The intelligence of 200 shunted hydrocephalic children was studied prospectively.
The following diagnostic categories were used: (1) simple internal hydrocephalus; (2) internal hydrocephalus in the child with meningomyelocele; (3) internal hydrocephalus associated with porencephaly; (4) external hydrocephalus; (5) the Dandy-Walker cyst.
The group with meningomyelocele was brightest and the group with porencephaly the dullest; whites scored higher than blacks.
The following groups were found to be of normal intelligence: white patients with internal hydrocephalusand with meningomyelocele, and black patients with meningomyelocele and with external hydrocephalus. Intelligence quotient was found to be unrelated either to number of shunt revisions or severity of hydrocephalus prior to initial surgery, but was related to age at initial shunt placement and shunt function. Children with internal hydrocephalus and hydrocephalus with meningomyelocele whose shunts were kept functioning were found to be of normal intelligence.