Incidence of Early-Onset Epilepsy: A Prospective Population-based Study

Abstract Purpose The first five years of life reflect a critical period of development prior to formal education yet few epidemiological studies focus on children with early-onset epilepsy (CWEOE; onset <60 months). This study aimed to determine early-onset epilepsy incidence using a comprehensive case identification strategy, and examined socioeconomic status (SES) and ethnicity as risk factors. Methods Through a prospective, population-based study, newly diagnosed CWEOE from Fife and Lothian, Scotland, were identified using multiple-source, active surveillance capture-recapture between May 2013 and June 2015. Crude, ascertainment-adjusted, age-adjusted, age- and gender-specific, and epilepsy-type incidence rates were determined. Risk ratios (RR) were calculated to examine SES and ethnicity as risk factors. Results 59 (36 Male) CWEOE were identified. Ascertainment was 98% (95% CI 94 - 103). Crude annual incidence of epilepsy in children 0-59 months was 60.2 (95% CI 44.8 – 75.5) per 100,000 per year; ascertainment-adjusted annual incidence was 61.7 (95% CI 46.2 – 77.3) per year. Cumulative incidence of West Syndrome/Infantile Spasms was 6.7 per 10,000 live births (95% CI 3.6 - 12.3). Aetiology was unknown in almost two-thirds of CWEOE. Compared to White-British Isles (BI) children, Asian children (RR 2.6 [95% CI 1.2 - 5.7], p=.02) and White-non-BI children (RR 2.5 [95% CI 1.2 - 5.2], p=.02) had increased risk. SES was not a risk factor. Conclusion The high incidence of early-onset epilepsy is similar to previous studies and demonstrates a substantial disease burden. Cause of epilepsy remains unknown in almost two thirds of CWEOE. Ethnicity but not SES affects early-onset epilepsy risk.