Incidence and clinical characterization of unprovoked seizures in adults: a prospective population-based study

Epilepsia. 1996 Mar;37(3):224-9. doi: 10.1111/j.1528-1157.1996.tb00017.x.

Abstract

In a population-based prospective study of epileptic seizures in adult s aged > 17 years, we identified 563 patients with possible seizures in a period of 34 months. Seizures were unprovoked in 160 patients, an incidence of 56 in 100,000 person-years. There was no difference in incidence between sexes. Age-specific incidences of unprovoked seizures increased sharply in men from age 60 years and in women from age 70 years. The incidence of unprovoked seizures in those aged > 65 years was 139 (men 166, women 116). The cumulative incidence of unprovoked seizures between the ages of 17 and 84 years was 4.6%. The proportion with an identified presumptive cause for unprovoked seizures increased with advancing age. A presumed etiology was identified in 77% of persons aged > 60 years. Stroke was the most common etiology, detected in 30% (incidence 16) and in 45% at ages > 60 years. Tumors were detected in 11% (incidence 6) and Alzheimer's disease was detected in 7% (incidence 4). Eighteen percent of patients were demented. Unprovoked seizures were partial in 68% of cases (incidence 38), and generalized in 16% (incidence 9). Another 13% of patients had generalized seizures, but seizure onset was not witnessed (incidence 7). In 16%, there was a delay of > 1 year from the first unprovoked seizure to initial diagnosis.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Distribution
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / complications
  • Brain Neoplasms / complications
  • Cerebrovascular Disorders / complications
  • Electroencephalography
  • Epilepsy / diagnosis
  • Epilepsy / epidemiology*
  • Epilepsy / etiology
  • Epilepsy, Generalized / diagnosis
  • Epilepsy, Generalized / epidemiology
  • Epilepsy, Generalized / etiology
  • Female
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Prospective Studies
  • Seizures / diagnosis
  • Seizures / epidemiology
  • Seizures / etiology
  • Sex Distribution
  • Sex Factors
  • Sweden / epidemiology