Characterization of laryngeal dysfunction in chronic persistent cough

Abstract

Objectives/hypothesis: Laryngeal symptoms are increasingly recognized to occur in chronic persistent cough and may result from the sensory hyperresponsiveness that characterizes this condition. Apart from cough, the motor consequences of sensory activation have not been well described in chronic persistent cough. The efficacy of speech pathology treatment for chronic cough suggests that laryngeal dysfunction may be relevant in chronic persistent cough. This study investigated the relationship between cough reflex sensitivity and laryngeal dysfunction, which was assessed as paradoxical vocal cord movement (PVCM) and extrathoracic airway hyperresponsiveness, in patients with chronic cough.

Study design: Cross-sectional case-control comparison of subjects with chronic cough and healthy controls.

Methods: Adults with chronic persistent cough (n = 25) and healthy controls (n = 11) were assessed by cough-specific quality of life questionnaire, extrathoracic airway hyperresponsiveness to hypertonic saline provocation, capsaicin cough reflex hypersensitivity, and fibreoptic laryngoscopy to assess PVCM.

Results: Laryngeal dysfunction was present in many patients with chronic persistent cough. PVCM was present in 56% of subjects with chronic cough and accompanied by cough reflex hypersensitivity and impaired quality of life. Inspiratory airflows were reduced in cough with PVCM, and there was significant extrathoracic airway hyperresponsiveness.

Conclusions: Laryngeal dysfunction is common in chronic cough, where it is manifest as paradoxical vocal cord movement and extrathoracic airway hyperresponsiveness. Laryngeal dysfunction in chronic cough is associated with reduced quality of life. Laryngeal hypersensitivity may be a common mechanism that can be effectively treated by speech language therapy.