Outcomes of a step-up approach to the treatment of neurogenic cough

Abstract

Introduction: Neurogenic cough (NC) is thought to be related to sensory neuropathy in the hypopharynx and larynx. Defined as a cough persisting longer than 8 weeks refractory to standard therapy, it is a diagnosis of exclusion when other common etiologies (asthma, gastroesophageal reflux disease (GERD), medication side effects) are ruled out. It affects roughly 11 % of Americans and can negatively impact quality of life.

Methods: Following institutional review board approval, we evaluated the medical records of adult patients seen at the University of Arizona's tertiary laryngology center from 2018 to 2023. Patients were included if their cough persisted for >8 weeks, and they either did not respond to prior proton pump inhibitor and asthma therapy or had GERD and asthma ruled out. These patients underwent a progressive escalation of therapy, which included neuromodulators with or without cough suppression therapy, superior laryngeal nerve (SLN) block, and laryngeal botulinum toxin injections. The primary outcome was patient-reported improvement in cough symptoms rated on a 1-5 scale: 1 = no response, 2 = mild improvement, 3 = moderate improvement, 4 = significant improvement, 5 = complete resolution.

Results: A total of 56 patients were included. Mean (SD) age was 64.6 (14.8) years, and 66 % were female. Overall, 42 patients (75.0 %) responded to treatment. Among responders, 7 (16.7 %) experienced mild improvement, 14 (33.3 %) experienced moderate improvement, 17 (40.5 %) experienced significant improvement, and 4 (9.5 %) experienced complete resolution of their cough. 33 patients (58.9 %) were managed exclusively with neuromodulators ± cough suppression therapy; 27 responded, with an average response rating of 3.0 (SD = 1.2). 11 patients (19.6 %) failed medical therapy and underwent SLN block without subsequent botox treatment; 7 responded, with an average response rating of 2.5 (SD = 1.4). 9 patients (16.1 %) failed all previous therapies and underwent laryngeal botulinum toxin injections; 6 responded with an average response rating of 2.4 (SD = 1.3). The remaining 3 patients underwent cough suppression therapy alone, with 2 responding and an average response rating of 3.3 (SD = 1.7).

Conclusions: Neurogenic cough can be effectively treated with a stepwise multimodal approach, including neuromodulators, cough suppression therapy, SLN block, and laryngeal botulinum toxin injections.

Keywords: Laryngeal botulinum toxin injection; Neurogenic cough; Neuromodulators; Superior laryngeal nerve block.