Impact of Laryngeal Paralysis and its Treatment on the Glottic Aperture and Upper Airway Flow Characteristics during Exercise

Abstract

Patients with unilateral vocal fold paralysis occasionally report shortness of breath during exercise. This symptom may persist in some patients after medialization thyroplasty. A review of the literature revealed no study that objectively evaluated laryngeal dynamics or airway flow characteristics during exercise after medialization thyroplasty for unilateral laryngeal paralysis. This study evaluates glottic aperture size and configuration as well as upper airway flow characteristics during exercise in 16 subjects. Six patients who underwent medialization thyroplasty for unilateral vocal fold paralysis were compared with 10 healthy control subjects. During a standardized exercise protocol on an incremental ergometer (bicycle type), real-time videolaryngoscopy was obtained and correlated in a synchronized fashion with maximum-effort respiratory efforts at the beginning, midpoint, and end of the exercise period. Direct calculations of glottic size during various phases of the exercise period were performed from digitized images. These data were correlated with inspiratory flow data for each patient. Patients with laryngeal paralysis demonstrated smaller mean glottic areas and lower peak inspiratory flow rates than controls both at rest and during all phases of the exercise period. This study suggests that after treatment of unilateral laryngeal paralysis with medialization thyroplasty, inspiratory flow rate and glottic area are significantly less than in normal controls.