Pressure and Flow Comparisons Across Vocal Pathologies

Objective: The aim of this study was to aid in the distinction among hyperadductive dysphonias by evaluating peak glottal pressure, release burst, and mid and final airflow values across repeated /pa/ syllable trains. Methods: Sixty subjects were assessed for aerodynamic patterns during onset-offset for the /papapapapa/ task in modal voice. Subject groups included adductory spasmodic dysphonia (AdSD), benign vocal fold lesion, primary muscle tension dysphonia (MTD-1), secondary muscle tension dysphonia with an identifiable primary benign vocal fold lesion (MTD-2), vocal fold paresis or paralysis, and normal controls. Results: Increased peak pressure (PP) was found for AdSD and MTD-2 subjects compared with controls. Release burst and mid airflow were not significantly different among groups. Final airflow was significantly higher for AdSD compared with the other groups. Final airflow was significantly lower for MTD-1. Conclusions: Significant differences in aerodynamics are seen in subjects with AdSD compared to MTD. AdSD was characterized by higher PP and higher final airflow. MTD-1 was characterized by lower final airflow, whereas MTD-2 was characterized by higher PP. Aerodynamic evaluation may aid in differential diagnosis for those patients in whom distinction among hyperadductive disorders is challenging.