In addition to the identification of epileptic syndromes associated with cognitive decline, the influence of suppression of secondarily generalized seizures on IQ is reviewed. Our own data concerning cognitive function in temporal lobe epilepsy show a decrease of IQ and verbal memory with long duration of epilepsy and frequent tonic-clonic seizures, but not with simple or complex partial seizures. The use of a 'nucleus shell structure model' may be helpful to visualize the dynamic changes ('running up') in seizure structures in the long-term course of epilepsies. In addition to the localization and extent of structural changes, functional monitoring of cognition and pathology of MR spectroscopy is now available for long-term studies in progressive epileptic disorders. Concepts for memory storage and consolidation and mechanisms of plasticity concerning epileptic activity as well as modification of long-term potentiation for plasticity with regard to memory functions are also discussed.