Chiari malformation is a condition in which brain tissue extends into the spinal canal – simply put, the brain is too big for the head. It occurs when part of a child’s skull is abnormally small or misshapen, pressing on the brain and forcing it downward. Current estimates are that up to 1% of children have this malformation.
Doctors categorize Chiari malformation into several types depending on the anatomy of the brain tissue displaced into the spinal canal and whether developmental abnormalities of the brain or spine are present.
Children with Chiari malformation can experience symptoms related to irritation of the covering of the brain, direct compression of brain structures, or dilation of the spinal cord due to an abnormal flow of spinal fluid (syringomyelia).