Superior Laryngeal Nerve Block Safe, Effective for Treatment of Neurogenic Cough

by Linda Kossoff •

CLINICAL QUESTION

How safe and effective is a superior laryngeal nerve (SLN) block for neurogenic cough?

BOTTOM LINE

An SLN block is a safe and efficacious procedure for the treatment of neurogenic cough.

BACKGROUND: Chronic cough is a common problem with a wide differential diagnosis. Some patients receive diagnoses of sensory neuropathy, or “neurogenic cough,” for which neuromodulating medications may be effective but carry significant side effects. Current data support the efficacy and safety of SLN blocks for neurogenic cough, but literature is limited.

STUDY DESIGN: Prospective placebo-controlled trial.

SETTING: Department of Otolaryngology–Head and Neck Surgery, Medical University of South Carolina, Charleston, S.C.

SYNOPSIS: Researchers enrolled 19 adult patients with a history of neurogenic cough from an outpatient tertiary care center. Seventeen patients (15 females, average age 56.3 years) completed the study. Patients were randomized into treatment or placebo groups and given two unilateral injections at approximately two-week intervals. The treatment group received 1–2 mL of a 1:1 triamcinolone 40 mg: 1% lidocaine with 1:200,000 epinephrines; the placebo group received saline. Primary outcome measures included a yes/no answer to cough improvement, questionnaire, and daily visual analog scale. In the treatment group of 10 patients, eight reported symptom improvement with at least one injection. Only 50% of these patients reported a greater than 50% improvement, however. Authors noted that this left open the question of whether clinical differences existed for these patients. Two treatment group patients did not improve until the contralateral side was injected, indicating that neuropathy may affect one or both sides in patients with neurogenic cough. Only one person from the placebo group (n = 7) reported any improvement. There were no significant adverse effects. Study limitations included the small sample size.

Citation: Tipton CB, Walters R, Gudipudi R, et al. The efficacy of superior laryngeal nerve black for neurogenic cough: a placebo-controlled trial. Laryngoscope. 2023;133:3068–3074.