Prevalence and clinical features of epilepsy in Argentina. A community-based study

To ascertain the prevalence of epilepsy in Junín, a town of 70,000-80,000 inhabitants from the Province of Buenos Aires, Argentina.

Some South American communities have reported extremely high prevalences of epilepsy. We investigated whether Junín would also have a high prevalence.

Systematic sampling was used to select 5,839 households (sampling fraction = 25%). Participating households amounted to 5,648 (97%), with 17,049 persons. A two-phase case-finding strategy was used. Phase 1 was the screening of the 17,049 persons, which was performed by trained but medically unsophisticated interviewers. Phase 2 was the neurological evaluation of the 250 persons who were screened positive for epilepsy. Diagnoses were based on defined diagnostic criteria.

As of January 1, 1991 (prevalence day), 106 persons had epilepsy, including 64 (60%) with active epilepsy. Among these, 9 (14%) were epilepsy cases newly diagnosed by survey neurologists, and 50 (78%) were on antiepileptic treatment at the time of the survey. Regarding the same 64 persons, seizures were generalized in 37 (58%) and partial in 24 (38%). Lifetime prevalence of epilepsy was 6.2/1,000 (6.3/1,000, age adjusted to the world standard population). Total point prevalence for active epilepsy was 3.8/1,000 (4.0 for females and 3.5 for males). In addition, prevalence peaked at the ages of 40-59 for females and 0-4 for males.

This is one of the first community-based studies of epilepsy in Argentina, and the prevalence results provide new epidemiological data contributing to our understanding of the different prevalence rates found in Latin America.