The Surgical Treatment of Arnold-Chiari Malformation in Adults

Abstract

The Arnold-Chiari malformation is a deformity of the hindbrain in which a tongue-like projection of the cerebellar tonsils protrudes through the foramen magnum down into the cervical cord. On the basis of surgical experience, the authors derive certain conclusions concerning this deformity. The Arnold-Chiari malformation is regarded as a foraminal herniation produced by obstructive hydrocephalus. The associated hydromyelia is due to the extrusion of fluid from the obstructed 4th ventricle into the central canal of the cord. Diagnosis may be confirmed by encephalog-raphy. The films show evidence of obstructive hydrocephalus with absence of air in the cisterna magna. Surgical treatment should be aimed at relieving the obstructive hydrocephalus.