They are located above and in front of the cerebellum, and their function is to produce and circulate cerebrospinal fluid (CSF), the protective fluid that circulates through the brain and the spinal cord.
Approximately 80-90 percent of children with Chiari malformation Type II also have hydrocephalus, a condition in which one or more of the ventricles becomes enlarged due to an accumulation of CSF.
CSF protects the central nervous system from injury, cushions it from the surrounding bone structure, provides it with nutrients, and removes waste products by returning them to the blood.
Hydrocephalus is an abnormal expansion of cavities, called ventricles, within the brain, which is caused by an abnormally large accumulation of cerebrospinal fluid (CSF).
Spinal tap: also called lumbar puncture, measures the amount of pressure in the spinal canal and/or to remove a small amount of cerebral spinal fluid (CSF) for testing.