Summary: Worldwide, about 65 million people are estimated to have epilepsy. Epidemiologic studies are necessary to define the full public health burden of epilepsy; to set public health and health care priorities; to provide information needed for prevention, early detection, and treatment; to identify education and service needs; and to promote effective health care and support programs for people with epilepsy. However, different definitions and epidemiologic methods complicate the tasks of these studies and their interpretations and comparisons. The purpose of this document is to promote consistency in definitions and methods in an effort to enhance future population‐based epidemiologic studies, facilitate comparison between populations, and encourage the collection of data useful for the promotion of public health. We discuss: (1) conceptual and operational definitions of epilepsy, (2) data resources and recommended data elements, and (3) methods and analyses appropriate for epidemiologic studies or the surveillance of epilepsy. Variations in these are considered, taking into account differing resource availability and needs among countries and differing purposes among studies.

Objective: To examine outcomes at age 4.5 years and compare to earlier ages in children with fetal antiepileptic drug (AED) exposure. Methods: The NEAD Study is an ongoing prospective observational multicenter study, which enrolled pregnant women with epilepsy on AED monotherapy (1999–2004) to determine if differential long-term neurodevelopmental effects exist across 4 commonly used AEDs (carbamazepine, lamotrigine, phenytoin, or valproate). The primary outcome is IQ at 6 years of age. Planned analyses were conducted using Bayley Scales of Infant Development (BSID at age 2) and Differential Ability Scale (IQ at ages 3 and 4.5). Results: Multivariate intent-to-treat (n = 310) and completer (n = 209) analyses of age 4.5 IQ revealed significant effects for AED group. IQ for children exposed to valproate was lower than each other AED. Adjusted means (95% confidence intervals) were carbamazepine 106 (102–109), lamotrigine 106 (102–109), phenytoin 105 (102–109), valproate 96 (91–100). IQ was negatively associated with valproate dose, but not other AEDs. Maternal IQ correlated with child IQ for children exposed to the other AEDs, but not valproate. Age 4.5 IQ correlated with age 2 BSID and age 3 IQ. Frequency of marked intellectual impairment diminished with age except for valproate (10% with IQ <70 at 4.5 years). Verbal abilities were impaired for all 4 AED groups compared to nonverbal skills. Conclusions: Adverse cognitive effects of fetal valproate exposure persist to 4.5 years and are related to performances at earlier ages. Verbal abilities may be impaired by commonly used AEDs. Additional research is needed.

Background: Breastfeeding is known to have beneficial effects, but there is concern that breastfeeding during antiepileptic drug (AED) therapy may be harmful to cognitive development. Animal and human studies have demonstrated that some AEDs can adversely affect the immature brain. However, no investigation has examined effects of breastfeeding during AED therapy on subsequent cognitive abilities in children. Methods: The Neurodevelopmental Effects of Antiepileptic Drugs Study is an ongoing prospective multicenter observational investigation of long-term effects of in utero AED exposure on cognition. Between 1999 and 2004, we enrolled pregnant women with epilepsy who were taking a single AED (carbamazepine, lamotrigine, phenytoin, or valproate). We recently reported on differential AED effects on age 3 year cognitive outcomes. In this report, we focus on the effects of breastfeeding during AED therapy on age 3 cognitive outcomes in 199 children. Results: A total of 42% of children were breastfed. IQs for breastfed children did not differ from nonbreastfed children for all AEDs combined and for each of the 4 individual AED groups. Mean adjusted IQ scores (95% confidence intervals) across all AEDs were breastfed = 99 (96–103) and nonbreastfed = 98 (95–101). Power was 95% to detect a half SD IQ effect in the combined AED analysis, but was inadequate within groups. Conclusions: This preliminary analysis fails to demonstrate deleterious effects of breastfeeding during AED therapy on cognitive outcomes in children previously exposed in utero. However, caution is advised due to study limitations. Additional research is needed to confirm this observation and extend investigations to other AEDs and polytherapy.

Objective: To characterize the cognitive deficits in children with gelastic seizures and hypothalamic hamartoma and investigate the relationship of seizure severity to cognitive abilities. Methods: Eight children with gelastic seizures and hypothalamic hamartoma completed a neuropsychological battery of standardized and age-normed tests, including the Woodcock–Johnson Psycho-Educational Battery–Revised: Tests of Cognitive Ability,Peabody Picture Vocabulary Test-III, and initial-letter word fluency measure. Results: All children displayed cognitive deficits, ranging from mild to severe. Gelastic/complex partial seizure severity was correlated with broad cognitive ability standard scores (r = −0.79; r² = 0.63; (F[1,6] = 10.28; p = 0.018]. Frequency of gelastic/complex partial seizures was also correlated with broad cognitive ability standard scores (r = −0.72; r² = 0.52; F[1,6] = 6.44; p = 0.044). Significant intracognitive standard score differences were found, with relative weaknesses in long-term retrieval (mean = 64.1; SD = 13.3) and processing speed (mean = 67.7; SD = 21.6) and a relative strength in visual processing (mean = 97.6; SD = 12.8). Performance in visual processing differed from performance in long-term retrieval (p = 0.009) and processing speed (p = 0.029). Conclusion: These findings are consistent with cognitive functions and affective/emotional states associated with conduction pathways of the hypothalamus involving cortical association areas and amygdala and hippocampal formation. These abnormalities can account for the prominent deficit found in integrating information in the processing of memories.

The American Academy of Neurology (AAN), representing over 20,000 neurologists and neuroscience professionals, has taken an active interest in the clinical, ethical, and policy considerations concerning the coverage of anticonvulsant drugs for people with epilepsy. The AAN has developed evidence-based guidelines that strongly support complete physician autonomy in determining the appropriate use of anticonvulsants for the patients with epilepsy. Based on this evidence, the AAN has adopted the following principles concerning coverage of anticonvulsants for adults and children with epilepsy. The Food and Drug Administration has allowed for significant differences between name-brand and generic drugs. This variation can be highly problematic for patients with epilepsy. Even minor differences in the composition of generic and name-brand anticonvulsant drugs for the treatment of epilepsy can result in breakthrough seizures.