What Is a Chiari Malformation?
Normally, the cerebellum sits at the back of the skull, just above the spine. When a person has a Chiari malformation, the space for the cerebellum is sometimes too small or oddly shaped. This decrease in space will squeeze part of the cerebellum or even part of the brain stem, down through foramen magnum. Having a Chiari malformation can put pressure on the cerebellum, brain stem, and spinal cord and can keep those body parts from working properly.
It may block the movement of cerebrospinal fluid (CSF), the liquid that surrounds the brain and spinal cord and protects them from injury. If cerebrospinal fluid doesn't flow properly, it can cause hydrocephalus. This buildup can block communication of the brain's messages to the body. It was estimated that Chiari malformation occurs in about one in every 1,000 births (National Organization for Rare Disorders [NORD], 2014).
There are four different types of Chiari malformation (I, II, III, and IV). Type I is the most common. Type I happens when the lower part of the cerebellum extends into the foramen magnum, where typically only the spinal cord passes through this opening. Type II generally will have symptoms that are more severe than in Type I and usually appear during childhood. This disorder can cause life-threatening complications during infancy or early childhood, and treating it requires surgery.…show more content… Often, people with type I Chiari malformation aren't diagnosed until they're teens or adults. If your doctor suspects a Chiari malformation, your child will be examined and tested for things like speech, balance, reflexes, and motor skills. The doctor will probably want your child to have one or more of these tests: Magnetic resonance imaging (MRI), X-rays, Computed tomography (CT or CAT) scans, Brainstem auditory evoked response (BAER), and Somatosensory evoked potential
