This paper describes a follow-up of 74 consecutive cases of occipital cranium bifidum born and treated between 1948 and 1965, and the surgical technique used in their repair.
When no hydrocephalus developed, 86% of the cases of cranial meningocele, but only 40% of those of encephalocele, showed normal mental development.
Even when hydrocephalus complicating cranium bifidum was controlled surgically, many of the children were mentally and some also physically handicapped. Hydrocephalus was more frequent when the sac had contained brain tissue than in cases of meningocele.
There were certain cases of massive posterior protrusion of brain tissue combined with an abnormally small cranial cavity in which reduction of the cerebral hernia was impossible: they showed no sign of intelligence for so long as they survived. In such circumstances operation is contraindicated.
Associated development anomalies were frequently encountered, the majority of these involving the neuraxis.