Can the Vagus Nerve Cause Seizures?

Can the vagus nerve cause seizures?

Stimulation of the vagus nerve is used to treat seizures.
Stimulation of the vagus nerve is used to treat seizures.

No, in fact, the vagus nerve is used to treat seizures that do not respond to medications. The vagus nerve is an important pathway to the brain in addition to helping to control seizures. Stimulation of the vagus nerve leads to the discharge of electrical energy into a wide area of the brain, disturbing the abnormal brain activity that causes seizures. Another theory suggests that stimulating the vagus nerve causes the release of special brain chemicals that decrease seizure activity.

What is the vagus nerve?

The vagus nerve is the 10th cranial nerve that supplies nerve fibers to the pharynx (throat), larynx (voice-box), trachea (air pipe), lungs, heart, esophagus and gut. It starts in the medulla oblongata and extends up to the intestine. The cranial nerves have either sensory or motor functions. Some cranial nerves bring information from the senses (touch or sight) to the brain (sensory) and some others control muscles (motor). The vagus nerve has both sensory and motor functions. The vagus nerve also brings sensory information back to the brain from the ears, tongue, pharynx and larynx.

What are the functions of the vagus nerve?

The vagus nerve has two functions.

The sensory functions of the vagus nerve include

  • Providing nerve supply for the skin behind the ears and the external part of the ear canal.
  • Providing nerve supply to the larynx, heart and gastrointestinal tract.
  • Playing a trivial role in the sensation of taste near the root of the tongue.

The motor functions include

  • Controlling the muscles of the pharynx, larynx and the soft palate present near the back of the roof of the mouth.

Other functions include

  • Controlling the heart rate.
  • Stimulating muscle contraction in the stomach to increase gastric emptying and acid production.
  • The vagus nerve is responsible for varied tasks like heart rate, sweating and quite a few muscle movements in the mouth, including speech and keeping the throat open for breathing.
  • It also controls a part of the meninges and the parasympathetic system, the involuntary system that slows down body functions and increases body secretions.

How is stimulation of the vagus nerve achieved?

Stimulation of the vagus nerve is achieved through vagal nerve stimulation (VNS). VNS involves placing a pacemaker-like device that produces an electrical impulse to stimulate the vagus nerve. Epilepsy is a disorder where unexpected electrical discharges from the brain cause seizures. Most seizures are resolved by antiseizure medications. However, some seizures that originate from one area of the brain cannot be controlled with just medications. VNS is a useful option in such instances because it affects one part of the brain.

Why is vagal nerve stimulation done?

VNS may be useful in patients with epilepsy, which hasn’t been controlled by antiseizure medications. About one-third of patients do not respond to antiseizure medications. VNS may help reduce the frequency of seizures in epileptic patients.

VNS may also be used to control


If you have had a seizure, it means you have epilepsy. See Answer
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