Epidemiology of epilepsy.

Epilepsy is a burden affecting no fewer than 50 million patients worldwide. It is a heterogeneous group of disorders comprising both common and very rare forms, thus rendering its epidemiological investigations rather difficult. Moreover, making an epilepsy diagnosis per se can be challenging due to an evolving system of classification, and its dependency on local habits and culture. Any attempt at meta-analyses must consider such biases when pooling data from different centers and countries. Differentiating a contextual seizure from chronic epilepsy is every epileptologist's daily mission, yet it is also crucial for achieving a proper estimation of the epidemiology of epilepsy. Our present objective was to provide an overview of the epidemiology of both syndromic and non-syndromic epilepsy. Most epileptic syndromes tend to be rare and, thus, the feasibility of epidemiological quantification in populations is also addressed. Regarding its prevalence and cost, epilepsy deserves greater attention than it generally receives, as it appears to continue to be a condition under persistent taboos.