Prevalence of childhood epilepsy in Estonia

Abstract

Purpose: To establish the prevalence rate (PR) and main characteristics of childhood epilepsy in Estonia. Methods: We performed a population-based case ascertainment of all the possible sources of medical care in seven counties of Estonia from January 1995 to December 1997. Only cases of patients from I month to 19 years of age with active epilepsy (i.e., at least one seizure during the last 5 years, regardless of treatment) were included. All patients were examined by a pediatric neurologist. Results: Five hundred sixty cases met the study criteria on the prevalence day, December 31, 1997. The total PR was 3.6 per 1,000 population (boy/girl ratio, 1.2:1.0). The PR was the highest - 4.3 per 1,000 - in the 5-to-9-year-old age group. The prevalence declined markedly in children age 14 years and on. The correlation between age and PR was negative (-0.542, p < 0.0001) by regression analyses. The most frequent seizure types in the total group were primarily generalized seizures - PR 2.1/1,000 [rate ratio (RR) 1.4, 95% confidence interval (CI) 1.2, 1.6]. The predominance of generalized seizures was significant in those younger than 10 years. In 14.8% of cases, there was a history of epilepsy among first- and second-degree relatives. Benign rolandic epilepsy - PR 0.2/1,000 - was the most frequent among idiopathic syndromes, and Lennox- Gastaut syndrome - PR 0.08/1,000 - was the most frequent among cryptogenic ones. Perinatal factors - PR 0.8/1,000 were the most frequently found cause of epilepsy. In 304 cases (54.2%), additional medical problems existed. Conclusions: The prevalence of childhood epilepsy was comparable with that found in developed countries. Generalized seizures predominated, and the main cause was perinatal factors.