Objective: Internal superior laryngeal nerve (iSLN) injections demonstrate short term improvements in patients with laryngeal neurosensory disturbances (ie, chronic refractory cough and globus pharyngeus) that can require multiple injections. A more targeted iSLN injection approach could provide greater effectiveness. This study prospectively evaluated whether transnasal endoscopic iSLN injections that target the internal iSLN as it transverses the piriform sinuses was effective at treating laryngeal neurosensory disturbances.
Methods: This was a prospective cohort analysis performed at a single tertiary care center. Patients with laryngeal neurosensory disturbances underwent transnasal endoscopic iSLN injections bilaterally using triamcinolone-40 mg/mL. Demographics, clinical history, and exam findings were recorded, along with post-injection complications. The primary outcomes were the Leister Cough Questionnaire (LCQ), Reflux Symptom Index (RSI), and the Voice Handicap Index-10 (VHI-10) collected at pre-injection, 3-weeks post-injection, and 2-months post-injection that were examined with linear mixed modeling.
Results: Eighteen patients with laryngeal sensory disturbances (11 with chronic cough and 7 with globus sensation) underwent the procedure. There were significant improvements in LCQ scores (all greater than 1.3 points) and RSI scores (all greater than 7-point improvement) at both 3-week and 2-month timepoints (P < .05). When stratified into globus sensation patients alone, there was significant improvements in LCQ at 3 weeks (3.92 points, P = .02) as well as across both 3-week and 2-month timepoints (14 points, P < .001; 7.4 points, P = .04). There were no aspiration events or major complications.
Conclusions: Targeted transnasal endoscopic iSLN injections of the piriform sinus mucosa appears to be a safe and effective way of treating laryngeal neurosensory disturbances. The technique provides a visual target for injection of the iSLN which may allow for exploration of alternative neuromodulating medicines for use in this patient population.
Keywords: globus sensation; irritable larynx syndrome; laryngeal hypersensitivity syndrome; refractory chronic cough; superior laryngeal nerve injections; unexplained chronic cough.