Are the dichotomies generalized versus focal epilepsies and idiopathic versus symptomatic epilepsies still valid in modern epileptology?


Address correspondence to Hans O. Lüders, Epilepsy Center, Neurological Institute, Case Medical Center University Hospitals, 11100 Euclid Avenue, Cleveland, OH 44106, U.S.A. E-mail:


In this commentary we discuss the basic concept of an epileptogenicity level, which is variable in different brain regions and is a function of multiple factors including the basic epileptogenicity level, routine environmental or internal stimuli, and various triggering and causative factors. This concept blurs the distinction between focal versus generalized and between idiopathic versus symptomatic epilepsies. We suggest dropping the dichotomy idiopathic versus symptomatic and to instead simply list the different etiologic factors that increase the epileptogenicity level. On the other hand, even if there is a continuum between focal and generalized epilepsies, most epilepsies are either predominantly focal or predominantly generalized. It is useful to maintain this distinction (even if somewhat artificial) because focal epilepsies can be treated with epilepsy surgery, and all focal epilepsies tend to respond to the same type of anticonvulsants. Generalized epilepsies cannot be treated surgically and respond to different anticonvulsants depending on the semiologic type of seizures.