INCIDENCE OF EPILEPSY IN CHILDHOOD AND ADOLESCENCE - A POPULATION-BASED STUDY IN NOVA-SCOTIA FROM 1977 TO 1985

Data from a regional EEG laboratory allowed us to identify almost all children in Nova Scotia (population 850,000) with one or more unprovok ed, afebrile seizures from 1977 through 1985. We then reviewed hospita l and pediatric neurology physician charts to limit cases to those wit h two or more definite afebrile seizures between the ages of 1 month a nd 16 years. In all, 693 children developed epilepsy: typical childhoo d absence seizures (AS) (97), either generalized tonic-clonic (GTCs) o r par tial seizures either secondarily generalized or not (511), and o ther generalized seizure types, including infantile spasms (IS) as wel l as myoclonic, akinetic, tonic, and atypical AS (85). The incidence o f epilepsy was 118 in 100,000 for children aged <1 year, 48 in 100,000 for those aged 1-5 years, 43 in 100,000 for those aged 6-10 years, an d 21 in 100,000 for those aged 11-15 years. The incidence for each yea r of age between 1 and 10 years was remarkably constant (mean 46 in 10 0,000 +/- 7 SD). Comparison of the incidence rates showed significant differences for those aged <1 year as compared with all others, and fo r those aged >10 years as compared with those aged 1-10 years. We conc lude that the incidence of epilepsy is highest in the first year of li fe, plateaus in early childhood, and decreases markedly after age 10 y ears. The overall incidence of epilepsy in childhood is lower than tha t reported in previous studies.