Management of Chiari II complications in infants with myelomeningocele.

Vocal cord paralysis with inspiratory stridor during infancy is a well-recognized complication of the Arnold-Chiari malformation associated with myelomeningocele. Management of these symptoms, however, remains controversial. The outcome in 19 infants with symptoms managed by us during 1978-1984 was therefore reviewed. Ten infants had stridor alone at presentation (clinical grade 1), four infants also had apnea (grade 2), and five infants also had associated cyanotic spells and dysphagia (grade 3). Of 14 ventricular shunt revisions performed, seven were associated with resolution: in five of eight infants with grade 1, two of four with grade 2, and none of two with grade 3 symptoms. Of the 10 posterior fossa decompressions performed, two were associated with clinical resolution: in one of four infants with grade 1, one of two with grade 2, and none of four with grade 3 symptoms. Mortality over 6 months following onset of symptoms was absent among infants with grade 1, one with grade 2, and three with grade 3 symptoms. We propose that differences in outcome among the three groups of infants reflect differences in pathologic processes within the brain stem. We speculate that infants with grade 2 or 3 symptoms have more extensive brain stem damage, such as hemorrhage, infarction, and necrosis. Use of our classification system may be helpful in further studies on intervention modalities in these infants.