Measles, minor neurological signs and intelligence

Retrospective study of intellectual development in children treated for acute lymphoblastic leukaemia

Nine younger children (mean age 6-3 years) and 6 older children (mean age 9-0 years), previously treated for acute lymphoblastic leukaemia by cranial irradiation and subsequently by 2 or 3 years of chemotherapy, were assessed in terms of intellectual development in relation to 15 controls, matched individually for age, sex, and social background. All children were functioning within a normal range. The older group of children performed as well as their matched controls in all tasks. However, the younger group tended to perform somewhat below their matched controls, and this applied especially to tasks measuring quantitative, memory, and motor skills, but not to language tasks. It is concluded that there is a continual need to monitor the development of children treated for leukaemia, especially when diagnosed in the 2- to 5- year age range.

Relationship between childhood infections and measured intelligence

The possibility that some of the common childhood infections lead to unrecognized impairments of neurological function was examined in 43 820 Birmingham children whose intelligence was assessed in the 11-plus examination. Mean verbal reasoning scores were lower for children who had had measles or pertussis than for those who had had neither of these diseases. However, since attack rates and measured intelligence are related inversely to social class, the lower scores of children with measles and pertussis may be due to class differences which are not eliminated completely by standardization for maternal age and birth order. Mean scores were a little higher for children who had had rubella than for those who had not, and it is suggested that this difference may be due to more frequent reporting of the disease by the more intelligent mothers.