Prevalence and characteristics of epilepsy in children in northern Sweden.

Active epilepsy was assessed in all children aged 0-16 years in an area of northern Sweden with about 250,000 inhabitants and around 50,000 children in the age group. One hundred and fifty-five children fulfilled the criteria of active epilepsy giving a prevalence rate of 4.2/1000. The proportion of boys to girls was 1:1.1. This dominance of girls had also been seen in a prospective study of incidence of epilepsy in the same area. Partial seizures were more common than generalized. Among the syndromes benign childhood epilepsy with centrotemporal spikes occurred in 17.4%, absence epilepsy in 6.5% and Lennox-Gastaut syndrome in 5.8%. Children with neurodeficit (ND) more often had generalized epileptic syndromes while the non-ND groups more often had localisation related syndromes. The aetiology was regarded to be remote symptomatic in 42%, idiopathic in 28% and cryptogenic in 30% of the children. Almost all children were on antiepileptic treatment, three quarters of them on monotherapy. Neurodeficit was noted in 42%. The prevalence of epilepsy and mental retardation was 1.7/1000. Relatively few children with neurodeficit had been seizure free during the last year, 43% had more than one seizures per month compared to 19% in the non-ND group.