Encephalocele (Pronounced en-cef-a-lo-seal)
In the minority of cases of NTD's, the split is high up and involves the back of the head (skull). There is a balloon-like swelling but this does not contain important nerves of the spinal column.
Some encephaloceles are small, covered with skin and the children usually grow up without major implications.
Sometimes, however, it is large and may contain some of the brain and this can severely affect the baby's eyesight and can cause learning disabilities.
In a minority of cases the encephaloceles can contain large volumes of brain tissue, so that the remaining brain is small, poorly developed, and severely hydrocephalic.