Abstract：
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.
摘要：
喘鸣是由狭窄的上呼吸道振荡引起的。新生儿喘鸣最常见的原因是喉软化,其次是声带外展功能障碍。在这里，我们介绍了2例新生儿特发性声带外展功能障碍。一名新生儿在生命的第4天因吸气式喘鸣而被送往新生儿重症监护病房（NICU），间歇性肋下收缩,和紫癜。在生命的第7天，第二名新生儿因哭泣时的吸气性喘鸣和紫癜而被送入NICU。患者均未出现畸形特征或异常的心脏超声检查结果。经喉支气管镜检查确诊。在两种情况下，采用双相气道正压通气的保守治疗均有效，症状在几个月内消失。通过重复内窥镜检查确认声带外展功能障碍的解决。声带外展功能障碍的临床表现差异很大。虽然大多数情况下自发解决，延长管饲，甚至气管造口术,在一些严重的情况下是需要的。声带外展功能障碍的诊断需要喉支气管镜检查研究；因此，可能有大量未确诊的患者。在新生儿吸气性喘鸣的鉴别诊断中应考虑声带外展功能障碍。
