What is Chiari Malformation?

There are a gazillion sites on the web that discuss Chiari Marlformation.... Basilar Invagination is much more difficult.   But here are some web sites that have helped and a little more info on Chiari....enjoy!  This is exciting stuff :) 

Mayo Clinic
Wikipedia
Conquer Chiari Brochure
Cedars-Sinai Chiari-Malformation

Chiari malformation type I

Definition

By Mayo Clinic staff

Chiari malformation (kee-AHR-ee mal-for-MAY-shun) is a condition in which brain tissue protrudes into your spinal canal. It occurs when part of your skull is abnormally small or misshapen, pressing on your brain and forcing it downward. Chiari malformation is uncommon, but improved imaging tests have led to more frequent diagnoses.
The adult form, called Chiari malformation type I, develops as the skull and brain are growing. As a result, signs and symptoms may not occur until late childhood or adulthood. The most common pediatric form, called Chiari malformation type II, is present at birth (congenital).
Treatment of Chiari malformation depends on the form, severity and associated symptoms. Regular monitoring, medications and surgery are treatment options. In some cases, no treatment is needed.