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Chiari Malformation

A Chiari Malformation is a birth defect in the area at the back of the head where the brain and spinal cord connect. The condition is also called Arnold Chiari Malformation and there are four types.
  • Type I - this is the most common type of Chiari malformation. Commonly goes unnoticed until problems arise in the adolescent or adult years of life.

  • Type II - Most children with Type II are born with spina bifida (myelomeningocele), a neurological condition that causes a portion of the spinal cord and the surrounding structures to develop outside, instead of inside, the body. Hydrocephalus may be a complication and a shunt may need to be inserted.

  • Type III - In this condition, the back of the brain protrudes out of an opening in the back of the skull area.

  • Type IV - In this condition, the back of the brain fails to develop normally.

What causes Chiari Malformation?

The exact cause of Chiari malformations is not known but exposure to harmful substances during fetal development or associated with genetic problems or syndromes may be contributory.

What are the symptoms of Chiari Malformation?

The following are the most common symptoms of a Chiari Malformation, however, each child may experience symptoms differently. If symptoms are present, the child may complain of headaches, or pain/stiffness at the back of the neck. In more involved cases, the child may have trouble swallowing, weakness in the hands and arms, breathing problems, balance problems, scoliosis, and developmental delays.

How is Chiari Malformation diagnosed?

If a Chiari Malformation occurs with other congenital (present at birth) defects, the diagnosis may be made at birth. Other times, the diagnosis is made after the onset of specific signs and symptoms, and after diagnostic testing. The physician obtains a complete prenatal and birth history of the child and may also ask if there is a family history of any medical problems. The physician will also ask about developmental milestones, such as the age the child sat up, crawled, or walked since a Chiari Malformation can be associated with other neuromuscular disorders. Developmental delays may require further medical follow up for underlying problems.

During the examination, a measurement of the circumference of the child’s head is taken and compared to a scale that can identify normal and abnormal ranges.

Diagnostic tests that may be performed to confirm the diagnosis of a Chiari Malformation including a Magnetic Resonance Imaging (MRI), a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.

Example of Chiari I on MRI.

Treatment of Chiari Malformation:

The majority of children with Chiari Malformations do not require surgery and will require regular checkups and MRIs to monitor the condition. If your child is symptomatic and needs treatment, then neurosurgery is performed to relieve the pressure on the spinal cord.