Relationship of head circumference to measures of school performance.

To study the possible relationship of head circumference (HC) to learning problems in children, a retrospective study was done, using records from 360 subjects who had been evaluated between the years 1976 and 1981. The data selected from the records included standardized academic test results, e.g., IQ scores and school achievement test results, as well as determinations of visual motor abilities. Statistical analyses demonstrated a positive correlation between full scale IQ (FSIQ) and HC (p less than 0.005). The incidence of specific learning disabilities based on significant academic and achievement discrepancies was 54% in those with HC greater than 2 S.D., 39% for normocephalic, and 23% for those with HC less than 2 S.D. Comparison of HC with results from the Wide Range Achievement Test (WRAT) demonstrated a tendency for those children with HC greater than 2 S.D. to have lower arithmetic scores when compared to results of children with normocephaly. Scores for spelling and reading ability did not demonstrate this tendency. The results of this study were found to be somewhat incongruous to those of previous studies of similar children. Further studies using large unselected populations are needed to better define the risks to learning that may be related to the extremes of head circumference.