Vocal Cord Paresis, Causes, Signs and Symptoms, Diagnosis andTreatment.

Vocal cord paresis, also known as recurrent laryngeal nerve paralysis or vocal fold paralysis, is an injury to one or both recurrent laryngeal nerves (RLNs), which control all muscles of the larynx except for the cricothyroid muscle. The RLN is important for speaking, breathing and swallowing.[1][2]

The primary larynx-related functions of the mainly efferent nerve fiber RLN, include the transmission of nerve signals to the muscles responsible for regulation of the vocal folds’ position and tension to enable vocalization, as well as the transmission of sensory nerve signals from the mucous membrane of the larynx to the brain.

A unilateral injury of the nerve typically results in hoarseness caused by a reduced mobility of one of the vocal folds. It may also cause minor shortages of breath as well as aspiration problems especially concerning liquids. A bilateral injury causes the vocal folds to impair the air flow resulting in breathing problems, stridor and snoring sounds, and fast physical exhaustion. This strongly depends on the median or paramedian position of the paralyzed vocal folds. Hoarseness rarely occurs in bilaterally paralyzed vocal folds.