medication may make it unsafe to drive. This caretaker should also remain with the patient at home for as long as possible to help with chores and daily activities.
Once implanted, the VNS device does not need routine maintenance or care. Patients may need several follow-up visits over the course of the first year after implantation to make adjustments to the programming of the device. The battery in the device usually last for 10 years or longer and needs no special care.
Patients are encouraged to follow their post-operative packet closely to ensure a swift and uncomplicated recovery. As with any surgical procedure, our team of clinicians works with each patient to ensure that the benefits of surgery outweigh the risks and that the patient is a candidate for surgery. For most patients, a vagus nerve stimulator offers an excellent and safe option to control seizures.