Intraspinal seeding from intracranial tumors in children.

Cerebrospinal fluid-borne metastases were demonstrated by metrizamide myelography in 20 children with primary intracranial tumors, posterior fossa medulloblastomas being the most common. The lumbosacral region was affected most often, with nerve root thickening, nodularity, and irregularity of the thecal sac. Cord cloaking, nodularity, and meningeal disease were common in the cervical and thoracic areas. Intraspinal spread from primary intracranial tumors signals a poor prognosis. However, the early detection of intraspinal spread afforded by metrizamide myelography can alter therapy and thereby improve prognosis.