Objectives: Neuromuscular control, glottal conformation and aerodynamics are the major factors affecting voice performance. We aimed to characterise the degree to which voice improvements following office-based intracordal hyaluronate injection laryngoplasty (HIL) depend on changes in voice aerodynamics in patients with unilateral vocal fold paralysis (UVFP), by assessing the correlations between these parameters.
Design: Prospective case series.
Setting: Otolaryngology Clinics in a Medical Center.
Participants: Patients with UVFP within 6 months of their first outpatient visit who received single HIL.
Main outcome measures: Videolaryngostroboscopy, aerodynamics and laboratory voice analysis were evaluated at baseline and 1 month after HIL. Quantitative laryngeal electromyography was evaluated at baseline to confirm UVFP.
Results: Seventy-five newly diagnosed patients with UVFP were analysed. The normalised glottal gap area (NGGA) decreased (P < 0.001) (Cohen's dz = 0.94) and all aerodynamic parameters improved (all P < 0.05) (Cohen's dz = 0.38-1.02) following HIL. Patients undergoing thoracic surgery had more profound aerodynamic impairments both before and after HIL. After adjusting for improvements in NGGA, the improvement in aerodynamics was correlated with voice improvement and most notably with maximum phonation time and jitter/shimmer.
Conclusions: Hyaluronate injection laryngoplasty improved glottal conformation, aerodynamics and voice, highlighting the benefit of early HIL intervention for patients with UVFP. Patients with UVFP caused by thoracic surgery continued to have poorer aerodynamics post-HIL, indicating the importance of speech therapy in these patients.
Keywords: aerodynamics; glottal gap; hyaluronate; injection laryngoplasty; laryngeal electromyography; unilateral vocal fold paralysis.
© 2019 John Wiley & Sons Ltd.