Laryngomalacia usually resolves of its own accord within 18-24 months. Vocal cord paralysis may cause a patient to have a weak cry. They also may be worse with feeding. Ruling out underlying conditions that may result in vocal cord paralysis in particular neurologic conditions such as Arnold-Chiari malformation, is important. Bilateral paralysis is more commonly associated with neurologic problems and is a life-threatening emergency.
Subglottic stenosis can be congenital or acquired.
Stridor of subglottic stenosis typically is biphasic. Other laryngeal abnormalities leading to stridor include webs, cysts, hemangiomas, papillomata, and laryngtracheoesophageal clefts. Tracheal causes of stridor Extrinsic compression of the trachea by vascular abnormalities is a common cause of stridor. Anomalies that may lead to stridor include double aortic arch, innominate artery compression, aberrant right subclavian vein, and pulmonary artery sling. Bronchogenic cysts also can cause extrinsic compression of the trachea.