Incidence and clinical characterization of unprovoked seizures in adults: a prospective population-based study.
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.
Forsgren
L
L
Department of Neurology, Umea University Hospital, Sweden.
Bucht
G
G
Eriksson
S
S
Bergmark
L
L
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications; D001932:Brain Neoplasms / Q000150:complications; D002561:Cerebrovascular Disorders / Q000150:complications; D004569:Electroencephalography; D004827:Epilepsy / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D004829:Epilepsy, Generalized / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012640:Seizures / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D017678:Sex Distribution; D012737:Sex Factors; D013548:Sweden / Q000453:epidemiology