Newly diagnosed epileptic seizures: focus on an elderly population on the French island of Réunion in the Southern Indian Ocean.

PURPOSE: To describe seizure types and risk factors among elderly people with newly diagnosed epileptic seizures living on La Réunion, a French Island in the Southern Indian Ocean.

METHODS: We describe an elderly population with newly diagnosed epileptic seizures using data from the EPIREUN study conducted between July 1, 2004 and June 30, 2005. The methodology is described in detail in the EPIREUN study report (Mignard et al., 2009).

KEY FINDINGS: There were 153 single unprovoked seizures (84.1%); their incidence was 278.1 [95% confidence interval (CI) 237.4-325.9] per 100,000. The incidence of newly diagnosed epilepsy was 125.4 (95% CI, 99.1-158.8) per 100,000. Twenty-eight acute symptomatic seizures occurred (15.4%); the incidence was 50.9 (95% CI 35.1-73.7) per 100,000. The annual incidence of newly diagnosed epileptic seizure in the elderly was 330.8 (95% CI 286.1-382.6) per 100,000: 403.0 (95% CI 328.5-494.3) per 100,000 in men and 279.6 (95% CI, 227.4-343.8) per 100,000 in women. Sex had a significant (p = 0.014) effect on incidence: elderly men had a risk ratio of 1.44 compared to women of developing a newly diagnosed epileptic seizure. The etiology of single unprovoked seizure was as follows: stroke, 77 cases (50.3%); cryptogenic, 36 (23.5%); alcoholism, 10 (6.6%); a combination of several causes such as polypathology, 9 (5.9%); degenerative disease, 6 (4.0%); HIV infection, 2 (2.0%), and undetermined causes (2.7%). Most patients (170; 93.4%) were hospitalized, and 110 (60.8%) were treated. Among patients treated, 49 (44.5%) were given sodium valproate, 25 (22.7%) benzodiazepines, 12 (10.9%) phenytoin, 9 (8.2%) lamotrigine, 8 (7.3%) Trileptal, and 7 (6.4%) gabapentin.

SIGNIFICANCE: Our findings show that the incidences of newly diagnosed epileptic seizures and newly diagnosed epilepsy were high in the elderly population of La Réunion. These incidences were significantly higher in men than in women. These results may be attributable to the high incidence of cerebrovascular diseases and comorbidities in this population.