Nature and severity of hydrocephalus and its relation to later intellectual function.

In 102 cases of infantile hydrocephalus, treated within 365 days of birth, the possibilities of predicting later intelligence were investigated, largely by means of multiple regression methods. No significant effect of aetiology, date of shunting or severity (measured in various ways) could be demonstrated. Within the spina bifida group however the 3 cases of encephalocele had considerably lower IQ's. There was no effect of lesion level in the rest of this group. Educational level of the parents had a significant, but not very marked impact on the IQ's of their children. Most outstanding was the difference between non-communicating and communicating hydrocephalus: nearly 50% of the non-communicating cases were mentally retarded, while this percentage was 22 for the communicating ones.