The vagus nerves transmit messages between the brain, heart, and digestive systems. Your parasympathetic nerves play an essential role in your body. Gastroparesis, in which food does not enter the intestines, can be caused by injury to the vagus nerve. Those with vasovagal syncope may experience fainting episodes due to low blood pressure. It has been found that stimulating the vagus nerve (VNS) can help those suffering from epilepsy and depression.
What is the Vagus Nerve?
The vagus nerve, or vagal nerves, are the primary afferent nerves of the parasympathetic division of the autonomic nervous system. Digestion, heart rate, and the immune system are just a few of the bodily processes regulated by this system. You don't have to make any effort to keep these processes running; they're automatic.
75% of the nerve fibers in your parasympathetic nervous system are located in your vagus nerves, both left and right. Some fibers carry signals from your brain to your heart and digestive system.
There are 12 cranial nerves, and number 10 is the vagus nerves. The vagus nerve is numbered ten on the cranial nerve chart (X in Roman numerals).
What Does the Vagus Nerve Affect?
The vagus nerve, commonly known as the pneumogastric nerve, controls the following various internal organs:
- Vital signs during digesting
- Respiratory and cardiac reflexes, including coughing, sneezing, swallowing, and puking
- It is part of the autonomic nervous system, which regulates things like breathing and digestion that people don't give much thought to
It may also connect the digestive system to the brain, forming part of the gut-brain axis. Researchers have been examining the gut-brain axis in recent years, hoping to find connections between obesity and depression.
Vagus Nerve Testing
The gag reflex can be used as a diagnostic tool for the vagus nerve. The doctor may use a cotton swab to gently tickle the back of your throat on both sides at this point in the examination. The target should be making gagging noises after this.
A problem with the vagus nerve, which could imply a problem with brainstem function if the patient does not gag, may be to blame.
As was stated in recent literature [1], doctors may also evaluate vagal nerve function when examining cardiovascular disease. Trauma to the vagus nerve can disrupt the cardiovascular system.
Cardiovagal tone refers to how well your vagal nerve functions in conjunction with your cardiovascular system. It may be assessed by monitoring your heart rate, blood pressure, and cardiovascular reaction to exercise. There may be information there on the condition of your heart.
Vagus Nerve Damage
The vagus nerve is very long; therefore, its damage can produce various symptoms.
Possible signs of damage to the vagus nerve include:
- Problems with expression
- Voice change
- Difficult swallowing
- Loss of gag reflex and hypotension
- Variations in Heart Rate during Digestion
- Sickness and throwing up
- Pain in the stomach or tummy
- Persons with respiratory difficulties or heart disease are more likely to suffer from depression and anxiety
Any possible signs and symptoms could result from nerve damage, depending on which section of the nerve is affected.
Vagus Nerve Stimulation
Placing a device that sends electrical impulses to the vagus nerve is known as vagus nerve stimulation (VNS). It's a go-to for patients with uncontrollable epilepsy and unrelenting depression who haven't found relief elsewhere.
Experts have linked the vagus nerve to depression, metabolic disorders, and cardiovascular disease. Scientists believe VNS has the potential to improve health in a wide range of ways and hope to validate this with further studies.
The implant is often connected to the left vagus nerve via a cable hidden beneath the chest's skin. When turned on, the device communicates with your brainstem by stimulating the vagus nerve.
A neurologist typically programs the device, but patients are often given a handheld magnet to adjust settings as needed. Multiple sclerosis, posterior autoimmune uveitis, Alzheimer's disease, and cluster headaches are only a few illnesses that may benefit from VNS treatment in the future.
Final Thoughts
Among its various roles, the vagus nerve may connect the brain with the digestive tract. Focusing on the vagus nerve has shown positive results in treating epilepsy and depression, and there is preliminary evidence that it may also help treat rheumatoid arthritis.
Some health professionals think more studies could help them figure out how to treat inflammatory diseases, including diabetes, obesity, and heart disease.