Bilateral internal superior laryngeal nerve injections for unexplained chronic cough

Abstract

Objective

Internal Superior laryngeal nerve (iSLN) injections with steroids and anesthetic for Unexplained Chronic Cough (UCC) was initially described as a unilateral injection. This study reports the safety profile and patient-reported outcomes of concurrent bilateral iSLN injections for UCC.

Study design

Retrospective chart review.

Setting

Tertiary center.

Methods

A chart review from 2018 to 2023 was performed for patients with UCC who underwent bilateral iSLN injections. Demographics, clinical history, and physical exam findings were recorded, along with any post-injection complications. The primary outcome was patient-reported percent improvement in cough symptoms. Nonparametric statistical analyses were performed to examine whether treatment effectiveness differed based on (a) duration of cough, (b) whether an upper respiratory illness (URI) preceded the start of the cough, (c) had undergone prior speech therapy or (d) neuromodulator treatment for cough, (e) laterality of symptoms, and (f) demonstrated abnormal flexible laryngoscopy/stroboscopy findings.

Results

12 UCC patients underwent a median of 2 injections (Interquartile Range (IQR): 1–5.5 injections) for a total of 42 injections). There were no aspiration events and only 3 self-limited minor complications. 75 % of patients reported improvement with at least one of their injections with a median percentage response of 73 % (IQR: 26–89 %) and a reported median duration of response of 2.2 months (IQR: 1.2–3.2 months). Nonparametric testing revealed greater responses to injection in patients with abnormal flexible laryngoscopy/stroboscopic findings with their initial injection (p ≤0.02).

Conclusion

Bilateral concurrent iSLN injections are a safe and effective way of treating UCC that may require fewer visits to effectively treat UCC.