Acute spinal cord swelling in a child with Chiari II malformation.

We report on a patient with Chiari II malformation who developed acute cervical myelopathy and brainstem dysfunction following a shunt failure. A brain and spine magnetic resonance image obtained immediately after admission evidenced swelling of the medulla and upper cervical spinal cord. After emergency placement of an external ventricular drain, the swelling receded, the child's respiratory pattern improved and the motor function of his upper and lower extremities progressively returned to its normal condition. The case reported here suggests that in patients with Chiari type II malformation, spinal cord swelling might have a similar pathophysiology to the periventricular edema observed in the supratentorial compartment, and thus may be independent of the early stages of syringomyelia or syringobulbia.