Table 1. Existing epilepsy classification schemes.

Organization	Name	Year	Salient features
ILAE	ILAE	1981	Partial: simple, complex, secondary Generalised: absence, myoclonic, clonic, tonic-clonic, tonic
		1985	Semiology: focal vs. generalised Idiopathic: idiopathic vs. symptomatic Epilepsies are syndromes
		1989	Localization-related epilepsies and syndromes, generalised epilepsies and syndromes, epilepsies and syndromes undetermined to be generalised or focal, and special syndromes
		1993 (proposed)	Location: Generalised, partial, multiple seizure types, and unclassified seizures Risk factors: provoked, unprovoked seizure of unknown etiology, cryptogenic
		2001 (proposed)	Five axes: ictal phenomenology, seizure type, syndrome, etiology, impairment
		2006 (proposed)	Five axes: ictal phenomenology, seizure type, syndrome, etiology, impairment Delineation of self-limited epilepsy syndromes
		2010 (proposed)	Focal replaced partial Etiology; genetic, structural, metabolic, unknown Constellations: electroclinical syndromes with specific combinations of semiological, radiological, or pathological findings
		2017	Focal: networks limited to one hemisphere Generalised: engage both hemispheres but begin anywhere within generalised networks Seizures of unknown onset: if more information required Epilepsies sequentially classified by seizure type, epilepsy type, and epileptic syndromes
Other	Semiology	1998	Semiology-based: auras, autonomic seizures, dialeptic seizures, motor seizures, special seizures
	Five dimensional	2005	Five dimensions: location of epileptogenic zone, seizure semiology, etiology, seizure frequency, related medical conditions
	4D-CS	2012	Four dimensions: semiology, location of epileptogenic zone, etiology, associated comorbidities
		2019	Epileptic paroxysmal events: semiology, location of epileptogenic zone, etiology of epilepsy, associated comorbidities Non-epileptic paroxysmal events: organic or psychogenic
	IEC	2020	Headline, seizure type, epilepsy type, etiology, comorbidities / relevant individual preferences

Integrated Epilepsy Classification (IEC), International League Against Epilepsy (ILAE), four-dimensional classification scheme (4D-CS).