Efficacy and Safety of Superior Laryngeal Nerve Block in the Management of Neuropathic Cough: A Systematic Review.

Abstract

Objectives: To systematically review the efficacy and safety, both short and long-term, of superior laryngeal nerve block (SLNB) for managing neuropathic cough.

Methods: A literature search was conducted using the keywords "Superior laryngeal nerve block," "Neurogenic Cough," "Neuropathic Cough," and "Refractory Chronic Cough." The primary outcome was cough-specific quality of life (QoL), evaluated with validated patient-reported outcome measures (PROMs) such as the Leicester Cough Questionnaire (LCQ), Cough Severity Index (CSI), and Hull Airway Reflux Questionnaire (HARQ). Additional data included SLNB technique, cough duration, use of neuromodulators and Behavioral Cough Suppression Therapy (BCST), injection frequency, vocal fold dysfunction (VFD), and adverse events. Quality assessments used the Methodological Index for Non-Randomized Studies (MINORS) criteria.

Results: Ten studies comprising 625 patients were included. The average cough duration prior to intervention was 78 months, with a mean follow-up of 5.01 months. Patients received an average of 2.5 injections. Short-term outcomes showed consistent improvements in PROMs and cough perception. Long-term outcomes (beyond three months) were reported in four studies, with minimal variations but no statistical comparisons to baseline scores. Significant heterogeneity was noted across studies, including differences in assessment protocols and adjunctive therapies. No significant adverse events were reported.

Conclusion: SLNB is a safe and effective treatment for refractory chronic cough, either alone or with systemic medications. However, the variability among studies highlights the need for standardized protocols and further research with long-term follow-up to confirm its efficacy.