Brain, Nervous System and Mental Conditions


What Is an Encephalocele?

An encephalocele (pronounced in-SEF-a-lo-seal) is a rare birth defect. It occurs early in a woman's pregnancy when part of the developing baby's skull does not close completely. Part of the baby's brain may come through the hole in the skull. Sometimes, part of the membrane that covers the brain and spinal cord (meninges) and cerebrospinal fluid (CSF) a lso come through the opening in the skull.

Normally, a baby's brain and spinal cord (central nervous system) develop inside a structure called the neural tube. When the neural tube does not close properly, part of the brain may stick outside the neural tube. Either skin or a thin membrane covers the portion of the brain that is outside the skull. Doctors call this covering a sac.

An encephalocele can be located:

  • In the base of the skull
  • In the area of the nose, sinuses and forehead
  • From the top of the skull around to the back of the skull at the midline

Encephalocele in Children

Encephaloceles are rare. The problem occurs in only about one of 5,000 babies born worldwide. The rate may be even lower in North America. Encephaloceles have other common characteristics:

  • Girls are more likely to have an encephalocele in the back (occipital) area of their skull.
  • Boys are more likely to have an encephalocele in the front of their skull.
  • In North America, encephalocele happens more commonly in the back of the skull.
  • In Southeast Asia, encephalocele happens more commonly in the front of the skull.

Encephalocele at Seattle Children's

We operate on one to four babies with encephaloceles a year. Some have small defects that are relatively simple to repair. Large defects require more extensive repair.