With a Chiari malformation, the space for the lower part of your brain (called the cerebellum) is either too small or unusually shaped. This can cause part of the cerebellum to push into the funnel-like opening at the bottom of the skull (called the foramen magnum) and into the space occupied by the spinal cord.
The most common type in the children we serve at CHoR’s center for craniofacial care is a Chiari 1 malformation. The development of a Chiari 1 malformation can be related to abnormal growth of the facial bones or skull (craniofacial conditions).
A Chiari 2 malformation is a specific type found most often in children with spina bifida.
Chiari 3’s are more severe malformations and may not support life.
Children with complex craniosynostosis or a craniofacial syndrome (abnormalities of the face and skull and possibly other areas) are at risk for developing a Chiari malformation.
The exact cause is not known. Suspected causes include early joining together of the bones of the skull that enclose the brain and the joints that form the skull and raised pressure within the skull. Blood flow and heart valve problems and hydrocephalus may also be a cause.
For children with craniofacial conditions, the Chiari malformation may develop in the first months of life and worsen over time. This may be due to the lower part of the brain growing too much while that part of the lower part of the skull remains unusually small.
Symptoms of Chiari malformation in infants include:
For toddlers and older children, symptoms may include:
It’s important to note that not all children with Chiari malformations develop symptoms. Children with a high risk of developing a Chiari malformation are monitored with MRI imaging studies. Sleep studies may also be used to determine if breathing is affected.
In some instances, surgery to enlarge the space within the back of the skull may be needed to treat a Chiari malformation. This may involve surgery to reshape the bones of the back of the skull or remove bone at the back of the skull.