RESUMO
INTRODUCTION: Stridor is a respiratory sound caused by turbulent air flow through narrow airways. The most common cause for acute inspiratory stridor is a viral infection of the upper airways, causing laryngotracheitis (Croup). Other common causes include an allergic reaction, foreign body aspiration and trauma. BACKGROUND: A nine week old infant with a history of meningomyelocele repair perinatally presented to the emergency room with alternating inspiratory stridor. The infant did not have a history of a recent febrile illness, and he did not suffer from cough or any other symptoms suggesting a foreign body aspiration. After the common causes of stridor were ruled out, an MRI was performed - demonstrating Chiari malformation Type 2, with herniation of the cerebellar tonsils and medullary compression. Bronchoscopy demonstrated the rare cause of the intermittent stridor - intermittent vocal cord paralysis, caused by the raised intracranial pressure and medullary compression. Due to rapid clinical deterioration, emergent surgical decompression was performed with complete recovery. CONCLUSIONS: This case report raises a rare and important cause of inspiratory stridor. Physicians should be alert to the symptoms suggesting a Chiari malformation in every child with a relevant medical history presenting with stridor. DISCUSSION: Intermittent stridor is mostly caused by an upper respiratory infection in a child with narrowed airways, allergic laryngotracheitis, or laryngomalacia. A less common cause of stidor of this kind is vocal cord paralysis, which may be caused by a symptomatic Chiari malformation.