This companion paper to the introduction of the International League Against Epilepsy(ILAE) 2017 classification of seizure types provides guidance on how to employ theclassification. Illustration of the classification is enacted by tables, a glossary of relevantterms, mapping of old to new terms, suggested abbreviations, and examples. Basic andextended versions of the classification are available, depending on the desired degreeof detail. Key signs and symptoms of seizures (semiology) are used as a basis for cate-gories of seizures that are focal or generalized from onset or with unknown onset. Anyfocal seizure can further be optionally characterized by whether awareness is retainedor impaired. Impaired awareness during any segment of the seizure renders it a focalimpaired awareness seizure. Focal seizures are further optionally characterized bymotor onset signs and symptoms : atonic, automatisms, clonic, epileptic spasms, orhyperkinetic, myoclonic, or tonic activity. Nonmotor-onset seizures can manifest asautonomic, behavior arrest, cognitive, emotional, or sensory dysfunction. The earliestprominent manifestation defines the seizure type, which might then progress to othersigns and symptoms. Focal seizures can become bilateral tonic–clonic. Generalized sei-zures engage bilateral networks from onset. Generalized motor seizure characteristicscomprise atonic, clonic, epileptic spasms, myoclonic, myoclonic–atonic, myoclonic–tonic–clonic, tonic, or tonic–clonic. Nonmotor (absence) seizures are typical or atypi-cal, or seizures that present prominent myoclonic activity or eyelid myoclonia. Sei-zures of unknown onset may have features that can still be classified as motor,nonmotor, tonic–clonic, epileptic spasms, or behavior arrest. This “users’ manual” forthe ILAE 2017 seizure classification will assist the adoption of the new system.
KEY WORDS:Classification, Seizures, Focal, Generalized, Epilepsy (taxonomy