Abstracts

Rationale: An indirect measure of the health of the intrauterine environment and prenatal adversities, low birth weight (1), increases the risk for epilepsy (2) and low IQ (3-5). To date, however, there have been no studies on birth weight in children with epilepsy. This study compared the relationship of birth weight with IQ in children with two epilepsy syndromes to that of healthy children (HC) controlling for perinatal adversity involving the mother and obstetric complications, as well as demographic variables. Methods: Mothers provided information (birthweight, pregnancy, and delivery complications) on an abbreviated version of the Yale Neuropsychoeducational Assessment Scales (6) for 131 children with epilepsy, 68 with localization related epilepsy and complex partial seizures (CPS), 63 with childhood absence epilepsy (CAE), and 69 HC, aged 6-15 years. First, we determined group differences in birth weights and IQ scores using ANCOVAs, controlling for age, gender, socioeconomic status, ethnicity, and perinatal items that were significantly different across groups (maternal age). Then, general linear models, with Full Scale, Verbal, and Performance IQ scores as the dependent variables and group, birth weight and interaction of group x birth weight as predictors, were estimated to determine if the three groups differed in the relationships between each of the three IQ quotients and birth weight. We also examined if seizure variables played a role in the relationship of IQ and birth weight in the epilepsy groups by performing ANCOVAs controlling for seizure-related measures. Results: The three groups had average mean birth weights (CPS: 3.5 (0.42), CAE: 3.4 (0.41), and HC: 3.4 (0.43)) and IQ scores (CPS: 95.7 (14.50), CAE: 100.3 (14.18; HC: 111.6 (12.93)). There was a significant interaction between birth weight and group (F (2,176) 3.81, p = .02) with a positive association between birth weight and Full Scale IQ in the HC (t = 2.15, p = .03) and a trend for a negative relationship in the CAE group (t = -1.76, p = .08) (Figure 1). Verbal IQ (F (2,176) = 5.53, p =.004; t(HC) = 1.98, p = .05; t(CAE) = -2.63, p = .01)) accounted for these findings. Seizure variables were unrelated to the findings.Conclusions: This is the first study to demonstrate that in children with chronic epilepsy and average intelligence the development of verbal cognition might reflect adverse perinatal effects that are unrelated to epilepsy syndrome and seizure variables.