A clinical approach to the classification of seizures and epileptic syndromes.

Seizures and epilepsies are heterogeneous. Their classifications are essential for clinicians to achieve a common understanding of the disorders. The diagnosis, treatment, and prognosis of seizure disorders depend on the correct identification of the types of seizures and epilepsy. The two currently accepted classifications are the International Classification of Epileptic Seizures and the International Classification of Epilepsies and Epileptic Syndromes. Both are based on clinical and electrophysiologic data, and both maintain a basic dichotomy between partial (focal, localization-related) and generalized epileptic disorders. Partial seizures are further classified into those that are simple partial, complex partial, and partial with secondary generalization. Generalized seizures are classified predominantly on the basis of their motor manifestations. Epilepsies are divided into idiopathic, cryptogenic, and symptomatic types. The utility and the limitations of these two classifications are discussed. A simplified system that encompasses neuroradiologic advances is offered to enhance the clinical usefulness of classifying epileptic disorders.