Clinical Perspectives of Chorda Tympani Nerve: A Scoping Review

The largest branch of the facial nerve in the intrapetrous region of temporal bone is the chorda tympani nerve (CTN), which emerges from the facial nerve right before to its existence through the styloid foramen. The CTN carries taste sensation from anterior two-thirds of the tongue. It also provides secretomotor innervation to the submandibular and sublingual salivary glands. The CTN is commonly injured during middle ear surgery. The location of CTN in the middle ear cavity and lack of bony wall are makes this nerve prone for injury. The severity of CTN injury depends on the extent of trauma, type of surgery, and patient factors. Injury of the CTN can lead to temporary taste disturbances or dysgeusia. The symptoms often improve over time; these symptoms can be persistent and significantly affect the quality of life. A proper understanding of the anatomy of CTN is helpful to decrease the chance of iatrogenic damage during the middle ear and head-and-neck surgery. The goal of this review is to discuss the clinical perspectives of the CTN by proper understanding of its anatomical course in relation to surgery at temporal bone and middle ear.