Arnold-Chiari malformation
Definition
Arnold-Chiari malformation is a rare genetic disorder. In this syndrome, some parts of the brain are formed abnormally. Malformations may occur in the lower portion of the brain (cerebellum) or in the brain stem. As of 2001, doctors are not sure of the cause of Arnold-Chiari malformation.
Description
A German pathologist named Chiari was the first to describe Arnold-Chiari malformation in 1891. Normally, the brain stem and cerebellum are located in the posterior fossa, an area at the base of the skull attached to the spinal cord. In Arnold-Chiari malformation, the posterior fossa does not form properly. Because the posterior fossa is small, the brain stem, cerebellum, or cerebellar brain tissues (called the cerebellar tonsils) are squeezed downward through an opening at the bottom...
[The entire page is 1264 words long]
Join eNotes
Over 3,500 study guides, question and answer forums, literature criticism, reference content, and much more!
