Doctors may refer to a Chiari malformation as "congenital," which means that a child developed it in the womb and had it at birth. Most cases of Chiari malformation are congenital, and often the cause is unknown.
Chiari malformations also can be related to other disorders that affect the development of the brain, spine, and bones. A Chiari malformation that is acquired develops later in life. When this happens, it's usually the after-effect of brain or spinal surgery performed for an unrelated condition. Acquired cases of Chiari malformation are sometimes reversible.
Although doctors haven't been able to identify a gene that causes Chiari malformation, it does sometimes run in families, which indicates that it could be hereditary.
Signs and Symptoms
Many kids with type I Chiari malformation have no signs and symptoms and don't even know that they have a malformation. They find out about it only when they're tested for another problem.
But if a Chiari malformation is severe enough to block the flow of CSF or put significant pressure on the brain or spinal cord, a child's nervous system can be affected. Symptoms can include dizziness and problems with balance and coordination. This means a child might fall down a lot, walk unusually, have trouble grasping items, or have poor hand-eye coordination.
Other symptoms can include:
neck or chest pain
headaches that are brought on by coughing, sneezing, or laughing
difficulty swallowing, which may cause gagging, choking, or vomiting
rapid eye movements or vision problems like light sensitivity or blurred vision
hearing problems like a tinnitus (ear ringing) or hearing loss
weakness, numbness, tingling, or other abnormal feelings in the arms and legs
Signs of Chiari malformation in babies include:
irritability when being fed
trouble gaining weight
Some children with Chiari malformations also have cognitive and behavioral problems. Doctors aren't sure whether a Chiari malformation directly causes these problems or whether they're simply the child's way of reacting to the condition and its symptoms.
Since the symptoms of Chiari malformations vary greatly and may mimic many other conditions, it's important to get an accurate diagnosis. If you feel unsure about your child's diagnosis, seek a second opinion.