Developmental and epileptic encephalopathies—or DEEs—are seizure disorders that are often treatment-resistant. They most often begin in infancy and are associated with seizures of long duration and major developmental delays.1 The term DEE refers to when cognitive functions are influenced by both seizure and interictal epileptiform activity and the neurobiological process behind the epilepsy.2
This term can be used for those with non-progressive diseases with cognitive impairment and co-existing epilepsy, in whom the epileptiform activity has minimal or no effect on function.2
This term is designated for patients whose seizure activity has a direct impact on cognition, as most can revert to their normal or near normal baseline cognitive state with effective treatment.2
DEEs are rare and also challenging to diagnose and treat effectively. They include, but are not limited to the conditions and syndromes listed below:1
Epilepsies that begin in childhood and persist into adulthood may also result in major challenges in the transition to adult care, including in the management of psychiatric disorders, migraine, movement disorders, and spasticity. Consideration of these disease sequelae must be evaluated early on in the disease course, and throughout the patient’s life.3,4
