Vagus Nerve Stimulation (VNS)
A clear, evidence-based guide to what vagus nerve stimulation (VNS) is, when it is recommended for epilepsy, what implantation involves, and what to expect after surgery.
Implantable neuromodulation
Vagus nerve (left)
Programmable parameters + optional manual activation
Gradual titration of settings during follow-up visits
What is VNS?
Vagus nerve stimulation (VNS) is a device-based neuromodulation therapy designed to reduce epileptic seizures. The implantable system has two main components: a pulse generator placed under the skin in the chest, and electrodes that are connected to the vagus nerve in the neck.
The device delivers low-intensity electrical impulses to the nerve. Parameters (intensity/duration/frequency) are programmable and can be safely tailored to each patient. In selected individuals, an additional “on-demand” activation using a magnet may be available, for example when warning symptoms (aura) occur.
When may VNS be recommended?
Vagus nerve stimulation is typically considered in individuals with epilepsy whose seizures persist despite appropriate medical therapy, or when medication side effects significantly limit daily life.
Common indications (indicative)
- Seizures not adequately controlled with medications
- Ineligibility for or failure of other options (e.g., ketogenic diet in selected cases)
- Not a candidate for, or not wishing to undergo, epilepsy surgery (depending on evaluation/focus)
- Persistent seizures even after prior surgery (in selected patients)
Practical goals
- Reduction in seizure frequency and/or severity (not a “curative” therapy)
- Improved seizure control through gradual programming during follow-up visits
- Optional use of an external magnet in some patients when warning symptoms occur
- Antiepileptic medications are continued; any dosage adjustments are individualized by the care team
Before implantation
Preparation focuses on safety and appropriate patient selection: seizure type, response to medications, and defining realistic therapeutic goals for your specific case.
Clinical evaluation & seizure history
Discussion of seizure type, frequency, triggers, medications, and side effects.
Preoperative assessment
Laboratory tests/anesthesia evaluation and review of comorbidities as indicated.
Follow-up plan
Education on activation/programming, possible stimulation-related effects, and a realistic timeline for improvement.
Day-of-surgery instructions
Fasting, medications, arranging a companion for discharge, and practical wound-care guidance.
How is VNS implanted?
Implantation is a surgical procedure performed through small incisions in the chest and neck. The pulse generator is placed in the chest and the electrode is connected to the vagus nerve in the neck.
Anesthesia & preparation
Typically performed under general anesthesia with continuous monitoring of vital signs.
Two small incisions
One on the left side of the neck to access the nerve and one in the left chest for the generator pocket.
Electrode placement & connection
The electrode is carefully wrapped around the nerve and connected to the battery (pulse generator) via a subcutaneous lead.
System check & closure
Function is verified and incisions are closed. In most cases, patients are discharged the same day.
After implantation: recovery & programming
Postoperatively, the focus is on wound healing and gradual activation/titration. VNS therapy is “built over time” through programmable adjustments.
First days
- Mild pain/discomfort in the chest or neck is common
- Monitor incisions for redness/swelling/drainage
- Gradual return to activity per instructions
- Contact your team if high fever or severe pain occurs
Activation & programming
- Activation often occurs at a subsequent visit (e.g., ~2 weeks), depending on practice and individual case
- Settings are adjusted gradually (intensity/duration/frequency)
- Possible sensations during stimulation: throat “tickling” or voice changes at certain settings
- The battery depletes over years and is replaced when needed, usually via a minor procedure
Risks & potential complications
Most patients do very well with vagus nerve stimulation. As with any procedure, however, there are potential complications associated with device-based neuromodulation, which are discussed clearly and on an individualized basis prior to implantation.
Procedure-related (less common)
- Infection at the incision/device site
- Bleeding, hematoma, pain, or scarring
- Rare: transient vocal cord paresis
- Device-related technical issues (e.g., lead problems) — uncommon
Stimulation-related effects (more common)
- Hoarseness/voice change (most common)
- Cough, throat irritation or discomfort
- Difficulty swallowing or shortness of breath at certain settings
- Paresthesias, nausea
- Worsening of sleep apnea in susceptible individuals or new symptoms in high-risk patients
Important: Risk and likelihood of side effects depend on diagnosis, medical history, and overall health, and are discussed individually. Many adverse effects improve with external adjustment of device parameters.
When to contact your team urgently
Contact your care team if you develop symptoms that are new, worsening, or concerning, particularly in the first days after implantation.
Contact us if you experience
- Fever, marked redness, swelling, or discharge from the incision
- Severe or worsening chest/neck pain
- Significant difficulty swallowing or breathing
- Persistent/severe hoarseness or symptoms not improving after adjustment
- Changes in seizure pattern (e.g., much more frequent or prolonged seizures)
Frequently asked questions (FAQ)
Concise answers to common practical questions. Specific instructions may vary based on your individual case.
Q When does VNS “start working”?
Q Will I stop my antiepileptic medications?
Q Will my voice sound different?
Q What is the “magnet” and when is it used?
Q Can I undergo MRI with a VNS device?
Q How long does the battery last and what happens when it runs out?
Consultation with a specialized team
If VNS has been suggested to you or you are seeking a second opinion, our team can review your history, studies, and seizure profile, and discuss a safe, individualized treatment plan.