The relationship between intellectual skills and the computerised axial tomograms of children with spina bifida and hydrocephalus.

Cranial CT-scans of 467 patients were graded in degrees of severity of hydrocephalus. The patients were aged from 2-22 years and had spina bifida and/or hydrocephalus or related disorders. Even large increases in the degree of hydrocephalus were found to have an insignificant effect upon verbal IQ, but there was a small but statistically significant effect upon performance scale IQ on the WISC. The abilities most affected were those involving the use of motor and perceptuo-motor skills. Assymetrical or other abnormal scans were found to be associated with lower IQ. Children with valves were only found to be substantially inferior in skills to those without valves when their ventricles were either very large, or abnormally small. The highest proportion of children with valves was found in the group with the smallest ventricles. Very small ventricles are known to be associated with an increased rate of valve complications, and this paper shows that there are psychological disadvantages also.