Syringobulbia as a cause of laryngeal stridor in childhood.

A 10-year, 11-month-old boy who had had chronic stridor since birth died suddenly following the development of slowly progressive symptoms of respiratory obstruction due to vocal cord paralysis. Autopsy showed extensive bilateral syringobulbia, with the greatest involvement in the nuclei ambigui. Other brain-stem tracts and nuclei were only partially affected. These findings support the theory of the early developmental origin of syringobulbia.