Chiari Malformation

What is Chiari malformation?

Chiari malformation is an abnormality in the back of the head where the brain and spinal cord meet. It causes some of the brain tissue at the base of the skull to be pushed into the spinal canal. This can cause pressure on the brain and block the normal flow of spinal fluid in and around the brain. Sometimes this leads to a buildup of spinal fluid within the spinal cord, called a syrinx.


Types of Chiari malformation?

There are four types of Chiari malformation. They are categorized by which parts of the brain are pushed into the spine and the severity of the condition:

  • Type I is the most common. It’s the only type that can also develop after birth. People with type I often have no symptoms and need no treatment.
  • Type II almost always affects children who have spina bifida and develops before birth. Most children with type II Chiari malformation need surgery.
  • Type III is a very serious, but rare, form of Chiari malformation. In this type, some parts of the brain may protrude from the skull. It usually causes severe disabilities.
  • Type IV is also very serious and very rare. In this type of Chiari malformation, part of the brain is not developed or is missing.

 Because type III and type IV Chiari malformations are so rare, we will focus only on type I and type II on this website.

How we care for Chiari malformation

At Boston Children’s Hospital, our team of experts has years of experience helping infants in the Department of Neurosurgery has years of experience helping infants, children and teens who have been diagnosed with a Chiari malformation.