Prospective incidence study and clinical characterization of seizures in newly referred adults

For 20 months, an extensive prospective search was made in a Swedish county to identify as many persons as possible aged greater than or equal to 17 years who had their first epileptic seizure or for the first time came to the attention of the medical community because of an epileptic seizure. The rate of initial diagnosis (first attendance rate) of non-provoked seizures was calculated as 34 in 100,000. For both sexes, the lowest age-specific incidences were found in persons aged 30-39 years. For males the highest age-specific incidence was found in the group aged 60-69 years and for females it was found in the group aged 50-59 years. The most common type of seizure was partial seizure, accounting for 60%. If seizures with rapid generalization and a known focal lesion are included, the number increases to 72%. A diagnostic delay greater than or equal to 1 year was found in 16%, mainly a patient delay. A cause for the epileptic seizure was found in 49%. A cerebrovascular disease was most common (21%). Brain tumors were found in 11% and trauma in 7%. A cause was more often identified in the older age groups. There was no significant difference between the sexes in the proportion of identified causes.