What is Vagus Nerve Stimulation?
Vagus nerve stimulation (VNS) is a medical treatment for epilepsy and treatment-resistant depression. It involves a device placed surgically under the skin in the chest region that is connected to the vagus nerve in the neck. The vagus nerve is responsible for communicating signals between the brain and different organs in the body including the heart, lungs, and digestion. The implanted device sends regular, mild pulses of electrical energy to the vagus nerve, which is thought to help control epileptic seizures or ease depression symptoms.
How Does Vagus Nerve Stimulators Work?
While the exact mechanisms of how Vagus Nerve Stimulators reduces seizures are still being researched, some key facts are known:
- Stimulation of the vagus nerve in the neck sends signals to many regions of the brain involved in seizures like the hippocampus, amygdala, and cortex.
- This VNS input may interfere with electrical signals in the brain that trigger seizures, effectively reducing their frequency and intensity over time.
- VNS may also modulate neurotransmitters levels in the brain like norepinephrine, GABA, serotonin that play a role in seizure control as well as mood.
- The vagus nerve acts as a general communication highway between the brain and body, so VNS input can broadly influence neural networks involved in seizures and mood disorders.
Who is a Candidate for VNS?
VNS is usually offered to patients whose epilepsy cannot be fully controlled with anti-seizure medications alone. Candidates generally meet the following criteria:
- Diagnosed with focal or generalized epilepsy with continuing seizures despite trials of 2 or more anti-seizure medications.
- Seizures originated in one or both hemispheres of the brain.
- No other potentially curative epilepsy treatment options.
- Able to comply with needed device adjustment and medical follow-ups.
- No pregnancy plans for women of child-bearing age.
For treatment-resistant depression, candidates likewise failed to benefit from multiple antidepressants before being considered for VNS. The device provides an alternative to electroconvulsive therapy for select depressed patients.
Vagus Nerve Stimulators Implant Procedure and Device
The VNS device implantation takes 1 to 2 hours under general anesthesia. An incision is made on the chest below the collarbone and the device is inserted and connected to the left vagus nerve. Wires then tunneled under the skin connect the device to electrodes placed around the vagus nerve in the neck. The device is programmed externally by the physician to send regular pulses. Battery life typically lasts several years before replacement is needed. It allows adjusting settings non-invasively to maximize results and minimize side effects over time.
Get More Insights on- Vagus Nerve Stimulators