Chiari Malformation

What is Chiari malformation?

Chiari malformation is a structural problem in the back of the head where the skull and the spine connect. It may occur when the skull is smaller than normal or shaped in an unusual way. This causes some of the brain tissue at the base of the skull to be pushed into the upper spinal canal and may block the normal flow of spinal fluid in and around the brain. In most cases, Chiari malformation is a condition a baby is born with.

Chiari malformation can range from very mild to severe, based on how much of the brain is affected.

Chiari malformation type I is the mildest form of the condition. It’s also the most common. It is usually not diagnosed until the teen years or later. In rare cases, it can develop after birth due to a trauma, illness or infection.

Chiari malformation type II is a more severe type of the condition. It is often found in children with a type of spina bifida called myelomeningocele or hydrocephalus, which is a buildup of spinal fluid in the brain.

Chiari malformation types III and IV are very rare forms of the condition. These types can include severe problems with the brain and can be life threatening.

What are the symptoms of Chiari malformation?

Children who have type I Chiari malformation often have no symptoms. If they do have symptoms, they don’t usually begin until the teen years or later. Children who have type II Chiari malformation usually do have symptoms. Symptoms of either type can include:

• Headaches
• Neck pain
• Hearing or balance problems
• Muscle weakness or numbness
• Dizziness
• Difficulty swallowing or speaking
• Vision problems
• Breathing problems
• Curvature of the spine (scoliosis)
• Loss of bowel or bladder control
• Difficulty swallowing
• Breathing problems

What causes Chiari malformation?

Chiari malformation most often occurs while a baby is developing during pregnancy. In rare cases, Chiari malformation type I may also be caused due to injury, disease or infection.

How is Chiari malformation treated?

Children with type I Chiari malformation often do not need treatment. Your child’s care team at Arkansas Children’s Hospital will monitor the condition with exams and MRIs.

Children who have symptoms typically need surgery.

• Brain decompression surgery is a type of surgery where the surgeon removes a small amount of bone from a child’s skull to release pressure. Electrical current is also commonly used to help shrink tissue.
• Children with spina bifida may need surgery to close the opening at the back of the skull and reposition the spinal cord.