Arnold-Chiari Malformation in Children

A rare genetic disorder that occurs in children is Arnold-Chiari malformation. This malformation occurs when areas of the brain are abnormally formed. Most often, these abnormalities occur in the brain stem or cerebellum (lower portion of the brain). It remains unknown what exactly causes this condition and this condition remains treatable; however, it's not curable.

In 1891, Arnold-Chiari, a German pathologist, first described this condition, naming it Arnold-Chiari malformation. This condition occurs when the area where the spinal cord and brain meet is formed abnormally. This causes part of the cerebellum to protrude into the spinal canal through the bottom of the skull. As a result, cerebral spinal fluid begins to accumulate into the spine and brain. It's not uncommon for the protruding cerebellum to become elongated.

Symptoms of Arnold-Chiari Malformation

While Arnold-Chiari malformation is most often present at birth, it may not be properly diagnosed until later in life. Due to the fact the cerebellum (which is responsible for balance) is directly effected by the malformation, many symptoms of Arnold-Chiari malformation can occur. This condition often causes muscle weakness, dizziness, vision problems, headaches, and numbness. It's very common for problems with coordination and balance to occur as well.

Typically, the symptoms of Arnold-Chiari may not be present if Type I of this condition occurs. While it's the most common form of the condition, it's generally diagnosed by accident after an injury has occurred.

Type II of this condition is most often present at birth. Children who have spina bifida often have Type II of Arnold-Chiari malformation. Children with spina bifida suffer from a deformation of the vertebrae. Spina bifida occurs when the vertebrae do not form correctly, often causing the spinal cord to be exposed or protrude through the opening in the vertebra. This can lead to paralysis.

Type III of this condition is the most severe. It causes the most severe complications, which include neurological defects, including hydrocephalus, syringomyelia, or spinal curvature.

Treatment of Arnold-Chiari Malformation

Many children with Type I Arnold-Chiari malformation never experience any symptoms. However, those with a more severe form can suffer from serious complications. Currently, the only treatment available for this condition involves surgery and managing the symptoms of the condition. With surgery, the progression of the symptoms can be slowed and some functions of the cerebellum can be corrected. However, it's not uncommon for more than one surgery to be needed. With proper treatment, children can have a prolonged future; however, some complications of the condition, such as paralysis, will be permanent.

References:
"Chiari Malformation Information Page" NINDS
"Arnold-Chiari Malformation" WebMD
"Arnold-Chiari Malformation" HealthLine