Chiari Malformation
Signs and Symptoms

The exact cause of Chiari malformation is unknown, but it may be genetic.

The term "Chiari Type I" refers to conditions in which brain tissue extends into the spinal canal without a myelomeningocele or a visible sac-like protrusion on the mid to lower back.

"Chiari Type II" describes a brain malformation with a visible protrusion, which occurs with spina bifida. Generally, the symptoms of Chiari Type II are worse than those of Type I.

Symptoms most often begin during infancy, although in many cases they don't emerge until a person reaches adolescence or adulthood. Symptoms may include:

• Deafness
• Difficulty coordinating movements
• Difficulty swallowing
• Dizziness
• Double vision
• Fatigue
• Headache
• Mental impairment
• Muscle weakness in the head and face
• Neck pain
• Occasional sharp pain in or near the eyes
• Paralysis of the arms and legs
• Rapid involuntary downward eye movements
• Vomiting

Reviewed by health care specialists at UCSF Benioff Children's Hospital.
Last updated July 14, 2010