Semiology: witness to a seizure--what to note and how to report.

This article reviews the Cleveland Epilepsy Classification (CEC) of seizure semiology. It defines the concept of semiology, and reviews its importance in epilepsy in defining the Symptomatogenic Zone, one of the five zones that make up the Epileptogenic Zone. It details the four broader spheres that contain all of the possible patient signs and symptoms (cognitive, autonomic, consciousness, and motor spheres), and reviews the specific seizure types that are classified within those spheres. Evidence-based information on usefulness of semiology for localization and lateralization is reviewed. A "user-friendly" reference table is provided.