In people diagnosed with neurogenic cough, superior laryngeal nerve block is an effective procedure with a good safety profile.

A prospective placebo-controlled trial was conducted to evaluate the effectiveness and safety of  superior laryngeal nerve (SLN) block in the treatment of neurogenic cough.

Patients who met the criteria for neurogenic cough and were at least 18 years old were included. To ensure the accuracy of the results, subjects with untreated chronic cough due to other causes, such as uncontrolled reflux, and those currently using neuromodulating medications were excluded. Randomization was performed to assign the volunteers to either the treatment group, which received 1-2 mL of a 1:1 mixture of 40 mg Triamcinolone and 1% Lidocaine with 1:200,000 Epinephrine, or the placebo group, which received saline injections.

Two unilateral injections were administered to each patient at around 2-week intervals. The primary measurement of outcomes was conducted using the Leicester Cough Questionnaire (LCQ) and a patient symptom log that incorporated visual analog scale (VAS) to assess the severity of cough.

A total of 17 individuals participated and completed the study, with 10 individuals assigned to the treatment group and 7 individuals in the placebo group. In the treatment group, 8 subjects (80%) reported experiencing betterment with at least one of the injections. In contrast, only 1 volunteer (14.3%) from the placebo group reported improvement.

The average total scores on the LCQ elevated in the treatment group from 10.09 to 13.15, with the most alteration observed in the social domain. No clinically meaningful alteration was witnessed in the LCQ scores for placebo group. No major adverse events were witnessed throughout the study.

Using SLN block is safe and effective to relieve neurogenic cough. However, there is a need for additional studies to refine the intervention protocol and evaluate the long-term outcomes of patients.