The prevalence of epilepsy along the Arizona-Mexico border

This study describes the epidemiology of epilepsy on the Arizona-Mexico border.

Households in Southern Arizona were identified using two strategies. County-wide random digit dialing telephone surveys were supplemented with door-to-door recruitment in three Arizona border communities. Utilizing a two-step screening process, individuals with a seizure disorder or epilepsy were identified. A consensus diagnosis was arrived at after reviewing results from the detailed interview, medical records and clinical examination.

A total of 15,738 household individuals were surveyed. Two hundred and three individuals were identified as having had epilepsy at some point in their life; 25% of them were previously not diagnosed. The sex and age-adjusted prevalence estimate was 14.3 per 1000 (95% CI: 12.5-16.1) for lifetime epilepsy, and 11.8 per 1000 (CI: 10.2-13.5) for active epilepsy (seizures in the past 5 years or currently taking antiseizure medications). Non-Hispanic Whites were two times more likely to have active epilepsy than Hispanics. The majority of individuals with lifetime history of epilepsy had idiopathic or cryptogenic epilepsy; most were localization-related epilepsy although the exact location could not be determined for the majority. Although most individuals with epilepsy report receiving care from a neurology specialist, they were more likely to have visited a non-specialist in the past 3 months.

The lower prevalence of epilepsy among Hispanics compared to non-Hispanics supports previous survey findings in the Southwest US and may be due to language, acculturation factors, stigma, or a reflection of the "healthy immigrant effect". The surprisingly high proportion of previously un-diagnosed individuals shows a need for further investigation as well as a need to increase community awareness.