Pediatric Chiari Malformations

At the University of Florida, children with chiari malformation are treated by:

What is a Chiari Malformation?

A Chiari malformation (CM) is an abnormality in the lower part of the brain called the cerebellum. In normal anatomy, the cerebellar tonsils are located in the skull above the foramen magnum. Normally only the spinal cord passes through the foramen, however in Chiari the tonsils extend below the foramen. The degree to which the tonsils extend varies and does not always correlate with symptoms.

Types of Chiari Malformation

Chiari Malformation, Type IChiari I

This is the most common type of malformation. It may also be called tonsillar herniation or tonsillar ectopia. Most Chiari malformations are asymptomatic. Most cases are congenital, however Chiari I can be acquired.

Chiari Malformation, Type IIChiari II

This type of Chiari malformation is associated with myleomeningocele (spina bifida). In Chiari II the tonsils as well as the cerebellum may extend through the foramen. This type of Chiari is congenital.

Syringomyelia or hydromyelia (syrinx)

Some individuals with Chiari will experience buildup of fluid in the spinal cord called syringomyelia or hydromyelia.



Chiari Malformation prior to surgery

Chiari Malformation prior to surgery

Chiari Malformation after surgery

Chiari Malformation after surgery


What are common symptoms of Chiari malformation?

The most common symptom of Chiari malformation is headache, usually at the back of the head or upper neck. The pain is often worse with coughing, sneezing or straining. In infants and children, headaches may manifest as irritability or crying, and the pain may be associated with arching of the neck in a hyperextended posture.

Symptoms of syrinx may include weakness and numbness in the hands and arms, other sensory changes or back pain. Some patients with syringomyelia will develop scoliosis (curvature of the spine) and have no symptoms.

Symptoms of cranial nerve compression may be seen in some patients. This is more common in patients with Chiari II. These include gagging, apnea, swallowing difficulties, weakness of the arms or hands.

Drawing: Operative exposure of a Chirai MalformationWhat is the treatment for Chiari malformation?

Frequently, patients are found to have a Chiari malformation and have no symptoms. No treatment is needed for these patients.

Some patients have mild symptoms that are not progressive. Conservative management, such as headache treatment or physical therapy may be recommended.

For patients with severe symptoms, or those with syringomyelia, an operation may be recommended. Surgery involves making a small incision in the back of the head and neck. It is possible to make the incision above the hairline and to avoid shaving hair. Bone is removed from the base of the skull and top of the neck to create extra room. This is called a suboccipital craniectomy and upper cervical laminectomy. The covering over the brain, called the dura, can either be thinned or opened and enlarged with a graft. Our recommendation for most patients is to avoid dural grafting to reduce postoperative discomfort and complications. Results are excellent in most cases. There will usually be improvement in the syringomyelia with treatment of the Chiari. Patients usually spend 3-5 days in the hospital after surgery.

For more information contact our office at (253) 273-9000.