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What is the Chorda Tympani?

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  • Written By: C. Martin
  • Edited By: Andrew Jones
  • Last Modified Date: 30 November 2016
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The chorda tympani is a facial nerve that transmits neural impulses from the tongue to the brain, where these impulses are translated into the sensation of taste. The origin of the chorda tympani nerve is a branch of one of the major facial nerves, referred to as the seventh cranial nerve. This branch occurs in the facial canal, a bony canal at the side of the skull, approximately level with the eye sockets. From the facial canal, the chorda tympani is routed via the middle ear, running from front to back along the eardrum, or tympanic membrane. Emerging from the skull into the mouth cavity, near the base of the tongue, the nerve joins up with a cluster of nerve tissue called the submandibular ganglion, and then continues into the tongue, and innervates the cells at the front of the tongue.

The main role that the chorda tympani nerve plays in the sensation of taste is to detect tastes on the front two thirds of the tongue, and to transmit the appropriate nerve impulses to the brain. This function is carried out by means of sensory fibers within the nerve. In addition to these sensory fibers, the nerve also contains fibers of a different type, which serve to stimulate the submandibular and the sublingual salivary glands, causing them to produce saliva. A further function of these stimulatory fibers is to cause blood vessels in the tongue to dilate.

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Chorda tympani anatomy is connected with a number of other, related facial nerves. The mandibular nerve transmits sensations of temperature, touch, and pain from the tongue. Another nerve, the glossopharyngeal nerve, transmits sensations of taste from the back third of the tongue to the brain. The vagus nerve innervates the epiglottis.

The mammalian taste system forms a complex feedback loop. The different nerves that are involved in this system have the ability to inhibit each other, which is how a person is able to become desensitized to a strong taste. For example, if a person holds a sweet with a strong sour flavor in his or her mouth, the taste will seem less intense after a while. The chorda tympani appears to serve an important role in inhibiting the signals from the other nerves involved in the sensation of taste. Chorda tympani damage can result in a disruption of the inhibitory function, causing the sensation of taste to become erratic and uncontrolled.

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anon256464
Post 4

@anon226075 - Post 3: I, too, have the same results after a stapedectomy. My first surgery was in July 2011, and had these side effects along with a strange dizzy sensation, neither of which has gone away. I had a re-surgery about six weeks ago, with no change. Have you had any improvement, and if so, did you do anything in particular to fix these symptoms?

anon226075
Post 3

I have chorda tympani damage from a stapedectomy which I had nearly seven months ago now. This had caused a dry mouth and constant phantom tastes and distortions which never seems to get any better.

I've found that certain stimulants, like coffee, and strong tasting foods, like garlic and chili, cause several days of worse symptoms. This condition is very debilitating and if I could turn back time, I'd rather be deaf than have this constant discomfort.

My specialist has told me nothing can be done to help. If anyone has helpful suggestions or knows of anything I can do, please post on here as I am desperate.

StarJo
Post 2

@Perdido - I am about to have tympanic membrane surgery, and I read a study conducted on the chorda tympani and how much it affects taste. The study mentioned that during surgery on the middle ear, the chorda tympani is often damaged or totally sacrificed.

Surgeons have varied opinions on whether it is better to try and preserve the chorda tympani and risk trauma to it or to go ahead and sacrifice it cleanly, which has been shown to cause less trauma at times. This particular study involved 31 patients who underwent middle ear surgery, and research showed that most of them recovered their tastes over time. However, in those whose chorda tympani was totally sacrificed, there was a 31% increased occurrence of permanent change in tastes.

Perdido
Post 1

My sister had to have surgery to repair a perforation in her tympanic membrane. Her doctor discovered the perforation when she came to his office complaining of hearing loss and a recurring discharge. He saw that she had an infection that must have been with her for quite some time to have caused the damage.

During her operation, the surgeon placed a graft under her perforation to act as an object for the perforation edges to heal over. The surgery went well, though she did have a few short-term complications.

She had temporary chorda tympani nerve damage. Because of this, she had a metallic taste in her mouth for about five weeks. They had warned her that this could happen, so she was prepared.

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