Thirty-nine children, 4-15 years of age, were evaluated using the Achenbach Child Behavior Checklist parent questionnaire to assess behavioral or emotional problems resulting from pre- or perinatal unilateral brain damage, in a study at UCSD School of Medicine, La Jolla, CA. Two-thirds had left hemisphere lesions (LH) and one-third had right hemisphere (RE) lesions. The cause was cerebral infarction or intraparenchymal hemorrhage. Age and IQ were assessed as covariates. Age was not a factor, whereas IQ was a consistent covariate. The mean Full-Scale IQ was 93.4 +/- 22 for the focal lesion group and 116.2 +/- 13 for the 54 controls (P<.0001). When differences in IQ between brain damaged and control children were excluded from the analysis, results showed no evidence of clinically significant differences on 9 Behavior Problem scales, even when frontal lobes were involved or seizures had occurred, or when RH and LH lesions were analyzed separately. If the lower IQ of brain damaged children was not ruled out, significant differences in behavior between focal lesion and control groups were observed. Abnormal scores mainly involved Social, Thought and Attention Problem scales, with over-representation of LH lesions in those affected. Qualitatively, more children in the focal lesion group than in controls had T-scores within the clinically significant abnormal range, on both Total Problem score and on one or more Behavior Problem scales. 
COMMENT. The social behavior and attention of children and adolescents who have suffered pre- or perinatal focal brain damage can be impaired, but the observed clinical behavioral abnormalities may be related to a significant reduction in IQ. The patient’s age, the specific side and localization of the unilateral damage, frontal lobe involvement, and the occurrence of seizures are not significant specific factors in the development of behavior problems. The effects on IQ, and genetic and environmental factors must be considered among possible causes of behavioral problems associated with early unilateral brain damage. Children with diffuse brain damage are at higher risk of behavioral and cognitive dysfunction than those with focal lesions.