Pharmacoresistant epilepsy: Definition and explanation

► PRE exacts an enormous toll on patients, caretakers and the society at large. ► The current definition, clinical predictors, patterns and causes of PRE are reviewed. ► Reliable biomarkers of PRE for early identification of “high risk” patients are lacking. ► Any definition is incomplete without understanding of cellular & molecular mechanisms. ► Epilepsy surgery provides a pragmatic benefit in many but not all patients with PRE. ► PRE constitutes an unmet and pressing need when caring for individuals with epilepsy.