Hydrocephalus, cervical cord lesions, and spinal deformity.

Twenty-six children (4-16 years) had hydrocephalus and spinal deformity; 22 children had scoliosis over 50 degrees, and five children had kyphosis over 100 degrees. Twenty-one children had metrizamide enhanced cord CT scans, and 12 had additional head scans. Two children died, and one was autopsied. Three children had intracranial pressures monitored during spinal surgery. All children had Type I and II Arnold-Chiari malformations, 58% had cord cavitation (syringo/hydromyelia), 67% had cord tethering. The anatomic study showed extensive fibrosis and scarring of the upper cord and brain stem, but intraoperative studies showed that there is free transmission of fluid pressure wave from the cord across the foramen magnum with a consequent rise in intracranial pressure. This study documents frequent coexistence of spinal deformity and central nervous system lesions (hydrocephalus, Arnold-Chiari malformation, cord tethering with atresia, and cord cavitation). It supports the theory that the Arnold-Chiari malformation is a primary developmental deformity and that cord cavitation noted in these patients is primarily syringomyelia formed on the basis of ischemic necrosis within the cord. The free transmission of a fluid pressure wave from the cord to the lateral ventricle supports the Williams theory of propagation of syringomyelic cavities once they have developed. It is conjectural but likely that the CNS lesions cause spinal deformity by disrupting coordinating control of spinal musculature by the normal postural reflex mechanisms. Hydrocephalic patients who develop spinal deformity require thorough investigation for CNS lesions with head scans, CT scans, and metrizamide enhanced CT scans. NMR technology, however, may supplant techniques currently employed.