Incidence of newly diagnosed epileptic seizures in a French South Indian Ocean Island, La Réunion (EPIREUN)

Abstract

To assess the incidence of newly diagnosed epileptic seizures in the population of La Réunion. From July 1, 2004 to June 30, 2005, we conducted a prospective, observational, and multicenter epidemiologic study to identify patients with newly diagnosed epileptic seizures. Febrile and neonatal seizures were excluded. Seven hundred sixty-six patients were included. The standardized (2000 U.S. population) incidence rate of all suspected cases of newly diagnosed (provoked and unprovoked) epileptic seizures was 115.4/100.000 person-years [95% confidence interval (CI) 106.7-124.0]. We observed a bimodal distribution: The crude incidence was 99.5/100,000 in the group aged 0-14 years and 330.8/100,000 in those older than 65 years. One hundred thirty-five cases were classified as provoked seizures (17.6%; incidence 17.7/100,000). Alcohol consumption, cranial trauma, and cerebrovascular disease were the most frequent causes (27.4%, 11.1%, and 10.4%, respectively). Six hundred twenty cases were classified as unprovoked seizures (single and recurrent) (80.9%; incidence, 81.2/100,000). Two hundred sixty cases of seizures were due to stable neurologic conditions (incidence, 34.1/100,000) and the most common causes were cerebrovascular disease (46.2%), alcoholism (20.4%), and cranial trauma (5.4%). Evolutive neurologic conditions contributed to 23 cases (incidence, 3.0/100,000). Lastly, unprovoked seizures with unknown etiology were 337 (incidence, 44.2/100,000). The global incidence rate of newly diagnosed epileptic seizures in La Réunion was clearly higher than those observed in industrialized countries and similar to those observed in developing countries. The major risk factors were represented by cerebrovascular disease, alcohol consumption, and cranial trauma. Surprisingly, there were few infections.