Incidence of childhood epilepsy: A population-based study in rural Japan

Introduction Epilepsy is a common childhood neurological condition and a major public health concern worldwide. A higher incidence of epilepsy is reported in low- and middle-income countries, particularly in rural areas. However, no Japanese reports on the incidence of childhood epilepsy have been published in the past 25 years. We estimated the annual incidence of epilepsy in children aged 1–14 years in Uwajima, a city in a rural, relatively isolated area of Japan. Methods Candidates were extracted from Japan’s public insurance database following the International Classification of Diseases code for epilepsy. Epilepsy was defined as two or more unprovoked seizures more than 24 hours apart, as per the International League Against Epilepsy definition. The study sample was divided into three cohorts based on age at diagnosis: 1–4, 5–9, and 10–14 years. The incidence of epilepsy was calculated as the number of children with epilepsy divided by the person-years in each cohort. Results The annual incidence rate of epilepsy in children aged 1–14 years was 70.4/100,000 children (95% confidence interval, 44.8–96.0). There was no significant difference in incidence between boys and girls. This rate was similar to those reported in other countries, although the incidence in children aged 1–4 years was slightly higher in our study than in other countries. Conclusion The annual incidence of childhood epilepsy in rural areas of Japan is generally comparable with rates of childhood epilepsy reported in other countries.