Abstracts

Rationale: Children with childhood absence epilepsy (CAE) are often initially suspected of having attention deficit hyperactivity disorder (ADHD) given that both conditions share some common semiological features. Not surprisingly, the neuropsychological profile of children with CAE is presumed to be similar to those with ADHD. However, given the perceived benign prognosis of CAE, very few children with CAE are referred for formal neuropsychological testing. The objective of this study was to determine whether the frequency of absence seizures correlates with neuropsychological impairment. Methods: Eighteen children and adolescents (mean age=10.7, SD=4.5, range=4.6-17.5) with an established diagnosis of CAE were referred for neuropsychological assessment. Mean levels of parental education were 13.8 years (SD=2.4) for mothers and 14.0 years (SD=2.5) for fathers. The sample was mostly Caucasian (77.8%) and right-handed (88.9%), with slightly more females (55.6%) than males (44.4%). Correlations between the number of absence seizures and standardized neuropsychological measures of attention, perception, as well as motor, linguistic and academic abilities were determined. Additionally, scores on the Parental ADHD Rating Scale, Impact of Impact of Childhood Neurologic Disorder rating of QOL and Teacher ADHD Rating Scale Teacher questionnaires were obtained. Results: Patients had a median of 45 absence seizures per month (range=0-3000, mean=304.5, SD=719.4). Spearman's rho correlations between number of absence seizures per month and ratings of inattention, hyperactivity, internalizing or externalizing behaviours, adaptive functioning, daily executive abilities, and quality of life were not significant. Several correlations did exceed rho>0.30 for parental (i.e., ADHD Rating Scale Parent Total Percentile, rho=-0.317; Impact of Childhood Neurologic Disorder, rho=0.444; Impact of Childhood Neurologic Disorder rating of QOL, rho=0.402) and teacher questionnaires (ADHD Rating Scale Teacher Total Percentile, rho=0.397). There was no statistically significant difference in the number of absence seizures over the course of one month between those with and those without an ADHD diagnosis (ADHD diagnosis, mean seizures=76.14, SD=129.69; No ADHD diagnosis, mean seizures=464.4, 50=916.51; Mann-Whitney U p=0.161, Cohen's d=0.66). Conclusions: In our cohort of children with CAE, only 39% (n=7) received a formal diagnosis of ADHD by a neuropsychologist. There was no statistically significant difference in the number of absence seizures over a given month between those with and without an ADHD diagnosis. However, despite a lack of a significant correlation, our results suggest that parents report fewer problems with inattention and quality of life in children with a greater frequency of absence seizures, whereas teachers tend to report more problems with inattention in these same children.