Bilateral Vocal Fold Abduction Dysfunction: A Report of Two Neonatal Cases.

Stridor is caused by oscillation of the narrowed upper airway. The most common cause of neonatal stridor is laryngomalacia, followed by vocal fold abduction dysfunction. Herein, we present two neonatal cases of idiopathic dysfunction of vocal fold abduction. A neonate was admitted to the neonatal intensive care unit (NICU) on day 4 of life for inspiratory stridor, intermittent subcostal retraction, and cyanosis. A second neonate was admitted to the NICU on day 7 of life for inspiratory stridor and cyanosis when crying. Neither patient had dysmorphic features or unusual cardiac ultrasonography findings. The diagnosis was confirmed by laryngo-bronchoscopy. Conservative treatment with biphasic positive airway pressure was effective in both cases and symptoms resolved within a few months. Resolution of vocal fold abduction dysfunction was confirmed by repeat endoscopy. Clinical manifestations of vocal fold abduction dysfunction vary widely. Although most cases resolve spontaneously, prolonged tube feeding, or even tracheostomy, is needed in some severe cases. Diagnosis of vocal fold abduction dysfunction requires a laryngo-bronchoscopy study; thus, there may be a large number of undiagnosed patients. Vocal fold abduction dysfunction should be considered in the differential diagnosis for neonatal inspiratory stridor.