What is czermak-hering test?

The Czermak-Hering test is a test used to determine the sensitivity of the larynx. The test involves the introduction of a catheter into the trachea, which causes stimulation of the laryngeal mucosa. The response of the larynx is then observed to determine its sensitivity to the stimulation. This test is used in the diagnosis of conditions such as vocal cord paralysis, laryngeal nerve damage or irritation, and other laryngeal disorders. The test is named after Josef Czermak and Ewald Hering, who developed it in the late 1800s. Although the Czermak-Hering test has been largely replaced by newer diagnostic methods, it remains a useful tool in the evaluation of certain cases of laryngeal dysfunction.