The superior laryngeal nerve: function and dysfunction

The superior laryngeal nerve (SLN) innervates the cricothyroid muscle via its external branch and provides afferent innervation to the entire hemilarynx above the vocal fold. Despite these well-known facts regarding its anatomy and function, significant ambiguities persist regarding the laryngeal appearance and clinical symptoms of SLN dysfunction. Only an approximate appreciation of its prevalence, treatment, and overall importance is possible under such circumstances. Increased diagnostic rigor is essential to defining this entity better.